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Cardiac rhabdomyomas are extremely uncommon in the adult patient. We describe a previously healthy man who presented with ventricular arrhythmias resulting from a right ventricular, cardiac rhabdomyoma. Echocardiography, CT scanning, and MRI are recognized as useful diagnostic modalities for intracardiac lesions. Cardiac catheterization in our patient demonstrated the presence of a tumor blush. This has not previously been reported with cardiac rhabdomyomas. Although lesions may spontaneously regress, surgery is often necessary and frequently resolves the underlying arrhythmia. [ABSTRACT FROM AUTHOR] more...

Background: Although transmyocardial laser revascularization (TMR) has provided symptomatic relief of angina over the short term, the long-term efficacy of the procedure is unknown. Angina symptoms as assessed independently by angina class and the Seattle Angina Questionnaire (SAQ) were prospectively collected up to 7 years after TMR., Methods: Seventy-eight patients with severe angina not amenable to conventional revascularization were treated with a CO(2) laser. Their mean age was 61+/-10 years at the time of treatment. Preoperatively, 66% had unstable angina, 73% had had >/=1 myocardial infarction, 93% had undergone >/=1 CABG, 42% had >/=1 PTCA, 76% were in angina class IV, and 24% were in angina class III. Their average pre-TMR angina class was 3.7+/-0.4., Results: After an average of 5 years (and up to 7 years) of follow-up, the average angina class was significantly improved to 1.6+/-1 (P=0.0001). This was unchanged from the 1.5+/-1 average angina class at 1 year postoperatively (P=NS). There was a marked redistribution according to angina class, with 81% of the patients in class II or better, and 17% of the patients had no angina 5 years after TMR. A decrease of >/=2 angina classes was considered significant, and by this criterion, 68% of the patients had successful long-term angina relief. The angina class results were further confirmed with the SAQ; 5-year SAQ scores revealed an average improvement of 170% over the baseline results., Conclusions: The long-term efficacy of TMR persists for >/=5 years. TMR with CO(2) laser as sole therapy for severe disabling angina provides significant long-term angina relief. more...

Background: Controversy exists regarding the perfusion status of chronically dysfunctional yet viable myocardium. Studies investigating the pathophysiology of this condition have reached different conclusions, with some suggesting that myocardial blood flow (MBF) in these regions is normal at rest with regional dysfunction resulting from repetitive stress-induced ischemia (stunned myocardium), whereas others have proposed that MBF is chronically reduced at rest (hibernating myocardium). However, adequately powered experimental studies investigating this question in an appropriate animal model using clinically available techniques have not been performed. Based on the mixed results of prior studies, we hypothesized that these chronically dysfunctional yet viable regions may actually represent a mixture of hibernation and stunning. Consequently, the purpose of this study was to quantitatively determine the distribution of MBF in left ventricular regions with chronically impaired resting function but preserved viability in a large population of animals with single-vessel coronary stenosis in an attempt to further elucidate the mechanism(s) responsible for chronic, reversible myocardial dysfunction., Methods: Fifty-two adult mini-swine with 90% proximal left circumflex (LCx) stenosis underwent dynamic positron emission tomography (PET) with 13N-ammonia and 18F-fluorodeoxyglucose and dobutamine stress echocardiography (DSE) (5 to 40 microg/kg/min) 1 month after stenosis creation. Values of MBF and FDG uptake by PET and wall motion score index (WMSI) by DSE were compared using a standard 16-segment model., Results: Of 312 possible LCx segments seen on PET, 303 (97.1%) were visualized by DSE. Of the 303 LCx segments, 279 (92.1%) had rest dysfunction (WMSI > or = 2) by DSE. One hundred eighty-two segments (60.1%) had decreased (< 85% reference) MBF at rest with preserved to increased (> 60% reference) FDG uptake and were classified as hibernating. Ninety-two segments (30.4%) had preserved MBF (> or = 85% reference) and were classified as stunned. Five segments (1.7%) with reduced (< or = 60% reference) FDG uptake by PET and akinesis or dyskinesis at rest (WMSI > or = 3) and no contractile reserve were considered infarcted. Hibernating segments had significantly higher FDG uptake at rest (360.7+/-48.3 vs 212.3+/-17.7% septal values; p < 0.001) than stunned segments consistent with greater resting ischemia. Likewise, mean rest WMSI was also worse in hibernating versus stunned segments (2.35+/-0.04 vs 2.13+/-0.04; p < 0.001). There was no difference in the percentage of hibernating versus stunned segments exhibiting contractile reserve during dobutamine infusion (55.5 vs 63.7%; p = 0.4), indicating similar degrees of viability., Conclusions: Myocardial hibernation and stunning appear to frequently coexist in regions served by a stenotic coronary vessel. Hibernating regions appear to have greater resting ischemia based on higher values of FDG uptake and greater resting dysfunction. Reversible left ventricular dysfunction in the setting of chronic coronary artery disease is likely due to a combination of these two mechanisms. more...

