Our findings show that up to 1 year after CMP, marked decreases in left ventricular volume are present. Our measurements suggest that CMP actively reduced the dilated ventricle but did not prevent a higher EDV on an increased venous return. The latissimus dorsi muscle wrap contraction results in better synchronization of contraction and more rapid emptying of the left ventricle.

No abstract

The three components of the Novacor left ventricular assist system, compact controller, battery, and back-up battery, have been miniaturized in the development of the wearable system. Therefore patients can be fully mobilized receiving mechanical circulatory support while awaiting heart transplantation. Between February 1992 and April 1994 a total of eight patients with decompensated heart failure (6 dilated cardiomyopathy, 1 acute myocarditis, 1 ischemic cardiomyopathy) were treated with the Novacor left ventricular assist systems. In the most recent four cases the wearable system (N100P) was used. Patients' ages ranged from 17 to 49 years. In five patients severe failure of the right side of the heart was present at the time of implantation. Hemodynamic stabilization was achieved in all patients during the 2 to 122 days (mean 30.8 +/- 42.5 days) of support. The following parameters were measured on average before and 24 hours after implantation of the left ventricular assist system: mean arterial pressure 70 +/- 11 versus 87 +/- 13 mm Hg (p < 0.05), cardiac index 1.71 +/- 0.42 versus 3.23 +/- 0.74 L/min/m2 (p < 0.05), pulmonary capillary wedge pressure 27.1 +/- 4.4 versus 9.9 +/- 5.2 mm Hg (p < 0.01), mean pulmonary pressure 41 +/- 9 versus 27 +/- 6 mm Hg (p < 0.05), and right ventricular ejection fraction 16.7% +/- 10.3% versus 22.0% +/- 11.6% (not significant). Patients who received the wearable system were capable of managing their own power supply during the bridging period and were able to walk to the hospital park and shopping area. One patient had a serious pulmonary infection, which was treated successfully, and two patients had a cerebrovascular accident, which resolved in one and resulted in a minor residual deficit in the other. All eight patients received a heart transplant. One patient died early after transplantation and seven patients are alive and well. In summary, the wearable Novacor left ventricular assist system provides major advantages regarding quality of life of patients during mechanical circulatory support. However, there is a remaining risk of thromboembolism despite anticoagulation therapy.

In order to evaluate selective differences of biological porcine valves versus pericardial valves and to analyze various valve models, 8 different bioprostheses (4 porcine valves, 4 pericardial valves) were studied in a 12-year follow-up. From 1978 to 1990, 476 porcine bioprostheses (Carpentier-Edwards: n = 104, Carpentier Edwards Supraanular: n = 59, Hancock I: n = 41, Hancock II: n = 272) and 647 pericardial valves (Hancock-Extracorporeal: n = 479, Ionescu-Shiley: n = 76, Carpentier-Edwards: n = 57, Mitroflow: n = 35) were implanted. At time of implantation, the patient age ranged from 21-85 years, mean 57.1 +/- 12.4 years. 831 patients were analyzed in the long-term follow-up (62.3 +/- 18.6 months, cumulative follow-up of 6632 patient-years). The incidences of thromboembolic complications (TE), endocarditis (E), primary tissue failure (PTF), rate of reoperation (ReOp), and late mortality due to prosthesis dysfunction were analyzed, calculated, and compared within the different valve models (actuarial data, chi 2 test, log rank analysis). The incidences of TE and E were lower for pericardial valves when compared with porcine bioprostheses (TE: 0.88 vs. 1.8%/patient year; E: 0.24 vs. 0.5%/patient year); within the 2 groups, the different valve models did not show any major differences. However, the incidence of PTF was significantly higher in the pericardial valve group, being 36 +/- 6.5%, 68 +/- 10% and 86 +/- 19.5% after 6, 8, and 10 years; the respective figures for the porcine valves were 6 +/- 3.5%, 18 +/- 7.1%, and 60 +/- 13.1% (p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Nonthoracotomy lead systems for implantable cardioverter defibrillators (ICDs) have reduced operative mortality and morbidity as compared to epicardial lead systems but are usually associated with higher defibrillation thresholds (DFTs). The purpose of this prospective randomized trial was to investigate if the second defibrillation electrode in the left subclavian vein can increase defibrillation efficacy and decrease DFT as compared to the superior vena cava (SVC) position in nonthoracotomy lead systems for ICDs. Seventeen patients (mean age: 49.9 +/- 11.3 years, mean ejection fraction: 46.1% +/- 15.8%) were implanted with an investigational unipolar electrode (Medtronic 13001) used as the defibrillation anode. DFT testing was started in the SVC (n = 10, group A) or the left subclavian vein (n = 7, group B), and repeated in the alternative position starting at the DFT of the initial position. Fifteen patients were eligible for analysis (group A: n = 9, group B: n = 6). With the electrode in the SVC, ventricular fibrillation could be successfully terminated in 9 out of 15 patients (60%). In the left subclavian vein the success rate was 100% (P < 0.01). Mean DFT in the SVC was 13.0 +/- 5.2 J and in the left subclavian vein 10.2 +/- 4.9 J. DFTs in the left subclavian vein were either lower (group A: n = 5/9, group B: n = 5/6) or equal to the results in the SVC position (P < 0.001). Thus, the left subclavian vein appears to be a superior alternative for positioning of the defibrillation anode as compared to the SVC for nonthoracotomy lead systems using two separate leads.