(MedPage Today) -- Case Findings: A 44-year-old male presents with palpitations of 3 months' duration. At first they were occasional and occurred about twice a week. However, they have increased over time with frequency up almost hourly. He has noticed a recent 10-pound weight gain, increased lower extremity swelling, and inability to lie flat. He denies any fevers or chills. His last exercise stress test 5 months ago was normal. His current medications include metoprolol 12.5 mg twice daily, lisinopril 10 mg daily, aspirin 81 mg daily, furosemide 40 mg daily. There have been no recent readjustments in his medical regimen. BP in the clinic on presentation was 110/80 mm Hg, HR 60/min, and the patient was in no acute distress. JVD is elevated, with bilateral basal pulmonary crackles and bilateral lower extremity pitting edema. No heart murmurs are apparent on examination. No baseline is available. Blood work reveals Hemoglobin 14 mg/dl, Creatinine 1.4 mg/dL and BNP 5000. The clinician obtains a Transthoracic Echocardiogram that shows an ejection fraction of 30% with no significant valvular pathology. The patient's ECG is shown below. What is causing the patient's cardiomyopathy?
via Make the Diagnosis: Puzzling Palpitations