Browsing by Autor "Pratali, Lorenza"

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Exercise induces rapid interstitial lung water accumulation in patients with chronic mountain sickness
(Facultad de Medicina, Enfermería, Nutrición y Tecnología Médica, 2012) Pratali, Lorenza
Background: Chronic mountain sickness (CMS) is a major public health problem in mountainous regions of the world. In its more advanced stages, exercise intolerance is often found, but the underlying mechanism is not known. Recent evidence indicates that exercise-induced pulmonary hypertension is markedly exaggerated in CMS. We speculated that this problem may cause pulmonary fluid accumulation and aggravate hypoxemia during exercise. Methods: We assessed extravascular lung water (chest ultrasonography), pulmonary artery pressure, and left ventricular function in 15 patients with CMS and 20 control subjects at rest and during exercise at 3,600 m. Results: Exercise at high altitude rapidly induced pulmonary interstitial fluid accumulation in all patients but one (14 of 15) with CMS and further aggravated the preexisting hypoxemia. In contrast, in healthy high-altitude dwellers exercise did not induce fluid accumulation in the majority of subjects (16 of 20) (P5.002 vs CMS) and did not alter arterial oxygenation. Exercise-induced pulmonary interstitial fluid accumulation and hypoxemia in patients with CMS was accompanied by a more than two times larger increase of pulmonary artery pressure than in control subjects (P,.001), but no evidence of left ventricular dysfunction. Oxygen inhalation markedly attenuated the exercise-induced pulmonary hypertension (P,.01) and interstitial fluid accumulation (P,.05) in patients with CMS but had no detectable effects in control subjects. Conclusions: To our knowledge, these findings provide the first direct evidence that exercise induces rapid interstitial lung fluid accumulation and hypoxemia in patients with CMS that appear to be related to exaggerated pulmonary hypertension. We suggest that this problem contributes to exercise intolerance in patients with CMS.
RV contractility and exercise-induced pulmonary hypertension in chronic mountain sickness : a stress echocardiographic and tissue doppler imaging study
(Facultad de Medicina, Enfermería, Nutrición y Tecnología Médica, 2013) Pratali, Lorenza
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)