Unlabelled: Renal dysfunction is a serious complication after coronary bypass surgery with cardiopulmonary bypass (CABG). Because duration of cardiopulmonary bypass (CPB) is associated with renal outcome, it has been proposed that avoidance of CPB with off-pump coronary bypass (OPCAB) may reduce perioperative renal insult. We therefore tested the hypothesis that OPCAB is associated with less postoperative renal dysfunction compared with CABG surgery. With IRB approval, we gathered data for 690 primary elective coronary bypass patients (OPCAB, 55; CABG, 635). Perioperative change in creatinine clearance (DCrCl) was calculated by using preoperative (CrPre) and peak postoperative (CrPost) serum creatinine values, and the Cockroft-Gault equation (DCrCl = CrPreCl - CrPostCl). Univariate and linear multivariate tests were used in this retrospective analysis; P: < 0.05 was considered significant. Multivariate analysis did not identify OPCAB surgery as an independent predictor of DCrCl. However, previously reported associations of PreCrCl, age, and diabetes with DCrCl were confirmed. Power analysis demonstrated an 80% power to detect a 7.0 mL/min DCrCl difference between study groups. In this retrospective study, we could not confirm that OPCAB significantly reduces perioperative renal dysfunction compared with CABG surgery. Our findings suggest that reduction of renal risk alone should not be an indication for OPCAB over CABG surgery., Implications: Retrospective analysis did not identify any significant difference in perioperative change in creatinine clearance after coronary revascularization with cardiopulmonary bypass compared with off-pump coronary surgery. more...

Objective: Previous studies have been inconsistent in defining a clinical benefit to the bicaval cardiac transplantation technique relative to the standard technique, and many major centers have not adopted this newer approach. The purpose of this study was to determine whether clinically significant benefits support utilization of the bicaval technique., Methods: Sixty-eight consecutive adult patients undergoing a standard cardiac transplant were compared with 75 consecutive patients who underwent the bicaval technique during the period from 1991 to 1999. Etiology, recipient sex, recipient age, donor age, and pulmonary vascular resistance were similar between the two groups., Results: Cardiac index at 24 hours after operation was increased for the bicaval group relative to the standard group (3.15 +/- 0.7 vs 2.7 +/- 0.5 L/min/m(2), P <. 05). Inotropic requirements were significantly less, and there was significantly less tricuspid regurgitation in the bicaval group relative to the standard group. In addition, the bicaval group more frequently had a nonpaced normal sinus rhythm at 24 hours after operation (73.9% vs 50.7% [standard group], P =.025) and had fewer postoperative arrhythmias (29.3% vs 47.7% [standard group], P <.01). Finally, although mortality was similar for the two groups, length of postoperative hospitalization was longer for the standard group relative to the bicaval group (12.1 +/- 11 vs 20.4 +/- 12 days, P <. 001). Review of the literature identified reduced tricuspid regurgitation and improved rhythm as consistent benefits of the bicaval technique., Conclusion: This review demonstrates a clinical benefit during the early postoperative period with bicaval cardiac transplantation (relative to standard) and encourages further utilization of this technique. more...

