Atrial Septal Defect as Unexpected Cause of Pulmonary Artery Hypertension

Methamphetamine abuse is an increasingly prevalent cause of pulmonary artery hypertension in the United States. Conversely, an atrial septal defect rarely presents late as pulmonary artery hypertension. We present the case of a 44-year-old methamphetamine abuser who had a 3-month history of worsening fatigue and near-syncope. She had elevated cardiac enzyme levels and right-sided heart strain. Angiographic findings suggested methamphetamine-induced pulmonary artery hypertension; however, we later heard S₂ irregularities that raised suspicion of an atrial septal defect. Ultimately, the diagnosis was pulmonary artery hypertension and a large secundum atrial septal defect with left-to-right flow. One year after defect closure, the patient was asymptomatic. In addition to discussing this unexpected case of a secundum atrial septal defect masquerading as methamphetamine-induced pulmonary artery hypertension, we briefly review the natural history of atrial septal defects and emphasize the importance of thorough examination in avoiding diagnostic anchoring bias.