Background

Whether reduced left ventricular global longitudinal strain (LV GLS) after COVID-19 contributes to a reduction in physical performance is not yet conclusively confirmed. In a preliminary study, we found a possible mild myocardial involvement in the form of reduced LV GLS in athletes after COVID-19 compared with a healthy athletic control group. Now, the aims of this prospective follow-up study were to investigate the development of LV GLS in athletes after COVID-19 and the possible relationship between LV GLS and physical performance.

Methods 

LV GLS was determined in four-, two-, and three-chamber views and assessed offline by a blinded investigator in 96 recreational athletes (mean age 33.15±12.40 years, 53 male, peak VO₂ 38.82±11.14 ml/min/kg) at a median of two (t₀₎and five months (t₁) after COVID-19. Cardiopulmonary exercise testing (CPET) was performed on a bicycle ergometer on both examination dates.

Results

LV GLS improved significantly between t₀ and t₁ (t₀ -18.82±2.02 vs. t₁ -19.46±2.05, p<0.001). Echocardiographic and spiroergometric parameters were within the normal clinical reference range. Maximum power increased significantly from t₀ to t₁ (t₀ 283.17 ± 83.20 Watt vs. t₁ 286.24 ± 85.22 Watt, p=0.009) and there was a trend toward increased peak oxygen uptake (t₀ 36.82 ± 11.14 ml/min/kg vs. t₁ 38.68 ± 10.26 ml/min/kg, p=0.069). We found no correlation between LV GLS and performance parameters, except for the respiratory exchange ratio (RER) (ρ -0.316, [-0.501; -0.102], p<.050).

Conclusions

Approximately five months after COVID-19, there was a significant improvement in LV GLS compared with two months after infection, but there was no correlation between LV GLS and performance parameters, with the exception of RER. Significant LV GLS differences may be due to mild myocardial involvement during or shortly after COVID-19. An inverse correlation of GLS with RER, indicates insufficient load intolerance at lower GLS values. Further studies in larger collectives or in the normal population are necessary.