Cardiology is the medical science and discipline concerned with the heart, its functions, and all diseases that affect this organ and may impair its normal function. The field of cardiology includes heart conditions such as myocardial infarction (heart attack), heart failure (insufficient cardiac performance), and cardiac arrhythmias.
To assess cardiac function, the cardiologist uses specialized diagnostic tests such as an electrocardiogram (ECG) or a chest X-ray.