Do patients with an implantable defibrillator live longer?

OBJECTIVES: This study was done to provide information on the potential benefit of implantable cardioverter-defibrillator therapy regarding sudden and arrhythmia-related deaths and to examine whether such therapy improves survival. BACKGROUND: Implantation of automatic cardioverter-defibrillators is reported to abort sudden cardiac death due to malignant tachyarrhythmias. METHODS: Between 1989 and 1992, 107 patients were screened for implantation of a third-generation implantable cardioverter-defibrillator combined with endocardial leads. Mean age was 57 +/- 13 years and mean ejection fraction was 40 +/- 15%. Sudden death, total arrhythmia-related death and total cardiac death were compared with the occurrence of fast ventricular tachyarrhythmias (> 240 beats/min), assuming that most of these arrhythmias would have been fatal without treatment by the implantable cardioverter-defibrillator. RESULTS: The surgical mortality rate was 2.7% in all 107 patients and 1% in the 99 patients who qualified for endocardial leads. During a follow-up period of 12 +/- 8 months, actuarial survival rate free of events at 6 months as well as at 12 and 18 months was 100% for sudden death, 97% for total arrhythmia-related death and 95% for total cardiac death. In contrast, after 6, 12 and 18 months, the rate of survival free of fast ventricular tachycardia was only 83%, 74% and 69%, respectively, and the rate of survival free of any ventricular tachyarrhythmia was only 59%, 49% and 40%, respectively. CONCLUSIONS: The outcome of patients treated with an implantable cardioverter-defibrillator and endocardial defibrillation leads is excellent. For many patients, this treatment is probably lifesaving.

Comparative analysis of plasminogen activator inhibitor-1 expression in different types of atherosclerotic lesions in coronary arteries from human heart explants.

OBJECTIVES: Clinical manifestations of coronary heart disease result primarily from the progressive development of atherosclerotic plaques and subsequent thrombus formation: processes which may be accelerated by an enhanced expression of plasminogen activator inhibitor (PAI-1) in the vessel wall. In the present study, content and expression of PAI-1 were comparatively analyzed in human coronary arteries in relation to the presence and severity of atherosclerotic lesions. METHODS: Segments of coronary arteries obtained from heart explants (n = 15) were classified by the presence and types of atherosclerotic lesions. Antigen and activity levels of PAI-1 were determined in protein extracts of intimal and medial layers. In situ hybridization and immunohistochemical analyses were performed on serial sections of representative tissue specimens. RESULTS: Total PAI-1 antigen consistently increased from macroscopically normal areas (MNAs) to early lesions (ELs) and to maximal levels in fibrous (FPs) and calcified (CPs) plaques. No PAI activity was detected, although PAI-1 in its free form was present in all vascular specimens. Both free PAI-1 and PAI-1 complexed with plasminogen activators were significantly increased in extracts of advanced lesions. However, there was a 2-3 fold molar excess of free versus complexed PAI-1 in FPs and CPs. These findings suggest the presence of relevant amounts of PAI-1 in its substrate rather than in its inhibitor conformation in areas of advanced lesions. Compared with MNAs, PAI-1 mRNA was strongly expressed within the thickened intima of ELs. The highest PAI-1 expression was observed in FPs and CPs, being mainly localized in areas surrounding the necrotic cores in co-localization with infiltrating macrophages. CONCLUSIONS: PAI-1 content is consistently increased in relation to the severity of the lesions in atherosclerotic coronary arteries. The concomitant elevation of PAI-1 mRNA suggests that the PAI-1 increase in regulated by local synthesis in the areas of atherosclerotic lesions.

Overexpression of tissue-type plasminogen activator in atherosclerotic human coronary arteries.

