[Severe arrhythmia in the elderly: a prospective hospital study].

The prevalence of arrhythmia increases with age. Considered as an "ordinary" event in elderly patients, these arrhythmias may nevertheless have serious consequences. This study was undertaken to determine the clinical, aetiological and prognostic features of serious arrhythmias in a population of elderly subjects (> or = 70 years) hospitalised over a 20 months period and comprising 202 patients (103 women, 99 men, mean age 79.6 +/- 5.9 years). Supraventricular arrhythmias are the most common by far (84.2%): 51.4% of patients had atrial fibrillation, 15.3% had atrial flutter; 12.9% had focal atrial tachycardia, 4.5% had junctional tachycardia. Of the ventricular arrhythmias (15.8%), there were 12 sustained ventricular tachycardias, 4 torsades de pointes and 1 ventricular fibrillation. The increased duration of hospital stay (10 +/- 6 days on average) is related not to age but to the type of arrhythmia (longer for ventricular arrhythmias) and to left ventricular dysfunction. The main complications of arrhythmias were cardiac failure (52.4%), neurological deficits (37.4%) and angina (18.6%). Electrocardiographic signs of atrioventricular block were present in 62% of cases and QRS changes in 47.3% of cases. Ventricular arrhythmias were more commonly associated with intraventricular conduction defects, signs of myocardial necrosis and prolongation of the QT interval; they were also common in patients with left ventricular dysfunction and when the left ventricle was dilated. The aetiology of ventricular arrhythmias was mainly iatrogenic (50%) and ischaemic (21.8%), whereas the aetiologies of the supraventricular arrhythmias were varied, 14.7% of cases being idiopathic. Conversion to stable sinus rhythm was obtained in half the patients. A pacemaker was implanted in 10.8% of cases. The hospital mortality was 4.9%.(ABSTRACT TRUNCATED AT 250 WORDS)