Israel Medical Association Journal

Background: Multiform fascicular tachycardia (FT) was recently described as a ventricular tachycardia (VT) that has a reentrant mechanism using multiple fascicular branches and produces alternate fascicular VT forms. Ablating the respective fascicle may cause a change in the reentrant circuit resulting in a change in morphology. Ablation of the septal fascicle is crucial for successful treatment.

Objectives: To describe four cases of FT in which ablation induced a change in QRS morphologies and aggravated clinical course.

Methods: Four out of 57 consecutive FT cases at three institutions were retrospectively analyzed and found to involve multiform FT. These cases underwent electrophysiological study, fascicular potential mapping, and electroanatomical mapping. All patients initially had FT with right bundle branch block (RBBB) and superior axis morphology.

Results: Radiofrequency catheter ablation (RFCA) targeting the distal left posterior fascicle (LPF) resulted in a second VT with an RBBB-inferior axis morphology that sometimes became faster and/or incessant and/or verapamil-refractory in characteristics. RFCA in the upper septum abolished the second VT with no complications and uneventful long-term follow-up.

Conclusions: The change in FT morphology during ablation may be associated with a change in clinical course when shifting from one route to another and may aggravate symptoms. Targeting of the proximal conduction system (such as bifurcation, LPF, left anterior fascicle, high septal/auxiliary pathway) may serve to solve this problem.

Background: Syncope prognosis varies widely: 1 year mortality may range from 0% in the case of vasovagal events up to 30% in the presence of heart disease. 

Objectives: To assess the outcomes and prognosis of patients with implantable cardiac defibrillator (ICD) and indication of primary prevention and compare patients presenting with or without prior syncope.

Methods: We reviewed the charts of 75 patients who underwent ICD implantation with the indication of primary prevention and history of syncope and compared them to a control group of 80 patients without prior syncope. We assessed the number of ventricular tachycardia (VT), ventricular fibrillation (VF), shock, anti-tachycardia pacing (ATP), and death in each group during the follow-up.

Results: Mean follow-up was 893 days (810–976, 95% confidence interval) (no difference between groups). Patients with prior syncope had a higher ejection fraction (EF) (35.5 ± 12.6 vs. 31.4 ± 8.76, P = 0.02), more episodes of VT (21.3% vs. 3.8%, P = 0.001) and VF (8% vs. 0%, P = 0.01) and also received more electric shocks (18.7% vs. 3.8%, P = 0.004) and ATP (17.3% vs. 6.2%, P = 0.031). There were no differences in inappropriate shocks (6.7% vs. 5%, P = 0.74), in cardiovascular mortality (cumulative 5 year estimate 29.9% vs. 32.2% P = 0.97) and any death (cumulative 5 year estimate 38.1% vs. 48.9% P = 0.18) during the follow-up.

Conclusions: Syncopal patients before ICD implantation seem to have more episodes of VT/VF and shock or ATP. No mortality differences were observed

 

Background: Syncope is a common clinical condition spanning from benign to life-threatening diseases. There is sparse information on the outcomes of syncopal patients who received an implantable cardiac defibrillator (ICD) for primary prevention of sudden cardiac death (SCD). 

Objectives: To assess the outcomes and prognosis of patients who underwent implantable cardiac defibrillator (ICD) implantation for primary prevention of SCD and compare them to patients who presented with or without prior syncope.

Methods: We compared the medical records of 75 patients who underwent ICD implantation for primary prevention of SCD and history of syncope to those of a similar group of 80 patients without prior syncope. We assessed the episodes of ventricular tachycardia (VT), ventricular fibrillation (VF), shock, anti-tachycardia pacing (ATP) and mortality in each group during follow-up.

Results: Mean follow-up was 893 days (810–976, 95%CI) (no difference between groups). There was no significant difference in gender or age. Patients with prior syncope had a higher ejection fraction rate (35.5 ± 12.6 vs. 31.4 ± 8.76, P = 0.02), experienced more episodes of VT (21.3% vs. 3.8%, P = 0.001) and VF (8% vs. 0%, P = 0.01), and received more electric shocks (18.7% vs. 3.8%, P = 0.004) and ATP (17.3% vs. 6.2%, P = 0.031). There were no differences in inappropriate shocks (6.7% vs. 5%, P = 0.74), cardiovascular mortality (cumulative 5 year estimate 29.9% vs. 32.2%, P = 0.97) and any death (cumulative 5 year estimate 38.1% vs. 48.9%, P = 0.18).

