Permanent cardiac pacing and thromboembolic risk in elderly patients

In patients undergoing permanent cardiac pacing, the maintenance of atrial contractility is important to ensure adequate ventricular filling and to guarantee an optimal ventricular ejection capacity. The appropriate pacing mode, assuring a suitable mechanical atrioventricular coupling, prevents the onset of atrial fibrillation and contributes to reduction of the risk of subsequent systemic and pulmonary thromboembolic episodes. We examined 461 patients (266 males and 195 females, aged between 52 and 97 years, average age 76.5 +/- 18) paced for conduction disturbances of various degrees and etiology. Of them, 323 patients received ventricular demand pacemaker (VVI group, average age 77.9 years); 138 underwent dual chamber pacing (DCP group, average age 75.2 years), 117 of the latter received universal demand pacing (DDD) and 21 atrial synchronous ventricular demand pacing (VDD). The patients were subsequently divided into two age-groups: Group A (/= 75 years, 287 patients). According to pacing mode and successive development of stable atrial fibrillation (AF), we analysed the occurrence of systemic and/or pulmonary thromboembolic episodes and the incidence of fatal events. During our study, performed from January 1986 to August 1993, 70 embolic episodes were observed in the VVI group and six in the DCP group. Eighty-four patients with VVI units developed AF during follow-up, compared with only five patients in the DCP group. Our data indicate that VVI patients have a higher incidence of AF, embolic complications and cerebrovascular mortality, in comparison with the DCP group. VVI pacing should be avoided, especially in older patients, when atrial rhythmical activity is present.