Added value of cardiac magnetic resonance in etiological diagnosis of ventricular arrhythmias.
BACKGROUND
Cardiac magnetic resonance (CMR) imaging is increasingly important in the diagnostic work-up of a wide range of heart diseases, including those with arrhythmogenic potential.


OBJECTIVE
To assess the added value of CMR in etiological diagnosis of ventricular arrhythmias after an inconclusive conventional investigation.


METHODS
Patients undergoing CMR between 2005 and 2011 for investigation of ventricular arrhythmias were included (n=113). All had documented arrhythmias. Those with a definite diagnosis from a previous investigation and those with evidence of coronary artery disease (acute coronary syndrome, typical angina symptoms, increase in biomarkers or positive stress test) were excluded. CMR results were considered relevant when they fulfilled diagnostic criteria.


RESULTS
Of the 113 patients, 57.5% were male and mean age was 41.7 ± 16.2 years. Regarding the initial arrhythmia, 38.1% had ventricular fibrillation/sustained ventricular tachycardia (VF/VT) and 61.9% had less complex ventricular ectopy. CMR imaging showed criteria of a specific diagnosis in 42.5% of patients, was totally normal in 36.3%, and showed non-specific alterations in the remainder. In VF/VT patients, specific criteria were found in 60.4%, and in 31.4% of those with less complex ectopy. The most frequent diagnoses were arrhythmogenic right ventricular dysplasia, ventricular non-compaction and myopericarditis. It is worth noting that, although there was no evidence of previous coronary artery disease, 6.2% of patients had a late gadolinium enhancement distribution pattern compatible with myocardial infarction.


CONCLUSIONS
CMR gives additional and important information in the diagnostic work-up of ventricular arrhythmias after an inconclusive initial investigation. The proportion of patients with diagnostic criteria was 42.5% (60.0% in those with VF/VT), and CMR was completely normal in 36.6%.
Serviço de Cardiologia, Hospital de Santarém, Santarém, Portugal. Electronic address: ncabanelas@gmail.com.
Nuno
N
Cabanelas
Maria João
MJ
Vidigal Ferreira
Paulo
P
Donato
António
A
Gaspar
Joana
J
Pinto
Filipe
F
Caseiro-Alves
Luís Augusto
LA
Providência
D000328:Adult; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D012189:Retrospective Studies; D017180:Tachycardia, Ventricular / Q000175:diagnosis* / Q000209:etiology*; D014693:Ventricular Fibrillation / Q000175:diagnosis* / Q000209:etiology*; D018879:Ventricular Premature Complexes / Q000175:diagnosis* / Q000209:etiology*
Arrhythmogenic substrate; Cardiac magnetic resonance; Diagnosis of ventricular arrhythmias; Etiologia de arritmias ventriculares; Ressonância magnética cardíaca; Substrato arritmogénico