Cardiac sarcoid in a heart transplant recipient: detection with cardiac magnetic resonance imaging.

We describe the case of a 54-year-old man who presented with cardiac sarcoid 1 month after tapering of corticosteroids and 3 years post-cardiac transplantation. In addition to evidence of noncaseating granulomas on endomyocardial biopsy, a cardiac magnetic resonance imaging (MRI) study showed a typical subepicardial pattern of fibrosis corroborating the pathological diagnosis of sarcoid. This is the first description of cardiac sarcoid developing so late after transplantation. This report suggests that MRI may be an effective noninvasive modality to identify sarcoid in cardiac allografts.

Acute cardiovascular responses to leg-press resistance exercise in heart transplant recipients.

BACKGROUND: Reduced skeletal muscle strength is characteristic of individuals following heart transplantation. Weight lifting exercise has been demonstrated as an effective means by which to increase muscular strength in other cardiac patients but the appropriateness of this form of exercise in heart transplant patients has not been investigated. The purpose of this study was to describe the cardiovascular responses of heart transplant patients to a single, prolonged bout of weight lifting training. METHODS: Twenty-three heart transplant recipients were stratified into early (Early; 3 months; n=6), intermediate (Intermediate; 1-3 years; n=7) and late (Late; 5-14 years; n=10) post transplant groups and studied in four experimental conditions: supine rest, upright rest, single leg-press exercise (28 repetitions over 2 min 20 s at 50% 1 repetition maximum) and recovery. Swan-Ganz catheterization allowed measurement of right heart pressures and cardiac output by thermodilution. Systemic arterial pressures and heart rate were measured continuously using a non-invasive finger cuff. RESULTS: Cardiac output increased by 30, 40 and 54% during exercise in Early, Intermediate and Late, respectively. Heart rate increased by 4.5% in Early compared to 11 and 16% increases in Intermediate and Late. At peak exercise, systolic blood pressures reached average values of 179+/-9, 180+/-14 and 176+/-8 mmHg in Early, Intermediate and Late, respectively. Average mean pulmonary artery pressure did not exceed 30 mmHg and average pulmonary wedge pressure did not exceed 15 mmHg in any group during the exercise. CONCLUSIONS: These observations indicate that a lengthened set of single leg-press exercise at a moderate lifting intensity can be performed within safe and acceptable physiological limits in patients following heart transplantation. To better address the specific rehabilitation needs of heart transplant recipients, future research should focus on developing training programs which include weight lifting exercise.

Increased circulating monocyte activation in patients with unstable coronary syndromes.

OBJECTIVES: The primary objective of this research was to assess the activation level of circulating monocytes in patients with unstable angina. BACKGROUND: Markers of systemic inflammatory responses are increased in patients with unstable coronary syndromes, but the activation state and invasive capacity of circulating monocytes have not been directly assessed. METHODS: Peripheral blood mononuclear cell (MC) activation in blood samples isolated from patients with stable and unstable coronary artery disease was measured in two studies. In study 1, a modified Boyden chamber assay was used to assess spontaneous cellular migration rates. In study 2, optical analysis of MC membrane fluidity was correlated with soluble CD14 (sCD14), a cellular activation marker. RESULTS: Increased rates of spontaneous monocyte migration (p < 0.01) were detected in patients with unstable angina (UA) (Canadian Cardiovascular Society [CCS] angina class IV) on comparison to patients with acute myocardial infarction (MI), stable angina (CCS angina classes I to III) or normal donors. No significant increase in lymphocyte migration was detected in any patient category. Baseline MC membrane fluidity measurements and sCD14 levels in patients with CCS class IV angina were significantly increased on comparison with MCs from normal volunteers (p < 0.001). A concomitant reduction in the MC response to activation was detected (p < 0.05). CONCLUSIONS: Using two complementary assays, activated monocytes with increased invasive capacity were detected in the circulation of patients with unstable angina. This is the first demonstration of increased monocyte invasive potential in unstable patients, raising the issue that systemic inflammation may both reflect and potentially drive plaque instability.

Quantitative assessment of in vitro jets based on three-dimensional color Doppler reconstruction.

