The magnitude and course of exercise-induced stroke volume changes determine the exercise tolerance in heart transplant recipients with heart failure and normal ejection fraction
| Authors | |
|---|---|
| Year of publication | 2014 |
| Type | Article in Periodical |
| Magazine / Source | EXPERIMENTAL & CLINICAL CARDIOLOGY |
| MU Faculty or unit | |
| Citation | |
| Field | Cardiovascular diseases incl. cardiosurgery |
| Keywords | Bioimpedance; Exercise tolerance; Heart failure; Stroke volume index |
| Description | Objectives: There is a large variability of exercise-induced stroke volume behavior in healthy subjects. We sought to assess the course of exercise-induced changes in stroke volume index (SVI) and other functional parameters in post-heart transplant patients with heart failure and normal left ventricular ejection fraction (HFNEF). Methods: Left ventricular function and systemic hemodynamics were assessed at 40 s intervals during the exercise in 39 patients using simultaneous right heart catheterization, bioimpedance, and echocardiography. Results: Twenty-six patients had exercise tolerance >/= 4.0 METs (Group A), while 13 patients exhibited severely limited exercise tolerance < 4 METs (Group B). Maximal SVI (maxSVI) achieved at any time during the exercise exceeded SVI at peak exercise (peakSVI) in 26 patients (67%). Both maxSVI and maxSVI (maxSVI minus SVI at rest) were significantly higher in Group A compared to Group B patients (59 ml/m2 vs 41 ml/m 2, p < 0.01, and 21 ml/m2 vs 6 ml/m2, p < 0.01, respectively). With peakSVI, maxSVI, peakSVI, maxSVI and other variables evaluated, only maxSVI was independently associated with exercise tolerance. Conclusion: When assessing exercise-induced SVI changes in HFNEF patients, SVI should be followed during the course of exercise and maximal SVI change from rest should always be determined. |