Transthorakale echokardiographische Untersuchungen zeigten unter Ruhebedingungen bei den single-chamber vs dual-chamber pacing for high-grade atrioventricular block OGF keine Unterschiede hinsichtlich der Ejektionsfraktion bei Patienten mit und ohne Herzinsuffizienz.
The variation of heart rate is the most significant factor of cardiac output during exercise conditions. The influence of the upper tracking rate on cardiac performance was investigated at a sample of twenty patients having a dual chamber pacemaker implanted for high degree AV block.
At randomly programmed upper tracking rates UPR ofor bpm oxygen uptake was determined at the anaerobic threshold and at peak exercise using the cardiopulmonary exercise test. Two-dimensional echocardiography at rest did not reveal any differences of ejection fraction between patients with or without heart failure at various UPR.
For patients with dual chamber acemakers the upper tracking rate can be optimised by the cardiopulmonary exercise test. Higher UPR should be set for patients without heart failure, whereas the UPR should be limited to lower values for patients with heart failure.