• Undue reliance on the electrocardiogram has created many problems in the diagnosis and management of heart disease. Subjective cardiac symptoms are frequently occasioned or intensified by the physician's unwarranted diagnosis of heart disease on the basis of some poorly understood or misinterpreted electrocardiographic aberrations. It is estimated that an average physician caring for cardiac patients sees from 10 to 25, and perhaps more, such cases of heart disease of electrocardiographic origin per year. The two most important symptoms of this disease are anxiety and chest pain.Departure from the assumed normal, especially of the S-T segment and the T wave, does not always mean abnormality of the myocardium. Severe myocardial abnormality is sometimes present without significant electrocardiographic abnormality. Diffuse changes in the deeper layers of the myocardium sometimes fail to alter the electrocardiogram, while relatively insignificant lesions in the superficial layer sometimes alter it markedly. The most reliable guide in the diagnosis and management of heart disease is the patient's clinical state.