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Left ventricular volume and ejection fraction response to exercise in chronic congestive heart failure: difference
Insights
The cause of chronic congestive heart failure (CHF) impacts how the left ventricle (LV) responds to exercise. Dilated cardiomyopathy (DC) and myocardial infarction (MI) show different LV volume and ejection fraction (EF) changes during physical activity.
Area of Science:
- Cardiology
- Exercise Physiology
- Heart Failure Research
Background:
- Chronic congestive heart failure (CHF) affects left ventricular (LV) function.
- The origin of CHF, such as dilated cardiomyopathy (DC) or myocardial infarction (MI), may influence cardiac response to stress.
Purpose of the Study:
- To investigate whether the etiology of CHF influences LV volume and ejection fraction (EF) responses during exercise.
- To compare exercise-induced hemodynamic and ventricular changes in CHF patients with different underlying causes.
Main Methods:
- Simultaneous hemodynamic monitoring and radionuclide ventriculography were performed in 24 CHF patients (13 DC, 11 MI) and 6 controls during semiupright bicycle exercise.
- Resting and exercise LV volumes, EF, and pulmonary wedge pressure were assessed.
Main Results:
- Both CHF groups exhibited similar resting hemodynamics, LV volumes, and EF.
- Exercise hemodynamics were comparable, but LV volume and EF responses differed significantly between CHF-DC and CHF-MI groups.
- CHF-MI patients showed a greater increase in LV end-diastolic volume (44%) compared to CHF-DC patients (15%) during exercise.
- EF increased in the CHF-DC group but remained unchanged in the CHF-MI group due to increased end-systolic volume.
- The pulmonary wedge pressure-LV end-diastolic volume relationship was steeper in the CHF-DC group.
Conclusions:
- The response of LV volume and EF to exercise in patients with CHF is dependent on the underlying cause (etiology).
- Different CHF etiologies, specifically DC versus MI, lead to distinct patterns of cardiac adaptation during physical exertion.
Abstract:
To determine if cause influences the left ventricular (LV) volume and ejection fraction (EF) response to exercise, 24 patients with chronic congestive heart failure (CHF) (13 dilated cardiomyopathy [DC], CHF-DC group; 11 previous myocardial infarction [MI], CHF-MI group) and 6 age-matched control subjects underwent simultaneous hemodynamic monitoring and radionuclide ventriculography during semiupright bicycle exercise. Both CHF groups had similar hemodynamic values, LV volumes and EF at rest. Exercise hemodynamics were also similar, but LV volume and EF responses to exercise were different. In the CHF-DC group LV end-diastolic volume increased by 15% during exercise, significantly less (p less than 0.01) than the 44% increase in CHF-MI group. During exercise, EF increased in CHF-DC group, but did not change in CHF-MI group because of a larger increase in end-systolic volume. The slope of mean pulmonary wedge pressure-LV end-diastolic volume relation was steeper in CHF-DC group than in CHF-MI group (p less than 0.01). The study suggests that LV volume and EF response to exercise in patients with CHF depends on the origin of the CHF.