UNLABELLED: The plasminogen activator (PA)/plasmin system is involved in various pathological processes that are considered important features of atherogenesis and atherothrombosis. These include the proteolysis of fibrin deposits and extracellular matrix components as well as the induction of cell migration and mitogenesis. Tissue-type PA (TPA) is a key enzyme mediating plasminogen to plasmin conversion. TPA plasma concentrations are elevated in patients with advanced atherosclerosis and correlate with an increased risk for myocardial infarction and stroke. In this study, we have analysed the content and expression of TPA in human coronary arteries and their relation to the presence and severity of atherosclerotic lesions. METHODS: Segments of coronary arteries obtained from heart explants (n = 15) were classified by the presence and types of atherosclerotic lesions. TPA was quantitatively determined in protein extracts of intimal and medial layers. In situ hybridization and immunohistochemical analyses were performed on serial sections of representative tissue specimens. RESULTS: PA activity entirely attributable to the presence of active TPA was consistently detected in the protein extracts. Extractable TPA antigen and activity showed a significant graded increase in relation to the presence and severity of atherosclerotic lesions. The ratios of active over total TPA were increased several-fold in extracts of advanced lesions despite a concomitant threefold increase in TPA complexed to its inhibitor PA-1. In macroscopically normal arterial segments and in early lesions, TPA was expressed in the endothelium and in colocalization with vascular smooth muscle cells (VSMCs). In advanced plaques, TPA mRNA was mainly detected in the lateral regions of the fibrous caps in association with migrating VSMCs and in the vicinity of the core areas infiltrated by CD68-positive macrophages. CONCLUSIONS: TPA content and expression is consistently increased in relation to the severity of the lesions in atherosclerotic coronary arteries. This may contribute to plaque destabilization and disruption. Conversely, the increased intramural TPA activity may counteract mural fibrin deposition.

Relation of urokinase-type plasminogen activator expression to presence and severity of atherosclerotic lesions in human coronary arteries.

Urokinase-type plasminogen activator (UPA) has been implicated in a broad spectrum of pathological processes - e.g. cell adhesion, migration and proliferation and matrix remodeling - that are considered important features of atherogenesis and plaque disruption. In this study, we have analyzed the content and expression of UPA in human coronary arteries and its relation to the presence and severity of atherosclerotic lesions. Segments of coronary arteries obtained from human heart explants (n = 15) were classified by the presence and types of atherosclerotic lesions. UPA was quantitatively determined in protein extracts of the intimal and medial layers. In situ hybridization and immunohistochemical analyses were performed on serial sections of representative tissue specimens. UPA was detected in the extracts as pro-UPA, UPA complexed to plasminogen activator inhibitor-1, or as otherwise inactive UPA antigen, but not in the active two-chain form. Both functional and total UPA were increased several-fold in extracts of advanced lesions, while the ratios of functional over total UPA showed the opposite trend suggesting enhanced UPA inactivation and turnover. UPA expression in early atherosclerotic lesions was particularly prominent in areas of proliferating SMCs in the abluminal part of the neointima, whereas in advanced lesions UPA was widely expressed in macrophage-rich areas adjacent to the rims and shoulder regions of the necrotic cores. The results strongly suggest a causal involvement of UPA in coronary atherogenesis and its clinical outcome.

Drugs or implantable cardioverter-defibrillators in patients with poor left ventricular function?

Poor left ventricular function is a predictor of sudden death. Both antiarrhythmic drugs and implantable cardioverter-defibrillators (ICDs) promise to reduce the sudden death rate in these patients and consequently improve survival. In patients without spontaneous ventricular tachyarrhythmias, only beta-blocking agents and amiodarone have been shown to reduce sudden death and improve survival in some studies, whereas class I antiarrhythmic drugs increased mortality. For patients with documented ventricular tachyarrhythmias, protection against sudden death by serially tested class I antiarrhythmic drugs is at best moderate. There is some evidence suggesting that therapy with class III antiarrhythmic drugs, either amiodarone or dl-sotalol, may reduce sudden death rates and improve overall mortality in comparison to therapy with class I antiarrhythmic drugs. ICDs have been shown to prevent sudden death reliably. In published patient cohorts in which only patients who were not inducible off antiarrhythmic drugs or still inducible on antiarrhythmic drugs received an ICD, the ICD seemed to improve overall survival in comparison to class I antiarrhythmic drugs. A small prospective randomized study that compared a conventional therapy strategy to primary ICD implantations showed an improved outcome with ICDs as therapy of first choice. However, these studies included many patients treated with class I antiarrhythmic drugs considered to be less effective. In matched control studies comparing the ICD to amiodarone or dl-sotalol, less sudden deaths and an improved overall survival could be shown for the ICD in general without stratification for left ventricular function. Thus, in patients with hemodynamically nontolerated ventricular tachyarrhythmias, the ICD seems to improve survival in comparison to class I antiarrhythmic drugs, dl-sotalol, or amiodarone. However, in patients with poor left ventricular function, therapy with ICDs seems to be less cost-effective than in patients with preserved left ventricular function. In patients with very poor left ventricular function who are evaluated for cardiac transplantation, the ICD seems to change only the mode of death from sudden to a nonsudden cardiac death if transplantation cannot be performed soon.

