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Malignant hyperthermia is a rare but well-described hypermetabolic disorder of skeletal muscle that can be potentially fatal if untreated. In our patient, malignant hyperthermia developed several minutes after discontinuation of the known triggering agent after an uncomplicated coronary revascularization. This case illustrates the dramatic presentation and successful management of a rare disease with a rare onset.

Background Left ventricular assist devices (LVADs) provide a bridge to recovery or heart transplantation but require serial assessment. Echocardiographic approaches may be limited by device artifact and acoustic window. Cardiovascular computed tomography (CCT) may provide improved non-invasive imaging of LVADs. We evaluated the diagnostic findings and clinical impact of CCT for non-invasive assessment of patients with LVADs. Methods CCT examinations performed between 2005 and 2008 in patients with LVADs were identified. Acquisitions were completed on the identical 64-detector-row scanner with intravenous contrast administration. Electrocardiographic gating was used in patients with pulsatile devices, and peripheral pulse gating was used in patients with continuous-flow devices. Comparison was made between CCT results and 30-day outcomes, including echocardiographic and intraoperative findings. Results We reviewed 32 CCT examinations from 28 patients. Indications included evaluation of low cardiac output symptoms, assessment of cannula position, low flow reading on the LVAD, and surgical planning. CCT identified critical findings in 6 patients, including thrombosis and inlet cannula malposition, all confirmed intraoperatively. CCT missed 1 case of intra-LVAD thrombus. Using intraoperative findings as the gold standard, CCT's sensitivity was 85% and specificity was 100%. Echocardiographic LVAD evaluation did not correlate with findings on CCT (κ = −0.29, 95% confidence interval, −0.73 to 0.13). Conclusions This preliminary observational cohort study indicates that non-invasive imaging using CCT of LVADs is feasible and accurate. CCT warrants consideration in the initial evaluation of symptomatic patients with LVADs.

Mechanical complications after myocardial infarction are uncommon with advances in medical reperfusion strategies. However, such strategies are associated with bleeding complications which typically contraindicate surgical management. We describe a patient with a post-infarction ventricular septal defect and an intraventricular hemorrhage following thrombolytic therapy for an acute myocardial infarction.

Purpose Evolution of anti-arrhythmia surgery beyond the Cox maze III has been hampered by the difficulty in implementing a complete lesion set in a truly minimally invasive approach. In this study, we introduce a true port-access procedure that addresses both autonomic and anatomic sources of atrial fibrillation, with real-time verification of all technical endpoints. Description A total of 32 patients with persistent or longstanding persistent atrial fibrillation underwent the totally thoracoscopic anti-arrhythmia procedure incorporating pulmonary vein isolation, mapping of epicardial autonomics, extended linear ablations across critical segments of atrial substrate, and ligation of the left atrial appendage. All aspects of the procedure were confirmed with intraoperative electrophysiologic testing. Evaluation With 1 week of continuous rhythm surveillance at 3, 6, and 13 months postoperatively in all patients, 21 of 24 patients with 6-month follow-up are in sinus rhythm with no anti-arrhythmia medications. Conclusions An anti-arrhythmia operation that is highly effective in patients with advanced forms of atrial fibrillation can be safely performed through a totally port-access approach.

Background Implantation of ventricular assist devices for cardiac support is normally performed using cardiopulmonary bypass. Post-operative complications could be minimized by the placement of these devices without the use of cardiopulmonary bypass. Methods We hypothesize that left ventricular assist devices (LVADs), in selected patients, can be implanted safely off-pump. Results In 25 patients, LVADs were implanted off-pump (mean age 50 years; 64% male, 36% female; average left ventricular ejection fraction 15%). Pre-operatively 68% of patients were on inotropes, 25% had an intra-aortic ballon pump, and 44% had a previous sternotomy. Blood utilization intra- and post-operatively was relatively minimal with 1 re-exploration for bleeding. There were 3 deaths. Conclusions We describe a technique for successful placement of a left ventricular assist device without the use of cardiopulmonary bypass.

Advances in imaging technology can provide a potentially more accurate, precise, and timely diagnosis. However, false-positive results, particularly when acute aortic pathology is being considered, can lead to unnecessary interventions. We present a case of a computed tomography scan that was false-positive for aortic dissection and highlight the importance of confirmatory studies.

