RV contractility and exercise-induced pulmonary hypertension in chronic mountain sickness : a stress echocardiographic and tissue doppler imaging study
Fecha
2013-12Autor
Pratali, Lorenza
Allemann, Yves
Rimoldi, Stefano F
Faita, Francesco
Hutter, Damian
Rexhaj, Emrush
Brenner, Roman
Bailey, Damian M
Sartori, Claudio
Salinas Salmón, Carlos E
Villena, Mercedes
Scherrer, Urs
Picano, Eugenio
Sicari, Rosa
Metadatos
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Objectives.
The aim of this study was to evaluate right ventricular (RV) and left ventricular function
and pulmonary circulation in chronic mountain sickness (CMS) patients with rest and stress echocardiography compared with healthy high-altitude (HA) dwellers.
BAC KG ROU N D CMS or Monge’s disease is defined by excessive erythrocytosis (hemoglobin >21 g/dl
in males, 19 g/dl in females) and severe hypoxemia. In some cases, a moderate or severe increase in
pulmonary pressure is present, suggesting a similar pathogenesis of pulmonary hypertension.
M E T H O D S In La Paz (Bolivia, 3,600 m sea level), 46 CMS patients and 40 HA dwellers of similar age
were evaluated at rest and during semisupine bicycle exercise. Pulmonary artery pressure (PAP), pulmonary vascular resistance, and cardiac function were estimated by Doppler echocardiography.
R E S U LT S Compared with HA dwellers, CMS patients showed RV dilation at rest (RV mid diameter:
36 5 mm vs. 32 4 mm, CMS vs. HA, p ¼ 0.001) and reduced RV fractional area change both at
rest (35 9% vs. 43 9%, p ¼ 0.002) and during exercise (36 9% vs. 43 8%, CMS vs. HA,
p ¼ 0.005). The RV systolic longitudinal function (RV-S0) decreased in CMS patients, whereas it increased
in the control patients (p < 0.0001) at peak stress. The RV end-systolic pressure-area relationship, a load
independent surrogate of RV contractility, was similar in CMS patients and HA dwellers with a significant
increase in systolic PAP and pulmonary vascular resistance in CMS patients (systolic PAP: 50 12 mm Hg
vs. 38 8 mm Hg, CMS vs. HA, p < 0.0001; pulmonary vascular resistance: 2.9 1 mm Hg/min/l
vs. 2.2 1 mm Hg/min/l, p ¼ 0.03). Both groups showed comparable systolic and diastolic left ventricular
function both at rest and during stress.
CO N CLU S I O N S Comparable RV contractile reserve in CMS and HA suggests that the lower resting
values of RV function in CMS may represent a physiological adaptation to chronic hypoxic conditions
rather than impaired RV function. (Chronic Mountain Sickness, Systemic Vascular Function [CMS];
NCT01182792)