The Frank vectorcardiogram in coal miner's pneumoconiosis*

Summary The relationship of the Frank vectorcardiogram to right ventricular hypertrophy in 22 coal miners with simple pneumoconiosis was investigated. Assessment of subjects without overt evidence of right ventricular enlargement was performed to delineate initial hemodynamic changes in the right ventricle as reflected in the vectorcardiogram. The parameters chosen failed to show evidence of right ventricular hypertrophy when right ventricular peak systolic pressures ranged from 20–38 mm.Hg. The results indicate that anatomic right ventricular enlargement is detected in the vectorcardiogram after pressure overloading of the right ventricle and not after the earlier stage of volume overloading.