Shortened Pulmonary Pulse Wave Transit Time in High-Altitude Residents Without Pulmonary Hypertension: An Doppler Echocardiography Study.

Pulmonary pulse wave transit time (pPTT) in high-altitude residents without pulmonary hypertension had not been well characterized. The purpose of this study was to investigate alterations in pPTT among high-altitude residents through comparative analysis with low-altitude counterparts. Between October 2024 and June 2025, 47 consecutive high-altitude (>=4000 meters above sea level) residents without pulmonary hypertension were enrolled in this study. pPTT was quantified by Doppler echocardiography. The factors related to pPTT were determined by multiple linear regression analysis. High-altitude residents exhibited significantly larger right cardiac dimension and function, but significantly lower left ventricular mass index and ejection fraction (p < 0.05). Notably, pPTT was markedly shorter in high-altitude residents compared to their low-altitude counterparts (144.00 [109.00-193.00] vs. 193.50 [179.00-285.00] ms, p < 0.0001). Furthermore, among high-altitude residents, males had significantly shorter pPTT than females (123.00 [102.00-162.00] ms vs. 181.50 [148.00-241.00] ms, p < 0.0001). Stepwise multiple regression analysis indicated that altitude was the independent determinant of pPTT in high-altitude residents (p < 0.05). The observed reduction in pPTT among high-altitude dwellers without pulmonary hypertension suggests adaptive vascular changes-likely mediated by hypoxia-driven arterial remodeling and elastin degradation. These findings position pPTT as a promising indicator for detecting subclinical pulmonary vascular adaptations in chronic hypoxic environments.