Conclusions: Patients presenting with syncope before ICD implantation seemed to have more episodes of VT/VF and shock or ATP. No differences in mortality were observed

 

Background: Left cardiac sympathetic denervation (LCSD) was reported to be effective in patients with intractable ryanodine receptor mutation-associated catecholaminergic polymorphic ventricular tachycardia (CPVT). 

Objectives: To report our experience with LCSD in calsequestrin (CASQ2) mutation-associated CPVT. 

Methods: LCSD was performed in three patients with CASQ2 mutation-associated CPVT with symptoms and exercise-induced ventricular arrhythmia despite high dose beta-blocker. 

Results: None of them experienced symptoms or exercise-induced ventricular arrhythmia after LCSD. However, all had recurrence of symptoms and/or exercise-induced ventricular arrhythmia after 6 months (6–18 months).

Conclusions: LCSD conferred short-term suppression but less than optimal long-term suppression of exercise-induced ventricular arrhythmia among CASQ2-associated CPVT patients.

 

Background: Defibrillation threshold (DFT) testing at the time of implantable cardioverter defibrillator (ICD) insertion is performed routinely. Recently this practice is being reconsidered due to doubts about its ability to improve ICD efficacy and evidence that survival may not be affected by the test.

Objectives: To compare the outcome of ICD recipients who underwent DFT testing and those in whom no testing was performed.

Methods: A total of 213 eligible patients were implanted with an ICD between 2004 and 2009. DFT testing was performed in 80. We compared total mortality, appropriate and inappropriate ICD shocks, and anti-tachycardia pacing (ATP) events between DFT and non-DFT patients during a follow-up of 2 years.

Results: On comparing the DFT and non-DFT groups, we found a 2 year mortality rate of 7.5% versus 8.3%, respectively (P = 0.8). Furthermore, 20.7% of patients in the DFT group and 12.4% in the non-DFT group had at least one episode of ICD shock (P = 0.15). With regard to ICD treatment (ICD shocks or ATP events), 57.7% in the DFT group and 64.2% in the non-DFT group received appropriate treatments (P = 0.78).

Conclusions: No significant differences in the incidence of 2 year mortality or percentage of ICD treatment emerged between the DFT and non-DFT groups.
 

Background: For patients with ventricular tachyarrhythmias, implantable cardioverter defibrillators are a mainstay of therapy to prevent sudden death. However, ICD[1] shocks are painful, can result in clinical depression, and do not offer complete protection against death from arrhythmia. Radiofrequency catheter ablation of ventricular tachycardia in the setting of ischemic cardiomyopathy has emerged recently as a useful adjunctive therapy to ICD.

Objectives: To assess the feasibility, safety and efficacy of our initial experience in ablation of scar-related VT[2].

Methods: Eleven patients (all males, mean age 71 ± 8 years) with drug-refractory ischemic VT were referred to our center for scar mapping and ablation procedures using the CARTO navigation system.

Results: Eleven clinical VTs (mean cycle length 436 ± 93 ms) were induced in all patients. An endocardial circuit, identified by activation, entrainment and/or pace mapping, was found in eight patients with stable VT. These patients were mapped and ablated during VT. Three patients had predominantly unstable VT and linear ablation lesions were performed during sinus rhythm. Acute success, defined as termination of VT and or non-inducibility during programmed electrical stimulation, was found in 9 patients (82%). During follow-up, a significant reduction in tachyarrythmia burden was observed in all patients who had successful initial ablation, except for one who had recurrence of VT 2 days after the procedure and died 2 weeks later.

Conclusions: Ablation of ischemic VT using electroanatomic scar mapping is feasible, has an acceptable success rate and should be offered for ischemic patients with recurrent uncontrolled VT.