In total, 493 ambulatory ECG recordings were studied. Women were preponderant (62.3% vs 37.7%). The average age of women and men patients was 66.9 and 64.7 years, respectively. Of the ECGs studied, 71.4% showed abnormalities and 28.6% appeared completely normal. Urgent abnormalities were noted in 1.4% of the recordings and significant abnormalities were present in 14.6%. Subjective complaints were noted in their logbooks by 18.8% of patients, but correlation of complaints with the electrocardiographic abnormalities was noted in only 1.2% of cases. The attending cardiologist concluded that 23.9% of the tests supported reasons of valid necessity for performance. Two hundred seventy-three recordings were classified as electrocardiographically abnormal (55.4%) but were clinically insignificant. General practitioners requested 59.8% of the tests versus 40.2% by specialists. Preponderant abnormalities included premature atrial and ventricular contractions, supraventricular tachycardia, and atrial fibrillation. Less frequent abnormalities included ventricular tachycardia (4.6%), atrial flutter, atrioventricular block, artificial pacemaker rhythm, nodal rhythm, and intermittent bundle branch block.