THE ROLE OF CARDIAC MAGNETIC RESONANCE IMAGING IN PATIENTS WITH VENTRICULAR TACHYCARDIA AND ABSENCE OF CAD

Introduction: Cardiac Magnetic Resonance Imaging (CMRI) can identify myocardial infarction(MI) scars. Detection of unrecognized substrate has significant clinical implications as a most common substrate for reentrant ventricular arrhythmias.In the absence of coronary artery disease(CAD) MI is rare.
Hypothesis: The use of MRI in patients without CAD after cardiopulmonary resuscitacion(CPR) could identify the substrate dependente VT/VF mechanizn.
Methods: Planimetry of gadolinium late enhacement images obtained from CMRI was used to measure scar mass and surface area by two readers blinded to electrophysiological study (EPS) resuls.The mean scar size was defined as a percentage of left ventricular mass.
Resuts: 32 patients without CAD (24 had dilated cardiomyopathy , 6 hypertrophic obstructive cardiomyopathy a 2 normal hearts),  mean age 49+-17 years, 73 % male, mean EF 0.39 +-13, underwent  CMRI and EPS because documented ventricular arrhythmias

Parameters	VT/VF non inducible  ( n = 18)	VT/VF inducible ( n = 14)	p
LV EF ( %)	39 ± 13	37 ± 11	ns
Mean scar size (% LV mass)	5 ± 3	11 ± 10	< 0.01

Conclusions: In patients without CAD undergoing EP testing because of documented ventricular arrhythmias, the prevalence of scars is higher in pts with inducible VT/VF than in then in non-inducible population. Cardiac MRI should be considered in patients with no evidence of CAD presenting with unexplained spontaneous or inducible ventricular arrhythmias.