"From Surface to Substrate: Advancing VT Ablation Strategies for Deep Arrhythmic Substrates"-A Review of Emerging Techniques in Intramural Lesion Formation.

Figures

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  Fig. 1.. Fluoroscopic images exhibiting the ablation sites. ABL, the ablation catheter; CS, coronary sinus; Endo, the endocardial ablation catheter; Epi, the epicardial ablation catheter positioned within the great cardiac vein (GCV); HB, His bundle; LAO, left anterior oblique view; RAO, right anterior oblique view. This figure was cited from reference [7] with permission.

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  Fig. 2.. Idiopathic intramural left ventricular outflow tachycardia successfully eliminated by a simultaneous unipolar radiofrequency ablation from the endocardial and epicardial sites. (A) Electrocardiograms exhibiting the ventricular tachycardia (left panel) and cardiac tracings exhibiting the successful ablation sites (right panel). Note that the patient was also in atrial flutter. A far-field ventricular pre-potential was recorded from the ablation catheter positioned within the GCV (ABL-d). (B) Cardiac tracings exhibiting the effective (upper panel) and successful ablations (lower panel). An effective ablation was achieved by a radiofrequency ablation within the GCV, and the successful ablation was achieved by a simultaneous unipolar radiofrequency ablation from the GCV and aorto-mitral continuity (AMC). Note that the ventricular tachycardia terminated more quickly during the successful ablation than the effective ablation. ABL (abl), the ablation catheter positioned within the GCV (AMC); CS 1 to 5, the first (most distal) to fifth (most proximal) electrode pairs of the CS catheter; V-QRS, the local ventricular activation time relative to the QRS onset. The other abbreviations are as…

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  Fig. 3.. Fluoroscopic images exhibiting the unsuccessful (left panels) and successful bipolar ablation sites (middle panels) and late Gadolinium-enhanced cardiac magnetic resonance image exhibiting the radiofrequency lesions on the posterior papillary muscle (PPM) in the left ventricle (right panel). The yellow, blue, and red arrows indicate deeper scar on the septal and lateral sides, and the deepest scar in the middle of the PPM. Abl, transaortic ablation catheter; APM, anterior papillary muscle; ICE, intracardiac echocardiographic catheter; LV, left ventricle; RV, right ventricle. The other abbreviations are as in Fig. 1. This figure was cited from reference [43] with permission.

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  Fig. 4.. An activation map (left panel) and intracardiac echocardiographic (ICE) image (right panel) exhibiting the successful ablation site. The red and pink tags in the activation map indicate the ablation sites. INF, inferior; LAT, local activation time; MV, mitral valve. The other abbreviations are as in the previous figures. This figure was cited from reference [43] with permission.

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  Fig. 5.. Ablation strategies for ventricular tachycardias. (a) In radiofrequency ablation, the lesion is created underneath the tip of the catheter and does not reach the deep myocardium below the surface. (b) Transcoronary ethanol ablation can be used to create a lesion deep inside the myocardium, although the location of the lesion is limited by the distribution of the coronary artery branches. (c) In needle ablation, the lesion created underneath the tip of the catheter expands to the tip of the needle, which can be located deep inside the myocardium. This figure was cited from reference [65] with permission.

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  Fig. 6.. Decision making algorithm for VT ablation in intramural arrhythmia substrates.