Acetazolamide for Hypoventilation in a Congenital Myopathy Patient with Advanced Heart Failure after a Heart Transplant; a Case Report

A 61-year-old man was admitted to our hospital for further treatment of worsening congestive heart failure with a mechanical ventilation. He had undergone a heart transplant due to dilated cardiomyopathy complicated with congenital myopathy at the age of 43. He had been suffering from cardiac allograft vasculopathy and had a history of right ventricular infarction complicated with acute inferior myocardial infarction when he was 59. Since then, refractory right-sided heart failure occurred and additional diuretics were required. A blood gas analysis on admission revealed mixed acid-base disorders with acidemia followed by respiratory acidosis and hypochloremic metabolic alkalosis due to diuretics and glucocorticoids. Advanced heart failure complicated with congenital myopathy could be the causes of the respiratory muscle failure and hypoventilation. The administration of acetazolamide is known to promote ventilator weaning and improve metabolic alkalosis, therefore, he was started on acetazolamide. His arterial blood gas analysis revealed that his pH and pCO₂ had decreased after the administration of acetazolamide. He recovered from refractory heart failure and was successfully extubated. We report a case of a congenital myopathy patient with advanced heart failure after a heart transplant treated by acetazolamide for hypoventilation.