Challenging Case: Right Ventricular Noncompaction or Multiple Diverticula?

Congenital ventricular diverticula, defined as a protrusion of the free wall of the ventricle including the endocardium, the myocardium, and the pericardium, behave similarly to an accessory ventricular chamber which contracts synchronously with the normal ventricles. A 42-year-old man presented with functional class II exertional dyspnea, fatigue, and flushing. Transthoracic echocardiography showed deep recesses with the outpouching of the basal-to-mid free wall and septal hyperkinesia. All the echocardiographic data were highly suggestive of isolated right ventricular (RV) noncompaction. Magnetic resonance imaging revealed multiple large outpouchings in the RV free wall, the RV outflow tract, and the basal anterior left ventricular wall, which had a wide neck and a normal contractility. The left ventricular myocardium was hypertrabeculated but did not fulfill the noncompaction criteria of cardiac magnetic resonance imaging. A muscular type of diverticula with prominent trabeculation and normal contractility, but without abnormalities, on both perfusion and gadolinium enhancement images was reported here. Such cases should not be mistaken for noncompaction or pseudoaneurysms.