Background— Left main trunk stenosis (≥50%) has traditionally been treated with coronary artery bypass grafting. Improvements in coronary stents have led some to advocate percutaneous coronary intervention. To provide a benchmark of outcomes against which percutaneous coronary intervention may be compared, we (1) assessed survival and freedom from coronary reintervention after coronary artery bypass grafting in these patients and (2) identified their risk factors. Methods and Results— From 1971 to 1998, the first 1000 primary coronary artery bypass grafting patients (n=26 927) were followed every 5 years. Of these, 3803 had left main trunk stenosis ≥50%. A multivariable, nonproportional hazards, time-related analysis was performed to model survival and freedom from coronary reintervention (percutaneous coronary intervention or reoperation) and to identify their risk factors. Survival at 30 days, 1, 5, 10, 15, and 20 years was 97.6%, 93.6%, 83%, 64%, 44%, and 28%, respectively, and freedom from coronary reintervention was 99.7%, 98.9%, 96.6%, 89%, 76%, and 61%, respectively. Worse left ventricular function ( P P P P =0.0002), smoking ( P P =0.01) decreased survival, and younger age ( P P= 0.005), and incomplete revascularization ( P= 0.003) increased coronary reintervention. Internal thoracic artery grafting of the left anterior descending improved survival and decreased coronary reintervention. Conclusions— This study provides a 20-year outcome benchmark for surgical treatment of left main trunk disease. It indicates that simple comparisons of new treatments are inadequate without risk adjustment. Risk factor adjustment should be used when comparing coronary artery bypass grafting with current and future treatment innovations and when selecting the best treatment strategy for individual patients.

Background Early diastolic intraventricular pressure gradient (IVPG), as derived by color M-mode echocardiography, has been proposed to correlate with left ventricular (LV) elastic recoil. However, any relationship to quantifiable indices of LV contractility is poorly defined. Methods To relate IVPG with invasive and noninvasive indices of contractility, 6 closed-chest dogs each had a high-fidelity conductance catheter placed into the LV for continuous determination of end-diastolic pressures, volumes, +dP/dt max , and the time constant of LV relaxation (tau) under baseline conditions and 4 different stages of β-receptor modulation. At each stage, IVPGs were determined from color M-mode echocardiography images. Doppler-derived strain rate (ϵ′) and myocardial systolic myocardial velocities (S m ) were also measured. E max was obtained from the slope of the end-systolic pressure-volume relationship during caval occlusion. Results of contractility indices were compared to IVPG with regression analysis. Results IVPG ranged from 0.72 to 3.95 mm Hg whereas E max ranged from 0.66 to 14.9 mm Hg/mL and end-systolic volume ranged from 1.9 to 59.7 mL. IVPG correlated with ϵ′ ( r = 0.71), S m ( r = 0.67), end-systolic volume ( r = 0.53), and invasive indices (+dP/dt max , r = 0.71, and E max , r = 0.82). Conclusions Early diastolic IVPGs are associated with LV contractility. These findings may explain the proposed mechanism in which potential energy stored during systole is released during diastole to provide for adequate ventricular filling, even under low filling pressures.

Typically acute dissections of the ascending aorta are considered operative emergencies with delays in treatment potentially resulting in considerable morbidity and mortality. However, occasionally associated unstable or poorly defined problems (such as neurologic impairment or end-organ ischemia) may warrant further investigation and possible treatment to facilitate safe aortic repair. We present a case of acute ascending aortic dissection associated with an intra-abdominal vascular and enteric catastrophe that was successfully managed prior to aortic repair.

Background: Guidelines recommend discontinuing clopidogrel for at least 5 days before elective coronary artery bypass graft surgery (CABG) to limit blood transfusions and for at least 24 hours before urgent CABG to reduce major bleeding complications. Studies have produced conflicting results regarding whether recent exposure to clopidogrel increases bleeding, the need for intraoperative and postoperative blood products, postoperative complications, and hospital length of stay. We evaluated the effect of clopidogrel exposure on major bleeding at our institution within 5 days of CABG.Methods: We conducted a retrospective review of patients who underwent CABG at a tertiary academic medical center. The primary outcome was major bleeding, defined as transfusion of 4 units of packed red blood cells (PRBCs) and/or a need for reexploration. Secondary outcomes included non-life-threatening bleeding, defined as transfusion of 2 units but Results: Of the 715 patients we reviewed, 169 patients received clopidogrel within 5 days before CABG, and 546 patients did not. A significantly higher incidence of major bleeding was observed in the clopidogrel group compared with the group not exposed to clopidogrel (32% versus 17%, P = .002). After adjusting for covariates, patients exposed to clopidogrel had significantly higher odds of major bleeding (odds ratio, 2.1; 95% confidence interval, 1.3-3.4; P = .003). The groups were similar with respect to postoperative complications, except for infection. The clopidogrel-exposed group had a significantly higher rate of leg site infections (3% versus 0.2%, P = .003).Conclusions: Clopidogrel exposure within 5 days of CABG is associated with an increased risk of major bleeding.