Three-dimensional (3-D) color Doppler imaging of flow jets was performed to investigate the effects of flow rate and orifice size on jet volumes. Flow jets were generated using a flow model to simulate mitral regurgitation. This flow model consisted of a ventricular chamber, a valvular plate and an atrial chamber. Steady flow was driven through circular orifices having diameters of 2.5, 3.5, 4.5, and 6 mm, respectively, with flow rates of 5, 10, 15, 20, and 25 mL/s to form free jets in the atrial chamber. An ATL Ultramark 9 HDI system was used to perform 3-D color Doppler imaging of the flow jets. A transesophageal probe was rotated by a stepper motor to create 3-D color Doppler images of the jets. The color jet volumes for different hemodynamic conditions were measured and then compared with the theoretical predictions. Results showed that the jet volume estimated from the 3-D color Doppler was directly proportional to the flow rate and inversely proportional to the orifice size. The estimated jet volumes correlated well (r > 0.95) with theoretical predictions. This study supports the use of color jet volume as a parameter to quantify mitral regurgitation.

Evaluation of 3-D colour Doppler ultrasound for the measurement of proximal isovelocity surface area.

Three-dimensional (3-D) colour Doppler ultrasound (US) enables flow rate estimation across a diseased valve without the need for a priori geometric assumptions. This study quantitatively evaluates the accuracy of 3-D colour Doppler US for measuring the flow rate (8. 3-75 mL/s) through a valve using the proximal flow convergence field. Flow rate measurements by this 3-D technique underestimate flow through finite circular orifices due to two major sources of error: 1. surface area slicing technique (18.3% +/- 3.8%) and 2. Doppler angle effect (41.0% +/- 1.5%). Combined total underestimation is 51% +/- 3.3%. To utilize 3-D US, the development of an improved proximal isovelocity surface area (PISA) measurement technique and a correction factor for the Doppler angle effect is required.

Intracoronary ultrasound imaging: methods and clinical applications.

OBJECTIVE: To review the development of intracoronary ultrasound, its current utility and the impetus for its continued development as a coronary imaging modality. DATA SOURCES: English-language literature (1966 to 1999) was searched in the MEDLINE database with the key words 'ultra- sound', 'intravascular' and 'intracoronary', and limited to human studies. In addition, an online public access catalogue was searched using the subject headings 'cardiovascular diseases - therapy', 'heart diseases' and 'vascular diseases'. STUDY SELECTION AND DATA EXTRACTION: Articles relating to the history of intravascular or intracoronary ultrasound, methods and materials employed, advantages and disadvantages, safety issues and future directions of research in the area of intracoronary ultrasound were selected. DATA SYNTHESIS: Intracoronary ultrasound has been shown to improve upon demonstrated weaknesses of coronary angiography. This imaging technique, while invasive, has not been associated with significant, acute adverse effects and has proved to be useful in guiding interventions, and evaluating the mechanism and extent of their success. Technological limitations with respect to the equipment employed, and the acquisition, processing and display of images are the subject of intense research focus because they hinder more widespread clinical use of intracoronary ultrasound. CONCLUSIONS: Intracoronary ultrasound has emerged as a safe and useful tool in the visualization of the coronary vasculature. Technological limitations and questions about long term safety are a concern. Its ability to overcome the inherent limitations of coronary angiography, and to guide and evaluate coronary interventions supports the notion that this technique will continue to assume an ever-expanding role in interventional cardiology.

The role of donor age and ischemic time on survival following orthotopic heart transplantation.

