To evaluate left ventricular (LV) diastolic function in long distance runners LV filling parameters were assessed by Doppler echocardiography during marathon race in 23 male subjects. On the basis of their personal record the athletes were divided into two groups: 12 endurance athletes (END; 218 min over 42 km) aged 34 years (29/37, median and 25%/75%-percentiles) and 11 ultra endurance athletes (ULTRA; 152 min over 42 km) aged 32 years (28/37). At rest 21 healthy untrained subjects (UT) aged 33 years (28/37) served as control group. In long distance runners the values for LV mass and LV mass index were significantly higher in END with 210 (168/253) g rsp. 110 (87/135) g/m2 and in ULTRA with 225 (179/267) g rsp. 118 (93/142) g/m2 as compared to UT with 129 (105/162) g rsp. 68 (57/79) g/m2 (p less than 0.001 each). Doppler-derived mitral flow was characterized by the early passive (E wave) and late (A wave) diastolic inflow. In particular atrial filling fraction (AFF) as the relative atrial contribution to LV filling was measured. At rest and at km 21 we saw a normal filling behaviour (AFF = 27% bzw. 28%) in both groups of long distance runners with an AFF of 27 (26/29)% in END and an AFF of 28 (26/29) in ULTRA. In END AFF rose to 42 (38/47)% at km 42 (p less than 0.001) and remained significantly elevated with 37 (35/42)% until 30 min post marathon (p less than 0.05). Only 60 min post exercise AFF returned to baseline values with an AFF of 28 (25/39)% in END. In contrast at km 42 in ULTRA AFF was significantly lower and at baseline levels with 26 (25/29)% compared to END (p less than 0.001) and did not significantly change in the further course of the post running period.
Conclusion: Long distance runners show a normal LV filling behaviour at rest despite significant LV hypertrophy. In contrast to top class athletes (ULTRA) there is a shift of LV filling from early (E wave) to late (A wave) diastole in less trained runners (END) during marathon. Thus, the results indicate an impairment of early diastolic LV filling in amateur endurance athletes (END) during extreme physical exercise.