Objective: To compare the cardiac structural and functional changes in high altitude heart disease (HAHD) patients with various grade of pulmonary artery hypertension (PAH).
Methods: Pulmonary artery systolic pressure (PASP) was evaluated by Doppler echocardiography in 100 patients with HAHD and patients were divided into 3 groups: mild (PASP: 30-49 mm Hg), moderate (PASP: 50-69 mm Hg) and severe (PASP ≥ 70 mm Hg) PAH and 50 patients without organic heart disease served as control group. Data on heart structure and function, heart rhythm and whole blood NT-proBNP were compared among groups.
Results: Right ventricular free wall was significantly thicker in moderate and severe PAH groups than in the control group [(5.10 ± 2.23) mm, (7.00 ± 2.29 ) mm vs.(3.70 ± 0.92)mm, P < 0.05], and in the severe PAH group than in mild and moderate PAH groups [ (7.00 ± 2.29) mm vs.(4.58 ± 1.80) mm, (5.10 ± 2.23) mm, all P < 0.05] and which was similar between the mild PAH group and the control group. Right ventricular inter diameter and right ventricular outflow tract inter diameter were significantly increased in all HAHD groups compared to the control group (all P < 0.01), and were also significantly increased in moderate and severe PAH groups than in the mild PAH group (P < 0.01). Thickness of interventricular septum was also significantly increased in HAHD patients than control group and in moderate and severe PAH groups than in moderate PAH group. Left atrium anterior-posterior diameter was significantly increased in HAHD patients than in control group and was similar among HAHD patients with various degree of PAH. Left ventricular ejection fraction (LVEF) was remarkably decreased in all HAHD groups than in the control group (P < 0.05) , moreover, LVEF was remarkably decreased in the moderate PAH group than in the mild PAH group (P < 0.05) . EF was similar between severe PAH group and moderate PAH group (P > 0.05) . There was no significant correlation between lgPASP and EF (R = -0.103, P = 0.298) . Compared with the control group, the incidences of decompensated heart failure and arrhythmia were remarkably increased in HAHD patients (P < 0.05) . The level of whole blood NT-proBNP increased in proportion to increasing PASP in HAHD patients (P < 0.05).
Conclusion: Increased PASP correlates with whole blood NT-proBNP and is an important determinant affecting the right ventricular structure and left and right ventricular function in HAHD patients.