Shortness of breath, syncope, and cardiac arrest caused by systemic mastocytosis.

During a 3-month period, a 33-year-old man presented to the emergency department on 4 occasions with dyspnea, palpitations, and syncope. His initial presentation was accompanied by acute myocardial injury and ventricular fibrillation. An extensive evaluation spanned the 3 months and included echocardiography, cardiac catheterization, electrophysiology study, tilt-table evaluation, pulmonary angiography, electroencephalography, and serum and urine analysis.