A morbidly obese patient may develop pulmonary hypertension as a complication of the obesity-hypoventilation syndrome (OHS).
Patient selection: morbid obesity
Criteria for pulmonary hypertension: mean pulmonary artery pressure (mPAP) >= 25 mm Hg (borderline if 21-24 mm Hg). A surrogate marker is a pulmonary artery systolic pressure greater than 45 mm Hg on echocardiography.
Possible mechanisms: obstructive sleep apnea, anorexigen use, obesity-related cardiomyopathy, thromboembolic disease, perivascular fat
Factors associated with pulmonary hypertension:
(1) greater daytime sleepiness
(2) no or limited use of noninvasive positive pressure ventilation (NPPV)
Clinical features:
(1) dyspnea on exertion
(2) fatigue
(3) chest pain
(4) syncope
(5) palpitations
(6) lower extremity edema
(7) murmur of tricuspid regurgitation
(8) deterioration in the 6-minute walking distance
(9) signs of right heart failure
The presence of pulmonary hypertension is associated with increased mortality. An obese patient with precapillary pulmonary hypertension has a lower mortality than for a non-obese patient with precapillary pulmonary hypertension.
Some patients may show improvement with significant weight loss. depending on the mechanism.
