A 29-year-old man presents with a 2-week history of progressive exertional dyspnea and chest discomfort. He reports a flu-like illness preceding his symptoms by three weeks. Vital signs are notable for a heart rate of 105/min and blood pressure of 110/70 mm Hg. Physical examination reveals bibasilar crackles and a soft S3. Laboratory studies show mildly elevated troponin I. ECG demonstrates diffuse ST-segment elevation without reciprocal changes. Transthoracic echocardiogram reveals a left ventricular ejection fraction of 35% with global hypokinesis. To clarify the etiology, cardiac MRI with late gadolinium enhancement (LGE) is performed and shows patchy subepicardial enhancement in the lateral wall. Right heart catheterization demonstrates right atrial pressure of 9 mm Hg, right ventricular pressure of 35/10 mm Hg, pulmonary capillary wedge pressure of 14 mm Hg, and a cardiac index of 2.0 L/min/m2. Which of the following is the most likely diagnosis?