Provokable left ventricular outflow tract obstruction in a patient without hypertrophy.

BACKGROUND: A 61-year-old man presented with shortness of breath and chest pain on exertion. He had been diagnosed as having hiatus hernia 2 years previously and was taking proton-pump inhibitors as necessary. He had a family history of ischemic heart disease and subarachnoid hemorrhage. INVESTIGATIONS: Physical examination, electrocardiography, echocardiography, cardiopulmonary exercise testing, coronary angiography, transoesophageal echocardiography, stress echocardiography. DIAGNOSIS: Provokable left ventricular outflow tract obstruction without electrocardiographic abnormalities or left ventricular hypertrophy on echocardiography. MANAGEMENT: Pharmacological therapy (atenolol 50 mg daily, disopyramide 250 mg twice daily), dual-chamber pacemaker implantation.