THE SPLEEN IS ONE OF THE MOST commonly injured organs after blunt abdominal trauma. Although most splenic injuries are discovered after investigation of either hemodynamic instability or suspected abdominal injury during the initial patient evaluation, occult injuries that present with delayed splenic rupture occur in a small percentage of patients.1 The occurrence of “overwhelming postsplenectomy infection” (OPSI) and its associated high mortality have prompted surgeons to preserve the spleen either by using operative techniques or with nonoperative management. Recently, several reports have described splenic artery embolization (SAE) as an adjunct to the nonoperative management of selected blunt splenic injuries,2,3 but the role of SAE in patients whose nonoperative management fails or who present with delayed rupture has not been defined. This report presents a patient with delayed splenic rupture who was treated successfully with SAE.

We hypothesize that a simplified version of the Euler equation (SEE) utilizing differences in velocity over a distance and time as obtained by color Doppler M-mode (CMM) echocardiography can approximate actual peak transmitral pressure gradients (/spl Delta/P/sub TM/). In 14 patients undergoing open-heart surgery, /spl Delta/P/sub TM/ was measured under various hemodynamic conditions using 2 high fidelity transducers, 5 cm apart. Transesophageal CMM images were simultaneously acquired and a customized image analysis application was wed to abstract spatiotemporal velocity characteristics. Using both the SEE and a simplified Bernoulli equations, /spl Delta/P/sub TM/ were determined and compared to the actual /spl Delta/P/sub TM/. While the simplified Bernoulli equation resulted in a poor estimate (y=0.075x+0.71, r=0.45), the /spl Delta/P/sub TM/ obtained using the SEE correlated strongly (y=0.79x+0.48, r=0.91) with the actual measurements. Semi-automated analysis of CMM images using a SEE can accurately estimate actual /spl Delta/P/sub TM/.

Color Doppler echocardiographic evaluation of valve regurgitation could be improved using a quantitative approach. While techniques have been proposed and utilized in research, their limitations restrict widespread clinical utilization. We have developed an approach to address several of these limitations and have tested the methodology in an in vitro model with flow through restrictive orifices under a wide range of operating conditions. Doppler images of flow velocities along the centerline path through the orifice were digitally acquired and processed to extract the distance (IAD) between aliasing boundaries proximal to the orifice. Flow rate and effective orifice area were computed from each IAD and compared to reference measurements. Calculated e (y=1.07x-22.8, r=0.97) and EOA (y=1.09x-0.03, r=0.98) demonstrated strong agreement with reference measurements. The IAD technique may improve the estimation of regurgitant volume and effective orifice area.

The determination of pulmonary venous velocities from pulsed Doppler echocardiography is valuable for the assessment of left ventricular diastolic dysfunction, yet little is known regarding the relationship between actual pressure gradients and measured velocities. Combining results of in vivo experiments and numerical modeling, a linear relationship was observed between actual pulmonary venous-left atrial pressure gradients and measured velocities (convective forces) measured using pulsed Doppler echocardiography. Strong model correlations were observed for the systolic (y=0.20x-0.13, r=0.97) and diastolic (y=0.25x-0.34, r=0.99) phases of the pulmonary venous waveform. In vivo results were similar for the systolic (y=0.234x+0.01x, r=0.82) and diastolic (y=0.22x+0.09, r=0.81) phases. Modeling, combined with in vivo experiments can complement each other in understanding complex physiology.

The assessment of left-ventricular (LV) filling pressure usually requires invasive hemodynamic monitoring to follow the progression of a disease or the response to therapy. Previous investigations have shown accurate estimation of wedge pressure using non-invasive Doppler information obtained from the ratio of the wave propagation slope from color M-mode (CMM) images to the peak early diastolic filling velocity from transmitral Doppler images. This study reports an automated algorithm that derives an estimate of wedge pressure based on the spatiotemporal velocity distribution available from digital CMM Doppler images of LV filling.

Inertial forces (Mdv/dt) are a significant component of transmitral flow, but cannot be measured with Doppler echo. We validated a method of estimating Mdv/dt. Ten patients had a dual-sensor transmitral (TM) catheter placed during cardiac surgery. Doppler and 2D echo measurements were performed while acquiring left-atrial (LA) and left-ventricular (LV) pressures. Mdv/dt was determined from the Bernoulli equation using Doppler velocities and TM gradients. The results were compared with numerical modeling. The TM gradients (range: 1.04-14.24 mmHg) consisted of 74.0/spl plusmn/11.0% inertial forcers (range: 0.6-12.9 mmHg). Multivariate analysis predicted Mdv/dt = -4.171(S/D) + 0.063(LA/sub VOLUME-MAX/) + 5, where S/D is the systolic/diastolic ratio. Using this equation, a strong relationship was obtained between the clinical data set (y = 0.98x - 0.045, r=0.90) and the results of the numerical modeling (y = 0.96x - 0.16, r=0.84). TM gradients are mainly inertial and, as validated by modeling, can be estimated with echocardiography.

