Pacemaker therapy in very elderly patients: long-term survival and prognostic parameters.

BACKGROUND: Permanent pacing is the therapy of choice for treating severe and/or symptomatic bradyarrhythmia. However, augmented life expectancy and increasing health care expenditures have led to questions concerning the routine use of electrotherapy in very elderly patients. This study is aimed at assessing data on the actual number, characteristics, and survival of patients requiring pacing therapy at age > or =80 years. METHODS: Between 1971 and 2000, 1588 patients aged > or =80 years completed a standardized 6- to 12-month follow-up after pacemaker (PM) implantation, resulting in a total of 5244 patient years. Kaplan-Meier analyses were computed to visualize survival differences in various subgroups and implantation periods. RESULTS: Today, patients aged > or =80 years account for 32% of all PM implantations. An increasing 5-year survival after PM implantation to the current rate of 66% was found, compared to 37% and 47% in the previous decades. Based on a mean survival time of 8 years, clinical symptoms can be effectively treated with costs of < or =500 dollars per patient per year. Prognostic parameters were the decade of implantation (relative risk [RR] 0.80, CI 0.67-0.96, P < or =.02), a history of presyncope (RR 0.73, CI 0.57-0.95, P < or =.02), and male sex (RR 1.20, CI 1.04-1.40, P < or =.02). However, none of these parameters can be recommended for estimating outcome or for guiding device selection. CONCLUSIONS: Patients aged > or =80 years account for an increasing portion of PM implantations. Considering the remaining life expectancy of 8 years in these patients, PM therapy is a clinically and economically effective therapeutic option to control bradyarrhythmia-related symptoms.

A technical approach to optimized atrial recognition in the ICD: the intrathoracic six-channel farfield ECG.

Present-day ICD systems offer the possibility to reconstruct an intrathoracic 6-lead ECG (IT-ECG), using the defibrillator coils in the right ventricle and superior vena cava and the left-laterally positioned ICD as electrodes according to Einthoven and Goldberger. The aim of this study was to assess the feasibility of (1). automated P wave recognition in the IT-ECG without an additional atrial electrode as the basis of AV synchronous ventricular pacing (VDD) and for improved differentiation between supraventricular tachyarrhythmias and, (2). the automated detection of pacing evoked atrial potentials (EAP) in dual chamber ICDs as the basis for atrial "autocapture"pacing systems. In 27 patients during ICD implanation intraoperatively, the IT-ECG was digitally recorded. A recently established algorithm for automatic P wave and EAP detection correctly identified 1663/1672 (99.5%) P waves (oversensing rate 0.6%) and 543/554 (98.0%) EAP (no oversensing). During subthreshold atrial stimulation, 405/412 (98.3%) P waves were correctly identified (oversensing due to pacemaker spikes, n = 421, without subsequent EAP, 1.9%,n = 8). During stimulated ventricular tachycardia in 26/27 patients retrograde P wave or AV dissociation were identified. The 6-lead IT-ECG, easily implementable in ICD systems, is a diagnostic tool providing reliable information about atrial activation, serving as a basis for VDD pacing in single chamber ICD systems, allowing reliable EAP recognition that enables atrial "autocapture"pacing in dual chamber ICDs, and improves the differentiation between supraventricular and ventricular tachycardia.