Background: Transmyocardial laser revascularization (TMR) is an emerging treatment for end-stage coronary artery disease. A variety of lasers are currently available to perform the procedure, although their relative efficacy is unknown. The purpose of this study was to compare changes in myocardial blood flow and function 6 months after TMR with holmium:yttrium-aluminum-garnet (holmium:YAG), carbon dioxide (CO2), and xenon chloride excimer lasers in a model of chronic ischemia., Methods: Miniswine underwent subtotal (90%) left circumflex coronary stenosis. Baseline positron emission tomography and dobutamine stress echocardiography were performed to document hibernating myocardium in the left circumflex coronary artery distribution. Animals were then randomized to sham redo-thoracotomy (n = 5) or TMR using a holmium:YAG (n = 5), CO2 (n = 5) or excimer (n = 5) laser. Six months postoperatively, the positron emission tomography and dobutamine stress echocardiography studies were repeated and the animals sacrificed., Results: In animals undergoing TMR with holmium: YAG and CO2 lasers, a significant improvement in myocardial blood flow to the lased left circumflex regions was seen. No significant change in myocardial blood flow was seen in sham- or excimer-lased animals. There was a significant improvement in regional stress function of the lased segments 6 months postoperatively in animals undergoing holmium:YAG and CO2 laser TMR that was consistent with a reduction in ischemia. There was no change in wall motion in sham- or excimer-lased animals. Significantly greater neovascularization was observed in the holmium:YAG and CO2 lased regions than with either the sham procedure or excimer TMR., Conclusions: Transmyocardial laser revascularization with either holmium:YAG or CO2 laser improves myocardial blood flow and contractile reserve in lased regions 6 months postoperatively. These changes were not seen following excimer TMR or sham thoracotomy, suggesting that differences in laser energy or wavelength or both may be important in the induction of angiogenesis. more...

Background: Hibernating myocardium describes persistently impaired ventricular function at rest caused by reduced coronary blood flow. However, a realistic animal model reproducing this chronic ischemic state does not exist. The purpose of this study was to explore whether chronic low-flow hibernation could be produced in swine., Methods: Miniswine underwent 90% stenosis of the left circumflex coronary artery. Positron emission tomography and dobutamine stress echocardiography were performed 3 and 30 days (n = 6) or 14 days (n = 4) after occlusion to evaluate myocardial blood flow and viability. Triphenyl tetrazolium chloride assessed percent infarction. Electron microscopy was used to identify cellular changes characteristic of hibernating myocardium., Results: Positron emission tomography (13N-labeled-ammonia) 3 days after occlusion demonstrated a significant reduction in myocardial blood flow in the left circumflex distribution. This reduced flow was accompanied by increased glucose use (18F-fluorodeoxyglucose), which is consistent with hibernating myocardium. Thirty days after occlusion, positron emission tomography demonstrated persistent low flow with increased glucose use in the left circumflex distribution. Dobutamine stress echocardiography 3 days after occlusion demonstrated severe hypocontractility at rest in the left circumflex region. Regional wall motion improved with low-dose dobutamine followed by deterioration at higher doses (biphasic response), findings consistent with hibernating myocardium. The results of dobutamine stress echocardiography were unchanged 30 days after occlusion. Triphenyl tetrazolium chloride staining (n = 6) revealed a mean of 8% +/- 2% infarction of the area-at-risk localized to the endocardial surface. Electron microscopy (n = 4) 14 days after occlusion demonstrated loss of contractile elements and large areas of glycogen accumulation within viable cardiomyocytes, also characteristic of hibernating myocardium., Conclusions: Chronic low-flow myocardial hibernation can be reproduced in an animal model after partial coronary occlusion. This model may prove useful in the study of the mechanisms underlying hibernating myocardium and the use of therapies designed to improve blood flow to the heart. more...