Efforts to improve mitral regurgitation (MR) are often performed in conjunction with coronary revascularization. However, the independent effects of a reduced MR area (MRa) are difficult to quantify. Using a previously-developed cardiovascular model, ventricular contractility (elastance 1-8 mmHg/ml) and relaxation (/spl tau/=40-150 ms) were independently adjusted for four grades of MR orifice areas (0.0-0.8 cm/sup 2/). Improvements in forward stroke volume (fSV) were determined for the permutations of reduced MRa. For all conditions, left ventricular (LV) end-diastolic pressure and volumes ranged from 7.3-24.2 mmHg and 64.8-174.3 ml, respectively. Overall, fSV ranged from 36.0-89.4 (mean: 64.2/spl plusmn/12.8) ml, improved between 6.4 and 35.3% (mean: 15.6/spl plusmn/8.1%), and was best predicted (r=0.97, p

Digital acquisition, storage, and review of echocardiographic data are feasible in a multivendor networked DICOM environment. The authors' echocardiographic laboratory currently stores 120 studies per day rising the ProSolv Echo Management System. Storage and retrieval is realized on standard computer hardware without the necessity for proprietary hardware solutions. DICOM storage has become more efficient as vendor solutions improve. Transmission rates over a 10/100 BT switched network are approximately 0.40 MB/s allowing a complete echo study (/spl sim/40 MB) to be transferred to the server in approximately 1.5 minutes, however the ability to send data during a study has also been realized by one vendor.

Real-time three-dimensional echocardiography has been introduced to provide improved quantification and description of cardiac function. Data compression is desired to allow efficient storage and improve data transmission. Previous work has suggested improved results utilizing wavelet transforms in the compression of medical data including 2D echocardiogram. Set partitioning in hierarchical trees (SPIHT) was extended to compress volumetric echocardiographic data by modifying the algorithm based on the three-dimensional wavelet packet transform. A compression ratio of at least 40:1 resulted in preserved image quality.

OBJECTIVE: The goal of this study was to analyze left ventricular outflow tract systolic acceleration (LVOT(Acc)) during alterations in left ventricular (LV) contractility and LV filling. BACKGROUND: Most indexes described to quantify LV systolic function, such as LV ejection fraction and cardiac output, are dependent on loading conditions. METHODS: In 18 sheep (4 normal, 6 with aortic regurgitation, and 8 with old myocardial infarction), blood flow velocities through the LVOT were recorded using conventional pulsed Doppler. The LVOT(Acc) was calculated as the aortic peak velocity divided by the time to peak flow; LVOT(Acc) was compared with LV maximal elastance (E(m)) acquired by conductance catheter under different loading conditions, including volume and pressure overload during an acute coronary occlusion (n = 10). In addition, a clinically validated lumped-parameter numerical model of the cardiovascular system was used to support our findings. RESULTS: Left ventricular E(m) and LVOT(Acc) decreased during ischemia (1.67 +/- 0.67 mm Hg.ml(-1) before vs. 0.93 +/- 0.41 mm Hg.ml(-1) during acute coronary occlusion [p < 0.05] and 7.9 +/- 3.1 m.s(-2) before vs. 4.4 +/- 1.0 m.s(-2) during coronary occlusion [p < 0.05], respectively). Left ventricular outflow tract systolic acceleration showed a strong linear correlation with LV E(m) (y = 3.84x + 1.87, r = 0.85, p < 0.001). Similar findings were obtained with the numerical modeling, which demonstrated a strong correlation between predicted and actual LV E(m) (predicted = 0.98 [actual] -0.01, r = 0.86). By analysis of variance, there was no statistically significant difference in LVOT(Acc) under different loading conditions. CONCLUSIONS: For a variety of hemodynamic conditions, LVOT(Acc) was linearly related to the LV contractility index LV E(m) and was independent of loading conditions. These findings were consistent with numerical modeling. Thus, this Doppler index may serve as a good noninvasive index of LV contractility.

