Assessment of pulmonary pulse transit time with respect to diastolic and left atrial functions

Abstract

Pulmonary pulse transit time (pPTT) is a new marker of pulmonary hypertension (PH), which shows the time needed for the pulse wave to propagate from the right ventricular outflow tract to the left atrium (LA), but the relationship between pPTT and diastolic-LA function is almost unknown. In this study, we investigated the relationship between pPTT and LA-diastolic functions without PH. One hundred and fifty-six patients were included in this prospectively designed study. Comprehensive echocardiographic evaluation was performed and pPTT was recorded as the time from the beginning of the R-wave on the electrocardiogram to the peak of the S-wave in the pulmonary veins. We found a statistically significant correlation between LA total stroke volume, passive stroke volume, LA max area, LA volume (LAV) max and LA volume index (LAVi) max, and pPTT (r = 0.263** P = 0.003, r = 0.240** P = 0.007, (r = 0.339** P < 0.001, r = 0.307** P < 0.001 r = 0.199*, P = 0.024, LA total stroke volume, passive stroke volume, LA max area, LAV max, LAVi max respectively). Heart rate (HRt) and LAVi were detected as independent predictors of pPTT (hazard ratio: -2.290 P < 0.001, 95% confidence interval (CI): -3.274-1.306, HR: 0.461, P = 0.028, 95% CI: 0.050-0.873, HRt and LAVi, respectively). LAVi and HRt also affected pPTT. The dominant effect of HRt on pPTT should be considered in future studies. Larger studies are needed to determine the change and clinical significance of pPTT in left heart disease.