CMR evaluation in patients with high grade ventricular arrhythmias

Purpose

To assess by cardiac-MR the prevalence of myocardial alterations in arrhythmic patients.

Materials and methods

43 patients with non ischemic ventricular arrhythmias. Premature ventricular complexes had left bundle branch block morphology (LBBB) in 29 cases, in 7 a right bundle branch block contour (RBBB) and 7 had polymorphic patterns(PV). US was negative in 78.4% of patients, while CMR was negative in only 13% of patients. Studies were performed on a 1.5 MR scanner with Cine sequences (Fastcard or FIESTA), bb-FSE and IR-prep FGRE 15 minutes after injection of 0.2 mmol/Kg of Gd-DTPA.

Results

CMR found a high prevalence of morphological, signal intensity and functional myocardial abnormalities. RV dilatation was found in 85% of patients with PV arrhytmias, 48.3% of patients with LBBB morphology, 12.5% of patients with RBBB morphology. LV dilatation was present in 28.6%, 25% and 24.1% of patients with LBBB, PV and RBBB type arrhytmias respectively. RV wall motion abnormalities were identified in 50% and 36.7% of patients with PV and LBBB pattern respectively while LV motion abnormalities in 25% and 10.3%. Free wall RV signal/thickness abnormalities were found in 23.3% of patients; LV signal abnormalities were found in 11.6% of patients.

Seven patients underwent myocardial biopsy: 5 positive for myocarditis, 1 positive for ARVD, one had a negative biopsy.

Conclusion

In patients with primary ventricular arrhythmias MR documented high prevalence (87%) of morphological, signal intensity and wall motion abnormalities even with negative echocardiogram.