BACKGROUND: The advances in immunotherapy, along with a liberalization of eligibility criteria have contributed significantly to the ever increasing demand for donor organs. In an attempt to expand the donor pool, transplant programs are now accepting older donors as well as donors from more remote areas. The purpose of this study is to determine the effect of donor age and organ ischemic time on survival following orthotopic heart transplantation (OHT). METHODS: From April 1981 to December 1996 372 adult patients underwent OHT at the University of Western Ontario. Cox proportional hazards models were used to identify predictors of outcome. Variables affecting survival were then entered into a stepwise logistic regression model to develop probability models for 30-day- and 1-year-mortality. RESULTS: The mean age of the recipient population was 45.6 +/- 12.3 years (range 18-64 years: 54 < or = 30; 237 were 31-55; 91 > 56 years). The majority (329 patients, 86.1%) were male and the most common indications for OHT were ischemic (n = 180) and idiopathic (n = 171) cardiomyopathy. Total ischemic time (TIT) was 202.4 +/- 84.5 minutes (range 47-457 minutes). In 86 donors TIT was under 2 hours while it was between 2 and 4 hours in 168, and more than 4 hours in 128 donors. Actuarial survival was 80%, 73%, and 55% at 1, 5, and 10 years respectively. By Cox proportional hazards models, recipient status (Status I-II vs III-IV; risk ratio 1.75; p = 0.003) and donor age, examined as either a continuous or categorical variable ([age < 35 vs > or = 35; risk ratio 1.98; p < 0.001], [age < 50 vs > or = 50; risk ratio 2.20; p < 0.001], [age < 35 vs 35-49 versus > or = 50; risk ratio 1.83; p < 0.001]), were the only predictors of operative mortality. In this analysis, total graft ischemic time had no effect on survival. However, using the Kaplan-Meier method followed by Mantel-Cox logrank analysis, ischemic time did have a significant effect on survival if donor age was > 50 years (p = 0.009). By stepwise logistic regression analysis, a probability model for survival was then developed based on donor age, the interaction between donor age and ischemic time, and patient status. CONCLUSIONS: Improvements in myocardial preservation and peri-operative management may allow for the safe utilization of donor organs with prolonged ischemic times. Older donors are associated with decreased peri-operative and long-term survival following. OHT, particularly if graft ischemic time exceeds 240 minutes and if these donor hearts are transplanted into urgent (Status III-IV) recipients.

Changes in skeletal muscle morphology and biochemistry after cardiac transplantation.

Skeletal muscle biopsies (vastus lateralis) were performed in 12 patients (mean age 47 +/- 11 years) before and at 3 and 12 months after cardiac transplantation. Fiber type analysis revealed a predominance of type II fibers before cardiac transplantation (66 +/- 10%); the ratio did not change after transplantation. Fiber cross-sectional area increased by 35% to 39% in all fiber types by 12 months after cardiac transplantation. Fiber cross-sectional area, however, remained below the reported normal values. The number of capillaries surrounding each fiber did not change after cardiac transplantation. Skeletal muscle enzyme activity of phosphofructokinase, citrate synthase, and beta-hydroxyacyl coenzyme A dehydrogenase increased by 26%, 47%, and 63%, respectively, after cardiac transplantation (p < 0.05). Peak oxygen uptake also increased significantly after cardiac transplantation (19.5 +/- 8.1 ml/kg/min at 12 months vs 9.8 +/- 1.4 ml/kg/min before transplant, p < 0.01); however, uptake remained 40% below that of predicted. Thus, significant improvement in skeletal muscle morphology and biochemistry occurs in the first year after cardiac transplantation in association with improved exercise capacity. Recovery, however, may be incomplete, which could explain residual impairment of exercise capacity in these patients.

Routine surveillance myocardial biopsies are unnecessary beyond one year after heart transplantation.

BACKGROUND: Myocardial rejection is most apt to occur in the first 90 days after heart transplantation. Nevertheless, surveillance endomyocardial biopsies are often performed on a regular basis, indefinitely. The benefit of this approach to patient management is uncertain. Our objective was to determine the frequency of abnormalities and the influence of a routine annual endomyocardial biopsy on patient management. METHODS: In a consecutive series of 235 transplant recipients who survived 1 year or more, the results of 1123 routine endomyocardial biopsies performed 1 year or more after transplantation were reviewed. The incidence of late rejection, presence of Quilty effect (focal endocardial or myocardial lymphocytic aggregates), and therapeutic reaction to the biopsy result were analyzed. RESULTS: Of 1123 biopsy specimens in 235 patients (1 to 12 years after transplantation), 1115 (99.3%) showed no evidence of significant rejection (grade 0 or 1). Only seven (0.6%) had evidence of rejection grade 2 or worse. Of the seven abnormal biopsy specimens in seven patients, two occurred at 1 year, two at 2 years, and one each at 4, 7, and 8 years. Of these, six were treated for rejection with an increase in the immunosuppressive therapy. One patient was identified as having a symptomatic condition at the time of biopsy. A focal endocardial or myocardial accumulation of lymphocytes (Quilty effect) was present in 311 biopsy specimens (27.6%). Beyond 1 year, 33 patients died, 14 because of graft vascular disease with or without rejection and 19 because of other causes. No deaths were predicted on the basis of a routine surveillance biopsy. CONCLUSIONS: Myocardial rejection is rare beyond 1 year after transplantation. The routine endomyocardial biopsy does not significantly impact patient management beyond 1 year. A selective approach to myocardial biopsies, on the basis of a change in clinical status or immunosuppressive medications, is justified.

