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Diastolic Left‐to‐Right Shunting in Uncomplicated Ventricular Septal Defect
Author(s) -
KRONZON ITZHAK,
CZINER DAVID G.,
TUNICK PAUL A.
Publication year - 1995
Publication title -
echocardiography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.404
H-Index - 62
eISSN - 1540-8175
pISSN - 0742-2822
DOI - 10.1111/j.1540-8175.1995.tb00836.x
Subject(s) - diastole , cardiology , ventricle , medicine , shunt (medical) , doppler echocardiography , shunting , doppler effect , flow velocity , hemodynamics , blood pressure , physics , astronomy , relaxation (psychology)
The systolic left‐to‐right shunt in patients with uncomplicated ventricular septal defect is associated with a classic loud murmur, and is well described. The additional diastolic left‐to‐right shunt, always silent, is less well recognized. Left‐to‐right diastolic shunt flow is directly related to the defect size, to the diastolic pressure gradient between the left and right ventricle, and to the duration of diastole. The purpose of this study was to evaluate by Doppler echocardiography the duration, magnitude, and flow velocity characteristics of the diastolic left‐to‐right shunt. There were 30 adult patients with uncomplicated ventricular septal defects studied by color, pulsed, and continuous wave Doppler echocardiography. In each patient, the uncomplicated ventricular septal defect was visualized by two‐dimensional echocardiography and/or Doppler echocardiography, and the systolic and diastolic left‐to‐right shunt flow was identified by Doppler echocardiography. Accurate Doppler flow velocity peaks twice, in beginning and again at end diastole. The mean diastolic flow velocity was 0.5–1.5 msec (average 0.83 ± .22 msec). This flow velocity was markedly lower than the mean systolic shunt flow velocity (2.4–5.3 msec, average 3.8 ± .7 msec). The Doppler flow velocity integral was 0.17–0.64 m (average 0.36 ± 0.14), markedly smaller than the systolic flow velocity integral (0.8–1.8 m, average 1.3 ± 0.3). The diastolic left‐to‐right shunt flow was 12–41% (average 21 ± 8) of total (systolic and diastolic) shunt flow. In conclusion: Diastolic left‐to‐right shunts can be identified in all patients with uncomplicated ventricular septal defects, and analyzed in the majority of patients. A significant degree of the left to right shunting in uncomplicated ventricular septal defects occur during diastole.