Table 1.

ECG findings in athletes based on the international criteria [44].

Normal ECG findings	Borderline ECG findings	Abnormal ECG findings
Sinus bradycardia or sinus arrhythmia	Left axis deviation	ST-T repolarization abnormalities (T-wave inversion, ST-segment depression)
First-degree AV block, Mobitz type 1 second-degree AV block	Left atrial enlargement	Pathological Q waves
Ectopic atrial or junctional escape rhythm	Right axis deviation	QRS $\ge$140 ms duration
Incomplete RBBB	Right atrial enlargement	Epsilon wave
Early repolarization/ST-segment elevation	Complete RBBB	Complete LBBB
Increased QRS voltage criteria for left or right ventricular hypertrophy		QT Abnormalities (Long and Short)
ST elevation followed by T-wave inversion V1–V4 in black athletes		Ventricular pre-excitation
T wave inversion V1–V3 in age 16 years		Brugada type 1 pattern
		Profound sinus bradycardia 30 bpm
		PR interval $\ge$400 ms
		Mobitz type 2 second-degree AV block, third-degree AV block
		$\ge$2 PVCs at rest
		Atrial tachyarrhythmias
		Ventricular arrhythmias

ECG, electrocardiogram; AV, atrioventricular; LBBB, left bundle branch block; PVC, premature ventricular contraction; RBBB, right bundle branch block.