Noninvasive and invasive evaluation of pulmonary arterial pressure in highlanders

The purpose of the present study was to evaluate Doppler echocardiography for the detection of pulmonary hypertension in high-altitude inhabitants. In total, 60 (55 male) patients aged 18-71 yrs were recruited from an ECG screening programme applied to 1,430 inhabitants living at an altitude of 2,500-3,600 m in Kyrgyzstan. Of these, 44 met ECG criteria for right ventricular hypertrophy. All underwent Doppler echocardiography followed by a cardiac catheterisation within 7 days of arrival in Bishkek (Kyrgyzstan; altitude 760 m). Pulmonary flow acceleration time and the maximum velocity of tricuspid regurgitation were measured. Sufficient quality tricuspid regurgitant jets were recovered in only 28% of the patients. Therefore, pulmonary artery pressure was estimated from the pulmonary flow acceleration time, which was recovered in 100% of the patients. It was found that 37 (62%) of the patients had pulmonary hypertension on echocardiography. Pulmonary hypertension was confirmed in 29 patients on catheterisation. Pulmonary hypertension was detected with 70% sensitivity and 88% specificity by echocardiography, as compared to 59% sensitivity and 81 % specificity by ECG. The correlation coefficient between echocardiography and catheterisation studies was r(2) = 0.78. It is concluded that a combination of ECG and echocardiography may be useful for screening high-altitude pulmonary hypertension.