Prognostic role of isolated left ventricular diverticuli detected by cardiovascular magnetic resonance

Background Isolated left ventricular diverticulum, a rare cardiac malformation, can be asymptomatic or associated with systemic embolization, ventricular arrhythmias, or sudden death. MRI allows for the detection of diverticuli and the distinction between fibrous and muscular types using the delayed enhancement technique. Aim To evaluate the prevalence of left ventricular diverticuli in nonselected consecutive patients who had undergone MRI. Methods In a total of 3273 consecutive patients who had undergone cardiac magnetic resonance from January 2001 to December 2005, isolated ventricular diverticuli were found in 25 patients (0.76%), with no apparent cardiac disease. A delayed enhancement technique was used to distinguish fibrous and muscular types. The prevalence of complications was evaluated with a follow-up of 52±8 months. Results The site of the left ventricular diverticuli was the septum in 10 (37%) cases, inferior wall in 6 (22%) cases, lateral wall in 4 (15%) cases, and apical in 7 (26%) cases. In two cases, multiple diverticuli were found. In delayed enhancement images, a partial or total fibrous diverticulum was found in 6 (24%) patients. At follow-up, clinical complications were recorded in 6 (24%) patients; 2 (8%) patients had arrhythmic complications and 4 (12%) patients had embolic complications of presumed cardiac origin. In addition, two patients (8%) had nonsustained ventricular tachycardia diagnosed using 24-h ECG Holter monitoring. Fibrous type diverticuli were associated with a higher incidence of arrhythmic complications than the muscular type. Conclusion The prevalence of isolated ventricular diverticuli detected by MRI is higher than that previously reported with other imaging techniques. Fibrous diverticuli are associated with a higher incidence of arrhythmic complications.