Comparison of frequency of aggravation of ventricular tachyarrhythmias after implantation of automatic defibrillators using epicardial versus nonthoracotomy lead systems.

The time of onset of 4,471 episodes of ventricular tachycardia (VT) or fibrillation (VF) in 40 of 65 patients with an implantable cardioverter-defibrillator (ICD) with endocardial defibrillation electrodes (group 1) and in 53 of 123 with epicardial defibrillation electrodes (group 2) was analyzed to examine whether the incidence of VT/VF immediately after surgery is greater than during further follow up and whether the site of lead placement exerts an influence on the occurrence of these arrhythmias. Actuarial survival rates free of VT/VF were 77, 65, and 54% at 1, 3 and 6 months, respectively, for group 1, and 84, 66 and 52%, respectively, for group 2. The probability of VT/VF was increased only during the first week after surgery; in that week, 12.8% of all patients had VT/VF, without significant differences between groups 1 and 2. Until the end of the first month, this percentage increased to 23%, whereas only 12 to 15% of patients had VT/VF during subsequent months. In 19 patients with third-generation devices capable of terminating tachycardias by overdrive pacing, 326 of 412 VT/VF episodes occurring in the first week after surgery were terminated by antitachycardia pacing, and only 86 had to be terminated by cardioversion or defibrillation. No postoperative exacerbation of inappropriate ICD therapies was observed in any group; 2 to 5% of patients per month received ICD therapies for atrial fibrillation or sinus tachycardia. Patients who received appropriate ICD therapies in the first week after surgery were at high risk of recurrence of VT/VF.(ABSTRACT TRUNCATED AT 250 WORDS)

Combining nonpharmacologic therapies for advanced heart failure: the Münster experience with the assist device-defibrillator combination.

Implantable cardioverter defibrillators (ICDs) and ventricular assist devices (VADs) have been used as a bridge to cardiac transplantation. In selected patients, the combined implantation may be required. This study was motivated by a case of a 33-year-old female patient with giant cell myocarditis who died of ventricular tachyarrhythmias after having been placed on a VAD with which she had been treated on an out-of-hospital basis for a prolonged period of time. A subsequent retrospective analysis of our data showed that, of 73 patients who had to be bridged mechanically (54 Novacor, 12 TCI Heartmate, 4 Thoratec, 3 Medos) in our institution between 1993 and 1998, 10 patients had undergone defibrillator implantation either before (n = 8) or after (n = 2) implantation of a VAD. The cases are presented, and the feasibility of the combination therapy discussed.

Long-term left ventricular assist device support: a novel pump rate challenge exercise protocol to monitor native left ventricular function.

A novel, hemodynamically guided exercise protocol with two different left ventricular assist device settings in two long-term recipients is presented. This protocol allows for quantitation of the contribution of the native left ventricle to total cardiac output. It facilitates estimation of the risk associated with device dysfunction, as well as prediction of left ventricular recovery and the potential for weaning.

Emergency versus elective/urgent left ventricular assist device implantation.

BACKGROUND: The risk and outcome in patients undergoing left ventricular assist device (LVAD) implantation on an emergency basis is still unclear. METHODS: Since April 1993, 40 patients received a Novacor and 8 patients a Heartmate LVAD in our institution. Patients with emergency LVAD placement were compared with the remainder in a retrospective manner. Parameters studied included underlying heart disease, preimplantation dysfunction of kidney, liver, lung, and cerebrum, interval of mechanical support, outcome, and complications. RESULTS: Patients with emergency LVAD placement predominantly were seen with postcardiotomy heart failure (47%) or acute myocarditis (20%) (group A) whereas elective and urgent candidates for LVAD implantation mainly had dilative cardiomyopathy (67%) or ischemic heart disease (30%) (group B). The incidence of secondary organ failure was significantly higher for all organs in group A patients (p < .01). Mean support interval in patients who underwent emergency LVAD implantation was lower (74+/-79 days vs 115+/-80 days), and fewer patients could be forwarded to heart transplantation in this group (22% vs 78%, p < .01). Moreover, bleeding complications were increased in group A (66% vs 30%, p < .01), but not thromboembolism and infection. CONCLUSION: In conclusion, the overall success rate after emergency LVAD implantation was lower, with bleeding being the most frequent complication. To achieve acceptable outcomes in disastrous situations, LVADs should be placed as early as possible.

Selection and management of ventricular assist device patients: the Muenster experience.

