Catheter ablation of ventricular tachycardia: Two decades of progress

Dissimilar ventricular rhythms: Implications for ICD therapy

“…In patient 1, the sudden change from 1:1 to 1:2 RV/LV relationship without change in CL documented in Figure 3 suggests that the tachycardia circuit actually generates the longer CL recorded by the RV lead and that the shorter CL recorded on LV electrogram may be due to "double counting," that is, recording of depolarization from a "bystander" region (blind loop in an infarcted area close to, but not part of, the reentry circuit) in the vicinity of the LV lead, which is initially "protected" by transient entrance block. 14,15 This mechanism would explain the alternans in CL and LV electrogram morphology and the observation that the tachycardia was successfully terminated by RV ATP with a much longer CL than the apparent CL of LV-VT. This mechanism would also be consistent with the double potential seen on the LV, but not the RV channel during pacing in Figure 2.…”

Emerging non-cancer applications of therapeutic ultrasound

“…3). Endocardial RF catheter ablation for treating ventricular arrhythmias is very well established, but ablating targets deep in the heart wall or located behind scar tissue remains a challenge [49]. HIFU has the potential to be more effective in these cases, which could allow it to compete with RF.…”

Catheter ablation of ventricular arrhythmias

“…Early work by Dr Josephson et al [9] defined the initial concepts of appropriate target sites for catheter ablation based upon activation mapping in the surgical setting. In the 3 decades since this early mapping and ablation work, advances in understanding of the anatomic and pathophysiologic basis of ventricular tachycardia as well as mapping and ablation technologies have improved the safety and outcomes [10]. And, with this progress, radiofrequency catheter ablation for ventricular tachycardia has emerged as a primary therapy for symptomatic and drug-refractory ventricular tachycardia [6].…”