Diastolic filling correlates of the third heart sound

Recently it has been suggested that sudden transmitral flow deceleration may play an important role in the production of the pathologic third heart sound (S3). In this study, we evaluated the pattern of left ventricular (LV) diastolic filling using transmitral pulsed Doppler in 15 patients with congestive cardiomyopathy (CCM) with an S3, 16 patients with CCM without and S3 and 33 normal patients. Both groups of CCM patients demonstrated shortening of the diastolic filling period, rapid filling period, and atrial filling period as compared to normals. CCM patients without S3s had similar diastolic filling parameters as compared to normals probably secondary to the high incidence of mitral regurgitation. CCM with S3s had an increased peak rapid filling velocity, a decreased peak atrial filling velocity, an increased peak rapid filling fraction (75 ± 27% vs. normals: 63 ± 12, p < 0.05), and increase in the mean deceleration rate (4.9 ± 1.5 m/s² vs. normals: 3.4 ± 1.2 m/s², p < 0.01), and a reduction in the pressure half time (58 ± 20 ms vs. normals: 73 ± 19 ms, p < 0.05) as compared to normal patients. The timing of the S3 preceded the peak deceleration rate by 70 ± 16 ms and occurred in all patients during rapid filling deceleration. Patients with CCM and S3s have LV diastolic filling patterns characterized by an increased rate and extent of rapid filling and an increased rate of flow deceleration during the latter portion of the rapid filling period.