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In this report, we present 12 patients (range 14-76 years, mean 40 +/- 22.7 years) who underwent surgical repair of a ventricular septal defect (VSD). Location, size, and surrounding anatomy of the VSD were assessed prior to intervention in all patients with live/real time three-dimensional transthoracic echocardiography (3DTTE). In 9 patients, measurements of maximum dimension, circumference, and area by 3DTTE correlated well with the same measurements from intraoperative three-dimensional transesophageal echocardiographic (3DTEE) reconstruction. 3DTTE measurement of maximum dimension of VSDs also agreed well with maximum dimension by surgery in 10 patients. Live/real time 3DTTE accurately defined VSD location, size, and surrounding anatomy in all patients studied by us. VSD characterization by live 3DTTE agreed well with surgery descriptions and 3DTEE measurements.

In this report we present 12 adult patients in whom surgical or percutaneous intervention was considered for repair of atrial septal defect (ASD). Location, size, and surrounding atrial anatomy of the ASD were assessed prior to intervention in all patients with standard and live three-dimensional transthoracic echocardiography (3D TTE). In the four patients in whom intraoperative three-dimensional transesophageal echocardiographic reconstruction (3D TEE) was done, 3D TTE measurements of maximum dimension, maximum circumference, and maximum area of ASD agreed well with 3D TEE. In the seven patients who underwent transcatheter closure device insertion, live 3D TTE measurements of maximum dimension, maximum circumference, and maximum area of ASD agreed well with the sizing balloon. Additionally, since the sizing balloon measures a stretched diameter and area, a live 3D TTE stretched ASD diameter and area (derived from the actual live 3D TTE maximum circumference) were calculated and demonstrated improved agreement with the sizing balloon measurements. In all patients, > or =5 mm of atrial tissue was visualized surrounding the ASD. Further, with the addition of contrast enhancement, characterization of a small patent foramen ovale (

Aortic valve stenosis (AS) severity can be estimated by various modalities. Due to some of the limitations of the currently available methods, the usefulness of live three-dimensional transthoracic echocardiography (3D TTE) in the assessment of AS was explored. Live 3D TTE was able to visualize the aortic valve orifice in all 11 patients studied. Live 3D TTE correctly estimated the severity of AS in all 10 patients in whom AS severity could be evaluated at surgery. These included eight patients with severe AS and two with moderate AS. Two of these 10 patients with AS had associated hypertrophic cardiomyopathy and underwent myectomy at the time of aortic valve replacement. Aortic valve orifice area measurements by live 3D TTE correlated well with intraoperative three-dimensional transesophageal echocardiographic reconstruction measurements (r=0.85) but not as well with two-dimensional transesophageal echocardiography measurements (r=0.64). Live 3D TTE measurements of the aortic valve orifice area also did not correlate well with two-dimensional transthoracic echocardiography measurements (r=0.46) but the number of patients studied with two-dimensional transthoracic echocardiography was smaller (only seven) and four of these did not undergo two-dimensional transthoracic echocardiography at the authors' institution. Altogether, four patients with severe AS by live 3D TTE, and subsequently confirmed at surgery, were misdiagnosed as having moderate AS by two-dimensional transthoracic echocardiography. Because it is completely noninvasive and views the aortic valve in three dimensions, 3D TTE could be a useful complement to the existing modalities in the evaluation of AS severity.

The Sulzer Carbomedics prosthetic heart valve (CP) is a commonly used mechanical valve in clinical practice. In the present study, we used conventional and color Doppler echocardiography to assess the hemodynamics of normally functioning CP in the aortic (n = 73) and mitral (n = 127) positions. Our findings demonstrate no significant correlation of Doppler-measured peak and mean pressure gradients and effective orifice area with implanted valve size and actual orifice areas, measured directly by the manufacturer for CPs in both the mitral and aortic positions. However, it is still useful to measure effective orifice area by Doppler because a value in the normal or nonstenotic range points to an unobstructed prosthesis in the aortic or mitral position, in the absence of poor left ventricular ejection fraction. A value in the stenotic range could mean a normally functioning or obstructed prosthesis and, therefore, may need further investigation, such as assessment of valve leaflet motion by transthoracic or transesophageal echocardiography or fluoroscopy. Valve regurgitation as evaluated by color Doppler flow mapping was mild in practically all CPs in the aortic position, and in the majority of CPs in the mitral position.

We evaluated the potential usefulness of three-dimensional (3D) transesophageal echocardiography (TEE) in assessing individual scallop/segment prolapse in 36 adult patients with mitral valve prolapse (MVP) undergoing surgical correction. Intraoperative 3D TEE correctly identified the location of scallop/segment prolapse in 34 of 36 patients (94%). However, in 6 of these patients 3D TEE images revealed more scallops or segments with prolapse than the surgeon noted intraoperatively. Prolapse of these areas was less prominent and this could possibly explain the lack of correlation with the surgical findings in these patients. In another 2 patients areas of prolapse seen by the surgeon were missed by 3D TEE because some of those scallops/segments could not be well imaged due to image "drop out" and artifacts. Thus, perfect correlation between 3D TEE and surgery was noted in 28 of 36 (78%) patients. Noncoaptation of the MV was also identified in 2 patients. The prolapsed area of posterior (n = 28 observations) and anterior (n = 9 observations) MV leaflets ranged from 1 cm2 to 9 cm2 (mean 3.50 cm2+/- 2.14) and 1.20 cm2 to 5.99 cm2 (mean 3.21 cm2+/- 1.33), respectively. Interobserver and intraobserver agreement for location and area of MVP was excellent (r = 0.97 and r = 0.99, respectively; all P values are

In a prospective study, the etiology of community-acquired pneumonia (CAP) was investigated among consecutive patients admitted to an academic, urban public hospital in Seattle. The study population was uniquely young, was predominantly male, and had high rates of homelessness, cigarette smoking, alcoholism, injection drug use, and human immunodeficiency virus (HIV) infection. Leading causes of CAP among HIV-negative patients were aspiration, followed by Streptococcus pneumoniae, Legionella species, and Mycoplasma pneumoniae. Among HIV-positive patients, Pneumocystis carinii, Mycobacterium tuberculosis, S. pneumoniae, and M. pneumoniae were the most common etiologic agents. Severe CAP was associated with typical bacterial infections and aspiration pneumonia but not Legionella infection among HIV-negative patients and with Pseudomonas aeruginosa infections among HIV-positive patients. These findings emphasize the need to tailor empirical antibiotic therapy according to local patient populations and individual risk factors and highlight the importance of recognizing underlying HIV infection in patients who are hospitalized with CAP.

