[Show abstract][Hide abstract] ABSTRACT: The goal of this study was to evaluate the ability of noninvasive programmed stimulation (NIPS) after ventricular tachycardia (VT) ablation to identify patients at high risk of recurrence.
Optimal endpoints for VT ablation are not well defined.
Of 200 consecutive patients with VT and structural heart disease undergoing ablation, 11 had clinical VT inducible at the end of ablation and 11 recurred spontaneously. Of the remaining 178 patients, 132 underwent NIPS through their implantable cardioverter-defibrillator 3.1 ± 2.1 days after ablation. At 2 drive cycle lengths, single, double, and triple right ventricular extrastimuli were delivered to refractoriness. Clinical VT was defined by comparison with 12-lead electrocardiograms and stored implantable cardioverter-defibrillator electrograms from spontaneous VT episodes. Patients were followed for 1 year.
Fifty-nine patients (44.7%) had no VT inducible at NIPS; 49 (37.1%) had inducible nonclinical VT only; and 24 (18.2%) had inducible clinical VT. Patients with inducible clinical VT at NIPS had markedly decreased 1-year VT-free survival compared to those in whom no VT was inducible (<30% vs. >80%; p = 0.001), including 33% recurring with VT storm. Patients with inducible nonclinical VT only, had intermediate 1-year VT-free survival (65%).
When patients with VT and structural heart disease have no VT or nonclinical VT only inducible at the end of ablation or their condition is too unstable to undergo final programmed stimulation, NIPS should be considered in the following days to further define risk of recurrence. If clinical VT is inducible at NIPS, repeat ablation may be considered because recurrence over the following year is high.
Journal of the American College of Cardiology 04/2012; 59(17):1529-35. · 14.09 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Despite advances in ablation of ventricular tachycardia (VT), recognized toxicity of amiodarone, and potential harm of implantable cardioverter defibrillator (ICD) shocks, there appears to be reluctance to pursue catheter ablation.
We tested the hypothesis that patients with structural heart disease and VT are referred late for ablation and may have worse outcomes as a result. Consecutive patients with VT and structural heart disease referred to a single center, between January 2008 and April 2009 were studied. Patients with prior VT ablations were excluded. Late referrals were defined as those with 2 or more episodes of VT, separated by at least 1 month. Ninety-eight consecutive patients were analyzed. Ninety-six percent of patients had an ICD implanted prior to ablation, 58% were in VT storm and 67% taking ≥400 mg daily of amiodarone or amiodarone intolerant (10%). Thirty-six patients fit the definition of early referral and 62 late. Overall acute procedural success was achieved in 89%. Amiodarone dose decreased from a mean and median of 559 and 400 mg daily preablation to 98 and 0 postablation (P < 0.01). Mean and median VT episodes decreased from 17 and 6 in the month preceding ablation to 1 and 0 in the 6 months following ablation (P < 0.01). In Kaplan-Meier analysis, the early referral group had superior 1-year VT free survival (P = 0.01).
VT ablation is frequently reserved for patients receiving recurrent ICD shocks despite high dose amiodarone. Stronger consideration should be given to earlier referral for VT ablation in patients with structural heart disease.
Journal of Cardiovascular Electrophysiology 05/2011; 22(10):1123-8. · 3.48 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Although most recent investigations into sudden cardiac death prevention in heart failure patients have been focused on primary prevention, secondary indications for defibrillators and medical therapy remain vitally important in this complex patient group. Antiarrhythmic therapy is currently used primarily as adjuvant therapy to implantable defibrillators. Secondary prophylaxis defibrillator trials have shown clear benefit in preventing recurrent sudden cardiac death, despite concern over inappropriate shocks and the potential detrimental effects of appropriate shocks. Device programming for secondary prophylaxis can help ameliorate these issues. This article discusses these issues as well as the continued underuse of defibrillators in specific populations.
[Show abstract][Hide abstract] ABSTRACT: After pacemaker or implantable cardioverter-defibrillator (ICD) implantation, it takes weeks for the leads to scar in place. Occasionally, newly implanted leads dislodge by retracting towards the device pocket. This phenomenon is generally called 'Twiddler's Syndrome,' with the invoked mechanism being patient manipulation of the device pocket. We present a case of a 27-year-old man who had complete retraction of the atrial lead, but not the ventricular lead, after a submuscular dual-chamber ICD implantation. The specifics of this case demonstrate that leads can spontaneously retract during normal arm movement, without any conscious or unconscious device manipulation by the patient. Leads must be firmly secured in the device pocket via their suture sleeves in order to minimize the risk of retraction, regardless of mechanism.
[Show abstract][Hide abstract] ABSTRACT: Paralleling the growth in ablation of complex arrhythmias such as atrial fibrillation and ventricular tachycardia, advanced imaging technologies are becoming more commonplace in the care of the electrophysiology patients. Although intracardiac ultrasound remains the most commonly used imaging technique, advances in real-time MRI may change this in the future. We discuss the current use of intracardiac ultrasound, CT, including rotational angiography, MRI, with an emphasis on delayed-enhancement MRI, and positron emission tomography-CT in advanced ablation procedures. Image integration is emphasized and new technologies such as direct endoscopic visualization are discussed.