Objectives: The purpose of this study was to determine the short-term effects of transmyocardial laser revascularization (TMR) on regional left ventricular systolic and diastolic function, myocardial blood flow (MBF) and myocardial water content (MWC)., Background: Clinical studies of TMR have noted a significant incidence of cardiac complications in the early postoperative period. However, the early post-treatment effects of laser therapy on the myocardium and their potential contribution to postoperative cardiac morbidity are unknown., Methods: Swine underwent holmium:yttrium-aluminum-garnet (holmium:YAG) (n = 12) or carbon dioxide (CO2) (n = 12) laser TMR. Regional systolic function for the lased and nonlased regions was quantitated using preload recruitable work area (PRWA) and regional diastolic function with the ventricular stiffness constant alpha., Results: Preload recruitable work area was significantly decreased in the lased regions both 1 (59.8+/-13.0% of baseline, p = 0.02) and 6 h (64.2+/-9.4% of baseline, p = 0.02) after holmium:YAG TMR. This decreased PRWA was associated with a significant reduction in MBF to the lased regions (13.2% reduction at 1 h, p = 0.02; 18.4% decrease at 6 h post-TMR, p = 0.01). These changes were not seen after CO2 laser TMR. A significant increase in MWC (1.4+/-0.3% increase with holmium:YAG, p = 0.004; 1+/-0.2% increase with CO2, p = 0.002) and alpha (217.4+/-44.2% of baseline 6 h post-holmium:YAG TMR, p = 0.05; 206+/-36.7% of baseline 6 h post-CO2 TMR, p = 0.03) was seen after TMR with both lasers., Conclusions: In the early postoperative setting, impaired regional systolic function in association with regional ischemia is seen after TMR with a holmium:YAG laser. Both holmium:YAG and CO2 lasers are associated with increased MWC and impaired diastolic relaxation in the lased regions. These changes may explain the significant incidence of early postoperative cardiac morbidity. The impact of these findings on anginal relief and long-term outcome are not known. more...

Background: Transmyocardial laser revascularization (TMR) provides relief for patients with chronic angina, nonamenable to direct coronary revascularization. Unmanageable, unstable angina (UUA) defines a subset of patients with refractory angina who are at high risk for myocardial infarction and death. Patients were classified in the UUA group when they had been admitted to the critical care unit with unstable angina for 7 days with three failed attempts at weaning them off intravenous antianginal medications., Methods: Seventy-six treated patients were analyzed to determine if TMR is a viable option for patients with unmanageable unstable angina. These patients were compared with 91 routine protocol patients (protocol group [PG]) undergoing TMR for chronic angina not amenable to standard revascularization. The procedure was performed through a left thoracotomy without cardiopulmonary bypass. These patients were followed for 12 months after the TMR procedure. Both unmanageable and chronic angina patients had a high incidence of at least one prior surgical revascularization (87% and 91%, respectively)., Results: Perioperative mortality (< or = 30 days post-TMR) was higher in the UUAG versus PG (16% vs 3%, p = 0.005). Late mortality, up to 1 year of follow-up, was similar (13% vs 11%, UUAG vs PG; p = 0.83). A majority of the adverse events in the UUAG occurred within the first 3 months post-TMR, and patients surviving this interval did well, with reduced angina of at least two classes occurring in 69%, 82%, and 82% of patients at 3, 6, and 12 months, respectively. The percent improvement in angina class from baseline was statistically significant at 3, 6, and 12 months. A comparable improvement in angina was found in the protocol group of patients., Conclusions: TMR carried a significantly higher risk in unmanageable, unstable angina than in patients with chronic angina. In the later follow-up intervals, however, both groups demonstrated similar and persistent improvement in their angina up to 12 months after the procedure. TMR may be considered in the therapy of patients with unmanageable, unstable angina who otherwise have no recourse to effective therapy in the control of their disabling angina. more...

