Hypercapnia Induced by Pectus Excavatum and Cardiomegaly

Key Words: pectus excavatum, cardiomegaly, hypercapniaAn 89-year-old man was admitted with acute decompensated heart failure, which was possibly due to nonischemic cardiomyopathy.Upon admission, arterial blood gas analysis demonstrated acute hypercapnia with pH 7.17, PCO 2 91.9 mm Hg, and HCO 3 33.6 mmol/L.Transthoracic echocardiography revealed that the left ventricular, end-diastolic diameter had increased to 55 mm.Computed tomography demonstrated heart enlargement and its dislocation leftward by the pectus excavatum, causing almost complete occupancy of the left thoracic cavity by the heart and a disturbance in left lung expansion (Figure 1).His hypercapnia resolved with intravenous furosemide and noninvasive positive pressure ventilation along with cardiomegaly improvement.Hypercapnia caused by the lung expansion restriction by the pectus excavatum and cardiomegaly was finally diagnosed.Pectus excavatum is a common deformation caused by depression of the anterior chest wall into the thoracic cavity.Although it is usually asymptomatic, severe cardiomegaly associated with this condition can decrease forced vital capacity by disrupting lung expansion (1), (2) , potentially leading to a lifethreatening hypercapnia.