Biomedical subjects

Rainer Gradaus

Publications and source records attributed to Rainer Gradaus.

21 records · Page 2Linked to original sources

PubMed2002

Therapeutic options and heart failure survival score predictability in an academic heart failure center: an analysis of 120 consecutive patients during a 1-year period.

BACKGROUND: the incidence and prevalence of patients with advanced heart failure is increasing worldwide and the number of cardiac transplantations remains limited. AIMS: it was the aim of the study to describe our experience with the increasing number of available medical, interventional and cardiac surgery options, and to assess heart failure survival score predictability in an academic heart failure center within a 1-year follow-up. METHODS AND RESULTS: in all patients who were referred for cardiac transplant evaluation within a 12-month period between April 1998 and March 1999 at our Interdisciplinary Heart Failure and Transplant Program, our team assessed all medical interventions as well as interventional and surgical treatment options that were available, based on the clinical profile on initial presentation. In 92% of the 120 patients referred for cardiac transplantation evaluation, drug therapy could be optimized. A considerable number of patients could be subjected to an organ-preserving intervention or surgery, either PTCA (n=11), CABG (n=4), valve repair (n=7), multisite pacing (n=7), or partial ventricular resection (n=5). Only a small group of patients with the worst heart failure survival score were listed for heart transplantation (n=17) or received a ventricular assist device (n=3). CONCLUSIONS: within a contemporary cohort of advanced heart failure patients, only a small number of patients will undergo cardiac transplantation, which is predictable by the heart failure survival score. Most patients will undergo optimized medical therapy and a considerable number will be subjected to interventional or surgical treatment options.

Adrenergic beta-Antagonists↗

PubMed2002

Effect of ventricular fibrillation duration on the defibrillation threshold in humans.

Early during ventricular fibrillation, the defibrillation threshold may be low, as ventricular fibrillation most probably arises from a localized area with only a few wavefronts and the effects of global ischemia, ventricular dilatation, and sympathetic discharge have not yet fully developed. The purpose of this study was to explore the effect of the timing of shock delivery in humans. During implantation of an ICD in 26 patients (24 men, 60 +/- 11 years, 19 coronary artery disease, NYHA 2.2 +/- 0.4, left ventricular ejection fraction 0.42 +/- 0.16), the defibrillation threshold was determined after approximately 10 and 2 seconds of ventricular fibrillation. Ventricular fibrillation was induced by T wave shocks. Mean defibrillation threshold was 9.9 +/- 3.6 J after 10.3 +/- 1.0 seconds. Within 2 seconds, 20 of 26 patients could be successfully defibrillated with < or = 8 J. In these patients, the mean defibrillation threshold was 4.0 +/- 2.1 J after 1.4 +/- 0.3 seconds compared to 9.5 +/- 3.1 J after 10.2 +/- 1.1 seconds (P < 0.001). There were no clinical differences between patients who could be successfully defibrillated within 2 seconds and those patients without successful defibrillation within 2 seconds. In the majority of patients, the defibrillation threshold was significantly lower within the first few cycles of ventricular fibrillation than after 10 seconds of ventricular fibrillation. These results should lead to exploration of earlier shock delivery in implantable devices. This could possibly reduce the incidence of syncope in patients with rapid ventricular tachyarrhythmias and ICDs.

Chi-Square Distribution↗

PubMed2002

European clinical experience with a dual chamber single pass sensing and pacing defibrillation lead.

Dual chamber ICDs are increasingly implanted nowadays, mainly to improve discrimination between supraventricular and ventricular arrhythmias but also to maintain AV synchrony in patients with bradycardia. The aim of this study was to investigate a new single pass right ventricular defibrillation lead capable of true bipolar sensing and pacing in the right atrium and integrated bipolar sensing and pacing in the right ventricle. The performance of the lead was evaluated in 57 patients (age 61 +/- 12 years; New York Heart Association 1.9 +/- 0.6, left ventricular ejection fraction 0.38 +/- 0.15) at implant, at prehospital discharge, and during a 1-year follow-up. Sensing and pacing behavior of the lead was evaluated in six different body positions. In four patients, no stable position of the atrial electrode could intraoperatively be found. The intraoperative atrial sensing was 2.3 +/- 1.6 mV and the atrial pacing threshold 0.8 +/- 0.5 V at 0.5 ms. At follow-up, the atrial sensing ranged from 1.5 mV to 2.2 mV and the atrial pacing threshold product from 0.8 to 1.7 V/ms. In 11 patients, an intermittent atrial sensing problem and in 24 patients an atrial pacing dysfunction were observed in at least one body position. In 565 episodes, a sensitivity of 100% and a specificity of 96.5% were found for ventricular arrhythmias. In conclusion, this single pass defibrillation lead performed well as a VDD lead and for dual chamber arrhythmia discrimination. However, loss of atrial capture in 45% of patients preclude its use in patients depending on atrial pacing.

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