We present a patient in whom the exact location of a right atrial lipoma identified with two- and three-dimensional transesophageal echocardiography (2-D and 3-D TEE) was correlated with the surgical findings. By orienting the 3-D TEE images to conform to the view of the surgeon from the right side of the patient and referencing the site of attachment of the tumor to the surrounding structures, this lipoma was correctly localized to a 7 o'clock position in the right atrium.

Background . Air leaks (ALs) are a common complication after pulmonary resection, yet there is no consensus on their management. Methods . An algorithm for the management of chest tubes (CT) and ALs was applied prospectively to 101 consecutive patients who underwent elective pulmonary resection. Air leaks were graded daily as forced expiratory only, expiratory only, inspiratory only, or continuous. All CTs were kept on 20 cm of suction until postoperative day 2 and were then converted to water seal. On postoperative day 3, if both a pneumothorax and AL were present, the CT was placed to 10 cm H 2 O of suction. If a pneumothorax was present without an AL, the CT was returned to 20 cm H 2 O of suction. Air leaks that persisted after postoperative day 7 were treated with talc slurry. Results . There were 101 patients (67 men); on postoperative day 1, 26 had ALs and all were expiratory only. Univariable analysis showed a low ratio of forced expiratory volume in 1 second to forced vital capacity (FEV 1 /FVC) ( p = 0.005), increased age ( p = 0.007), increased ratio of residual volume to total lung capacity (RV/TLC) ( p = 0.04), increased RV ( p = 0.02), and an increased functional residual capacity (FRC) ( p = 0.02) to predict the presence of an AL on postoperative day 1. By postoperative day 2, 22 patients had expiratory ALs. After 12 hours of water seal, 13 of the 22 patients' ALs had stopped, and 3 more sealed by the morning of postoperative day 3. However, 2 of the 6 patients whose ALs continued experienced a pneumothorax. Five of the 6 patients with ALs on postoperative day 4 still had ALs on postoperative day 7, and all were treated by talc slurry through the CT. All ALs resolved within 24 hours after talc slurry. Conclusions . Most ALs after pulmonary resection are expiratory only. A low FEV 1 /FVC ratio, increased age, increased RV/TLC ratio, increased RV, and an increased FRC were predictors of having an ALs on postoperative day 1. Conversion from suction to water seal is an effective way of sealing expiratory AL, and pneumothorax is rare. If an expiratory AL does not stop by postoperative day 4 it will probably persist until postoperative day 7, and talc slurry may be an effective treatment.

Background . Cardiac surgical patients consume a significant fraction of the annual volume of allogeneic blood transfused. Scavenged autologous blood may serve as a cost-effective means of conserving donated blood and avoiding transfusion-related complications. Methods . This study examines 834 patients after cardiac operations at the University of Alabama Hospital. Data were collected on patients receiving unwashed, filtered, autologous transfusions from shed mediastinal drainage and those receiving allogeneic transfusions. The data were incorporated into clinical decision models; confidence intervals for parameters were estimated by bootstrapping sample statistics. Costs were estimated for transfusing both allogeneic and autologous blood. Results . The study found a 54% reduction in transfusion risk or a mean reduction of 1.41 allogeneic units per case (95% confidence interval, 1.04 to 1.79 units). The process saved between $49 and $62 per case. Conclusions . The use of autologous blood has the potential to significantly reduce the costs and risks associated with transfusing allogeneic blood after cardiac operations.

The aim of the study was to compare the accuracy of multiplane transesophageal echocardiography (TEE) with the more conventional biplane technique in the direct assessment of aortic valve area in patients with aortic stenosis. Short-axis images of the aortic valve adequate for measuring aortic valve area were obtained in all 81 patients studied by multiplane TEE but in only 56 of 64 patients (88%) using the biplane approach. The correlation coefficient for aortic valve area determined by multiplane TEE (r = 0.89; SEE = 0.04 cm 2 ) was higher (p 2 ). Correlations were higher for bicuspid valves (multiplane, r = 0.93; biplane, r = 0.75) than tricuspid valves (multiplane, r = 0.87; biplane, r = 0.75). Our study has demonstrated the superiority of multiplane TEE to both biplane TEE and transthoracic echocardiography (TTE) in the direct evaluation of aortic valve area in patients with aortic stenosis. Our study has demonstrated the superiority of multiplane transesophageal echocardiography over both biplane transesophageal echocardiography and transthoracic echocardiography in the direct evaluation of aortic valve area in patients with aortic stenosis.

In the present study, we compared three-dimensionally (3-D) reconstructed images with multiplane two-dimensional (2-D) transesophageal echocardiographic (TEE) images in 17 patients with various cardiac masses and defects. To overcome the problem of making measurements from 3-D reconstructed images, we carefully “dissected” the 3-D dataset using paraplane and anyplane 2-D sections, which were then used to obtain the maximum sizes of the cardiac masses and defects. Of the 15 vegetations and 9 abscesses detected by 3-D TEE in 7 patients, only 8 (53%) vegetations and 4 (44%) abscesses were detected by multiplane 2-D TEE (P < 0.02). Also, the exact anatomical location, shape, geometry, and extent of various cardiac masses and defects were more clearly delineated by 3-D than 2-D TEE. The maximum dimensions of cardiac masses and defects were larger by 3-D than by 2-D TEE in 17 (89%) of the 19 lesions available for comparison (P < 0.002). In addition, 3-D TEE correlated more closely than 2-D TEE when compared to surgical measurements in three patients in whom they were available. Thus, it would appear that in several instances, the exact size of the cardiac lesion could only be assessed by analysis of the 3-D volumetric dataset. Out preliminary study has demonstrated the superiority of transesophageal 3-D reconstruction over multiplane 2-D TEE in both qualitative and quantitative assessment of various cardiac mass lesions and pathological defects.

