The normal resting heart rate is 65-75 beats per minute. In athletes it may be as low as 40 beats per minute. In extreme athletic activity, the heart rate can go as high as 200/min. The heart rhythm may be regular or irregular. In an irregular rhythm (arrhythmia), there may be early beats which interrupt the regular rhythm (premature beats); or the thythm may vary with respiration; or it may be completely irregular, as in fibrillation. When patients are aware of irregularity,they describe the symptom as palpitations.

责任编辑：admin