How to map and ablate left ventricular summit arrhythmias

Bipolar radiofrequency catheter ablation between the left ventricular endocardium and great cardiac vein for refractory ventricular premature complexes originating from the left ventricular summit

“…First, bipolar RFCA between the LV endocardium and GCV was effective for refractory VPCs originating from the LV summit. In general, unipolar RFCA from the GCV and anterior intraventricular vein was attempted for VAs originating from the LV summit; however, it is sometimes unsuccessful because of intramural origin of the VAs . There are some reports on bipolar ablation for VAs originating from the LV summit; however, the methods are not established.…”

Effect of radiofrequency on epicardial myocardium after ablation of ventricular arrhythmias from within coronary sinus

“…The RF ablation from within the CVS has been increasingly performed for IVAs as well. Unfortunately, a successful ablation may not be always possible due to various reasons, such as inaccessibility of CVS due to anatomical obstacles or anomalies (i.e., tortuosity, coronary sinus ostial obstruction, well‐developed Vieussens valve which was reported to be present in 15% of patients, or small GCV/AIV/side branch diameter), or inability to deliver sufficient ablative energy at the site of the earliest activation (presence of thick fat layer, high impedance, or rapid rise in temperature during ablation, unfavorable course of the vein which is far away from the true epicardial focus or close proximity of major epicardial coronary arteries <5 mm) . Specific maneuvers can be used to overcome these obstacles.…”

“…Intravenous unfractionated heparin was administered to maintain an activated clotting time > 250 seconds. Electroanatomic mapping and ablation methods have been previously described . Briefly, point‐by‐point activation mapping was performed to create electroanatomic maps of the RVOT, supra‐ and infravalvular LVOT, and CSV in patients with spontaneously induced IVAs.…”

“…IVAs arising from LVS are not rare with a prevalence of 9–12%, and they can be ablated from anatomically adjacent sites, such as distal CSV, i.e., GCV/AIV, aortic sinuses of Valsalva, subvalvular endocardial LVOT, or the most posterolateral portion of the right ventricular outflow tract (RVOT) or by percutaneous epicardial route which is seldom successful due to close proximity to major coronary arteries and/or presence of overlying epicardial fat . The ablation of these IVAs is usually performed inside the coronary venous system (CVS), but unfortunately, in spite of recent advances in the ablation technologies, detailed knowledge of complex regional anatomy, and the experience of electrophysiologists, their ablation can still be very challenging with respectively higher failure rates compared to outflow IVAs, the reasons for which have been reported to be intramurally located foci, close proximity of coronary arteries, inability to deliver sufficient radiofrequency (RF) due to high impedance in small caliber vessels, or inability to deliver the ablation catheter to the site of interest due to small vessel caliber/high tortuosity …”

2019 APHRS expert consensus statement on three‐dimensional mapping systems for tachycardia developed in collaboration with HRS, EHRA, and LAHRS

“…MRI has been the most used and helpful tool to provide structural and functional features of arrhythmias, but ICE is the only and most used current imaging modality in real time that we can integrate to a 3D model to reduce x‐ray radiation. Hence, ICE must be part of electrophysiology training . MRI compatible guidance platform for mapping and ablation has been incorporated to visualize 3D anatomy and 3D maps .…”