The third heart sound after exercise in athletes: an exploratory study.

The purpose of our study was to investigate the frequency of the third heart sound (S3) of athletes after exercise, and to determine whether the frequency and amplitude of S3 were related to cardiac function. The phonocardiogram exercise test (PCGET) was used in this study, and healthy volunteers consisting of 84 athletes (age 21.0±1.7 years; 62 males and 22 females) and 45 non-athletes (age 24.1±2.0 years; 33 males and 12 females) were enrolled. All subjects were healthy except one with a cardiac murmur without known cause. Immediately after exercise, S3 occurred in 21 athletes (25.0%) and 10 non-athletes (22.2%) during PCGET. There were very significant differences between pre-exercise and post-exercise in the frequency of S3 (P<0.01), and no significant difference between athletes and nonathletes (P>0.05). The prevalence of S3/S2≥1 was significantly (P<0.05) higher for the athlete group (47.1%) as compared to the non-athlete group (10%). Those results indicated that the emergence of S3 was an indicator of heart burden, and S3 after exercise in the athlete group was physiological. Our study showed that the amplitude of S3 had a very sensitive response to cardiac function reduction and S3/S2≥1 could eventually be used to assess cardiac fatigue states.

Change of cardiac reserve during abnormal pregnancy and its evaluation / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the change of cardiac reserve during abnormal pregnancy and explore its evaluation methods.</p><p><b>METHODS</b>Totally 96 women with abnormal pregnancies (AP group), 356 women with normal pregnancies (NP group), and 100 women of childbearing age (CBA group) were monitored by the exercise cardiac contractility monitor (ECCM). Phonocardiogram of participants at resting status was recorded by ECCM. The amplitude of first heart sound (S1), the amplitude of second heart sound (S2), cardiac cycle, diastolic duration (D), and systolic duration (S) were detected and then the S1/S2 ratio,the D/S ratio, and heart rate (HR) were calculated.</p><p><b>RESULTS</b>Compared with the CBA group, S1/S2 ratio and HR were significantly higher and D/S was significantly lower in both AP group and NP group (all P<0.001). Compared with the NP group, S1/S2 ratio and HR were significantly higher in AP group and D/S was significnatly lower (all P<0.001). A D/S ratio less than 1.1 or S1/S2 ratio higher than 1.8 was associated with higher risk of poor pregnancy outcomes. Among four common pregnancy-associated abnormalities, the level of cardiac reserve was lowest in eclampsia, followed by twins, gestational diabetes mellitus, and gestational hypertension.</p><p><b>CONCLUSIONS</b>Cardiac reserve is mobilized during pregnancy, and is especially during the abnormal pregnancies due to the heavy cardiac burden. S1/S2 ratio, D/S ratio, and HR are useful in evaluating the cardiac reserve during abnormal pregnancy.</p>