Importance of Heart Rate Response During Exercise in Patients Using Atrioventricular Synchronous and Ventricular Pacemakers

Abstract

Atrioventricular synchronous pacing offers advantages over fixed-rate ventricular (VVI) pacing both at rest and during exercise. This study compared the hemodynamic effects at rest and exercise of ventricular pacing at a rate of 70 beats/min, ventricular pacing where the rate was increased during exercise and dual chamber pacing. Ten patients, age 63 +/- 8 years, with multiprogrammable DDD pacemakers were studied using supine bicycle radionuclide ventriculography. Radionuclide data during dual chamber pacing was acquired at rest and during a submaximal workload of 200-400 kpm/min. The pacemakers were then programmed to VVI pacing at a rate of 70 beats/min, and 1 week later, studies were repeated in the VVI mode at rest, during exercise at a rate of 70 beats/min, and during exercise with the VVI pacemaker programmed to a rate adapted to the DDD pacing exercise rate. At rest, the cardiac output was lower in the VVI compared with the AV sequential mode (4.1 +/- 1.1 vs 5.7 +/- 1.1 1/min, P less than 0.01). During exercise, the cardiac output increased from resting values in the DDD and VVI pacing modes, however cardiac output in the rate-adapted VVI mode was higher than in the VVI mode with the rate maintained at 70 beats/min (8.1 +/- 1.5 vs 6.3 +/- 1.1 1/min, P = 0.02). Three patients completed lower workloads with VVI pacing at 70 beats/min compared with AV synchronous pacing. At rest, AV sequential pacing was superior to VVI pacing, suggesting the importance of the atrial contribution to ventricular filling. With VVI pacing during exercise, cardiac output was improved with an increased pacemaker rate, suggesting that the heart rate response during exercise was the major determinant of the higher cardiac output.

Pacing-associated left ventricular dysfunction? Think reprogramming first!

“…There was no reduction in peak heart rate or peak oxygen consumption and no difference in quality of life. Rate-adaptive pacing in pacemaker patients without CHF is associated with a greater cardiac output rise during exercise,21 and although studies have shown improvements in exercise capacity ranging from the marginal22 23 to the dramatic,24 there is no consistency on measures of quality of life in either AF or SR 26–28. The literature is equally inconsistent about whether rate-adaptive CRT pacing does29 30 or does not31 improve exercise capacity in patients with heart failure, but there seems to be no benefit on quality of life 32.…”

Rate adaptive pacing in people with chronic heart failure increases peak heart rate but not peak exercise capacity: a systematic review

“…A larger proportion of males was reported across studies (63.3 [32] to 90% [33]). Ischemic aetiology was [17] The Heart Rhythm Society and British Pacing Electrophysiology Group guide to pacemaker modes of operation…”

“…Rate adaptive cardiac pacing (RAP) is now available in all IECD's and was developed to assist in restoration of a physiological HR response to an increase in metabolic demand [10]. However, RAP is controversial and not well evidenced, demonstrating mixed results among other cardiac populations [17][18][19][20]. Excessive increases in HR may lead to ischemia, decreased LV diastolic filling time, and reduced contractility in CHF [21].…”

Herzschrittmacher und implantierbare Kardioverter-Defibrillatoren in der perioperativen Phase

“…Bei erhöhtem Sauerstoffbedarf des Organismus, z. B. unter Belastung, ist nämlich das Herzzeitvolurnen durch Anheben der ventrikuiären Stimulationsfrequenz um bis zu 28 010 zu steigern (71). E i e M r i s t i g e Umprogrammierung der Stimulationsfrequenz erfordert jedoch spezielle, häufig nicht direkt verfügbare Programmiergeräte.…”