Serial left ventricular adaptations in world-class professional cyclists

Abstract

Objectives

The purpose of this research was to study long-term left ventricular (LV) adaptations in very-high-level endurance athletes.

Background

Knowledge of cardiac changes in athletes, who are at particularly high risk of sudden cardiac death, is mandatory to detect hypertrophic cardiomyopathy (HCM) or dilated (DCM) cardiomyopathy.

Methods

We carried out echocardiographic examinations on 286 cyclists (group A) and 52 matched sedentary volunteers (group C); 148 cyclists participated in the 1995 “Tour de France” race (group A1), 138 in the 1998 race (group A2), and 37 in both (group B).

Results

In groups A, A1, A2, and C, respectively, diastolic left ventricular diameter (LVID) was 60.1 ± 3.9 mm, 59.2 ± 3.8 mm, 61.0 ± 3.9 mm, and 49.0 ± 4.3 mm (A vs. C and A1 vs. A2, p < 0.0001), and maximal wall thickness (WT) was 11.1 ± 1.3 mm, 11.6 ± 1.3 mm, 10.6 ± 1.1 mm, and 8.6 ± 1.0 mm (A vs. C and A1 vs. A2, p < 0.0001). Among group A, 147 (51.4%) had LVID >60 mm; 17 of them had also a below normal (<52%) left ventricular ejection fraction (LVEF). Wall thickness exceeded 13 mm in 25 athletes (8.7%) (always <15 mm), 23 with LVID >55 mm. In group B, LVID increased (58.3 ± 4.8 mm to 60.3 ± 4.2 mm, p < 0.001) and WT decreased (11.8 ± 1.2 mm to 10.8 ± 1.2 mm, p < 0.001) with time.

Conclusions

Over one-half of these athletes exhibited unusual LV dilation, along with a reduced LVEF in 11.6% (17 of 147), compatible with the diagnosis of DCM. Increased WT was less common (always <15 mm) and scarce without LV dilation (<1%), eliminating the diagnosis of HCM. Serial examinations showed evidence of further LV dilation along with wall thinning. These results might have important implications for screening in athletes.