Basis for aerobic impairment in patients after heart transplantation.

BACKGROUND AND METHODS: To evaluate the physiologic basis for the suboptimal peak oxygen uptake observed after heart transplantation, we calculated the functional aerobic impairment ([(peak predicted oxygen uptake-peak observed oxygen uptake)/peak predicted oxygen uptake] x 100) and related it to donor/recipient, operative, and maximal exercise variables. Fifty-seven heart transplant recipients (mean age 50 +/- 10 years, 1 to 9 years after transplantation) underwent maximal upright cycle exercise testing. Concomitant exercise central hemodynamic measurements were obtained in 36 patients (63%). RESULTS: The mean peak oxygen uptake was 21.7 +/- 6.5 ml/kg/min and functional aerobic impairment was 34% +/- 17%. Functional aerobic impairment correlated positively (p < 0.01) with peak systemic vascular resistance (r = 0.55) and negatively with peak cardiac index (r = -0.62) and peak systemic arteriovenous oxygen difference (r = -0.66). A weak correlation was found between functional aerobic impairment and the duration of cardiac disease (r = 0.35, p < 0.01) but not the origin of heart failure. No correlation was seen between functional aerobic impairment and donor age, total ischemic time, time since transplantation, recipient age, and resting and exercise right and left ventricular filling pressures. CONCLUSIONS: These results suggest that the decreased exercise capacity observed in heart transplant recipients is in part due to increased peripheral vascular resistance and decreased oxygen extraction possibly due to skeletal muscle atrophy. These factors may be the result of irreversible changes from long-standing heart disease, deconditioning, or the effect of cyclosporine and prednisone.

Latissimus dorsi dynamic cardiomyoplasty: role of combined ICD implantation.

Latissimus dorsi cardiomyoplasty is a promising surgical therapy in some patients with congestive heart failure. Although the mortality in heart failure patients is attributable primarily to heart failure and ventricular arrhythmias, the mechanism of death after cardiomyoplasty is not well characterized. We describe the clinical course of a patient undergoing cardiomyoplasty and discuss the role of combined use with an implantable cardioverter defibrillator. A 39-year-old man with congestive heart failure due to a massive anterior wall myocardial infarction was evaluated for latissimus dorsi cardiomyoplasty. The patient was in NYHA Functional Class III due to heart failure. He did not have any significant exertional or rest angina. During a Naughton stress test, the patient could exercise for 10 minutes, achieving 4 METS. Pulmonary function study showed a peak V O2 of 22.1 mL/min per kg. Radionuclide angiography demonstrated that the anterior wall was akinetic with a left ventricular ejection fraction of 22%. Cardiac hemodynamic studies suggested moderate pulmonary hypertension, elevated wedge pressure, and suboptimal response to exercise. A Holter recording showed frequent ventricular extrasystoles. Cardiomyoplasty was preferred to heart transplantation because the patient did not have end-stage heart failure. Postoperatively, the patient required low doses of dopamine. He developed recurrent, sustained, and hemodynamically significant episodes of ventricular tachycardia. He was treated with a combination of amiodarone and procainamide. He died 2 days postoperatively with ventricular fibrillation. Ventricular arrhythmias are a major cause of death in patients with heart failure. Latissimus dorsi cardiomyoplasty appears to be a promising but unproven therapy in such patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Cholesterol-lowering therapy after heart transplantation: a 12-month randomized trial.

