Catheter Ablation Of Idiopathic Ventricular Arrhythmias Research Articles

Catheter ablation of ventricular arrhythmias with QRS morphology resembling that of aortic sinus cusp arrhythmias: Significance of mapping the left pulmonary sinuscusp.

There is a close anatomical relationship between aortic sinus cusp (ASC) and the left pulmonary sinuscusp (LPSC). The study was to investigate the significance of mapping and ablation of LPSC for ventricular arrhythmias (VAs) with QRS morphology resembling that of ASC arrhythmias. In 33 consecutive patients undergoing successful catheter ablation of idiopathic VAs with ASC arrhythmia-like QRS morphology, LPSC was mapped carefully. Among the 33 patients studied, QRS morphology resembled that of arrhythmias of either right or left coronary cusp (LCC or RCC) origin in 17 and 16 patients, respectively. Out of 12 arrhythmias with the earliest potential in LCC during left-sided mapping, an earlier potential in LPSC than in LCC was recorded in 2 arrhythmias, the same earliest potential in LPSC as in LCC was recorded in 6 arrhythmias, and 5 (42%) were finally ablated successfully in LPSC using the reversed U curve. Out of 16 arrhythmias with the earliest potential in the RCC during left-sided mapping, an earlier potential in LPSC than in RCC was recorded in 4 arrhythmias, the same earliest potential in LPSC as in RCC was recorded in 3 arrhythmias, and 4 (25%) were finally ablated successfully in LPSC using the reversed U curve. For VAs with ASC arrhythmia-like QRS morphology, mapping in LPSC could have unique electrophysiologic characteristics, and some of them could be eliminated in LPSC using reversed U curve.

Anatomical Consideration in Catheter Ablation of Idiopathic Ventricular Arrhythmias.

Idiopathic ventricular arrhythmias (VAs) are ventricular tachycardias (VTs) or premature ventricular contractions (PVCs) with a mechanism that is not related to myocardial scar. The sites of successful catheter ablation of idiopathic VA origins have been progressively elucidated and include both the endocardium and, less commonly, the epicardium. Idiopathic VAs usually originate from specific anatomical structures such as the ventricular outflow tracts, aortic root, atrioventricular (AV) annuli, papillary muscles, Purkinje network and so on, and exhibit characteristic electrocardiograms based on their anatomical background. Catheter ablation of idiopathic VAs is usually safe and highly successful, but can sometimes be challenging because of the anatomical obstacles such as the coronary arteries, epicardial fat pads, intramural and epicardial origins, AV conduction system and so on. Therefore, understanding the relevant anatomy is important to achieve a safe and successful catheter ablation of idiopathic VAs. This review describes the anatomical consideration in the catheter ablation of idiopathic VAs.

Combined Approach Improves the Outcomes of Catheter Ablation of Idiopathic Ventricular Arrhythmias Originating from the Vicinity of Tricuspid Annulus

Ablation of idiopathic ventricular arrhythmias (VAs) originating from the vicinity of tricuspid annulus (TA) is often unsuccessful via inferior approach. We report the initial experience with catheter ablation of VAs arising from the vicinity of the TA via superior approach. We retrospectively studied 36 patients with VAs arising from the vicinity of TA who underwent ablation via transfemoral vein approach first. If patients had a failed prior ablation or VAs recurred during follow-up, they were referred for repeat ablation via transsubclavian vein approach. Among 36 patients, 11 (30.6%) patients (five failed during the index procedure and six recurred during the follow-up) were assigned to perform repeat ablation via the transsubclavian vein approach. After the final procedure two patients recurred again, and success rate increased from 69.5% (25/36) to 94.4% (34/36). Amplitudes of the atrial electrograms of all successful ablation sites via the transsubclavian vein approach was <0.036 mV. The transsubclavian vein approach plus transfemoral vein approach improve the outcomes of catheter ablation of idiopathic VAs originating from the vicinity of TA. The transsubclavian vein approach is a feasible alternative for VAs, which has been refractory to ablation via the inferior approach.