Objective: Transmyocardial laser revascularization (TMR) is emerging as a potential treatment option for patients with end-stage CAD, and adjuvant gene therapy may be helpful in further improving the results of the procedure. However, the effects of TMR on gene transfer are unknown., Methods: Swine underwent left thoracotomy. TMR was performed to create five channels at 2-cm intervals in the anterolateral free wall of the left ventricle (LV) followed by injection of 1 x 10(9) plaque-forming units (pfu) of a replication-deficient adenovirus vector carrying the reporter gene beta-galactosidase (Ad.Pac beta-gal). An additional five direct injections of 1 x 10(9) pfu Ad.Pac beta-gal were made at 2-cm intervals in the posterolateral LV of each heart. Control animals underwent TMR alone/vehicle alone (n = 3) or empty virus alone/no treatment (n = 3) of the anterolateral/posterolateral LV, respectively., Results: ELISA revealed significantly greater transgene expression in the direct Ad.Pac beta-gal injection versus TMR plus Ad.Pac beta-gal inject regions at both 3 (n = 6) (273.0 +/- 58.5 vs. 133.4 + 28.1 pg beta-gal/g protein, P = 0.02) and 7 days (n = 6) (180.0 + 59.9 vs. 56.7 + 18.1 pg beta-gal/g protein, P = 0.02) postoperatively. At 14 days postoperatively (n = 2), no transgene expression was detected in either region. No transgene expression was detected in any of the control regions at 3 days postoperatively. CD-18 staining revealed significantly greater inflammation in the TMR plus Ad.Pac beta-gal and TMR alone regions as compared to Ad.Pac beta-gal or vehicle (P < 0.001)., Conclusions: Adenoviral-mediated gene transfer in conjunction with TMR is possible, although TMR appears to limit the degree of transgene expression attained as compared to direct intramyocardial injection alone, likely due to the greater immune response observed with the former. These findings may have important implications for therapeutic strategies aimed at combining TMR with gene therapy for CAD. more...

Background: Transmyocardial laser revascularization (TMR) is an emerging therapy for the treatment of coronary artery disease not amenable to percutaneous transluminal coronary angioplasty (PTCA) or coronary artery bypass surgery (CABG)., Objective: To summarize the experimental and clinical experience to date with TMR. Specifically, the history of the technique, preclinical and clinical data, patient selection and perioperative management, as well as future applications of TMR are discussed., Data Sources: All English language articles pertaining to TMR published through March 1999. MEDLINE was searched with the key words 'myocardial revascularization', 'lasers' and 'laser surgery', as well as the text terms 'transmyocardial laser revascularization', 'TMR' and 'TMLR'. Reference lists of articles obtained from MEDLINE were studied for additional references not discovered in computer searches. Pertinent abstracts published within the past two years were reviewed as well., Study Selection: Studies that produced original experimental or clinical data were selected., Data Synthesis: Experimental studies demonstrate that TMR channels become occluded in the early postoperative period. However, experimental data indicate that laser injury appears to promote neovascularization with secondary improvements in perfusion in treated regions. Human clinical studies confirm the efficacy of the procedure, with significant improvements in anginal class up to at least one year postoperatively, although documented improvements in myocardial perfusion have been less consistent. Perioperative morbidity and mortality appear to be increased in patients with unstable angina or reduced left ventricular function., Conclusions: With careful patient selection and peri- operative management, TMR is a safe and effective therapy for severe angina pectoris secondary to end-stage coronary artery disease. Additional studies are required to define the role of TMR in combination with PTCA, CABG and angiogenic growth factors, as well as the safety and efficacy of catheter-based TMR. more...

Background: Clinical improvement after transmyocardial laser revascularization (TMR) is typically delayed, and patients therefore remain at risk for ischemic events after the procedure. The purpose of this study was to define the range of creatine phosphokinase (CPK) and CPK-MB enzyme elevation after TMR and to assess the incidence of early postoperative ischemic events., Methods: Twenty-one patients undergoing isolated TMR were evaluated for 48 hours after surgery with serial CPK and CPK-MB enzymes and 12-lead electrocardiograms for evidence of myocardial ischemia or injury. Clinically evident postoperative ischemic events including angina pectoris, myocardial infarction (MI), and cardiac death were recorded as well., Results: Eleven patients (52.4%) had ischemic electrocardiographic changes in the first 48 hours after TMR. Ischemia was clinically silent in 7 (63.6%) of these 11 patients. Cardiac death occurred in 1 patient (4.8%) as a result of acute MI. Nonfatal MI occurred in an additional 4 patients (19.0%). Of the 5 patients with MI, 4 had angina pectoris versus no angina in the 16 patients without MI (P =.02). All patients had elevated CPK and CPK-MB levels after TMR: however, peak CPK (P =.02) and CPK-MB (P =. 005) levels were significantly higher for patients suffering postoperative MI compared with those without MI., Conclusions: Transient ischemia occurs frequently after TMR and is clinically silent in the majority of patients. Patients with postoperative MI are more likely to have symptomatic ischemia as well as significant cardiac enzyme elevation. The combination of 12-lead electrocardiogram and cardiac enzymes appears to have significant merit for the diagnosis of myocardial ischemia and infarction after TMR. These studies should be obtained in all patients undergoing TMR for the first 48 hours after surgery. more...