BACKGROUND: Hypercholesterolemia, a common problem after heart transplantation, may be important in the genesis and progression of allograft coronary artery disease. The current study was performed to compare the efficacy of gemfibrozil, simvastatin, and cholestyramine for cholesterol lowering in heart transplant recipients. METHODS: In this prospective 1-year study, 48 heart transplant recipients with moderate hypercholesterolemia were randomized to therapy with gemfibrozil 600 mg twice daily (n = 17), simvastatin 10 mg daily (n = 13), and cholestyramine 4 gm twice daily (n = 18). Detailed lipoprotein analysis was performed at baseline and after 3, 6, and 12 months of treatment. RESULTS: Total cholesterol and low-density lipoprotein cholesterol were reduced 19% and 29%, respectively, after 3 months of simvastatin therapy (p < 0.0001) with a sustained reduction in total cholesterol (25%) and low-density lipoprotein cholesterol (39%) at 1 year. Gemfibrozil and cholestyramine treatment did not result in a reduction in cholesterol levels. Apolipoprotein B levels were reduced by 29% at the end of 1 year with simvastatin but not with the other treatments. Serum triglyceride levels were reduced significantly by treatment with gemfibrozil (up to 36%, p < 0.01) but not by the other treatments. High-density lipoprotein cholesterol initially rose in patients treated with simvastatin and gemfibrozil; however, this effect did not persist to 12 months. However, the ratio of low-density lipoprotein/high-density lipoprotein was favorably affected by simvastatin, with a 38% reduction by 12 months (p < 0.0001) but not by the other treatments. Over the course of 1 year, 14 patients dropped out of the study: four from the gemfibrozil arm and ten from the cholestyramine arm. Gastrointestinal intolerance was the most common reason for study termination (8 of 14). All patients in the simvastatin treatment arm completed 12 months of therapy. No biochemical abnormalities resulted from any therapy, and no therapy caused significant alteration in cyclosporine blood levels. CONCLUSIONS: Of the three therapies studied, simvastatin was found to be the most efficacious and well tolerated for cholesterol lowering in patients after heart transplantation.

Evolution of resting lung function in the first year after cardiac transplantation.

The aim of our study was to characterize the time course and magnitude of the changes in lung function in the first year after cardiac transplantation. Resting pulmonary function tests (spirometry, lung volumes and transfer factor) were performed in 14 patients prior to and at 1, 3 and 12 months after surgery. Resting central haemodynamics were also measured serially in the first year post-transplantation. Before transplantation, patients had impaired resting lung function with marked decrease in transfer factor (TL,CO). Although resting central haemodynamics improved markedly within the first week after cardiac transplantation, lung function (forced expiratory volume in one second (FEV1)) was significantly improved only at three months post-transplantation. TL,CO, however, decreased further early after cardiac transplantation. By 12 months, FEV1 and forced vital capacity had increased significantly by 31 and 33%, respectively, while total lung capacity increased by 22%. On the other hand, TL,CO did not increase significantly and remained well below normal at 12 months after cardiac transplantation, at a value equal to 68% of predicted. We conclude that the resting abnormalities in lung function of most patients with heart failure are reversible after cardiac transplantation, except for TL,CO which remains below normal values. Recovery of lung function, however, lags behind the improvement in cardiac function.

Effect of cardiac filling pressures on the release of atrial natriuretic peptide during exercise in heart transplant recipients.

OBJECTIVE: To determine the influence of body posture and central hemodynamics on the plasma levels of immunoreactive atrial natriuretic peptide (irANP) during exercise in cardiac transplant patients. METHODS: Central hemodynamics, mixed expired gas and ventilatory measurements, and venous blood sampling (for irANP determination) were obtained in cardiac transplant patients at rest and during supine (n = 12) or upright (n = 12) graded cycle exercise. Cardiopulmonary and irANP responses to exercise were compared between the upright and supine postures. RESULTS: At rest (supine), irANP concentrations were similar in both groups (172 +/- 87 pg/mL supine and 182 +/- 72 pg/mL upright) and did not correlate with resting supine central hemodynamics. During exercise, central filling pressures increased in both groups but patients exercising in the supine position had a greater increase. Peak exercise right atrial pressure was 12 +/- 4 mmHg supine versus 7 +/- 5 mmHg upright (P < 0.005). Peak exercise pulmonary capillary wedge pressure was 22 +/- 6 mmHg supine versus 14 +/- 5 mmHg upright (P < 0.005). At peak exercise, irANP levels were greater in the supine than upright position (419 +/- 166 pg/mL supine versus 277 +/- 40 pg/mL upright, P < 0.05). The change in irANP from rest to peak exercise correlated (P < 0.05) with changes in pulmonary capillary wedge pressure (r = 0.67), systolic pulmonary artery pressure (r = 0.78) and right atrial pressure (r = 0.53). There was, however, no correlation between change in irANP and peak oxygen consumption, change in heart rate or change in mean arterial blood pressure. CONCLUSIONS: In cardiac transplant recipients, exercise is a stimulus for ANP secretion, and augmentation in plasma irANP levels during exercise is modulated by changes in central hemodynamics.