BACKGROUND: Because of the growing discrepancy between the availability of donor organs and the number of patients with end-stage heart disease who need heart transplantation, a larger proportion of patients waiting for a suitable donor heart require pre-operative mechanical circulatory assistance. The criteria for the selection and management of these patients as applied at Muenster University Hospital are reviewed. METHODS: The study population consists of 631 patients referred to our center for transplantation between January 1, 1990, and December 31, 1996. Two hundred ninety-seven patients were listed for transplantation and 157 were transplanted. Of 41 patients who underwent implantation of a ventricular assist device (n = 34, Novacor; n = 6, TCI HeartMate; n = 1, Medos), 39 received the device as a bridge to transplantation and 2 as permanent support. For the purpose of the analysis, the study population was divided into 3 groups (elective bridging, urgent bridging, emergency bridging) and compared with heart transplant candidates who did not require mechanical circulatory assistance. RESULTS: Patients who underwent elective or urgent assist-device implantation were younger and had greater hemodynamic compromise than the remainder of patients waiting for heart transplantation, as suggested by a higher functional class and lower mean arterial pressure, cardiac index, serum sodium, and pulmonary artery wedge pressure. Survival of patients who electively underwent implantation of an assist device was better than that of patients who were stable on the waiting list and did not undergo heart transplantation during follow-up. CONCLUSIONS: This finding suggests that earlier implantation of assist devices may facilitate resolution of organ dysfunction before heart transplantation.

Selection and outcome of ventricular assist device patients: the Muenster experience.

BACKGROUND: Because the number of patients on the waiting list for transplantation is increasing and the stagnation in the number of organs donated has led to a more restrictive listing for transplantation, an increased fraction of patients needs to be bridged mechanically. We examined the hypothesis that selection of these patients with regard to urgency status is critical in determining outcome. METHODS: A cohort of 631 patients referred for transplantation to our center between January 1, 1990, and December 31, 1996, was analyzed. Two hundred ninety-seven patients were listed for transplantation and 157 were given transplantation. Forty-one patients had to undergo ventricular assist device implantation (n=34, Novacor; n=6, TCI Heartmate; n=1, Medos), 39 for bridging to transplantation and 2 for permanent support. Initial transplantation evaluation data were analyzed in 3 subgroups (elective bridging, urgent bridging, emergency bridging) and compared with another and with other patients referred for transplantation, specifically those who did not have to be bridged on the waiting list. RESULTS: Patients who underwent elective or urgent assist device bridging were younger and more compromised than the rest of patients accepted on the waiting list (higher functional class, lower mean arterial pressure, lower cardiac index, lower serum sodium, higher pulmonary capillary wedge pressure). In the elective group, overall survival including perioperative mortality rate was better than in the urgent/emergency group and at least as good as in patients who were stable on the waiting list and did not undergo heart transplantation during follow-up. This should prompt cardiologists and cardiac surgeons to consider assist device implantation earlier.

A simple new model of physiologically working heterotopic rat heart transplantation provides hemodynamic performance equivalent to that of an orthotopic heart.

BACKGROUND: The widely used non-volume-loaded abdominal heterotopic heart transplant (NL) in rats undergoes atrophy after transplantation. Various techniques have been designed to load the transplanted heart because of its potential immunological impact. Our aim was to create a volume-loaded heterotopic heart transplantation model (VL) capable of ejection and practical for routine studies. Using this model, we tested the hypothesis that VL isografts would retain myocardial performance comparable to native hearts (NH). METHODS: Heterotopic hearts were transplanted using and end-to-side anastomosis between the donor's superior vena cava and the recipient's abdominal inferior vena cava. The right ventricle loads the left ventricle (LV) via a direct anastomosis of the pulmonary artery to the left atrium. The LV ejects volume through an end-to-side anastomosis of the donor's aorta to the recipient's abdominal aorta. Hemodynamic data (systolic and diastolic LV pressures, dP/dt max and min, tau) were studied in-situ (at baseline and after adding volume) and in a Langendorff perfusion system (at baseline and after stimulation with isoproterenol) 2 weeks after transplantation. RESULTS: In situ systolic pressure and diastolic function of VL was superior to NL, and beta-adrenergic stimulated performance in the Langendorff perfusion of VL showed hemodynamic performance equivalent to NH, unlike NL which had a diminished response. CONCLUSION: This technique results in a volume-loaded ejecting heart transplant model that preserves anatomical structures. The VL can be evaluated in situ and after explantation in Langendorff perfusion system and may offer advantages if workload of the graft is of significance to the study performed.