Objectives: The purpose of this study was to describe the incidence and spectrum of perioperative cardiac and noncardiac morbidity and mortality after transmyocardial laser revascularization (TMR) and to identify predictors of these adverse clinical events., Background: Clinical studies have demonstrated the efficacy of TMR for relieving angina pectoris, although no study to date has specifically addressed the associated perioperative morbidity and mortality., Methods: Between October 1995 and August 1997, 34 consecutive patients with end-stage coronary artery disease (CAD) underwent isolated TMR. The majority of patients (94%) had class III or IV angina pectoris, and two patients (6%) had unstable symptoms preoperatively. Patient records were reviewed for fatal and nonfatal adverse cardiac and noncardiac events., Results: Perioperative death occurred in two patients (5.9%) due to cardiogenic shock complicating acute myocardial infarction. Perioperative cardiac morbidity occurred in 16 patients (47.1%); noncardiac morbidity was seen in 12 patients (35.3%). Preoperative unstable angina was the only variable predictive of perioperative death (p = 0.005). Cardiac (p = 0.005) and noncardiac (p < 0.001) morbidity rates were significantly higher for the initial 15 patients undergoing the procedure. Other predictors of perioperative complications included lack of postoperative treatment with a furosemide infusion (p < or = 0.04) and preoperative unstable angina (p = 0.05)., Conclusions: Perioperative mortality in patients undergoing isolated TMR is low. Transmyocardial laser revascularization patients are at higher risk for adverse perioperative cardiac and noncardiac events, likely reflecting the lack of immediate benefit from the procedure in the setting of severe CAD. These patients merit vigilant surveillance for adverse events and aggressive medical management in the perioperative period. more...

Background: The mechanism of clinical improvement after transmyocardial laser revascularization (TMR) is unknown. One hypothesis holds that TMR causes increased myocardial perfusion through neovascularization. This study sought to determine whether angiogenesis occurs after TMR in a porcine model of chronic myocardial ischemia., Methods: Six miniature pigs underwent subtotal left circumflex coronary artery occlusion to reduce resting blood flow to 10% of baseline. After 2 weeks in the low-flow state, dobutamine stress echocardiography and positron emission tomography were performed to document ischemic, viable myocardium. The animals then underwent TMR and were sacrificed 6 months later for histologic and immunohistochemical analysis., Results: Histologic analysis of the lased left circumflex region demonstrated many hypocellular areas filled with connective tissue representing remnant TMR channels. Histochemical staining demonstrated a highly disorganized pattern of neovascularization consistent with angiogenesis located predominantly at the periphery of the channels. Immunohistochemical analysis confirmed the presence of endothelial cells within neovessels. Vascular density analysis revealed a mean of 29.2+/-3.6 neovessels per high-power field in lased ischemic myocardium versus 4.0+/-0.3 (p<0.001) in nonlased ischemic myocardium., Conclusions: This study provides evidence that neovascularization is present long term in regions of ischemic, viable myocardium after TMR. Angiogenesis may represent the mechanism of clinical improvement after TMR. more...

