Systolic and diastolic cardiac function time intervals and exercise capacity in women

Purpose: To determine the relationship between exercise capacity and restin g cardiac function time intervals in women. Methods: The noninvasive method of seismocardiography was used to measure resting cardiac intervals in 12 female subjects. On the basis of maximal treadmill time (Bruce protocol), t wo groups were studied and categorized as long duration runners (LDR;N = 6) or short duration runners (SDR, N = 6). The following resting atrial and l eft ventricular (LV) cardiac function time intervals were determined: atria l systole, LV systole, LV diastole, LV isovolumetric contraction, LV isovol umetric relaxation, LV ejection, LV preejection, LV filling, LV rapid filli ng, and Tei index. Results: Heart rate (HR) (65 +/- 3 vs 61 +/- 4 b.min(-1) for LDR and SDR, respectively; P = NS ) and atrial systolic lime (75 +/- 6 vs 81 +/- 5 ms for LDR and SDR, respectively; P = NS) were similar between groups. LV systole (348 +/- 15 vs 302 +/- 8 ms for LDR and SDR, respective ly; P < 0.05) and LV ejection (297 +/- 13 vs 247 +/- 7 ms For LDR and SDR, respectively; P < 0.01) were longer in LDR, despite a similar LV isovolumet ric contraction time. There was a general trend for a shortened LV diastole in LDR with a significantly shortened LV isovolumetric time in LDR (80 +/- 8 vs 107 +/- 8 ms for LDR and SDR, respectively; P < 0.05). LV preejection was shorter in LDR versus SDR (LDR; 114 +/- 6 vs SDR; 130 +/- 3 ms, P < 0. 05), and the Tei index was less in LDR versus SDR. Conclusions: Independent of HR, increased treadmill time in young women is associated with greater resting systolic time intervals and decreased diastolic cardiac function ti me intervals.