Electrocardiographic and Electrophysiological Characteristics in Idiopathic Ventricular Arrhythmias Originating From the Papillary Muscles in the Left Ventricle

Background— Idiopathic ventricular arrhythmias (VAs) can originate from the left ventricular papillary muscles (PAMs). This study investigated the electrophysiological characteristics of these VAs and their relevance for the results of catheter ablation. Methods and Results— We studied 19 patients who underwent successful catheter ablation of idiopathic VAs originating from the anterior (n=7) and posterior PAMs (n=12). Although an excellent pace map was obtained at the first ablation site in 17 patients, radiofrequency ablation at that site failed to eliminate the VAs, and radiofrequency lesions in a relatively wide area around that site were required to completely eliminate the VAs in all patients. Radiofrequency current with an irrigated or nonirrigated 8-mm-tip ablation catheter was required to achieve a lasting ablation of the PAM VA origins. During 42% of the PAM VAs, a sharp ventricular prepotential was recorded at the successful ablation site. In 9 (47%) patients, PAM VAs exhibited multiple QRS morphologies, with subtle, but distinguishable differences occurring spontaneously and after the ablation. In 7 (78%) of those patients, radiofrequency lesions on both sides of the PAMs where pacing could reproduce an excellent match to the 2 different QRS morphologies of the VAs were required to completely eliminate the VAs. Conclusions— Radiofrequency catheter ablation of idiopathic PAM VAs is challenging probably because the VA origin is located relatively deep beneath the endocardium of the PAMs. PAM VAs often exhibit multiple QRS morphologies, which may be caused by a single origin with preferential conduction resulting from the complex structure of the PAMs.

Idiopathic Left Ventricular Arrhythmias Originating Adjacent to the Left Aortic Sinus of Valsalva: Electrophysiological Rationale for the Surface Electrocardiogram

Idiopathic ventricular arrhythmias (VAs) may be amenable to catheter ablation within or adjacent to the left sinus of Valsalva (LSOV). However, features that discriminate these sites have not been defined. The purpose of this study was to determine the electrocardiographic and electrophysiological features of VAs originating within or adjacent to the LSOV. We studied 48 consecutive patients undergoing successful catheter ablation of idiopathic VAs originating from the left coronary cusp (LCC, n = 29), aortomitral continuity (AMC, n = 10) and great cardiac vein or anterior interventricular cardiac vein (Epi, n = 9). A small r wave, or rarely an R wave, was typically observed in lead I during the VAs and pacing in these regions. An S wave in lead V5 or V6 occurred significantly more often during both the VAs and pacing from the AMC than during that from the LCC and Epi (p < 0.05 to 0.0001). For discriminating whether VA origins can be ablated endocardially or epicardially, the maximum deflection index (MDI = the shortest time to the maximum deflection in any precordial lead/QRS duration) was reliable for VAs arising from the AMC (100%), but was less reliable for LCC (73%) and Epi (67%) VAs. In 3 (33%) of the Epi VAs, the site of an excellent pace map was located transmurally opposite to the successful ablation site (LCC = 1 and AMC = 2). The MDI has limited value for discriminating endocardial from epicardial VA origins in sites adjacent to the LSOV probably due to preferential conduction, intramural VA origins or myocardium in contact with the LCC.

Catheter ablation of ventricular arrhythmias originating in the vicinity of the His bundle: Significance of mapping the aortic sinus cusp

There is a close anatomical relationship between the right coronary cusp (RCC) and noncoronary aortic cusp (NCC) and sites recording His bundle (HB) activation in the right ventricle (RV). The purpose of this study was to examine the electrocardiographic and electrophysiological characteristics of ventricular arrhythmias (VAs) that originate near the HB and their potential as predictors of successful catheter ablation sites. We studied 147 consecutive patients undergoing successful catheter ablation of idiopathic VAs originating from the ventricular outflow tract of either ventricle or the HB region. In 13 (9%) patients with an origin in the RCC (n = 5), NCC (n = 1), or RV HB region (n = 7), the local RV activation in the HB region preceded the QRS onset. In two VAs originating from the RCC or NCC, failed radiofrequency applications near the HB region in the RV delayed the near-field ventricular electrogram and separated the far-field electrograms before the QRS onset in the HB region. The QRS transition in the precordial leads did not discriminate between an RV origin near the HB and an NCC or RCC origin. A QS pattern in lead aVL might be helpful for predicting an RCC origin. VAs originating near the HB have similar electrocardiographic and electrophysiological characteristics, regardless of whether the ablation site is in the RV or aortic sinuses because of the close anatomical relationship of these structures and rapid transseptal conduction. When RV mapping reveals an earliest ventricular activation in the HB region during VAs, mapping in the RCC and NCC should be added to accurately identify the site of origin.