Background: Intravascular perfluorochemical emulsions together with a high oxygen tension may increase the delivery of dissolved oxygen to useful levels. The hypothesis of this study is that increasing the dissolved oxygen content of blood with incremental doses of a perfluorochemical emulsion improves tissue oxygenation during cardiopulmonary bypass in a dose-related fashion. Methods and Results: Oxygen utilization was studied in a profoundly anemic canine model of hypothermic cardiopulmonary bypass. Forty-two dogs (mean ± standard error of the mean). Cardiopulmonary bypass was begun and resulted in a hematocrit of 9.4% + 0.6%. A standard primng solution was used in the control group (n = 12), and the test groups received 1.35 gm perfluorochemical · kg-1 (n = 10 dogs), or 5.4 gm perfluorochemical · kg-1 (n = 10 dogs), 2.7 gm perfluorochemical · kg-1(n = 10 dogs) through the venous return cannula. Each animal underwent a series of randomized pump flows (0.25,0.5, 1.0, 1.5, 2.0, and 3.0 L · min-1 · m-2 ) at 32° C. After the randomized flows were completed at 32° C, the temperature was raised to 38° C and cardiopulmonary bypass was discontinued. Mortality from cardiac failure on separation from cardiopulmonary bypass was 42% in the control group and 20% in perfluorochemical-treated groups. The mean perfluorochemical dose was higher in surviviors than in nonsurvivors (2.9 + 0.4 versus 1.3 + 0.5 gm perfluorochemical · kg-1; p < 0.05). No differences in oxygen consumption or transbody lactate gradient were found between groups during cardiopulmonary bypass. Analysis of mixed venous oxygen tension (a surrogate measure for tissue oxygenation) as a function of cardiopulmonary bypass flow normalized to body surface area showed that the control group had significantly lower mixed venous oxygen tension (p < 0.05) than the perfluorochemical emulsion-treated groups. Furthermore, the differences were related to the perfluorochemical emulsion dose. These differences in mixed venous oxygen tension continued after termination of cardiopulmonary bypass. The coronary sinus oxygen tension and cardiac arterial-venous oxygen content differences during and after cardiopulmonary bypass were similar among the control and perfluorochemical emulsion-treated animals. Dissolved oxygen consumption during and after cardiopulmonary bypass was calculated. Dissolved oxygen consumption increased in the perfluorochemical-treated animals in a perfluorochemical dose-related manner and was significantly higher in perfluoro-chemical-treated animals than in the control animals (p < 0.05). Conclusions: Graded increases in mixed venous oxygen tension during cardiopulmonary bypass were observed in response to graded increases in the dissolved oxygen delivery. These data suggest that enhancing oxygenation with perfluorochemical-dissolved oxygen is an effective temporary substitute for the use of hemoglobin-bound oxygen during cardiopulmonary bypass. Perfluorochemical-dissolved oxygen may be particularly beneficial in the setting of multiple hypoxic stresses. (J THORAC CARDIOVASC SURG 1995;110: 774-85)J THORAC CARDIOVASC SURG 1995;110:1-85.

We describe multiplane transesophageal echocardiographic findings in a patient with severe mitral regurgitation secondary to dehiscence of a Duran ring.

This case report describes a patient with a known left ventricular mass which was documented by transthoracic echocardiography and which had not changed in size after anticoagulation. The mass was characterized as fatty tumor or hemorrhagic by cardiovascular magnetic resonance imaging study, and surgical removal of the mass was performed. Transesophageal echocardiogram was performed intraoperatively. The tumor appeared homogenous with no echolucencies or echodensities and an overall bright echotexture. In vitro ultrasound studies done using similar instrument gain settings showed the lipoma specimen to have a much brighter appearance than a myxoma. This finding may be helpful in differentiating a lipoma from other left ventricular masses such as myxoma or thrombus.

Testou-se uma nova emulsão de perfluorocarbonos (OxygentMR, Alliance Pharmaceutical, San Diego, CA 92121, EUA) em circulação extracorpórea (CEC) com hipotermia de 32ºC e hematócrito de 12%. Estudaram-se 42 cães, 12 dos quais não receberam a droga e serviram de controle (Grupo 1), enquanto os demais constituíram 3 grupos de 10 animais cada, tratados com doses de Oxygent de 1,5 ml/kg (Grupo 2), 3 ml/kg (Grupo 3) e 6 ml/kg (Grupo 4) as quais geraram fluorocritos de, respectivamente, 1 %, 2% e 3%. Foram analisadas variáveis do metabolismo do oxigênio (O2) em 6 diferentes fluxos de perfusão (Q), ordenados ao acaso. Reaqueceram-se os cães, interrompeu-se a CEC e acompanharam-se os animais por 1 hora. Diferenças intergrupos foram analisadas pelo teste das médias dos quadrados mínimos e pelo teste de Duncan, considerando-se significantes os valores de p< 0,05. Embora algo maiores no Grupo 4, a pressão parcial bem como o conteúdo arterial de oxigênio (CaO2) foram estatisticamente semelhantes ao grupo controle. A pressão parcial de O2 no sangue venoso misto (PvO2) do Grupo 4, em função do Q, mostrou-se significativamente maior (p < 0,03) que a do grupo controle, conquanto isto não tenha se repetido ao ser analisada em função da oferta tecidual de O2 . Também não houve diferença quanto ao consumo de O2 total e dissolvido, nem quanto aos gradientes sistêmico e miocárdico de lactato, porém a maior dose da emulsão (Grupo 4) expressa efeito dose-dependente benéfico, ainda que de natureza especulativa, do Oxygent sobre o metabolismo do oxigênio.A novel perfluorocarbon emulsion (OxygentTM - Alliance Pharmaceutical Corp., San Diego, CA 92121, USA) was tested during hypothermic (32ºC) cardio pulmonary bypass (CPB) under severe hemodilution (Hto = 12%). Forty-two mongrel dogs were allocated to 4 groups. Group 1 (n=12) was not given Oxygent and served as control whereas Groups 2, 3, and 4 (10 animals each) were given a bolus dose of the emulsion (1.5,3.0, and 6.0 ml/kg, respectively) at the onset of CPB. O2 metabolism variables were then studied at 6 randomized pump flow rates (Q) ranging from 0.25 to 3.0 l/min/m². After rewarming CPB was discontinued and the animals were followed-up for one hour and then killed by IV KGI injection. Differences between groups were evaluated by the least squares means and Duncan's tests and considered significant for p

Background: This study compares oxyhemoglobin dissociation during the nonperfused periods of hypothermic cardioplegic arrest in two blood cardioplegic solutions with different hemoglobin concentrations. The hypothesis is that more oxygen will dissociate from hemoglobin in a blood cardioplegic solution with a higher hemoglobin content than from a cardioplegic solution with a lower hemoglobin content. However, the increment in the volume of oxygen that dissociates from hemoglobin will be less than anticipated by a ratio of hemoglobin concentrations in the cardioplegic solution. Methods and results: Pigs ( n = 22) were supported by bypass and subjected to 60 minutes of hypothermic cardioplegic arrest with either a high-hemoglobin ( n = 10) or low-hemoglobin ( n = 12) blood cardioplegic solution. Aortic root and coronary sinus blood samples were obtained before bypass and 5 seconds after the start of cardioplegic infusions at 20, 40, and 60 minutes of cardioplegic arrest. Oxyhemoglobin dissociation occurred in both experimental groups during the ischemic intervals of cardioplegic arrest. However, there were no significant differences between the high- and low-hemoglobin groups in the arterial-venous oxygen content differences for samples taken after each of the three ischemic intervals ( p values: control=0.78; cardioplegia interval 1=0.95; interval 2=0.56; and interval 3=0.12). Conclusions: The present study emphasizes the inherent limitations of unmodified erythrocyte hemoglobin as an oxygen source in hypothermic alkalotic cardioplegic solutions. These limitations may be obviated by methods that increase the dissolved oxygen content of the cardioplegic solution or methods that decrease the affinity of hemoglobin for oxygen under conditions of hypothermia and alkalosis. (J THORAC CARDIOVASC SURG 1994;108:664-71)

