Exploring the determinants of the cardiac changes after ultra-long duration exercise: The echocardiographic Spartathlon study

Aim: The investigation of the pathophysiological determinants of cardiac changes following ultra-long duration exercise.

Methods: Twenty-seven runners who finished a 246 km running race were examined both before and after the finish of the race. Examinations included echocardiography and measurement of body weight and blood biochemical parameters.

Results: Exercise increased left ventricular end-diastolic interventricular septum thickness (LVIVSd) (p < 0.001) and posterior wall thickness (LVPWTd) (p = 0.001) and right ventricular end-diastolic area (p = 0.005), while reduced tricuspid annular plane systolic excursion (TAPSE) (p = 0.004). A minor decrease in the peak absolute values of both left ventricular (from -20.9 ± 2.3% to -18.8 ± 2.0%, p = 0.009) and right ventricular (from -22.9 ± 3.6% to -21.2 ± 3.0%, p = 0.040) global longitudinal strains occurred. There was decrease in body weight (p < 0.001) and increase in both circulating high-sensitivity troponin I (p = 0.028) and amino-terminal pro-B type natriuretic peptide (NT-proBNP) (p = 0.018). The change in the sum of LVIVSd and LVPWTd correlated negatively with percentage change of body weight (r = -0.416, p = 0.049). The only independent determinant of post-exercise NT-proBNP was pulmonary artery systolic pressure (r = 0.797, p = 0.002). Post-exercise NT-proBNP correlated positively with percentage changes of basal (RVbas) (r = 0.582, p = 0.037) and mid-cavity (RVmid) (r = 0.618, p = 0.043) right ventricular diameters and negatively with percentage change of TAPSE (r = -0.720, p = 0.008). Similar correlations with RVbas, RVmid and TAPSE were found for pulmonary artery systolic pressure. Post-exercise high-sensitivity troponin I correlated negatively with percentage change of body weight (r = -0.601, p = 0.039), but was not associated with any cardiac parameter.

Conclusion: The main cardiac effects of ultra-long duration exercise were the decrease in left ventricular end-diastolic dimensions and increase in left ventricular wall thickness, as well as minimal dilatation and alteration in systolic function of right ventricle, possibly due to the altered exercise-related right ventricular afterload.