The incidence of cardiovascular morbid events is higher in patients with left ventricular (LV) hypertrophy detected by electrocardiography than in those without LV hypertrophy.1 Hypertensive patients with electrocardiographic LV hypertrophy have more frequent and complex ventricular premature complexes (VPCs) than those without LV hypertrophy.2 Echocardiography has a greater sensitivity, specificity, positive predictive value and negative predictive value than electrocardiography in diagnosing LV hypertrophy.3 We performed a prospective study to correlate the prevalence of complex ventricular arrhythmias detected by ambulatory electrocardiographic monitoring with increased LV mass detected by technically adequate M-mode and 2-dimensional echocardiograms in unselected persons older than 62 years in a long-term health care facility. © 1987.