This study compared myocardial blood flow during postcardioplegia reperfusion asystole and ventricular fibrillation. Pigs (n = 20) were placed on cardiopulmonary bypass and blood cardioplegic solution at 38 degrees C was then infused. A preischemia microsphere injection was given in asystolic hearts. All animals then had 1 hour of hypothermic cardioplegic arrest and underwent reperfusion with high-dose (n = 10) or low-dose (n = 10) 38 degrees C blood cardioplegia. At 30 seconds after reperfusion, all hearts were asystolic. The second microsphere injection was then given. At 3 and 6 minutes after reperfusion, the animals' hearts were either in asystole (n = 10) or ventricular fibrillation (n = 10), and the third and fourth microsphere injections were then given. At 10 minutes after reperfusion, all hearts were beating and the final (fifth) microsphere injection was given. There was an initial increase in the global myocardial blood flow during reperfusion versus the preischemic control value. However, later, during reperfusion (ie, at the third and fourth injections), there was a significant (p0.05) decrease in the global myocardial blood flow. There was no discernible response in either the global myocardial blood flow or regional myocardial blood flow distribution to electromechanical activity (ie, ventricular fibrillation) for the third and fourth injections, suggesting that coronary autoregulation was abnormal. Postcardioplegia reperfusion ventricular fibrillation imposes metabolic demands that may cause reperfusion injury, especially in hearts affected by hypertrophy, ventricular distention, or coronary obstruction.

Transesophageal echocardiographic findings in a patient with anomalous drainage of both right- sided pulmonary veins into the right atrium are described. The atrial septum was intact and the left- sided veins connected normally with the left atrium. transesophageal echocardiography, partial anomalous pulmonary venous connection of the right pulmonary veins to the right atrium

Cryopreserved aortic valve homografts have become an accepted aortic valve substitute, but long-term studies with echocardiographic assessment of valve function are largely unavailable. Between 1981 and January 1, 1991, a total of 178 patients aged 9 months to 80 years (median 46 years) underwent implantation of a cryopreserved aortic valve homograft. Serial two-dimensional Doppler echocardiographic studies were obtained in 149 patients. Overall survival was 91% at 1 year and 85% at 8 years. Survival of patients undergoing isolated primary infracoronary aortic valve replacement was 99% at 1 month and 94% at 8 years. Twelve patients underwent homograft explanation. Freedom from explantation for leaflet degeneration was 95% at 8 years. Freedom from presumed leaflet failure (valve degeneration at explantation or aortic insufficiency grade 3/4 or more without reoperation on echocardiography) was 94% at 5 years and 85% at 8 years. By multivariable analysis younger recipient age was the only risk factor identified for leaflet failure. Ninety-five percent of patients followed up for 4 or more years were in New York Heart Association class I or II.

The purpose of this study was to quantitate the uncertainty inherent in the electrophysiologic mapping of ventricular preexcitation as seen in Wolff-Parkinson-White syndrome. An ink-coated needle electrode was constructed to serve as a point source of unipolar stimulation along the atrioventricular junction. Activation times for 11 ventricular mapping sites at the atrioventricular junction were measured for each stimulation point. Maps were successfully completed for 18 right free wall and 14 posterior septal stimulation points. The activation time at the mapping site closest to the stimulation point was termed the index activation time. Activation times identical to the index activation time were noted at 1.3 +/- 0.5 mapping sites for each free wall stimulation point and 1.9 +/- 0.9 mapping sites for each septal stimulation point (p < 0.05, septal versus free wall stimulation points). Activation times falling within 5 msec of the index activation time were noted at 2.4 +/- 1.0 mapping sites for each free wall stimulation point and at 3.9 +/- 1.4 mapping sites for each septal stimulation point (p < 0.05, septal versus free wall stimulation points). The uncertainty of electrophysiologic mapping can be quantitated, and this error should be considered when making inferences regarding the anatomy of accessory pathways based on electrophysiologic data. A knowledge of the uncertainty inherent in the localization of accessory atrioventricular connections by electrophysiologic mapping can be used to plan borders of surgical dissection that will account for this uncertainty at a 95% confidence level.

Survival after entry and survival after repair (94%, 91%, and 91% at 1 month, 1 year, and 5 years, respectively) were similar in two institutions treating 196 consecutive patients, and there was no advantage (and a possible disadvantage) of a protocol of preliminary shunting and later repair in very young patients. Size and configuration of the right and left pulmonary arteries had no demonstrable effect on survival, prevalence of transannular patching, or postrepair right ventricular-left ventricular pressure ratio. Small size of the pulmonary “anulus” and trunk were risk factors for death, transannular patching, and high postrepair pressure ratio. High postrepair pressure ratio was a risk factor for death after repair. Very young age (less than about 3 months) was a risk factor for death after repair, particularly when other risk factors coexisted. The prevalence of transannular patching in patients with mild infundibular and pulmonary anulus and trunk hypoplasia decreased across the time of the study, without ill effect. The usefulness of measuring postrepair right ventricular-left ventricular pressure ratio is emphasized by the data. (J T horac C ardiovasc S urg 1992;103:706-23)

To assess the usefulness of transesophageal echocardiography in the evaluation of proximal coronary artery stenosis, 111 consecutive patients (mean age 61 years) who had intraoperative transesophageal echocardiography and coronary angiography within 1 week of surgery were studied. Transesophageal echocardiography visualized the entire length of the left main artery (0.2 to 2.2 cm, mean 0.93), 0.2 to 2.2 cm of the proximal left anterior descending artery and 0.1 to 3.4 cm of the proximal left circumflex artery in 103 patients (93%) and 0.1 to 4.6 cm of the proximal right coronary artery in 55 patients (49%). In the coronary artery segments visualized by echocardiography and compared with the corresponding angiographic segments, transesophageal echocardiography correctly identified 23 (96%) of 24 left main stenoses, 11 (78%) of 14 stenoses involving the left anterior descending artery, 6 (75%) of 8 left circumflex stenoses and all 7 stenoses (100%) of the right coronary artery. In all seven patients with ostial stenosis (left main artery in five and right coronary artery in two), the condition was correctly diagnosed by this technique. The sensitivity and specificity of transesophageal echocardiography in the overall evaluation of proximal coronary artery stenosis as customarily defined by angiography were 96% and 99% for the left main artery, 48% and 99% for the left anterior descending artery, 67% and 100% for the left circumflex artery and 37% and 100% for the right coronary artery, respectively. The distance of the stenotic lesion from the origin of the vessel by transesophageal echocardiography also correlated well with that measured by angiography (r = 0.63 to 0.99). Color flow mapping was found to be less useful because significant narrowing of the flow channel was seen in only 40 of 53 stenoses visualized by two-dimensional echocardiography.

