[Regularization of ventricular intervals in atrial fibrillation--electrophysiologic findings on the underlying mechanism]. / Regularisierung der Kammerintervalle bei Vorhofflimmern-- elektrophysiologische Befunde zum zugrundeliegenden Mechanismus.

In 13 patients with chronic atrial fibrillation, programmed right ventricular pacing was performed before and after intravenous administration of 4 mg gallopamil. Application of the Ca-antagonist resulted in a marked decrease in the ventricular response in all and in a regularization of the ventricular response (variation coefficient of the ventricular cycle length: less than 10%) in 7 of 13 cases, while atrial fibrillation persisted. During regularization right ventricular extrastimulus testing showed a constancy of the postextrasystolic interval irrespective of the changes in the coupling interval of the extrasystole. The postextrasystolic cycle was slightly longer than the basic cycle; the difference amounts to a mean value of 107 +/- 22 ms. During the control period the postextrasystolic cycle showed the same irregularity as the basic cycle. The same random distribution was observed if the first 10 cycles of the spontaneous rhythm were analyzed after a short period of ventricular overdrive pacing. After regularization the first 2-3 postpacing cycles were markedly prolonged, and during the following cycles a gradual adjustment to the length of the basic cycles before overdrive pacing was seen, resembling the warming up of a pacemaker. It is concluded that regularization is most probably due to atrioventricular nodal depression and the occurrence of a junctional escape pacemaker.

Perioperative myocardial infarction in coronary artery bypass surgery.

Perioperative myocardial infarction (PMI) as diagnosed by standard electrocardiograms (appearance of persistent Q-waves of at least 0.4 sec duration) and/or autopsy, occurred in 51 (3.8%) out of 1341 consecutive patients undergoing coronary artery bypass surgery using saphenous vein grafts. Retrospective analysis of the available data revealed that preoperative factors like sex, age, history of myocardial infarction, functional class, coronary risk factors, number of vessels diseased, and ventricular function had no influence on the incidence of PMI. However, intraoperative parameters, e.g., type and duration of cardiac arrest as well as technical errors leading to graft occlusion, significantly affected the incidence of PMI. The clinical relevance of PMI is indicated by a high early mortality of 25.5% as compared to 2.3% in patients without PMI. Improvement as well as complete alleviation of angina pectoris was less frequent in patients with PMI than in patients without PMI. The decrease in the rate of PMI from more than 18% in 1970 to less than 1% in 1978/79 confirms that such incidents should not be regarded as an inevitable risk but as a complication which can largely be avoided by proper operative technique.

[Patient survival with pacemaker (author's transl)]. / Lebenserwartung mit Herzschrittmacher.

The survival rate for age groups from 50--59, 60--69, 70--79, 80--89 was worked out from 1065 patients with implanted pacemakers form 1963 to the end of 1977. In all age groups the life expectancy was under the survival of the general population in the Federal Republic of Germany. Analysing the data it seems that two groups of different longevity superimpose in all age groups; the first group shows an unproportional high mortality rate in the first 12 months while the other has an almost identical survival to the tenth year. The initial high mortality rate respective to the increasing age probably results in accompaning diseases; in this aspect further studies are required.