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. Author manuscript; available in PMC: 2017 Aug 1.
Published in final edited form as: Cardiol Clin. 2016 Aug;34(3):451–472. doi: 10.1016/j.ccl.2016.04.005

Figure 8.

Figure 8

The systolic (S) to diastolic (D) time ratio from tricuspid regurgitation velocity can be measured as a measure of right ventricular function. An increase in the S/D ratio predicts worse outcome in children with PH.

Alkon et al in 2010 used an simple measure of systolic to diastolic time (S/D) ratio from the TR jet to evaluate pediatric PH patients and found that as the RV function worsens, the systolic portion of the cardiac cycle lengthens leading to an increased S:D ratio. S/D ratio was found to be higher in PH patients compared to controls and is associated with worse RV FAC change, worse hemodynamics by cath, shorter 6 minute walk test, and worse clinical outcomes independent of PVR or pressures. S/D ratio < 1 is associated with low risk of negative outcome and S/D ratio > 1.4 was associated with high risk of negative outcome.

From Alkon J, Humpl T, Manlhiot C, et al. Usefulness of the right ventricular systolic to diastolic duration ration to predict functional capacity and survival in children with pulmonary arterial hypertension. Am J Cardiol 2010;106(3):430–6; with permission.