INTRODUCTION The number of humans living at high altitudes varies widely across different parts of the world. The findings of a study that employed a geographic information system-based approach to identify the number of people living at high altitudes estimated that more than 500 million, 81 million, and 14 million people reside at altitudes of more than 1.5 km, 2.5 km, and 3.5 km, respectively.1 Long-term high-altitude residents are prone to developing high-altitude pulmonary hypertension (HAPH) due to prolonged hypoxia, polycythemia, genetic susceptibility, and low ventilatory response to hypoxia.2 The findings of a cross-sectional study done among high-altitude residents of Himachal Pradesh and 3.23% of natives of Spiti Valley were diagnosed with HAPH.3 The objectives of the current article are to enlist the role of high altitude in the development of pulmonary hypertension and identify the utility of echocardiography in the detection of pulmonary hypertension. PULMONARY HYPERTENSION AND HIGH ALTITUDES Elevated pulmonary artery pressure at high altitude significantly contributes toward exercise intolerance, dyspnea, and gradual progression to right-heart dysfunction, which cumulatively reduces daily functioning and impairment of the quality of life.4 In severe cases, HAPH might lead to cor pulmonale and an augmented risk of heart failure and can become life-threatening.2 Moreover, residence in high-altitude areas can also increase the risk of pregnancy complications (such as preeclampsia, impaired uteroplacental oxygenation), which can eventually result in maternal pulmonary vascular stress.2,3 Similarly, chronic hypoxia at altitude affects fetal/newborn oxygenation and child growth, while occupations with repeated or prolonged altitude exposure experience intermittent hypoxia that predisposes them to long-term adverse cardiopulmonary consequences. ECHOCARDIOGRAPHY AND DETECTION OF PULMONARY HYPERTENSION Echocardiography is a non-invasive bedside screening tool, available in different settings (compared to right-heart catheterisation) and is cost-effective. It is an effective tool for population-level assessment of pulmonary hypertension, including longitudinal monitoring of disease progression or response to treatment.5 Multiple echocardiographic markers (viz. tricuspid regurgitation velocity, right ventricular dilatation and hypertrophy, abnormal right ventricle wall strain, etc.) have been identified as suggestive of pulmonary hypertension.5,6 In remote, resource-constrained, and high-altitude areas, rapid cardiac assessment can be done through handheld echocardiography devices, as depicted in a study done among intensive care unit patients in Turkey.7 Moreover, these handheld devices can facilitate serial assessments and triage decisions in remote high-altitude locations where healthcare facilities are not accessible.8 The existing guidelines and expert consensus support echocardiographic surveillance in defined high-risk populations (like BMPR2 mutation carriers, etc.) to detect pulmonary hypertension earlier.9,10 In fact, the approach to initiate population and clinic-based screening using echocardiography can improve the detection of unrecognized pulmonary hypertension among asymptomatic individuals.10 The results from a study done in a cohort living in Tibet revealed that the integration of echocardiographic parameters into predictive tools can significantly improve the identification of at-risk individuals and optimize screening strategies for pulmonary hypertension.11 CONCLUSION In conclusion, echocardiography is a cost-effective tool for the screening and timely detection of HAPH, which can prove to be lifesaving. The strategy of integrating echocardiography into routine screening can improve treatment outcomes and ensure equity for vulnerable high-altitude populations globally. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.
Shrivastava et al. (Wed,) studied this question.