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Comparison of Ventricular Function in Atrial Rate Adaptive Versus Dual Chamber Rate Adaptive Pacing During Exercise
Author(s) -
GALLIK DONNA M.,
GUIDRY GERALD W.,
MAHMARIAN JOHN J.,
VERANI MARIO S.,
SPENCER WILLIAM H.
Publication year - 1994
Publication title -
pacing and clinical electrophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.686
H-Index - 101
eISSN - 1540-8159
pISSN - 0147-8389
DOI - 10.1111/j.1540-8159.1994.tb01370.x
Subject(s) - medicine , single chamber , cardiology , ventricular pacing , ventricular function , cardiac pacing , dual (grammatical number) , heart failure , art , literature
The hemodynamic effects of two different pacing modes—rate adaptive atrial (AAIR) versus dual chamber (DDDR) pacing—were assessed in 12 patients with DDDR pacemakers during upright bicycle exercise first‐pass radionuclide angiography using a multiwire gamma camera with tantalum‐178 as a tracer. All patients had sinus node disease with intact AV conduction. Patients exercised to the same heart rate in random order in these two different pacing modes, AAIR and DDDR with AV delay (of 100 msec) selected to maintain 100% ventricular capture. Cardiac output in creased significantly above baseline values during exercise in both pacing modes: 154 ± 41% (mean ± SEM, P = 0.002) with AAIR, versus 95 ± 24% (P = 0.004) with DDDR (P = NS between the two modes). The peak filling rate, likewise, increased in both pacing modes (2.3 ± 0.21 end‐diastolic volumes/sec to 3.8 ± 0.31 end‐diastolic volumes/sec in AAIR [P = 0.0004] and 2.2 ± 0.18 end‐diastolic volumes/sec to 3.4 ± 0.27 end‐diastolic volumes/sec in DDDR [P = 0.0008]). LV ejection fraction was normal at rest (60 ± 4%, SEM) and did not significantly change with submaximal exercise in either pacing mode (both 56%, P = NS). No significant changes in end‐diastolic volume or stroke volume indexes occurred with exercise in either pacing mode. Our study demonstrates that in patients with normal resting LV function, AAIR and DDDR pacing are equally effective in attaining appropriate increases in cardiac output and LV filling during exercise.