AIM: The aim of this study was to investigate the feasibility and accuracy of using symmetrically rotated apical long axis planes for the determination of left ventricular (LV) volumes with real-time three-dimensional echocardiography (3DE). METHODS AND RESULTS: Real-time 3DE was performed in six sheep during 24 haemodynamic conditions with electromagnetic flow measurements (EM), and in 29 patients with magnetic resonance imaging measurements (MRI). LV volumes were calculated by Simpson's rule with five 3DE methods (i.e. apical biplane, four-plane, six-plane, nine-plane (in which the angle between each long axis plane was 90 degrees, 45 degrees, 30 degrees or 20 degrees, respectively) and standard short axis views (SAX)). Real-time 3DE correlated well with EM for LV stroke volumes in animals (r=0.68-0.95) and with MRI for absolute volumes in patients (r-values=0.93-0.98). However, agreement between MRI and apical nine-plane, six-plane, and SAX methods in patients was better than those with apical four-plane and bi-plane methods (mean difference = -15, -18, -13, vs. -31 and -48 ml for end-diastolic volume, respectively, P

Background — Myocardial fiber strain is directly related to left ventricular (LV) contractility. Strain rate can be estimated as the spatial derivative of velocities (dV/ds) obtained by tissue Doppler echocardiography (TDE). The purposes of the study were (1) to determine whether TDE-derived strain rate may be used as a noninvasive, quantitative index of contractility and (2) to compare the relative accuracy of systolic strain rate against TDE velocities alone. Methods and Results — TDE color M-mode images of the interventricular septum were recorded from the apical 4-chamber view in 7 closed-chest anesthetized mongrel dogs during 5 different inotropic stages. Simultaneous LV volume and pressure were obtained with a combined conductance–high-fidelity pressure catheter. Peak elastance (E max ) was determined as the slope of end-systolic pressure-volume relationships during caval occlusion and was used as the gold standard of LV contractility. Peak systolic TDE myocardial velocities (S m ) and peak (ε′ p ) and mean (ε′ m ) strain rates obtained at the basal septum were compared against E max by linear regression. E max as well as TDE systolic indices increased during inotropic stimulation with dobutamine and decreased with the infusion of esmolol. A stronger association was found between E max and ε′ p ( r =0.94, P y =0.29 x +0.46) and ε′ m ( r =0.88, P m ( r =0.75, P Conclusions — TDE-derived ε′ p and ε′ m are strong noninvasive indices of LV contractility. These indices appear to be more reliable than S m , perhaps by eliminating translational artifact.

The spread of pandemic Influenza A (H1N1-2009) was believed to have been attenuated by the effectiveness of worldwide vaccination initiatives. Despite the immunogenicity of a safe vaccine, we report a case of vaccine failure resulting in catastrophic influenza-associated respiratory failure.

Background Following the 2009 H1N1 Influenza pandemic, extracorporeal membrane oxygenation (ECMO) emerged as a viable alternative in selected, severe cases of ARDS. Acute Respiratory Distress Syndrome (ARDS) is a major public health problem. Average medical costs for ARDS survivors on an annual basis are multiple times those dedicated to a healthy individual. Advances in medical and ventilatory management of severe lung injury and ARDS have improved outcomes in some patients, but these advances fail to consistently “rescue” a significant proportion of those affected. Discussion Here we present a synopsis of the challenges, considerations, and potential controversies regarding veno-venous ECMO that will be of benefit to anesthesiologists, surgeons, and intensivists, especially those newly confronted with care of the ECMO patient. We outline a number of points related to ECMO, particularly regarding cannulation, pump/oxygenator design, anticoagulation, and intravascular fluid management of patients. We then address these challenges/considerations/controversies in the context of their potential future implications on clinical approaches to ECMO patients, focusing on the development and advancement of standardized ECMO clinical practices. Summary Since the 2009 H1N1 pandemic ECMO has gained a wider acceptance. There are challenges that still must be overcome. Further investigations of the benefits and effects of ECMO need to be undertaken in order to facilitate the implementation of this technology on a larger scale.

The pressure-velocity relationship across the normal mitral valve is approximated by the Bernoulli equation ΔP = ½ ρΔ v 2 + M · d v/d t, where ΔP is the atrioventricular pressure difference, ρ is blood density, v is transmitral flow velocity, and M is mitral inertance. Although M is indispensable in assessing transvalvular pressure differences from transmitral flow, this term is poorly understood. We measured intraoperative high-fidelity left atrial and ventricular pressures and simultaneous transmitral flow velocities by using transesophageal echocardiography in 100 beats (8 patients). We computed mean mitral inertance ( [Formula: see text] ) by [Formula: see text] = ∫(ΔP−½ · ρ v 2)d t/∫(d v/d t)d tand we assessed the effect of the inertial term on the transmitral pressure-flow relation. [Formula: see text] ranged from 1.03 to 5.96 g/cm2 (mean = 3.82 ± 1.22 g/cm2). ΔP calculated from the simplified Bernoulli equation (ΔP = ½ · ρ v 2) lagged behind (44 ± 11 ms) and underestimated the actual peak pressures (2.3 ± 1.1 mmHg). [Formula: see text] correlated with left ventricular systolic pressure ( r = −0.68, P < 0.0001) and transmitral pressure gradients ( r = 0.65, P < 0.0001). Because mitral inertance causes the velocity to lag significantly behind the actual pressure gradient, it needs to be considered when assessing diastolic filling and the pressure difference across normal mitral valves.