Influence of enoximone on systemic and splanchnic oxygen utilization and endotoxin release following cardiopulmonary bypass.

OBJECTIVE: We investigated whether the administration of enoximone during and after cardiopulmonary bypass (CPB) improves splanchnic oxygen utilization and thereby gut mucosal integrity in humans by its vasodilating and inotropic properties. SETTING: Surgical intensive care unit (ICU) in a university hospital. DESIGN/PATIENTS: 21 patients (ASA III classification) scheduled for elective coronary artery bypass grafting were enrolled in the study. After induction of general anesthesia, patients were randomly assigned to received a bolus of 0.2 mg/kg enoximone, followed by 5 microg/kg per min (enoximone group), or followed by an equal volume of saline (NaCl group) during and 24 h after the surgical procedure. The following parameters were evaluated at different time intervals: systemic and pulmonary hemodynamics, blood gas analysis of arterial, mixed venous, and liver venous blood, venous and liver venous lactate level, venous and liver venous endotoxin level and intramucosal partial pressure of carbon dioxide for calculation of intramucosal pH (pHi). RESULTS: Enoximone raised cardiac output and oxygen delivery to higher levels than those observed in the NaCl group. In both groups, gastric pHi fell continuously during the study period. The values were significantly decreased 12 h following admission to the ICU. Endotoxin was not detectable at baseline. Both groups showed increased endotoxin levels, with the highest values during the first 6 h postoperatively. The hepatic venous endotoxin level was almost doubled in the NaCl group in comparison to the enoximone group. Endotoxin levels differed in the two groups 6 and 12 h after admission to the ICU. CONCLUSIONS: Improvement of oxygen delivery by enoximone did not prevent gastric mucosal acidosis following CPB. However, since the increase in endotoxin levels in liver venous blood was diminished by using enoximone, the drug seems to have a beneficial effect on tissue damage and barrier function of the gut.

Noncardiac surgery in patients with left ventricular assist devices.

BACKGROUND: Noncardiac surgery, especially abdominal surgical procedures in patients with long-term mechanical circulatory support and strong anticoagulation, is difficult. METHODS: We report on 14 patients (aged 44 +/- 15 years) with a portable Novacor or HeartMate system, who underwent noncardiac surgical procedures while being supported by the device. RESULTS: The patients underwent 20 procedures for noncardiac reasons; most had an intestinal operation or cholecystectomy. Half of the procedures were performed within 30 days after placement of the device (mean interval, 53 +/- 57 days), only 6 interventions were necessary after 100 days of mechanical support. Complications occurred in 8 patients (57%), 5 of whom had undergone cholecystectomy and had unacceptably high sanguineous drainage losses. CONCLUSIONS: An elective surgical procedure can be performed with an acceptable risk if the operation is carefully managed. Postponing resumption of full anticoagulation is advisable as it may reduce bleeding complications without apparently increasing the risk for thromboembolism. Emergency interventions remain a difficult task.

Control of perigraft bleeding during ventricular assist device implantation.

This report describes a surgical technique devised to reduce perigraft bleeding in left ventricular assist devices, which has yielded excellent results in our institution. The technique may be applied during implantation of the Novacor N100, HeartMate 1000 VE, and Thoratec systems.

Nonthoracotomy defibrillator implantation: a single-center experience with 200 patients.

Nonthoracotomy leads for defibrillator implantation and biphasic shocking devices are under investigation. Implantation success and mortality and morbidity of the procedure determine the operative course. Lead-associated complications, late infection, and freedom of sudden cardiac death characterize the follow-up period with respect to the implanted device. From October 1989 to March 1993 in 200 patients, 205 (including five infections caused by reimplantations) transvenous or transvenous-subcutaneous lead systems were tested. Mean ejection fraction was 0.40 +/- 0.16. In 62.5% (125/200) coronary artery disease and in 19% (38/200) cardiomyopathy was the underlying disease (59 patients with prior cardiac operations). Leads were implanted with defibrillation thresholds less than 25 J in 195 patients, whereas 10 patients received intrathoracal patches. Since biphasic shocks became available, no nonthoracotomy lead system has failed in the last 115 consecutive patients. Perioperative mortality in the nonthoracotomy group was 1% (2/195). In 6.2% (12/193) of the surviving patients, perioperative complications occurred. Major problems were bleeding from the device or patch pocket (n = 6) and early infection (n = 2). During the follow-up of 20 +/- 10 months, lead-associated complications (dislocation, lead fracture, insulation defect, loss of sensing) occurred in 9 patients and in 5 patients late infection appeared. Within the follow-up period no patient died suddenly, and 134 patients received therapeutic interventions by the device. Defibrillator implantation using nonthoracotomy leads, especially combined with biphasic shocking devices, is applicable in almost every patient. During the operative course and follow-up, the defibrillator-associated morbidity and mortality is at the same level as or lower than when using patch lead systems.