The purpose of this study is to present data comparing the penetration of cryolesions created by various sizes and shapes of cryoprobes in human cadaveric myocardium, fat, and tissue of the central fibrous body. Ten cryolesions were made for each combination of tissue and cryoprobe studied. All cryolesions enlarged most rapidly during the first minute of cryothermia (p less than 0.01). Maximal cryothermic penetration into nontrabeculated myocardium was 8.5 +/- 0.5 mm (15-mm flat probe) and 6.1 +/- 1.0 mm (5-mm small probe). Maximal cryothermic penetration into trabeculated myocardium was 9.4 +/- 1.0 mm (10-mm cone-tipped probe) and 7.4 +/- 0.5 mm (10-mm flat probe). Maximal cryothermic penetration into fat was 4.7 +/- 0.7 mm (15-mm flat probe) and 3.9 +/- 0.7 mm (5-mm flat probe). The deeper penetration of cryothermia into myocardium as compared with fat (p less than 0.05) is related to the lower thermal conductivity of fat. Maximal cryothermic penetration of the central fibrous body was similar to that of the myocardium with transmural freezing of the central fibrous body after 4.4 +/- 0.3 minutes of cryothermia. These data can be used when determining the optimal cryothermic exposure for ablation of arrhythmogenic tissue.

BACKGROUND The value of transesophageal echocardiography in the assessment of patients with aortic dissection was studied. METHODS AND RESULTS Group 1 (34 patients) represented all patients studied at our institution with this technique in whom aortic dissection was proven by aortography, surgery, or autopsy. Group 2 (27 patients) represented all patients studied with this technique at our institution in whom aortic dissection was excluded by aortography. Transesophageal echocardiography made a correct diagnosis of aortic dissection in 33 of 34 patients (sensitivity, 97%; specificity, 100%). It also correctly demonstrated the type of dissection in all 29 patients with aortographic or surgical proof. On the other hand, computed tomography scanning, performed in 24 of 34 patients in group 1, made a correct diagnosis in only 67% of patients and misclassified the type of dissection in 33%. Transesophageal echocardiography correctly identified involvement of the coronary arteries by aortic dissection in six of seven patients as well as absence of both left and right coronary artery involvement in 10 patients with aortic dissection. This technique was also useful in detecting communications between the true and false lumens, presence of thrombi in the false lumen, and, in two patients, localized dissection rupture with formation of a false aneurysm. In both groups 1 and 2, transesophageal echocardiography correctly identified patients with moderate to severe aortic regurgitation. CONCLUSIONS Transesophageal echocardiography is very useful in the assessment of aortic dissection.

ObjectiveIn 1990, Fontan, Kirklin, and colleagues published equations for survival after the so-called “Perfect Fontan” operation. After 1988, we evolved a protocol using an internal or external polytetraflouroethylene tube of 16 to 19 millimetres diameter placed from the inferior caval vein to either the right or left pulmonary artery along with a bidirectional cava-pulmonary connection. The objective of this study was to test the hypothesis that a “perfect” outcome is routinely achievable in the current era when using a standardized surgical procedure.MethodsBetween 1 January, 1988, and 12 December, 2005, 112 patients underwent the Fontan procedure using an internal or external polytetraflouroethylene tube plus a bidirectional cava-pulmonary connection, the latter usually having been constructed as a previous procedure. This constituted 45% of our overall experience in constructing the Fontan circulation between 1988 and 1996, and 96% of the experience between 1996 and 2005. Among all surviving patients, the median follow-up was 7.3 years. We calculated the expected survival for an optimal candidate, given from the initial equations, and compared this to our entire experience in constructing the Fontan circulation.ResultsAn internal tube was utilized in 61 patients, 97% of whom were operated prior to 1998, and an external tube in 51 patients, the latter accounting for 95% of all operations since 1999. At 1, 5, 10 and 15 years, survival of the entire cohort receiving polytetraflouroethylene tubes is superimposable on the curve calculated for a “perfect” outcome. Freedom from replacement or revision of the tube was 97% at 10 years.ConclusionUsing a standardized operative procedure, combining a bidirectional cavopulmonary connection with a polytetraflouroethylene tube placed from the inferior caval vein to the pulmonary arteries for nearly all patients with functionally univentricular hearts, early and late survival within the “perfect” outcome as predicted by the initial equations of Fontan and Kirklin is routinely achievable in the current era. The need for late revision or replacement of the tube is rare.

Doppler color flow mapping in conjunction with two-dimensional echocardiography was used to evaluate ventricular septal rupture after myocardial infarction (seven anterior and eight inferior) in 15 patients and to correlate these findings with cardiac catheterization and surgical or autopsy data. Ventricular septal rupture was diagnosed by turbulent flow traversing the ventricular septum. The direction and velocity of shunt flow was determined by color M-mode and conventional Doppler methods. In all patients, Doppler color flow mapping correctly defined the site of septal rupture, which occurred at areas of discordant septal wall motion or "hinge points" (six posterior inlet, three anterior inlet, and six apical trabecular septum). Each of three patients with moderate tricuspid regurgitation and three of four patients with right-to-left shunting during diastole died, and all had an elevated right ventricular end-diastolic pressure. Right ventricular wall motion index was significantly higher in the patients who died compared with those who survived (mean +/- SEM; 2.8 +/- 0.2 vs. 2.0 +/- 0.2, p = 0.012), but there was no difference in left ventricular wall motion index. The rupture size measured by Doppler color flow imaging (1.7 +/- 0.1 cm) correlated with the size determined during surgery or autopsy (1.8 +/- 0.2 cm, r = 0.68, p = 0.022) and the pulmonic-to-systemic shunt flow ratio by cardiac catheterization (2.4:1 +/- 0.3, r = 0.74, p = 0.004). Color-guided continuous-wave Doppler estimates of right ventricular systolic pressure (47 +/- 2 mm Hg) correlated with cardiac catheterization measurements (48 +/- 3 mm Hg, r = 0.90, p = 0.0002).(ABSTRACT TRUNCATED AT 250 WORDS)

In this report, we present 34 patients in whom surgical intervention was undertaken for severe mitral insufficiency due to mitral valve prolapse (MVP). Location and severity of MVP and regurgitation were assessed preoperatively by live/real time three-dimensional transthoracic echocardiography and closely agreed with the surgical findings.

