In a general population sample of 5,209 in Framingham, Mass., the prevalence of left ventricular hypertrophy by electrocardiogram was commoner in men than in women, and it rose with age. In 12 years 3.0% developed a definite and 4.5% developed a possible pattern. Incidence was strongly related to blood pressure, but less than half of those with the pattern had definite heart enlargement on X ray. Some 55% of the cases of congestive heart failure and 27% of the coronary heart disease cases were either preceded or followed by the pattern.
Prognosis was very grave. A definite pattern even when unassociated with coronary heart disease, congestive heart failure, or rheumatic heart disease resulted in mortality of 59% within 12 years. One in 2 men over 45 years old died within 8 years of developing a definite pattern. Altogether, 44% of the 264 cardiovascular deaths were preceded by a definite or possible finding of left ventricular hypertrophy by electrocardiogram.