Background: Percutaneous balloon mitral valvuloplasty and durable mitral prostheses have made the role of open mitral commissurotomy (OMC) uncertain., Methods and Results: Results from the use of St Jude mitral valve replacement (SJMVR) were compared with those of the use of OMC in 312 consecutive patients with mitral stenosis between 1983 and the present. OMC and SJMVR patients were well matched for age, sex, and comorbidity except that SJMVR patients had more severe stenosis and were more likely to undergo concurrent aortic valve replacement. Compared with OMC, SJMVR without chordal preservation involved a longer pump time (158 +/- 81 versus 87 +/- 41 min, P < 0.05), more frequent in-hospital complications or death (57 of 219 [26%] versus 4 of 52 [8%], P < 0.01), and longer hospital stay (13 +/- 11 versus 10 +/- 6 days, P = 0.001). Preservation of chordae to at least 1 mitral valve leaflet decreased early morbidity and mortality rates of SJMVR to values comparable to those of OMC (3 of 41 [7%]). Survival was greater at 10 years for OMC versus SJMVR (86 +/- 5% versus 67 +/- 4%, P = 0.03). Ten-year freedom from cardiac events was not different between groups (49 +/- 9% for OMC versus 55 +/- 4% for SJMVR, P = 0.7). Freedom from subsequent mitral procedures at 10 years was better for SJMVR (96 +/- 2% versus 58 +/- 8%, P < 0.001)., Conclusions: In the modern era, SJMVR offers significantly greater durability than does OMC. Chordal preservation at the time of SJMVR may reduce perioperative complications to levels comparable to those of OMC. more...

Background: Previously the authors showed that myocardial beta-adrenergic (betaAR) function is reduced after cardiopulmonary bypass (CPB) in a canine model Whether CPB results in similar effects on betaAR function in adult humans is not known. Therefore the current study tested two hypotheses: (1) That myocardial betaAR signaling is reduced in adult humans after CPB, and (2) that administration of long-term preoperative betaAR antagonists prevents this process., Methods: After they gave informed consent, 52 patients undergoing aortocoronary surgery were enrolled. Atrial biopsies were obtained before CPB and immediately before discontinuation of CPB. Plasma catecholamine concentrations, myocardial betaAR density, and functional responsiveness (basal, isoproterenol, zinterol, sodium fluoride, and manganese-stimulated adenylyl cyclase activity) were assessed., Results: Catecholamine levels increased significantly during CPB (P < 0.005). Myocardial betaAR adenylyl cyclase coupling decreased during CPB, as evidenced by a 21% decrease in isoproterenol-stimulated adenylyl cyclase activity (750 [430] pmol cyclic adenosine monophosphate per milligram total protein 15 min before CPB compared with 540 [390] at the end of CPB, P = 0.0062, medians [interquartile range]) despite constant betaAR density. Differential activation along the betaAR signal transduction cascade localized the defect to the adenylyl cyclase moiety. Administration of long-term preoperative betaAR antagonists did not prevent acute CPB-induced myocardial betaAR dysfunction., Conclusions: These data indicate that the myocardial adenylyl cyclase response to betaAR agonists decreases acutely in adults during aortocoronary surgery requiring CPB, regardless of whether long-term preoperative betaAR antagonists are administered. The mechanism underlying acute betaAR dysfunction appears to be direct impairment of the adenylyl cyclase moiety. Similar increases in manganese-stimulated activity before and at the end of CPB show preserved adenylyl cyclase catalytic activity, suggesting that other mechanisms (such as decreased protein levels or altered isoform expression or function) may be responsible for decreased adenylyl cyclase function. more...

