Utility of cardiovascular magnetic resonance in identifying substrate for malignant ventricular arrhythmias.
BACKGROUND
Sudden cardiac death (SCD) and sustained monomorphic ventricular tachycardia (SMVT) are frequently associated with prior or acute myocardial injury. Cardiovascular magnetic resonance (CMR) provides morphological, functional, and tissue characterization in a single setting. We sought to evaluate the diagnostic yield of CMR-based imaging versus non-CMR-based imaging in patients with resuscitated SCD or SMVT.


RESULTS
Eighty-two patients with resuscitated SCD or SMVT underwent routine non-CMR imaging, followed by a CMR protocol with comprehensive tissue characterization. Clinical reports of non-CMR imaging studies were blindly adjudicated and used to assign each patient to 1 of 7 diagnostic categories. CMR imaging was blindly interpreted using a standardized algorithm used to assign a patient diagnosis category in a similar fashion. The diagnostic yield of CMR-based and non-CMR-based imaging, as well as the impact of the former on diagnosis reclassification, was established. Relevant myocardial disease was identified in 51% of patients using non-CMR-based imaging and in 74% using CMR-based imaging (P=0.002). Forty-one patients (50%) were reassigned to a new or alternate diagnosis using CMR-based imaging, including 15 (18%) with unsuspected acute myocardial injury. Twenty patients (24%) had no abnormality by non-CMR imaging but showed clinically relevant myocardial disease by CMR imaging.


CONCLUSIONS
CMR-based imaging provides a robust diagnostic yield in patients presenting with resuscitated SCD or SMVT and incrementally identifies clinically unsuspected acute myocardial injury. When compared with non-CMR-based imaging, a new or alternate myocardial disease process may be identified in half of these patients.
Division of Cardiology, Department of Medicine, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada. james.white@lhsc.on.ca
James A
JA
White
Nowell M
NM
Fine
Lorne
L
Gula
Raymond
R
Yee
Allan
A
Skanes
George
G
Klein
Peter
P
Leong-Sit
Heather
H
Warren
Terry
T
Thompson
Maria
M
Drangova
Andrew
A
Krahn
D015331:Cohort Studies; D003287:Contrast Media; D016757:Death, Sudden, Cardiac / Q000473:pathology; D005260:Female; D019786:Gadolinium DTPA; D006352:Heart Ventricles / Q000473:pathology*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods; D008297:Male; D008875:Middle Aged; D009942:Organometallic Compounds; D011446:Prospective Studies; D015203:Reproducibility of Results; D017180:Tachycardia, Ventricular / Q000473:pathology*
D003287:Contrast Media; D009942:Organometallic Compounds; C090600:gadobutrol; D019786:Gadolinium DTPA