Diagnosis and Treatment of the Cardiac Arrhythmias
DISTURBANCES of the rhythm of the heart comprise one of the most common problems in clinical cardiology. They may occur as a complication of organic cardiac disease or in the entire absence of a structural abnormality of the heart. Certain arrhythmias are of no significance although they often cause disagreeable symptoms. Others result in an important reduction in the mechanical efficiency of the heart and may precipitate congestive myocardial failure or intensify pre-existing decompensation. Still others, among the more uncommon disorders, constitute a direct threat to life. Accurate diagnosis is essential not only for appropriate treatment but also for correct estimation of the clinical importance of the condition. Fortunately, most of the arrhythmias can be recognized by physical examination alone. Electrocardiographic corroboration of the diagnosis is always desirable, however, and a few of the disturbances can be identified only by instrumental means.
Premature beats, the most common type of cardiac arrhythmia, may arise from the auricles, ventricles, auriculoventricular node or main stem of the bundle of His. They are of clinical significance only in exceptional instances although they not infrequently cause uncomfortable symptoms due either to the pause which follows the premature beat or to the unusual force of the next normal ventricular contraction. Patients frequently report a sensation that the heart has stopped momentarily or skipped a beat. Occasionally, in sensitive persons, there may be fleeting lightheadedness, a choking sensation in the throat, or transient pain in the precordial or substernal area.
Premature beats usually can be. . .