No abstract

With the benefit of a simpler implant procedure, long-term outcome of single lead VDD pacing is equivalent to DDD pacing in patients with AV block and preoperative normal sinus node function.

Background: Knowledge on clinical characteristics and prognosis of patients with heart failure originates from studies of selected populations in clinical trials or from epidemiological observations. Reports on the large numbers of patients with heart failure treated in community hospitals are sparse. Objecti¨e: Are there differences in patient characteristics and heart Ž . Ž . failure management between a metropolitan heart center HC and a rural community hospital RCH ? Patients and methods:Ž . Retrospective analysis of medical charts from all patients admitted for heart failure ICD 428.x, NYHA II᎐IV, EF -45% between May 1997 and April 1998 and discharged alive from a rural community hospital. A similar, but prospective registry was available at the HC. Follow-up information was obtained by request at registration authorities. Results: Patient groups Ž . Ž . comprised 120 in RCH and 146 in HC. Mean age was 75 " 11 and 66 " 11 years, respectively P-0.001 ; 48% RCH vs. 74% Ž . Ž . Ž . Ž . HC of patients were male P-0.001 . On admission the proportion of functional class IV was 69% RCH vs. 17% HC Ž . Ž . Ž . Ž . Ž . P-0.001 . At discharge, the rate of ACE-inhibitors was 74% RCH vs. 98% HC ; 11% RCH vs. 43% HC of patients received ␤-blocker therapy. Ninety-six percent of patients in HC underwent and 22% in RCH had undergone invasive Ž diagnostics. One-year mortality rate of patients discharged alive was 26% in RCH and 19% in HC Ps n.s. after adjustment . for age and gender . Conclusion: Heart failure management according to current guidelines, using ␤-blockers and ACE inhibitors, and invasive cardiac examination was significantly less performed in the rural community hospital than in the metropolitan heart center. Therefore, strategies to improve heart failure management according to guidelines are urgently needed. ᮊ

The pacemaker syndrome refers to symptoms and signs in the pacemaker patient caused by an inadequate timing of atrial and ventricular contractions. The lack of normal atrioventricular synchrony may result in a decreased cardiac output and venous cannon A waves. The objective of this study was to define the left atrial and pulmonary venous flow response to ventricular pacing in a group of 14 unselected consecutive patients with total heart block and sinus rhythm. Pulmonary venous flow was assessed by transesophageal pulsed Doppler echocardiography in the VVI and DDD pacing modes. An inappropriate atrial timing caused a marked augmentation of the normally small pulmonary venous z wave in all patients ("negative atrial kick," peak z wave in DDD pacing 14.5 +/- 4.6 cm/s, VVI pacing 51.8 +/- 15.0 cm/s). Restoration of AV synchrony (DDD pacing, AV interval 100 ms) abolished these "cannon z waves" in all patients, and a normal pattern of pulmonary venous flow was achieved. Abnormal pulmonary venous flow characteristics were observed in 2 of 14 patients during DDD pacing with short AV intervals (100 ms). The Doppler pattern was similar to the findings seen in VVI pacing. Assessment of pulmonary venous flow by transesophageal pulsed Doppler echocardiography may provide a simple, sensitive, and relatively noninvasive technique to evaluate patients with suspected pacing induced adverse hemodynamics.

In a controlled study, the following four bipolar leads with passive fixation were implanted in 46 patients with the Siemens-Multilog-VVI or Sensolog-VVIR-pacemakers: membrane covered activated porous carbon with steroid elution (Siemens 1402 T, 11 patients) and without (Siemens 1403 T, 15 patients); activated carbon (Siemens 1010 T, 10 patients); and platinum with steroid elution (Medtronic Cap-Sure 5026, 10 patients). Stimulation threshold (STH) (assessed by a vario-test), impedance (IMP), and the intracardial R wave potential (IRW) (both gauged by a telemetric method) were measured 1, 5, and 10 days as well as 3 and 6 months after implantation during unipolar and bipolar stimulation, chronaxie rheobase product (CRP) and energy consumption (EC) were systematically determined. Differing insignificantly at the first day after implantation, STH is significantly lower for the 1402 T and CapSure 5026 leads at the tenth day. However, the 1402 T lead shows a significant increase of STH in the follow-up, in contrast to the other leads. The lowest chronic STH was found in the CapSure 5026 lead (CRP is significantly lower in all other leads, too). IMP is significantly lower in the CapSure 5026 lead compared to 1010 T lead. EC does not differ significantly during chronic stimulation in spite of the best possible programming of pulse amplitude and duration. No significant changes of IRW were observed. Unipolar versus bipolar stimulation shows significantly lower STH, CRP, and IMP, differences of EC and IRW were insignificant. In conclusion, the addition of steroid in membrane covered carbon leads protracts the increase of STH, but does not prevent it. The CapSure 5026 lead shows advantageous stimulation characteristics, but energy consumption is not significantly reduced because of low impedance and impossibility of programming an appropriate low output in Multilog pacemakers.