This preliminary study demonstrates the superiority of live three-dimensional transthoracic echocardiography (3D TTE) over two-dimensional (2D) TTE in the assessment of left atrial (LA) tumors in four patients studied by us (three myxomas, one hemangioma, all subsequently pathologically proven). Because of the unique ability of live 3D TTE to systematically section and view the contents of an intracardiac mass, LA myxomas in the three patients studied could be more confidently diagnosed by noting isolated echolucent areas consistent with hemorrhage/necrosis in the tumor mass. On the other hand, a definite echolucent area was found by 2D TTE in only two of the three patients with myxoma. In the fourth patient with a hemangioma, live 3D TTE showed much more extensive and closely packed echolucencies with little solid tissue as compared to a myxoma consistent with a highly vascularized tumor. In contrast, 2D TTE demonstrated only two isolated echolucencies in the tumor suggesting an erroneous diagnosis of myxoma.

We evaluated 44 consecutive patients who underwent standard two-dimensional (2D) and live three-dimensional (3D) transthoracic echocardiography (TTE), as well as left heart catheterization with left ventriculography. Mitral regurgitant vena contracta area (VCA) was obtained by 3D TTE by systematic and sequential cropping of the acquired 3D TTE data set. Assessment of mitral regurgitation (MR) by ventriculography was compared to measurements of VCA by 3D TTE and to 2D TTE measurements of MR jet area to left atrial area (RJA/LAA), RJA alone, vena contracta width (VCW), and calculated VCA. VCA from 3D TTE closely correlated with angiographic grading (rs=0.88) with very little overlap. VCA of0.2 cm2 correlated with mild MR, 0.2-0.4 cm2 with moderate MR, and0.4 cm2 with severe MR by angiography. Ventriculographic grading also correlated well with 2D TTE measurements of RJA/LAA (rs=0.79) and RJA alone (rs=0.76) but with more overlap. Assessment of VCW and calculated VCA by 2D TTE agreed least with ventriculography (rs=0.51 and rs=0.55, respectively). Live 3D TTE color Doppler measurements of VCA can be used for quantitative assessment of MR and is comparable to assessment by ventriculography.

Aortic valve stenosis (AS) severity can be estimated by various modalities. Due to some of the limitations of the currently available methods, the usefulness of live three-dimensional transthoracic echocardiography (3D TTE) in the assessment of AS was explored. Live 3D TTE was able to visualize the aortic valve orifice in all 11 patients studied. Live 3D TTE correctly estimated the severity of AS in all 10 patients in whom AS severity could be evaluated at surgery. These included eight patients with severe AS and two with moderate AS. Two of these 10 patients with AS had associated hypertrophic cardiomyopathy and underwent myectomy at the time of aortic valve replacement. Aortic valve orifice area measurements by live 3D TTE correlated well with intraoperative three-dimensional transesophageal echocardiographic reconstruction measurements (r=0.85) but not as well with two-dimensional transesophageal echocardiography measurements (r=0.64). Live 3D TTE measurements of the aortic valve orifice area also did not correlate well with two-dimensional transthoracic echocardiography measurements (r=0.46) but the number of patients studied with two-dimensional transthoracic echocardiography was smaller (only seven) and four of these did not undergo two-dimensional transthoracic echocardiography at the authors' institution. Altogether, four patients with severe AS by live 3D TTE, and subsequently confirmed at surgery, were misdiagnosed as having moderate AS by two-dimensional transthoracic echocardiography. Because it is completely noninvasive and views the aortic valve in three dimensions, 3D TTE could be a useful complement to the existing modalities in the evaluation of AS severity.

We present two- and three-dimensional transesophageal echocardiographic findings of two adult patients who presented for reoperation after previous repair of a partial atrioventricular (AV) septal defect. Both patients had a cleft in the left AV valve with severe regurgitation. One patient had an additional 10 x 5 mm defect connecting the left ventricle to the right atrium through the AV junction. Three-dimensional echocardiography was superior to two-dimensional echocardiography in comprehensively delineating the anatomical defects in the left AV valve and the AV junction.

We report three-dimensional transesophageal echocardiographic findings in an adult patient with Ebstein's anomaly. Using the anyplane technique and multiple views, especially the short-axis view of tricuspid valve, three-dimensional transesophageal echocardiography clearly demonstrated the intermittent tethering of all three leaflets of tricuspid valve to the right ventricular walls giving a “bubble-like” appearance. On the other hand, two-dimensional transesophageal echocardiography demonstrated well the tethering of the septal tricuspid leaflet, but tethering of the other two leaflets was not well seen. To our knowledge, these findings have not been demonstrated by three-dimensional transesophageal echocardiography before. (ECHOCARDIOGRAPHY, Volume 20, April 2003)

This case report describes a patient in whom a thin dissection of the proximal aorta was diagnosed by transesophageal echocardiography. Dissection was not firmly diagnosed in our patient with computed tomography, angiography, or magnetic resonance imaging. A definitive diagnosis was made prospectively using intraoperative transesophageal echocardiography by demonstrating the presence of a thin immobile dissection flap located very close to the anterior aortic wall. Color Doppler examination showed absence of flow signals in the small false lumen, suggesting that it may be clotted. At surgery the presence of dissection involving the ascending aorta, as well as a clotted false lumen were confirmed. This finding demonstrates the utility of transeophageal echocardiography in the diagnosis of aortic dissection and the ability of this test to differentiate a thin dissection from intimal thickening. (ECHOCARDIOGRAPHY, Volume 11, May 1994)

