Electrophysiological Predictors of Transplantation and Left Ventricular Assist Device-Free Survival in Patients With Nonischemic Cardiomyopathy Undergoing Ventricular Tachycardia Ablation

Abstract

Wider native QRS duration, greater bipolar scar percentage, VT storm, and lower LVEF are potent predictors of time to death, transplantation, or LVAD. By combining these variables into an "electrophysiological risk score," patient risk can be refined.

Imaging characteristics of papillary muscle site of origin of ventricular arrhythmias in patients with mitral valve prolapse

“…In all patients, a 3D electroanatomic map (CARTO, Biosense Webster, Diamond Bar, CA, USA) was created during sinus or paced rhythm to identify areas of low voltage and abnormal electrograms consistent with scar, using a 3.5‐mm open irrigation tip catheter (Navistar Thermocool, Biosense Webster) as previously described . An 8Fr (AcuNav, Siemens Medical Solutions, Mountain View, CA) or 10Fr ICE probe (SoundStar, Biosense Webster) was advanced into the right atrium and right ventricle to define the anatomy, facilitate mapping, and assess contact during ablation.…”

Three‐dimensional myocardial scar characterization from the endocardium: Usefulness of endocardial unipolar electroanatomic mapping

“…26,28,31 Myocardial fibrosis produces a leftward shift in the F I G U R E 6 Adjustment of the endocardial unipolar voltage slider bar from the reference 8.3 mV value in different pathological scenarios. 26,28,31 Myocardial fibrosis produces a leftward shift in the F I G U R E 6 Adjustment of the endocardial unipolar voltage slider bar from the reference 8.3 mV value in different pathological scenarios.…”

“…A, In the setting of LV hypertrophy (LV thickness 14 mm), adjustment of the UNIP voltage slider bar from the standard cutoff of 8.3 to 10 or even 12 mV results in clearer representation of a localized confluent area of epi scarring on bipolar voltage mapping and MR imaging that was only suggested at the conventional 8.3 mV value. 31 This superiority of endo BP mapping over UNIP mapping suggests that a nonischemic disease process demonstrating sizable endo BP scar is associated with a great likelihood of mechanical failure and more extensive/irreversible disease. The size and characteristics of the intervening tissue must be considered in using UNIP endo signals to identify epicardial bipolar scar.…”

“…B, In a patient with severe diffuse cardiomyopathy and VT and in presence of endo BP scarring, adjustment of the slider bar from less than 8.3 mV down to less than 5 mV results in a more accurate estimation of the confluent epi BP scar area (black circles represent sites of abnormal electrogram). 10,31,54,57,58 Most VTs in LV NICM patients originate from the basal free wall and septum and apical VTs in the absence of bundle branch reentry also signal more extensive NICM substrate and poor clinical outcome and are typically associated with more extensive endo UNIP and BP scar areas. BP, bipolar; endo, endocardium; epi, epicardium; LV, left ventricle; MR, magnetic resonance; UNIP, unipolar; VT, ventricular tachycardia shift in the endo UNIP voltages, 5.4% vs 12.6% (P < 0.01), which is associated with a very modest but diffuse interstitial fibrosis.…”

“…The size and characteristics of the intervening tissue must be considered in using UNIP endo signals to identify epicardial bipolar scar. 31,54 Regardless of its limitations for identifying intramural and epi substrate in ICM due to typical presence of prominent endo scarring, endo UNIP EAVM can still be a useful indicator of a greater degree and irreversibility of LV dysfunction in this setting. 26 A sizable area (>145 cm 2 and/or ≥54% of the total endo LV surface) of endo UNIP voltage amplitudes below the conventional 8.3 mV cutoff value was associated with cardiac death and VT recurrence in patients with NICM.…”