Shortened early transmitral deceleration times ( E DT) have been qualitatively associated with increased filling pressure and reduced survival in patients with cardiac disease and increased left ventricular operating stiffness ( K LV). An equation relating K LV quantitatively to E DT has previously been described in a canine model but not in humans. During several varying hemodynamic conditions, we studied 18 patients undergoing open-heart surgery. Transesophageal echocardiographic two-dimensional volumes and Doppler flows were combined with high-fidelity left atrial (LA) and left ventricular (LV) pressures to determine K LV. From digitized Doppler recordings, E DT was measured and compared against changes in LV and LA diastolic volumes and pressures. E DT(180 ± 39 ms) was inversely associated with LV end-diastolic pressures ( r = −0.56, P = 0.004) and net atrioventricular stiffness ( r = −0.55, P = 0.006) but had its strongest association with K LV ( r = −0.81, P < 0.001). K LV was predicted assuming a nonrestrictive orifice ( K nonrest) from E DT as K nonrest= (0.07/ E DT)2 with K LV = 1.01 K nonrest − 0.02; r = 0.86, P < 0.001, Δ K( K nonrest − K LV) = 0.02 ± 0.06 mmHg/ml. In adults with cardiac disease, E DT provides an accurate estimate of LV operating stiffness and supports its application as a practical noninvasive index in the evaluation of diastolic function.

Myocardial tissue Doppler echocardiography (TDE) has been proposed as a tool for the assessment of diastolic function. Controversy exists regarding whether TDE measurements are influenced by preload. In this study, left ventricular volume and high-fidelity pressures were obtained in eight closed-chest dogs during intermittent caval occlusion. The time constant of isovolumic ventricular relaxation (τ) was altered with varying doses of dobutamine and esmolol. Peak early diastolic myocardial ( E m) and transmitral ( E) velocities were measured before and after preload reduction. The relative effects of changes in preload and relaxation were determined for E m and compared with their effects on E. The following results were observed: caval occlusion significantly decreased E (Δ E = 16.4 ± 3.3 cm/s, 36.6 ± 13.7%, P < 0.01) and E m (Δ E m = 1.3 ± 0.4 cm/s, 32.5 ± 26.1%, P < 0.01) under baseline conditions. However, preload reduction was similar for E under all lusitropic conditions ( P = not significant), but these effects on E m decreased with worsening relaxation. At τ < 50 ms, changes in E m with preload reduction were significantly greater (Δ E m = 2.8 ± 0.6 cm/s) than at τ = 50–65 ms (Δ E m = 1.2 ± 0.2 cm/s) and at τ >65 ms (Δ E m = 0.5 ± 0.1 cm/s, P < 0.05). We concluded that TDE E m is preload dependent. However, this effect decreases with worsening relaxation.

OBJECTIVESWe sought to determine the relationship between different echocardiographic indices and pulmonary capillary wedge pressures (PCWP) in normal volunteers.BACKGROUNDIndices based on tissue Doppler (TDE) and color M-mode (CMM) echocardiography have been proposed to reflect left (LV) ventricular filling pressures. These include the ratio of early diastolic transmitral velocity (E) to early myocardial velocity measured by TDE (E′) and the ratio of E to the wave propagation velocity (Vp) measured from CMM images. These indices, however, have not been validated in normal individuals.METHODSWe studied seven volunteers during two phases of preload altering maneuvers, baseline, with two stages of lower body negative pressure, and repeat baseline with two stages of volume loading. The PCWP obtained from right heart catheterization was compared with diastolic indices using pulsed Doppler, TDE and CMM echocardiography.RESULTSThe PCWP ranged from 2.2 to 23.5 mm Hg. During preload alterations, significant changes in E and septal E′ (both p < 0.05) but not lateral E′ or Vp were observed. Furthermore, E, septal E′ and E/Vp correlated with PCWP (all r > 0.80) but not combined E and TDE indices (both r < 0.15). Within individuals, a similar linear relationship was observed among E/Vp, E and septal E′ (average r > 0.80).CONCLUSIONSIn subjects without heart disease, E, septal E′ and E/Vp correlate with PCWP. Because the influence of ventricular relaxation is minimized, the ratio E/Vp may be the best overall index of LV filling pressures.

Coronary aneurysms in adults are rare. Surgical treatment is often concomitant to treating obstructing coronary lesions. However, the ideal treatment strategy is poorly defined. We present a case of successful treatment of a large coronary artery aneurysm with a reverse saphenous interposition vein graft. This modality offers important benefits over other current surgical and percutaneous techniques and should be considered as an option for patients requiring treatment for coronary aneurysms.

