Physiology of the third heart sound: novel insights from tissue Doppler imaging

J Am Soc Echocardiogr. 2008 Apr;21(4):394-400. doi: 10.1016/j.echo.2007.06.007. Epub 2007 Jul 20.


Background: The third heart sound (S(3)) is thought to be caused by the abrupt deceleration of left ventricular (LV) inflow during early diastole, increased LV filling pressures, and decreased LV compliance. We sought to determine whether the ratio of early mitral inflow velocity to diastolic velocity of the mitral annulus (E/E') could confirm the proposed mechanism of the S(3).

Methods: A total of 90 subjects underwent phonocardiography, echocardiography, tissue Doppler imaging, and left-sided heart catheterization.

Results: Phonocardiography detected an S(3) in 21 patients (23%). Subjects with an S(3) had lower ejection fraction (P = .0006) and increased E deceleration rate (P < .0001), E/E' (P < .0001) and filling pressures (P < .0001). The phonocardiographic S(3) confidence score correlated with E/E' (r = 0.46; P < .0001) and E deceleration rate (r = 0.43, P = .0001). Of the echocardiographic variables, only E/E' was independently associated with the S(3) confidence score (P = .009), independently of invasively determined LV filling pressures (P = .001).

Conclusions: The most important determinants of the pathologic S(3) are an increased deceleration rate of early mitral inflow, elevated LV filling pressures, and abnormal compliance of the myocardium as measured by tissue Doppler imaging.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Echocardiography, Doppler / methods*
  • Female
  • Heart Sounds
  • Heart Ventricles / diagnostic imaging
  • Heart Ventricles / physiopathology
  • Humans
  • Male
  • Middle Aged
  • Mitral Valve Insufficiency / diagnosis*
  • Mitral Valve Insufficiency / physiopathology*
  • Phonocardiography / methods*
  • Ventricular Dysfunction, Left / diagnosis*
  • Ventricular Dysfunction, Left / physiopathology*