The Lead Episode 95: Personalized voltage maps guided by cardiac magnetic resonance in the era of high-density mapping-Heart Rhythm Journal (Visual Aid)

Heart Rhythm Journal (Visual Aid)

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The study focuses on improving ventricular tachycardia (VT) substrate mapping using personalized voltage maps guided by Cardiac Magnetic Resonance (CMR) imaging. Traditional threshold settings used for voltage mapping, defined by amplitudes between 0.5 and 1.5 mV on electroanatomical maps, have shown limitations due to their inability to accurately identify VT substrates like scar and conducting channels (CCs) associated with VT circuits. This study customizes these voltage thresholds based on CMR findings, utilizing high-density mapping catheters for a detailed anatomical characterization of endocardial substrates.<br /><br />The study included 32 patients with scar-related VT undergoing mapping using CMR-guided and standard voltage thresholds to identify deceleration zones (DZs) and VT isthmus sites during ablation procedures. Results demonstrated that personalized CMR-guided voltage maps offered greater accuracy in identifying BZs and correlating voltage channels with VT circuits, with a substantial increase in the correlation rate to 75% from a previous 44.2%, compared to using fixed thresholds.<br /><br />The research suggests using CMR to adjust voltage mapping standards offers better identification of VT-related substrates, improving the precision of VT ablation strategies. One significant finding was the high variability in optimal voltage thresholds across individuals, reinforcing that a fixed threshold is not universally effective. This adjustment in mapping techniques aims to lower VT recurrence rates by enhancing the accuracy of target identification during ablation procedures.<br /><br />CMR provides a detailed view of scar tissue characteristics, highlighting its relation to electrical activity and enabling more tailored ablation strategies. The study supports incorporating advanced CMR-enabled high-density mapping to precisely define electrical substrates integral to VT, suggesting clinical guideline updates to improve patient outcomes in VT management.

Keywords

ventricular tachycardia

VT substrate mapping

personalized voltage maps

Cardiac Magnetic Resonance

CMR imaging

endocardial substrates

ablation procedures

voltage thresholds

scar tissue

high-density mapping