To compare the magnitude and rates of change of peak systolic (epsilon(')(SYS)) and diastolic (epsilon(')(DIAS)) strain rates, as measured using tissue Doppler echocardiography, to pressure and volumes left-ventricular indices during acute coronary occlusion.Six closed-chest dogs had a combination high-fidelity conductance pressure transducer placed into the left ventricle for determination of end-diastolic and end-systolic pressures (EDP and ESP) and volumes (EDV, ESV, and ejection fraction [EF]). Other indices included the time constant of left-ventricular relaxation (tau), +dP/dt(max), -dP/dt(max), end-systolic pressure/volume index (ESPV). A coronary angioplasty catheter was positioned into the left-anterior descending coronary artery. During coronary occlusion, strain rates and hemodynamic parameters were recorded continuously for 2 minutes.During occlusion, significant decreases in strain rates occurred within 30 seconds. Systolic indices (ESPV and +dP/dt(max)) changed at rates similar to epsilon(')(SYS) (each p = NS). Diastolic indices (tau, EDP, EDV, -dp/dt(max)) also changed at rates similar to epsilon(')(DIAS) (each p = NS). However, EF decreased at a significantly slower rate than did strain rates (p0.05).CONCLUSIONS:Peak systolic and diastolic strain rates decrease with acute ischemia similar to corresponding indices of left-ventricular systolic and diastolic function. Strain rates may be used in the noninvasive assessment of ischemic-induced left-ventricular dysfunction.

Background —Infarct exclusion (IE) surgery, a technique of left ventricular (LV) reconstruction for dyskinetic or akinetic LV segments in patients with ischemic cardiomyopathy, requires accurate volume quantification to determine the impact of surgery due to complicated geometric changes. Methods and Results —Thirty patients who underwent IE (mean age 61±8 years, 73% men) had epicardial real-time 3-dimensional echocardiographic (RT3DE) studies performed before and after IE. RT3DE follow-up was performed transthoracically 42±67 days after surgery in 22 patients. Repeated measures ANOVA was used to compare the values before and after IE surgery and at follow-up. Significant decreases in LV end-diastolic (EDVI) and end-systolic (ESVI) volume indices were apparent immediately after IE and in follow-up (EDVI 99±40, 67±26, and 71±31 mL/m 2 , respectively; ESVI 72±37, 40±21, and 42±22 mL/m 2 , respectively; P P P P Conclusions —RT3DE can be used to quantitatively assess changes in LV volume and function after complicated LV reconstruction. Decreased LV volume and increased ejection fraction imply a reduction in LV wall stress after IE surgery and are predictive of symptomatic improvement.

With high-resolution network transmission required for telemedicine, education, and guided-image acquisition, the impact of errors and transmission rates on image quality needs evaluation. METHODS: We transmitted clinical echocardiograms from 2 National Aeronautics and Space Administration (NASA) research centers with the use of Motion Picture Expert Group-2 (MPEG-2) encoding and asynchronous transmission mode (ATM) network protocol over the NASA Research and Education Network. Data rates and network quality (cell losses [CLR], errors [CER], and delay variability [CVD]) were altered and image quality was judged. RESULTS: At speeds of 3 to 5 megabits per second (Mbps), digital images were superior to those on videotape; at 2 Mbps, images were equivalent. Increasing CLR caused occasional, brief pauses. Extreme CER and CDV increases still yielded high-quality images. CONCLUSIONS: Real-time echocardiographic acquisition, guidance, and transmission is feasible with the use of MPEG-2 and ATM with broadcast quality seen above 3 Mbps, even with severe network quality degradation. These techniques can be applied to telemedicine and used for planned echocardiography aboard the International Space Station.

A drawback to large-scale multicentre studies is the time required for the centralized evaluation of diagnostic images. We evaluated the feasibility of digital transfer of echocardiographic images to a central laboratory for rapid and accurate interpretation. Ten patients undergoing trans-oesophageal echocardiographic scanning at three sites had representative single images and multiframe loops stored digitally. The images were analysed in the ordinary way. All images were then transferred via the Internet to a central laboratory and reanalysed by a different observer. The file sizes were 1.5-72 MByte and the transfer rates achieved were 0.6-4.8 Mbit/min. Quantitative measurements were similar between most on-site and central laboratory measurements (all P > 0.25), although measurements differed for left atrial width and pulmonary venous systolic velocities (both P < 0.05). Digital transfer of echocardiographic images and data to a central laboratory may be useful for multicentre trials.

