High-density Grid and Magnetic Resonance Imaging Working Together

DOI: 10.19102/icrm.2021.120113S

GABRIEL MARTÍN, MD,¹ SANDRA CABRERA, MD,¹ ORIOL MARTÍN TEJADA, BS,¹ and AMIN ELAMRANI, MD, PhD¹

¹Hospital Universitario de Tarragona Joan XXIII, Tarragona, Spain

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KEYWORDS. Ischemic heart disease, ventricular tachycardia, voltage substrate mapping.

The authors report no conflicts of interest for the published content.
Address correspondence to: Gabriel Martín, MD. Email: gabims85@hotmail.com.

A 65-year-old man with arterial hypertension, dyslipidemia, and ischemic cardiomyopathy together with three-vessel coronary disease, for which surgical revascularization was performed in 1999, presented to the clinic. In the acute postoperative period, he had experienced a cerebrovascular accident with the sequelae of left hemiplegia, then an episode of cardiorespiratory arrest in June 2019, with an echocardiogram showing dilated ischemic cardiomyopathy with severe ventricular dysfunction, so a single-chamber automatic defibrillator was implanted. He was discharged with bisoprolol and amiodarone as antiarrhythmic treatment. In October 2020, he displayed episodes of sustained ventricular tachycardia (VT) treated with electrical cardioversion. His bisoprolol and amiodarone were exchanged for sotalol. Despite this change, however, the patient had new episodes of VT requiring implantable cardioverter-defibrillators shocks, so ablation was decided. Cardiac magnetic resonance imaging showed extensive areas of fibrosis in the basal and middle areas of the inferoseptal, inferolateral, and anterolateral segments of the left ventricle.

In November 2020, we performed mapping and ablation using a double-access (transseptal and retroaortic) approach. We used the Advisor™ HD Grid Mapping Catheter, Sensor Enabled™ for mapping and TactiCath™ SE catheter for ablation. Initially, we performed substrate mapping of the left ventricle, observing two channels matching the fibrosis zone previously revealed by magnetic resonance imaging (Figure 1). Subsequently, a hemodynamically unstable VT was induced with a 700-ms cycle (left bundle branch block, V4 transition, upper right axis). We positioned the Advisor™ HD Grid catheter in the area of interest, observing mid-diastolic signals on the inferobasal channel. We created ablation lines perpendicular to the diastolic channel (Video 1).

In this case, the Advisor™ HD Grid multipolar catheter allowed us to perform substrate mapping with a high density of points and short mapping time. In addition, we were also able to map the VT in a very short time (approximately three minutes) due to poor hemodynamic tolerance, which required electrical cardioversion.