Effect of aging on the cardiothoracic ratio of men

The potential usefulness of chest radiographs in the assessment of physical dimensions was examined in 243 men (age range 20-95 years) who had been followed up for an average of 12.3 years. From 1,124 of these films, measurements of cardiac diameter (CD) and thoracic diameter (TD) were made, and the cardiothoracic ratio (CTR) was calculated. Cross-sectional age differences were associated with a tendency toward increases in the CD and CTR throughout the lifespans of the 243 men, regardless of the presence or absence of heart disease. The thoracic diameter (TD) was greater in middle-aged than in young subjects, but less in the oldest than in the middle-aged subjects. Cumulative percentage curves for the CTR showed a shift to higher fiftieth to ninetieth percentile values with age. However, among the subjects free of heart disease, only one (age 95) had a CTR exceeding 50 per cent. Longitudinal analysis data agreed with the cross-sectional data. Forty-nine deceased subjects were matched with living subjects of the same heart disease classifications. Increases in the CD and CTR were predictive of death in the group with heart disease but not in the group without identifiable heart disease. An increase in CD was not correlated with an increase in systolic blood pressure. The decline in TD appeared to reflect a decline in rib-cage mobility with aging.