Comparative prevalence of the fourth heart sound in hypertensive and matched normal persons

Occurrence of the fourth heart sound (S₄) as a physiologic phenomenon would limit its usefulness as a discriminator of disease. Reports of a high prevalence rate of S₄, as determined by auscultation and by phonocardiography in normal older persons, have provoked support and rebuttal. A blind, randomized phonocardiographic study of 50 normal and 50 age- and sex-matched hypertensive persons (mean age 53.9 ± 6.6 years) drawn from an outpatient screening clinic showed a high and virtually equal prevalence of S₄ (35 instances in each group) or possible S₄ (3 and 5 cases, respectively). It appears that in middleaged persons, as in older persons, there is a high and equal prevalence rate of S₄. Quantitative studies appear to be indicated to determine when this sound can be considered a presystolic gallop.