Clinical consequences of angiotensin-converting enzyme inhibitor withdrawal in chronic heart failure: a double-blind, placebo-controlled study of quinapril. The Quinapril Heart Failure Trial Investigators.

OBJECTIVES: This study was performed to assess the efficacy, safety and clinical consequences of abrupt cessation of quinapril therapy in a placebo-controlled, randomized, double-blind withdrawal trial. BACKGROUND: Angiotensin-converting enzyme inhibitor therapy has assumed a pivotal role in the treatment of chronic heart failure. Quinapril hydrochloride, a nonsulfydryl angiotensin-converting enzyme inhibitor, has shown beneficial clinical effects in previous studies. METHODS: After > or = 10 weeks of single-blind quinapril therapy, 224 patients with New York Heart Association class II or III heart failure were randomized in double-blind fashion to continue quinapril (n = 114) or to receive placebo (n = 110) for 16 weeks. Changes in treadmill exercise time, New York Heart Association functional class, quality of life and symptoms of heart failure were assessed. RESULTS: Patients withdrawn to placebo had a significant deterioration in exercise tolerance (median change -16 s with placebo vs. +3 s with quinapril, p = 0.015). New York Heart Association functional class (p = 0.004) and quality of life were improved and signs and symptoms of congestive heart failure were lessened in those remaining on quinapril therapy compared with those receiving placebo. During double-blind treatment, 18 patients were withdrawn from the placebo group because of worsening heart failure compared with 5 patients withdrawn from quinapril treatment (p < 0.001). Rather than a precipitous deterioration of clinical status or early incidence of adverse events, withdrawal from quinapril was associated with steady worsening of heart failure, beginning 4 to 6 weeks after randomization to placebo. CONCLUSIONS: Quinapril is effective and safe for maintaining clinical stability in patients with moderate congestive heart failure. Withdrawal of quinapril from patients with heart failure results in a slow progressive decline in clinical status.

Enhanced detection of cardiac allograft arterial disease with intracoronary ultrasonographic imaging.

Intracoronary ultrasonographic imaging was performed in 60 patients 0.3 to 9 years (mean 2.9 +/- 1.9) after heart transplantation. By using a 1.8 mm intravascular ultrasonographic catheter, 192 (80%) of 240 angiographically visualized major epicardial coronary arteries (right, left main, anterior descending, and circumflex) were imaged by ultrasonography. Coronary luminal irregularities were detected in 15% of arteries by angiography compared with 34% by ultrasonography (p < 0.0001). The typical abnormality detected by ultrasonography consisted of crescentic and/or concentric intimal and medial thickening. Calcification in vascular lesions was rare (< 1% of arteries studied). Although the prevalence of angiographic abnormalities tended to be time dependent, ultrasonographic abnormalities were more strongly associated with donor age (normal, 22 +/- 8 years, vs abnormal, 33 +/- 10 years; p < 0.0001). Cardiac allograft coronary arterial disease is significantly underestimated by contrast angiography. Intravascular ultrasonography may provide a useful adjunct for identification and serial follow-up of this significant problem.

Heart transplantation after cardioverter-defibrillator implantation. A case control study.

A case control study was performed to determine whether previous implantable cardioverter-defibrillator (ICD) insertion adversely affects outcome after heart transplantation. Six male heart transplant recipients who had undergone ICD insertion 12 +/- 5 months before heart transplantation were compared to a cohort of six heart transplant recipients who were matched according to age, preoperative status and hemodynamics, date of transplantation, graft ischemic time, history of a previous cardiac operation, and duration of follow-up. There were no significant differences in operating room time, chest tube drainage, time to extubation, and the duration of intensive care unit or hospital stay between the two groups. Furthermore, there were no significant differences in the number of units of packed cells, fresh frozen plasma, platelets and cryoprecipitate transfused. The number of treated rejection episodes and the number of patients requiring intravenous antibiotics for infection in the first 90 days was identical between groups. It was concluded that heart transplantation after ICD implantation did not appear to carry more risk than heart transplantation after a previous cardiac operation. Our limited experience supports the potential use of the ICD in patients with life-threatening ventricular dysrhythmias who are awaiting transplantation.