Late Diastolic dyssynchrony: A novel method to determine RV function in pulmonary hypertension?

Background/Aims: Right intraventricular systolic dyssynchrony has prognostic significance in pulmonary hypertension. We evaluated the significance of dyssynchronous measurements of the right ventricle (RV) in diastole and systole in idiopathic pulmonary arterial hypertension (IPAH). Methods: Speckle tracking analysis of cardiac function in patients with IPAH was performed. Longitudinal strain (myocardial wall deformation) measurements of the RV were recorded. These included time to peak systolic strain and rate, greatest strain, early diastolic and late diastolic strain rates. The standard deviation of timings across the four segments (SD4), mid and basal, of the RV free wall and interventricular septum were calculated in systole and diastole. These measurements were correlated against prognostic markers from right heart catheter data, NT-proBNP, and magnetic resonance (MR) imaging. Results: Late diastolic dyssynchrony, measured by the SD4 of time from greatest strain, representing peak contraction, to late diastolic strain rate, representing atrial filling, correlated significantly with NT-proBNP (p Conclusion: This SD4 measurement of right intraventricular late diastolic dyssynchrony, shows stronger correlation with prognostic factors, such as RVEF and CI than systolic measurements. This study identifies that a greater understanding of diastolic function and its contribution to cardiac performance in pulmonary hypertension is crucial.