A Case of Isolated Congenital Left Ventricular Diverticulum with Acute Myocarditis

Isolated congenital left ventricular diverticulum is a rare congenital heart malformation with an incidence ranging from 0.05% to 0.4%[1]. This lesion was defined by a protrusion of the threelayer left ventricular free walls, and was first described in 1838[1]. Multiple clinical phenotypes were presented in literature, such as chest pain, arrhythmia, systemic embolisation, valve regurgitation, ventricular wall rupture and sudden death. However, most patients would be asymptomatic and detection usually occurred by accident, often during echocardiography. Cases of left ventricular diverticulum accompanying myocarditis were rarely reported. A nine-year-old boy diagnosed with left ventricular diverticulum accompanying acute myocarditis underwent surgical management and was followed up for two years after surgery in our hospital. We proposed that conventional surgical treatments are not suitable for our patient during the period of acute myocarditis, except for heart transplant. A nineyear-old boy who had been suffering from palpitation and edema fo half a month was referred to our hospital in 2010. In physical examination a mild systolic heart murmur was auscultated at the apex and the liver was palpated 4 cm below the subcostal margin. Echocardiography revealed four enlarged cardiac chambers and a diverticulum, 55 mm in diameter and 70 mm in length, without other congenital cardiac malformations. Mild mitral valve regurgitation was detected by color Doppler flow imaging. The left ventricular ejection fraction (EF) and fractional shortening (FS), which mirrored cardiac function, was 33% and 16%, respectively. Magnetic resonance imaging confirmed that the diverticulum with a narrow short neck was connected to the left ventricle. The electrocardiogram showed a few ventricular premature beats. No evidence showed that the patient had a recent viral infection, particularly influenza. The surgical procedure was performed. The diverticulum was observed to be full of thrombi upon incision. After cleaning the thrombi, the opening (8 mm × 8 mm) to the left ventricle was sewn and closed by a Teflon patch with 4/0 prolene through the incision. A myocardial specimen was harvested and sent for pathological examination. The examination revealed an active lymphocytic myocarditis with cell necrosis and thrombi. Upon surgical manipulation, the echocardiograph indicated exclusion of the diverticulum with only mild mitral valve regurgitation. The postoperative course was uneventful and vasoactive drugs, like dopamine (6 μg/kg·min-1) and adrenaline (0.05 to 0.1μg/kg·min-1), were administrated for five days. The size of the four cardiac chambers did not change compared with their size before surgery during the two-year follow-up period; whereas more mitral and tricuspid valve regurgitations were observed. Cardiac function was significantly weaker (EF: 28%, FS: 13%) (Table 1 and Fig. 1). The patient suffered from chronic heart failure and had to