As compared with two-dimensional (2-D) transesophageal echocardiography (TEE), 3-D echocardiography now permits more realistic visualization of cardiac anatomy and of intracardiac lesions. The aim of this study was to apply newer 3-D echocardiographic techniques to quantify volumes of intracardiac masses undergoing surgical resection seen during an intraoperative TEE. The calculated volumes were compared with actual in vitro measurements of surgically resected masses. A total of 14 patients (9 men; 5 women; age range between 21 and 77 years) with intracardiac mass lesions (4 tumors: 3 left atrial myxomas and 1 mitral valve fibroelastoma, and 10 vegetations: 5 aortic valve, 3 mitral valve, 1 tricuspid and 1 pulmonary valve) were studied. Using commercially available 3-D reconstruction software (TomTec v. 4.1), the volumes of intracardiac masses were estimated using both the average rotation (rotation around the long axis, AR) and disk summation (parallel short axis cuts, DS) methods. Volumes of these lesions were also measured in vitro by water submersion. They ranged from 0.20 mL to 24 mL (mean ± SD = 8.07 ± 9.21 mL). Both 3-D TEE AR and 3-D TEE DS calculated volumes correlated excellently with in vitro measured volumes (r = 1.00 and r = 0.98, respectively, p = < 0.0001). The correlation between 3-D TEE AR and 3-D TEE DS calculated volumes was also excellent (r = 0.98, p = < 0.0001). In conclusion, the volume assessments by 3-D TEE of intracardiac mass lesions correlated well with in vitro measured volumes of surgical specimens. This technique may prove to be valuable in further defining intracardiac pathology and is a further advancement toward the application of clinically useful 3-D echocardiography. (E-mail: nanda@uab.edu)

Pulmonary vasospasm and hypertension may occur after repair or palliation of congenital cardiac defects, and can be fatal in spite of conventional treatment. Nitric oxide has been shown to improve pulmonary hypertension unresponsive to conventional measures after a variety of repairs, but use has infrequently been reported after palliative systemic to pulmonary artery shunts. We report a case of pulmonary hypertension and life threatening desaturation after a modified Blalock-Taussig shunt that responded rapidly to inhaled nitric oxide. Clinical use, further study, and prospective analysis of prophylactic use of nitric oxide appear warranted.

The incremental value of three-dimensional echocardiography over transesophageal multiplane two-dimensional imaging in the assessment of sinus venosus atrial septal defect is demonstrated in the present study.

Background . This report describes technical details of the right thoracotomy approach for mitral surgery, and analyzes our experience with this procedure for patients with a prior sternotomy. Three methods for myocardial management (hypothermic cardioplegic arrest, beating heart, and fibrillating heart) are compared. Methods . Records were abstracted of patients who had a right thoracotomy between January 1, 1992 and July 1, 1999 for mitral surgery after at least one prior sternotomy. Demographic, operative, and outcome data were collected for analysis. Telephone follow-up was used to measure postoperative New York Heart Association functional status. Results . Eighty-four patients (mean age 60 ± 15 years) had reoperative mitral surgery via a right thoracotomy. Myocardial management included ventricular fibrillation in 10 patients, operation on the beating heart in 58 patients, and hypothermic blood cardioplegia arrest in 16 patients. The mean time in the operating room was 185 ± 73 minutes, and the mean duration of cardiopulmonary bypass was 63 ± 56 minutes. There were no perioperative strokes and the prevalence of death for patients who received cardioplegic arrest was significantly higher than the prevalence of death for patients who had mitral surgery with perfused fibrillating or beating heart techniques ( p = 0.007; Fisher's exact test comparing risk- unadjusted mortality). Conclusions . Right thoracotomy provides efficient exposure for reoperative mitral surgery. Mitral valve procedures on the fibrillating or beating heart are feasible in most patients and are at least as safe as surgery using cardioplegic arrest.

Information describing outcome after myocardial revascularization and renal transplantation in patients with end-stage renal disease and coronary artery disease is limited in scope. There are several case reports that describe the results of cardiac operations in small numbers of renal transplant patients. 1–9 If these reports are considered together, there are 35 renal allograft patients who subsequently underwent cardiac operations. Of these 35 patients, 29 had isolated coronary artery bypass grafting (CABG). The aggregate immediate postoperative survival rate in these patients was 97%; however, intermediate- and long-term survival rates cannot be determined from the information contained in these reports. A larger study by Bolman et al published in 1984 included 14 patients who had cardiac operations. 10 Ten of the patients in this series had isolated CABG. There were two deaths; 12 patients were alive at 8 to 93 months after surgery. More recent studies of cardiac operations performed in renal transplant recipients 11,12 include more patients and a more complete outcome analysis. These studies, together with the earlier analysis of Bolman et al, indicate that surgical revascularization can be performed in renal transplant recipients without an unusually high incidence of postoperative infection despite immunosuppression, and with an acceptable short-term mortality rate relative to cardiac operations performed in patients without renal disease. In all three series, the short-term preservation of renal allograft function was good. Data have also been published that describe the outcome of patients who are maintained on dialysis and who receive either CABG or percutaneous transluminal coronary angioplasty (PTCA). 5,13–20 Several of these reports describe individual patients who had renal transplantation after revascularization; however, there is no report that describes long-term outcome and defines risk factors for patients with chronic renal failure who undergo a myocardial revascularization procedure and renal transplantation. The present report takes advantage of the large population of patients with renal disease treated at this institution. The goal was to generate a comprehensive review of myocardial revascularization in patients with chronic renal failure who also receive, at some point in their lives, a renal allograft. The specific aims of this analysis were to quantify the number of deaths in patients who had renal transplantation and myocardial revascularization at this institution, and to identify risk factors that influenced survival in these patients.

The diagnosis and site of graft dehiscence determined by transesophageal echocardiography (TEE), transthoracic echocardiography (TTE), and aortography in 6 patients, and by computed tomography (CT) scan in 3 patients were compared with surgery. Sensitivity of TEE was 100%, aortography 83%, CT scan 67%, and TTE 33%; TEE accurately identified severe aortic regurgitation (3), graft narrowing (2), distal aortic dissection (1), and a fistulous communication between the aortic root and the right ventricle (1) when compared with surgery or aortography.

