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[Left ventricular performance during exercise in patients with constant heart rate].
Journal of Cardiography
|March 1, 1983
Summary
Pacemaker patients with good exercise capacity showed improved left ventricular performance during exercise. Those with depressed capacity had limited adaptation due to impaired cardiac reserves.
Area of Science:
- Cardiology
- Exercise Physiology
Context:
- Assessing left ventricular (LV) function in pacemaker patients (PMI pts) during exercise is crucial.
- Constant heart rate pacing may alter normal cardiac responses to physical exertion.
Purpose:
- To evaluate the exercise response of LV performance in pacemaker patients.
- To compare adaptation in patients with varying physical work capacities.
Summary:
- 21 pacemaker patients and 4 controls underwent supine bicycle ergometry.
- Group I (good capacity) showed increased LV end-diastolic dimension, stroke excursion, fractional shortening, and posterior wall velocity, with decreased end-systolic dimension during exercise.
- Group II (depressed capacity) and controls showed less pronounced changes, with Group II exhibiting impaired resting cardiac parameters and insufficient exercise adaptation.
Impact:
- Findings suggest Group I utilizes the Frank-Starling mechanism and enhanced contractility for exercise adaptation.
- Group II demonstrates limitations in preload and contractility reserves, impacting exercise tolerance.
- This research highlights the importance of assessing physical work capacity in pacemaker patients for tailored management.