cardiovascular disorders
Athlete’s Heart
Key Points
Intensive physical exercise increases left ventricular muscle mass, wall thickness, and chamber size but systolic function and diastolic function remain normal. Resting heart rate is slow and there may be a systolic ejection murmur at the left lower sternal border, a 3rd heart sound (S3), and/or a 4th heart sound (S4). ECG shows bradycardia and signs of hypertrophy and sometimes other findings such as sinus arrhythmia, atrial or ventricular ectopy, and 1st or 2nd degree atrioventricular (AV) block. Structural and ECG changes due to athlete's heart are asymptomatic; the presence of cardiovascular symptoms (eg, chest pain, dyspnea, palpitations), third-degree AV block should prompt a search for an underlying cardiac disorder. 