Objectives: The purpose of this ongoing study is to determine whether transmyocardial laser revascularization (TMLR) can lessen inducible ischemia and improve contractile reserve in patients with refractory angina pectoris., Background: TMLR is an emerging surgical technique for the treatment of myocardial ischemia and angina pectoris not amenable to conventional percutaneous or surgical revascularization. Objective data documentating a reduction in ischemia during noninvasive stress testing after TMLR are rare., Methods: Fifteen patients with severe coronary artery disease unsuitable for treatment with standard revascularization techniques were studied with dobutamine stress echocardiography (DSE) before TMLR. Of the 12 patients who underwent TMLR, DSE was repeated at 3 months postoperatively in 11 patients and at 6 months in 9 patients. Stress echocardiograms were analyzed for inducible ischemia, with calculation of the wall motion score index (WMSI). Heart rate and dobutamine dose achieved at peak stress were also assessed as indexes of stress tolerance., Results: Compared with that before TMLR, wall motion at rest for all myocardial segments did not change significantly after TMLR, although there was a mild improvement in the WMSI of the lased myocardial regions ([mean +/- SD] 1.64 +/- 0.34 after vs. 1.78 +/- 0.34 before TMLR, p < 0.05). Overall WMSI at peak stress improved markedly after TMLR (1.70 +/- 0.30 after vs. 2.06 +/- 0.31 before TMLR, p < 0.002), with the improvement in WMSI limited to the lased segments only (1.47 +/- 0.31 after vs. 2.15 +/- 0.34 before TMLR, p < 0.0004). The improvement in WMSI with stress resulted primarily from a decrease in the percentage of ischemic segments (47% before vs. 23% after TMLR, p < 0.0008), with no change in the percentage of infarcted segments (23% before vs. 26% after TMLR). Heart rate (83 +/- 5 beats/min before vs. 102 +/- 21 beats/min after TMLR, p = 0.01) and dobutamine infusion rate (26 +/- 9 micrograms/kg body weight per min before vs. 34 +/- 9 micrograms/kg per min after TMLR) achieved at peak stress also increased postoperatively, consistent with improved stress tolerance. The reduction in ischemic wall motion abnormalities and improved stress tolerance persisted at 6 months, without evidence of further improvement or deterioration of function over time., Conclusions: TMLR performed in patients with refractory angina pectoris reduces ischemic wall motion abnormalities and improves stress-induced tolerance during dobutamine echocardiography. These beneficial effects persist up to 6 months postoperatively. more...

Objective: Heart and lung transplantation has gained acceptance as therapy for end-stage cardiac and pulmonary failure. The early and intermediate survival benefits of one center's 10-year experience with 177 patients undergoing thoracic transplantation were examined., Summary Background Data: As experience in cardiac and pulmonary transplantation has increased, improvements in patient selection, organ preservation, preoperative support, and perioperative care have significantly reduced the early threats to patient survival. Graft dysfunction due to chronic rejection appears to be the main risk for longer-term survival, and data compiled by the United Network for Organ Sharing (UNOS) indicate a 70% 5-year survival for heart transplants and a 50% 5-year survival for lung transplant recipients., Methods: The medical records of 120 heart recipients, 52 lung transplant recipients, and 5 heart-lung recipients were reviewed. Cumulative survival estimates were made using Kaplan-Meier analysis. The etiologies of operative and long-term mortality in each transplant population were identified. A comparison of long-term survival after heart transplantation versus coronary revascularization in a group of patients with ischemic cardiomyopathy was performed., Results: Operative mortality in both the cardiac and pulmonary transplant recipients was 8%. From 1990 to 1995, 70 consecutive adult cardiac transplant procedures were performed without an operative mortality. Three of five patients survived heart-lung transplantation. The extended actuarial survival rate at 5 years was 80% for the cardiac transplant recipients. The 2-year actuarial survival rate for the lung transplant recipients was 88%. Graft dysfunction was the most common cause of operative mortality in the heart transplant group whereas infection was responsible for most of the operative mortality after lung transplantation., Conclusions: Cardiac and pulmonary transplantation can be applied to morbidly ill patients with excellent operative and intermediate-term survival. more...

Objective: To examine the results of surgery performed in patients with annulo-aortic ectasia extending to the arch., Design: Retrospective hospital record review., Setting: A Canadian teaching hospital., Patients: Five patients (mean age 57 years) had annulo-aortic ectasia with severe aortic insufficiency, a maximum aneurysmal diameter ranging from 6.5 to 13 cm at the root or ascending aortic level, and extending into the arch with a diameter of at least 5 cm at the innominate artery level. They all had reconstruction with a composite prosthetic valve and Dacron tube graft employing standard techniques of aortic root replacement as well as aortic arch reconstruction with a single bevelled anastomosis in a state of profound hypothermia and circulatory arrest., Main Results: No perioperative deaths, neurological complications nor significant cardiac complications. At a median follow-up period of 46 months all patients are alive, free from cardiovascular symptoms and show no evidence of aortic aneurysmal disease., Conclusions: This safe, effective and durable repair should be applied to selected patients with annulo-aortic ectasia which extends to the arch. more...