Estudaram-se a demanda metabólica e a distribuição do fluxo coronariano na presença de fibrilação ventricular (FV), durante a reperfusão pós-cardioplegia. Foram colocados 15 suínos em circulação extracorpórea e submetidos a parada cardíaca cardioplégica sangüínea anterógrada hipotérmica intermitente, durante uma hora, seguida por reperfusão miocárdica controlada. Os animais foram divididos em três grupos (n=5), conforme estivessem em assistolia (Grupo 1) ou em FV de curta (Grupo 2) ou longa duração (Grupo 3), durante os dez primeiros minutos de reperfusão. Os valores do consumo miocárdico de oxigênio (MVO2), em ml O2/min/g (média ± erro padrão) durante a reperfusão foram de 1,325 ± 0,144 (Grupo 1); 2,472 ± 0,208 (Grupo 2) e 2,469 ± 0,228 (Grupo 3). A diferença entre o MVO2 dos corações em assistolia e o dos corações em FV, quer de curta ou longa duração, foi significante (pMetabolic coronary blood flow recruitment and distribution were studied in the setting of ventricular fibrillation (VF) during post-cardioplegia reperfusion. Fifteen pigs were placed on cardiopulmonary bypass and subjected to one hour of intermittent cold blood antegrade cardioplegia, followed by controlled myocardial reperfusion. According to the electromechanical status during the first ten minutes of reperfusion, the animals were allocated into 3 groups (n=5). Whereas Group 1 remained asystolic, the other two groups developed short (Group 2) or long duration VF (Group 3). Myocardial oxygen consumption (MVO2), in m/O2 /min/g (mean ± standard error) during reperfusion was 1.325 ± 0.144 (Group 1); 2.472 ± 0.208 (Group 2) and, 2.469 ± 0.228 (Group 3). MVO2 difference between asystolic and both short and long duration VF hearts was significant (p

We describe our preliminary experience in assessing normal and stenosed coronary arteries using transesophageal three-dimensional echocardiography (3-D echo) in 27 adult patients. Multiplane transesophageal two-dimensional images of the coronary arteries (20 left, 3 right, 3 both left and right, and 1 posterior descending) were first acquired in the TomTec computer in 3 degrees sequential increments, from 0 degrees to 180 degrees, and then 3-D reconstruction was performed. The entire left main (LMC, measuring 0.5 to 1.7 cm, mean 1.0 cm) as well as variable lengths of proximal or both proximal and middle segments of the left anterior descending (LAD, measuring 0.2 to 2.5 cm, mean 0.8 cm) and circumflex (LCX, measuring 0.2 to 2.8 cm, mean 0.9 cm) coronary arteries together with some of their branches could be visualized in 3-D in 22 of 23 patients. In the remaining patient, the LMC was absent, and both LAD and LCX could be visualized in 3-D as having separate but adjacent origins from the left sinus of Valsalva (proven by angiography). In two patients, long segments of interventricular and great cardiac veins were also visualized accompanying the LAD and LCX, respectively. The right coronary artery (RCA, measuring 0.7 to 3.0 cm, mean 1.9 cm) was also successfully delineated in 3-D in all six patients in whom an attempt was made to visualize it during echo examination. Using the transgastric approach, a long (1.8 cm) segment of the posterior descending branch (PDA) of RCA was imaged in one patient. In addition, nine significantly stenotic lesions (>50% lumen diameter) were identified by 3-D in eight patients involving LMC (1), proximal LAD (1), mid LAD (1), proximal LCX (2), proximal RCA (3), and mid PDA (1). Eight of these 9 lesions were confirmed by coronary angiography. The remaining lesion (mid PDA) could not be confirmed since the patient did not undergo angiography. Our preliminary study demonstrates the usefulness of transesophageal 3-D echo not only in delineating normal coronary arteries but also diagnosing significant atherosclerotic stenosis in these vessels. (ECHOCARDIOGRAPHY, Volume 13, September 1996)

This case report describes a patient with systemic lupus erythematosus who demonstrated by transesophageal echocardiography (TEE) a flail right coronary cusp of the aortic valve causing severe aortic regurgitation. This finding was confirmed at surgery, which showed near detachment of the right coronary leaflet near the commissure. Destruction of areas of the aortic valve has been reported in one previous case report in the absence of infective endocarditis or a traumatic process. This is the second case to our knowledge and the first to describe identification by TEE. (ECHOCARDIOGRAPHY, Volume 13, July 1996)

Prostaglandin E1 (PGE1) causes skeletal hypertrophy, a phenomenon noted when it is administered for several weeks to maintain ductus arteriosus patency in neonates with congenital heart disease. This effect, a dose-dependent and reversible hyperostosis, was described radiologically as bone within bone, but skeletal histopathology was not studied. We compared postmortem gross, radiological, and histological bone findings for untreated controls and term gestation infants after 4, 27, and 56 days of continuous 0.1-0.2 microgram/kg/min PGE1. Bone was not significantly different from controls after 4 days of PGE1. Radiographs were negative after 27 days, but femoral cortex showed early periosteal osteoblast proliferation. At 56 days of PGE1, there was severe, radiologically apparent neocortex formation in tubular, rib, and scapular bones. Corresponding sections of femoral shaft revealed distinctive histopathology with thickened periosteum and fibrocartilage-like tissue covering an exuberant neocortex of closely aligned, gracile, woven bone trabeculae. Paratrabecular stroma contained ectatic capillaries orthogonally oriented to the periosteum, suggesting that a vascular reaction to PGE1 is important in the observed effect. The native cortex was partially resorbed; because it is stress shielded by the neocortex and no inflammation was present, this was interpreted as a secondary effect. We conclude that PGE1-associated paracortical bone hypertrophy is distinct from inflammatory processes and that its early stages may not be apparent radiologically. Moreover, the time course of PGE1-induced osteoblast proliferation and mineralization suggests that experimental use for 4-8 weeks may benefit conditions such as ununited fractures.

The authors previously published data that describe acute alterations in ventricular dimensions and in the severity of mitral and tricuspid regurgitation (MR/TR) after initiation of left ventricular assist device (LVAD) pumping. In the current study, measurements of ventricular size and regurgitant jet area acquired after LVAD implantation are presented. Eight patients had LVAD implanted pending cardiac transplantation (duration of assist 70-279 days; mean, 162 +/- 29 days). Echocardiograms were obtained at the time of LVAD implant and later during LVAD support (mean time for late echo, 95 +/- 32 days post-implant). Comparisons of pre-implant with late post-implant data showed: increased TR jet area (4.8 +/- 1.0 cm2 vs. 8.0 +/- 1.7 cm2 P < 0.05); increased right ventricular (RV) end-systolic dimension (31 +/- 4 vs 40 +/- 5 mm, P < 0.05); and increased RV end-diastolic dimension (35 +/- 4 vs. 45 +/- 5 mm, P < 0.065). Decreased MR jet area and decreased LV dimensions (P < 0.05) also were noted on comparison of pre-implant and late post-implant data. There were no significant differences between any immediate post-implant and late post-implant echocardiographic measurements. No patient had clinical evidence of RV failure. LV mechanical assist causes an acute increase in TR, presumably by volume loading the RV. TR and RV enlargement persisted but did not discernibly worsen on subsequent post-implant echocardiograms. LV dimensions and MR remained less than the pre-implant values on later post-implant determinations.