Preoperative immunoglobulin treatment in patients with Werlhof's disease undergoing cardiac operation.

BACKGROUND: Patients with Werlhof's disease and undergoing a cardiac surgical procedure with cardiopulmonary bypass are at increased risk for bleeding complications. We report the usefulness of preoperative immunoglobulin treatment in selected patients. METHODS: Between May 1995 and July 1998, 10 patients with Werlhof's disease underwent a cardiac surgical procedure with cardiopulmonary bypass in our department. Five patients with mean platelet counts of less than 80x10(9)/L received immunoglobulin therapy preoperatively (group 1). The other 5 patients with mean platelet counts higher than 80x10(9)/L were not so treated (group 2). RESULTS: In group 1, mean platelet count increased from 54x10(9)/L 5 days before operation to 112x10(9)/L after immunoglobulin treatment (p = 0.018) and did not fall to less than 60x10(9)/L postoperatively. Patients in group 1 received 16 units of packed red blood cells and 5 units of platelet concentrate. Patients in group 2 required 24 units of packed red blood cells, 5 units of platelet concentrate, and 23 units of fresh frozen plasma. Only 1 patient (group 2) had a surgical bleeding complication that required reexploration. Mean drainage loss was 1,100 mL in group 1 and 1,210 mL in group 2. CONCLUSIONS: Our data demonstrate that immunoglobulin treatment of patients with Werlhof's disease and mean platelet counts of less than 80x10(9)/L significantly augments platelet counts preoperatively. It may be useful in selected patients.

Wound complications after left ventricular assist device implantation.

BACKGROUND: Wound necrosis and infection pose a tremendous risk for patients with left ventricular assist devices. METHODS: We analyzed our database of patients with left ventricular assist devices for those who developed wound dehiscence and concomitant infection after left ventricular assist device implantation. RESULTS: Three of our 66 patients (4.5%) with implantable ventricular assist devices had had severe wound complications with necrosis of the abdominal or thoracic wall uncovering part of the device. The predominant impact on the development of these complications was presumably related to multiple surgical interventions on the same site. CONCLUSIONS: Nevertheless, these patients can recover and undergo successful heart transplantation if adequately managed.

Single-incision implantation of cardioverter defibrillators using nonthoracotomy lead systems.

This study describes the placement of a newly designed implantable cardioverter defibrillator in a subpectoral device pocket using the incision for venous access in 16 patients undergoing implantation of an implantable cardioverter defibrillator with a nonthoracotomy lead system. The endocardial lead system consisted of a right atrial/superior vena cava defibrillation spring electrode and a right ventricular bipolar sensing/defibrillation electrode, inserted by cephalic venotomy or by puncturing of the subclavian vein. As a result of intraoperative testing using biphasic shocks the defibrillation threshold (DFT) had to be less than 24 J, otherwise an additional subcutaneous patch electrode was placed in the lateral chest wall near the cardiac apex through another incision. All patients received a nonthoracotomy lead system in combination with a subpectoral device placement. In 11 of 16 patients the endocardial leads alone were sufficient (DFT, 13.4 +/- 7.0 J), 5 of 16 patients (31%) required an additional subcutaneous patch electrode to achieve proper device function (DFT, 14.6 +/- 9.0 J). The operation lasted 93 +/- 20 minutes. This was a significant (p < 0.05) lower time consumption than standard nonthoracotomy approach combined with abdominal device placement (120 +/- 50 minutes). There were no postoperative complications. During follow-up period (average, 4 months), none of the patients reported major local symptoms, especially no device migration occurred. This approach, in contrast to an abdominal device placement, avoids another incision and subcutaneous tunneling of leads. In 11 of 16 patients defibrillator implantation by a single incision in the deltoideopectoral groove was possible.

Pheochromocytomas with extension into central vascular structures.

Two cases of pheochromocytomas, 1 with extension into the inferior vena cava and the second with involvement of the right atrium, are reported. Both tumors were resected in toto, 1 using inferior to superior vena cava vein-to-vein bypass and the second with the aid of hypothermic circulatory arrest. Both patients are free of recurrences or metastasis 20 and 24 month postoperatively.