Microelectrode voltage mapping for substrate assessment in catheter ablation of ventricular tachycardia: A dual‐center experience

Abstract

Introduction:The assessment of the ventricular myocardial substrate critically depends on the size of mapping electrodes, their orientation with respect to wavefront propagation, and interelectrode distance. We conducted a dual-center study to evaluate the impact of microelectrode mapping in patients undergoing catheter ablation (CA) of ventricular tachycardia (VT).Methods: We included 21 consecutive patients (median age, 68 [12], 95% male) with structural heart disease undergoing CA for electrical storm (n = 14) or recurrent VT (n = 7) using the QDOT Micro catheter and a multipolar catheter (PentaRay, n = 9).The associations of peak-to-peak maximum standard bipolar (BV c ) and minibipolar (PentaRay, BV p ) with microbipolar (BV μMax ) voltages were respectively tested in sinus rhythm with mixed effect models. Furthermore, we compared the features of standard bipolar (BE) and microbipolar (μBE) electrograms in sinus rhythm at sites of termination with radiofrequency energy.Results: BV μMax was moderately associated with both BV c (β = .85, p < .01) and BV p (β = .56, p < .01). BV μMax was 0.98 (95% CI: 0.93−1.04, p < .01) mV larger than corresponding BV c , and 0.27 (95% CI: 0.16−0.37, p < .01) mV larger than matching BVp in sinus rhythm, with higher percentage differences in low voltage regions, leading to smaller endocardial dense scar (2.3 [2.7] vs. 12.1 [17] cm 2 , p < .01) and border zone (3.2 [7.4] vs. 4.8 [20.1] cm 2 , p = .03) regions in microbipolar maps compared to standard bipolar maps. Late potentials areas were nonsignificantly greater in microelectrode maps, compared to standard electrode maps. At sites of VT

Arrhythmic Mitral Valve Prolapse and Sports Activity: Pathophysiology, Risk Stratification, and Sports Eligibility Assessment

“…Although challenging, ablation of foci within the papillary muscles has been reported to be effective, and long-term success rates for PVC ablation in MVP range between 60 and 84% [ 52 , 53 , 68 , 69 , 96 , 97 , 103 , 104 , 105 ]. The development of catheters with contact force sensors, the use of intracardiac echocardiography, which improves catheter positioning on the PM, or cryoablation catheters that ensure better catheter stability during freezing, has led to improved success rates [ 103 , 104 , 105 , 106 ], and the continuous ideation and clinical validation of novel catheter platforms (i.e., catheters allowing ablation with different energy sources [such as electroporation], higher radiofrequency energy settings, improved irrigation) may further ameliorate procedural outcomes in future years [ 107 , 108 ].…”

Challenges in Ventricular Arrhythmia Ablation: Difficult Substrates and Advanced Ablation Strategies

“…Microelectrode mapping can overcome some limitations associated with standard bipolar mapping performed using classic diagnostic or ablation catheters. Utilizing electrophysiological signals recorded using catheters equipped with microelectrodes enables the recording of electrograms of higher specificity in regions characterized by low bipolar voltage during sinus rhythm [11]. Enhancing sampling density through the use of microelectrodes improves resolution and increases the probability of capturing near-field electrical information [12].…”

“…Enhancing sampling density through the use of microelectrodes improves resolution and increases the probability of capturing near-field electrical information [12]. Due to such features, microelectrode mapping surpasses standard bipolar mapping in its sensitivity to identify viable myocytes during sinus rhythm, potentially facilitating the recognition of proper targets for CA [11]. Nevertheless, classic endocardial mapping can be still limited if the substrate is located in the intramural area [13].…”

The age of computational cardiology and future of long-term ablation target prediction for ventricular tachycardia

“…With the rapid advancement in catheter design and technology [for instance, microelectrode electroanatomic mapping (EAM) for higher resolution maps] to get accurate information about the patient heart's electrophysiological condition invasively as well as the development of powerful algorithms like coherent mapping, LAT hybrid module and map replay modules from CARTO®3 (Biosense Webster Inc., Diamond Bar, CA, USA) that provide information critical to accurate VT ablation, these powerful tools can be used to validate our proposed PDE models ( 29 , 30 ). In the future, with more powerful computational resources and development in the field of AI-accelerated modelling, our proposed PDE models can be deployed to work in real-time, while simultaneously incorporating information from the EAM mapping systems and presenting the clinician with the best VT ablation strategy for each patient for long-term freedom from arrhythmia ( 31 ).…”