Background: This study explored phosphodiesterase type 5 (PDE5) inhibition as a strategy for treating high altitude pulmonary arterial hypertension (HAPH). Methods: 689 subjects (313 men) of mean (SD) age 44 (0.6) years living above 2500 m were screened for HAPH by medical examination and electrocardiography, and 188 (27%) met the criteria for right ventricular hypertrophy. 44 underwent cardiac catheterisation and 29 (66%) had a resting mean pulmonary artery pressure (PAP) above 25 mm Hg. 22 patients with a raised mean PAP were randomised to receive sildenafil (25 or 100 mg) or matching placebo taken 8 hourly for 12 weeks. Results: At 3 months, patients on sildenafil 25 mg 8 hourly (n = 9) had a significantly (p = 0.018) lower mean PAP (26.9 mm Hg) at the end of the dosing interval than those on placebo (n = 8) (95% CI 212.4 to 21.3). The treatment effect for sildenafil 100 mg 8 hourly (n = 5) compared with placebo was 26.4 mm Hg (95% CI 212.9 to 0.1). Both doses improved 6 minute walk distance, the lower dose by 45.4 m (95% CI 11.5 to 79.4; p = 0.011) and the higher dose by 40.0 m (95% CI 0.2 to 79.8; p = 0.049). Sildenafil was well tolerated. Necroscopic lung specimens from three subjects with HAPH showed abundant PDE5 in the muscular coat of remodelled pulmonary arterioles. Conclusions: PDE5 is an attractive drug target for the treatment of HAPH and a larger study of the long term effects of PDE5 inhibition in HAPH is warranted.
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 50.78.It is concluded that a combination of ECG and echocardiography may be useful for screening high-altitude pulmonary hypertension.
In recent years, high medical-social importance of most nosological types of cardiovascular diseases reflects an increase of surgery activity in this medical field. The enlargement of endovascular procedures is obvious and logical process. Today Endovascular therapy department of Scientific Research Institute of Heart Surgery and Organ Transplantation is one of the medical facility, where conducted scientific researches and new methods of diagnostics and treatment of vascular and cardiac diseases are being introduced.
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