The rhythm of the heart in active elderly subjects

Abstract

The dynamic electrocardiogram (DCG) is an increasingly important investigation for the diagnosis of symptoms which might be ascribed to cardiac arrhythmias. This study was designed to document DCG findings in apparently healthy people over the age of 75 years in order to provide a data base with which to compare DCG results in symptomatic patients. The study was performed on 106 subjects at home and consisted of a clinical questionnaire, physical examination, resting 12-lead ECG, and 24-hour taped DCG. Eight subjects had established atrial fibrillation (AF) and three had paroxysmal AF. Established AF resulted in a rapid ventricular response in one case and a slow ventricular rate in two. A controlled ventricular response was found in five subjects who were on no treatment. Of 98 subjects in sinus rhythm, 73 had a heart rate of between 50 and 100 beats/minute; 11 had sinus bradycardia, and in only 15 instances did the heart rate intermittently exceed 100 beats/minute. Thirty-five subjects had sinus rates that did not vary by more than 10 beats/minute throughout the 24 hours. The DCG demonstrated isolated ventricular premature beats in 45 subjects and potentially more serious ventricular arrhythmias in 32 cases. Ventricular bradycardias of any variety were rarely seen. Arrhythmias were detected two to four times more frequently by DCG than by 12-lead ECG. Within this sample age, ischemic heart disease, systolic hypertension, smoking habits, and a history of syncope, palpitations, or dizziness did not affect the prevalence of any type of arrhythmia. The results of this study demonstrate that although ectopic cardiac rhythms and tachycardias are common in apparently healthy, elderly people, ventricular pauses and bradycardias are extremely uncommon.