Cardiac function measurements by electrical cardiometry in 24-hour ultra-marathoners

Yu-Jui Chiu, Jian-Sing Li, Yu-Hui Chiu, Hsiu-Hua Lin, Ming-Long Chang, Wei-Fong Kao


Background: To investigate cardiac function measurements and athletic performance by Noninvasive Method with Electrical Cardiometry among elite participants in 24-hour ultra-marathon.
Methods: This is a prospective study, where twenty endurance athletes completed 24-hour runs on a 400 m track. Cardiac function measurements were taken a day before, immediately after the race and 24-hour post-race. All enrolled athletes than were classified into four groups according to (I) received intravenous hydration intervention or not, (II) total running distances greater than 200 km or not, (III) body weight (BW) change greater than 3 percent or not, and (IV) blood pressure (BP) declined over 10 percent or not. Both cardiac fatigue phase and recovery phase were than discussed in detail before all subjects divided into groups and after divided into groups, in order to assess cardiac function and performance.
Results: Before stratify participants into groups, cardiac fatigue phase of all subjects is represented by a decline in left ventricular ejection time (LVET) (P<0.002), an incline of cardiac output (CO) (P=0.007) and heart rate (HR) at laying (P<0.001), seating (P<0.001) and standing (P<0.001). As well as BW loss is observed (P<0.001). When breakdown each group individually, athletes whom did not receive IV intervention showed higher BW loss comparing to intervention group. Running greater distance (>200 km) is associated with a decline of LVET comparing to less than 200 km group (P=0.024) in cardiac fatigue phase. Performance is associated with greater BW loss and participants with greater BW loss have a lower thoracic fluid index (P=0.046). No evidence of suggesting clinically significant cardiac function changes were detected.
Conclusions: Our current study indicates that the electric Cardiometry device is a useful device in measuring cardiac function during an ultramarathon setting. As well as, strenuous exercise will cause acute reversible clinically non-significant worsening in cardiac function.