Effects of postsystolic shortening and diastolic dyssynchrony on myocardial work in untreated early hypertension patients

Objectives: Myocardial work is estimated from noninvasive pressure-strain loop for advanced assessment of left ventricular function. Postsystolic shortening and diastolic dyssynchrony of left ventricle were noted early in hypertension. Their novel effects on myocardial work will be illustrated in this study. Methods: We recruited 43 newly diagnosed hypertensive patients (mean age 51.3 +/- 12.5 years, 55.8% men) and 32 age-matched and sex-matched healthy individuals (mean age 52.7 +/- 10.5 years, 37.5% men) as control. Pressure-strain loop derived myocardial work incorporated global longitudinal strain from speckle tracking echocardiography with brachial artery cuff pressure. Postsystolic strain index (PSI) was defined by the percentage of postsystolic shortening over peak strain. Diastolic dyssynchrony was assessed by standard deviation of time to peak early diastolic strain rate (TDSr-SD) of 18 segments, and maximal difference of time to peak early diastolic strain rate (TDSr-MD) between any two segments. Results: After multivariate regression analysis, global myocardial work index (GWI) was independently correlated with TDSr-SD (B = -0.498, P = 0.001) and TDSr-MD (B = -0.513, P = 0.001). Global myocardial constructive work (GCW) was independently correlated with TDSr-SD (B = -0.334, P = 0.025) and TDSr-MD (B = -0.397, P = 0.007). Global myocardial wasted work (GWW) was independently correlated with PSI (B = 0.358, P = 0.019). Global myocardial work efficiency (GWE) was lower in hypertensive patients than healthy control (P = 0.001). The untreated hypertensive patients were different from the healthy individuals with higher TDSr-SD, TDSr-MD, GWI, GCW, GWW, and PSI (all P < 0.05). Conclusion: In conclusion, the effect of diastolic dyssynchrony mainly influenced constructive work, whereas postsystolic shortening affected wasted work in early untreated hypertension.