Abstract Background Sports activities may promote arrhythmias in the setting of acute myocarditis. International cardiovascular society recommendations to return to sports activities following acute myocarditis are based on expert consensus in the absence of prospective studies. Purpose We sought to identify patients who may safely resume sports activities 3 months after acute myocarditis. Methods We prospectively enrolled 27 patients with newly diagnosed myocarditis based on clinical parameters, elevated high sensitive troponin (TnT-hs) and cardiac magnetic resonance imaging (CMR) with mildly reduced or preserved LVEF. Follow-up examination included laboratory findings, electrocardiogram (ECG), 48-hour-Holter ECG, echocardiography, exercise stress testing and CMR. Cessation of physical activity was recommended for 3 months. All patients were followed for cardiac events for 12 months. Results Average age was 35 (19–80) years with 73% male patients. All patients performed 3- and 6-month follow-up with above mentioned diagnostic tests. Eight patients did not present for 12-month follow-up, but were contacted by phone. No cardiac events occurred within the interval of 12 months. After 3 months, participants achieved an average of 92% of predicted maximum power on stress test. One case of non-sustained ventricular tachycardia was recorded during 48-hour-Holter ECG. Except for this case, all patients were allowed to resume physical exercise after 3 months. At 6- (n=26) and 12-month (n=19) follow-up no arrhythmias, recurrent myocarditis, worsening left ventricular ejection fraction (LVEF) or physical performance were recorded. TnT-hs, creatine kinase (CK), myoglobin (Mb), and C-reactive protein (CRP) normalized. Conclusion The risk of cardiac events and decreasing LVEF appears to be low after early resumption of exercise in asymptomatic patients who recover from acute myocarditis. Acknowledgement/Funding Forschungskredit of the University of Zurich,the Holcim Foundation, the Hartmann Müller Foundation, and the Walter and Gertrud Siegenthaler Foundation
International recommendations for electrocardiographic interpretation in athletes
Cardiac channelopathies are potentially lethal inherited arrhythmia syndromes and an important cause of sudden cardiac death (SCD) in young athletes. Other cardiac rhythm and conduction disturbances also may indicate the presence of an underlying cardiac disorder. The 12-lead ECG is utilised as both a screening and a diagnostic tool for detecting conditions associated with SCD. Fundamental to the appropriate evaluation of athletes undergoing ECG is an understanding of the ECG findings that may indicate the presence of a pathological cardiac disease. This article describes ECG findings present in primary electrical diseases afflicting young athletes and outlines appropriate steps for further evaluation of these ECG abnormalities. The ECG findings defined as abnormal in athletes were established by an international consensus panel of experts in sports cardiology and sports medicine.