To the Editor: As the world struggles with the challenges of influenza A pandemic (H1N1) 2009, it is clear that treatment options for critically ill infected patients are suboptimal because deaths continue to be reported in otherwise young and healthy patients. Extracorporeal membrane oxygenation (ECMO) is an established therapeutic option for patients with medically refractory cardiogenic or respiratory failure. We describe the successful use of ECMO in a patient with complicated pneumonia and influenza A pandemic (H1N1) 2009 virus infection. Our patient, a 21-year-old woman who was 4 months postpartum, had poorly controlled insulin-dependent diabetes (hemoglobin A1C level 13.2 mg/dL). She sought treatment at another hospital after 3 days of respiratory symptoms, a productive cough after working in her garden, and a fever >103°F. Her condition rapidly deteriorated, and she required mechanical ventilation, vasoactive medications, and drotecogin-α (Xigris; Eli Lilly and Company, Indianapolis, IN, USA) for profound shock. The patient was then transferred to Ohio State University Medical Center on August 24, 2009; at admission she exhibited hypotension (83/43 mm Hg) and tachycardia (159 bpm), despite having received high doses of vasoactive medications (norepinephrine 1.0 µg/kg/min, phenylephrine 2.0 µg/kg/min). A transthoracic echocardiograph showed severe biventricular failure (ejection fraction 5%–10%); peak tropinin level was 6 mg/dL. Arterial blood gas confirmed metabolic acidosis (pH 7.12, partial carbon dioxide pressure [pCO2] 48 mm Hg, pO2 117 mm Hg, HCO3 15.3 mmol/L). Despite fluid resuscitation and administration of epinephrine (0.06 µg/kg/min), her condition failed to improve, and she was given femoral vein–femoral artery ECMO. A comprehensive search for infectious causes was undertaken. Treatment with broad-spectrum empiric antimicrobial drugs such as linezolid (Pfizer, Inc, New York, NY, USA), piperacillin/tazobactam (Wyeth, Madison, NJ, USA), and doxycycline (Pfizer, Inc) and the antiviral drug oseltamivir (Tamiflu; Roche Laboratories Inc., Nutley, NJ, USA), 150 mg 2×/d, was started. Respiratory cultures were positive for methicillin-sensitive Staphylococcus aureus and Aspergillus glaucus. Nafcillin and voriconazole were added to the treatment regimen. PCR of a bronchoalveolar lavage specimen later identified pandemic (H1N1) 2009 virus. The patient was weaned from ECMO on hospital day (HD) 10 and extubated on HD11. Repeat cardiovascular evaluation showed normal biventricular function and no coronary disease. She was discharged from hospital for rehabilitation on September 15, 2009 (HD 22), with an oxygen saturation of 98% on room air and is now fully recovered. The use of ECMO is an established option for patients with medically refractory acute and reversible cardiopulmonary failure (Table) (1–3). For isolated respiratory failure, veno–veno support can be used by femoral vein to femoral vein or femoral vein to right internal jugular vein cannulation. With concomitant cardiogenic shock, veno–arterial cannulation may be required with cannulation of the right internal jugular or femoral vein for outflow, and for inflow, the femoral artery directly or the axillary artery by a surgically placed side graft. Central venous (right atrium) and arterial (ascending aorta) cannulation is an option but requires median sternotomy. Table Relative indications and contraindications for extracorporeal membrane oxygenation* This case is not the first reported use of ECMO for respiratory failure secondary to viral pneumonia (4), and recently, ECMO was used with limited success for complications of pandemic (H1N1) 2009 (5). Its broader use in treating critically ill patients has been limited, however, because ECMO requires substantial institutional and multidisciplinary commitment for implementation and is typically only available at major medical centers offering cardiovascular surgery. Although we cannot say specifically why our patient survived, clearly, aggressive and comprehensive empiric treatment, physiologic support, and close multidisciplinary communication were vital to managing the condition of this critically ill patient. ECMO may have assisted in organ recovery and patient survival. However, further studies should be conducted to critically evaluate ECMO in the armamentarium of therapeutic options for severe pandemic (H1N1) 2009 respiratory failure.

The use of assist devices for ventricular support after myocardial infarction with cardiogenic shock has become common practice. Thrombosis, bleeding, and infection are common complications. However, native valve thrombosis is a rare complication. We present a case of aortic valve thrombosis after implantation of a left ventricular assist device (LVAD) treated with thrombus removal at time of device exchange.

Gastrointestinal surgical problems often mimic symptoms and signs of nonsurgical conditions that occur during pregnancy. This mimicry presents a particular challenge to diagnosis because avoiding a delay in treatment is critical to successful management. Some of these conditions, such as acute appendicitis and biliary colic, are common in younger women; however, the anatomic and physiologic changes of pregnancy can alter their usual manner of presentation. Many elective and urgent operations can be performed during pregnancy with minimal risk to the mother and fetus. The mother's condition should always take priority because her proper treatment usually benefits the fetus as well.