Changes of Pre Ejection Period and Left Ventricular Ejection Time during Head up Tilt

Objective of the Study: Evaluate changes in Pre ejection period (PEP) and left ventricular ejection time (LVET) during head up tilt (HUT).

Methods: Twenty healthy male subjects were involved in this study, with mean age 29.3±5 years, mean body mass index (BMI) 21.3±0.2Kg/m2. Measurement of PEP, LVET of Doppler wave form of the aortic flow were done at supine, 30 and 60 degree HUT. Measurement of HR and BP were done at these positions of tilting. Comparison of changes of these variables at different degrees of HUT was done by paired T-Test.

Results: PEP values were significantly higher in 60 degree and 30 degree HUT than PEP values at supine position (p<0.0001). PEP values at 60 degree HUT were significantly higher than PEP values at 30 degree HUT (P=0.05).

LVET values were significantly lower at 60 degree and 30 degree HUT than values at supine position (p<0.001), and LVET values were significantly lower at 60 degree HUT than values at 30 degree HUT (p<0.001).

Conclusion: Key findings of PEP and LVET during HUT are progressive prolongation of PEP and shortening of LVET with increasing head up tilting.