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Background: Ventricular fibrillation (VF) storm after myocardial infarction (MI) is a life-threatening condition that necessitates multiple defibrillations. Catheter ablation is a potentially effective treatment strategy for VF storm refractory to optimal medical treatment. However, its impact on patient survival has not been verified in a large population. Methods: We conducted a multicenter, retrospective observational study involving consecutive patients who underwent catheter ablation of post-MI refractory VF storm without preceding monomorphic ventricular tachycardia. The target of ablation was the Purkinje-related ventricular extrasystoles triggering VF. The primary outcome was in-hospital and long-term mortalities. Univariate logistic regression and Cox proportional-hazards analysis were used to evaluate clinical characteristics associated with in-hospital and long-term mortalities, respectively. Results: One hundred ten patients were enrolled (age, 65±11years; 92 men; left ventricular ejection fraction, 31±10%). VF storm occurred at the acute phase of MI (4.5±2.5 days after the onset of MI during the index hospitalization for MI) in 43 patients (39%), the subacute phase (>1 week) in 48 (44%), and the remote phase (>6 months) in 19 (17%). The focal triggers were found to originate from the scar border zone in 88 patients (80%). During in-hospital stay after ablation, VF storm subsided in 92 patients (84%). Overall, 30 (27%) in-hospital deaths occurred. The duration from the VF occurrence to the ablation procedure was associated with in-hospital mortality (odds ratio for each 1-day increase, 1.11 [95% CI, 1.03–1.20]; P =0.008). During follow-up after discharge from hospital, only 1 patient developed recurrent VF storm. However, 29 patients (36%) died, with a median survival time of 2.2 years (interquartile range, 1.2–5.5 years). Long-term mortality was associated with left ventricular ejection fraction P =0.014), New York Heart Association class ≥III (hazard ratio, 2.68 [95% CI, 1.16–6.19]; P =0.021), a history of atrial fibrillation (hazard ratio, 3.89 [95% CI, 1.42–10.67]; P =0.008), and chronic kidney disease (hazard ratio, 2.74 [95% CI, 1.15–6.49]; P =0.023). Conclusions: In patients with MI presenting with focally triggered VF storm, catheter ablation of culprit triggers is lifesaving and appears to be associated with short- and long-term freedom from recurrent VF storm. Mortality over the long-term follow-up is associated with the severity of underlying cardiovascular disease and comorbidities in this specific patient population.

Ventricular fibrillation (VF) storm after myocardial infarction (MI) is a life-threatening condition that necessitates multiple defibrillations. Catheter ablation is a potentially effective treatment strategy for VF storm refractory to optimal medical treatment. However, its impact on patient survival has not been verified in a large population.We conducted a multicenter, retrospective observational study involving consecutive patients who underwent catheter ablation of post-MI refractory VF storm without preceding monomorphic ventricular tachycardia. The target of ablation was the Purkinje-related ventricular extrasystoles triggering VF. The primary outcome was in-hospital and long-term mortalities. Univariate logistic regression and Cox proportional-hazards analysis were used to evaluate clinical characteristics associated with in-hospital and long-term mortalities, respectively.One hundred ten patients were enrolled (age, 65±11years; 92 men; left ventricular ejection fraction, 31±10%). VF storm occurred at the acute phase of MI (4.5±2.5 days after the onset of MI during the index hospitalization for MI) in 43 patients (39%), the subacute phase (1 week) in 48 (44%), and the remote phase (6 months) in 19 (17%). The focal triggers were found to originate from the scar border zone in 88 patients (80%). During in-hospital stay after ablation, VF storm subsided in 92 patients (84%). Overall, 30 (27%) in-hospital deaths occurred. The duration from the VF occurrence to the ablation procedure was associated with in-hospital mortality (odds ratio for each 1-day increase, 1.11 [95% CI, 1.03-1.20]; P=0.008). During follow-up after discharge from hospital, only 1 patient developed recurrent VF storm. However, 29 patients (36%) died, with a median survival time of 2.2 years (interquartile range, 1.2-5.5 years). Long-term mortality was associated with left ventricular ejection fraction30% (hazard ratio, 2.54 [95% CI, 1.21-5.32]; P=0.014), New York Heart Association class ≥III (hazard ratio, 2.68 [95% CI, 1.16-6.19]; P=0.021), a history of atrial fibrillation (hazard ratio, 3.89 [95% CI, 1.42-10.67]; P=0.008), and chronic kidney disease (hazard ratio, 2.74 [95% CI, 1.15-6.49]; P=0.023).In patients with MI presenting with focally triggered VF storm, catheter ablation of culprit triggers is lifesaving and appears to be associated with short- and long-term freedom from recurrent VF storm. Mortality over the long-term follow-up is associated with the severity of underlying cardiovascular disease and comorbidities in this specific patient population.

Background— Implantable cardioverter-defibrillator indications in Brugada syndrome remain controversial, especially in asymptomatic patients. Previous outcome data are limited by relatively small numbers of patients or short follow-up durations. We report the outcome of patients with Brugada syndrome implanted with an implantable cardioverter-defibrillator in a large multicenter registry. Methods and Results— A total of 378 patients (310 male; age, 46±13 years) with a type 1 Brugada ECG pattern implanted with an implantable cardioverter-defibrillator (31 for aborted sudden cardiac arrest, 181 for syncope, and 166 asymptomatic) were included. Fifteen patients (4%) were lost to follow-up. During a mean follow-up of 77±42 months, 7 patients (2%) died (1 as a result of an inappropriate shock), and 46 patients (12%) had appropriate device therapy (5±5 shocks per patient). Appropriate device therapy rates at 10 years were 48% for patients whose implantable cardioverter-defibrillator indication was aborted sudden cardiac arrest, 19% for those whose indication was syncope, and 12% for the patients who were asymptomatic at implantation. At 10 years, rates of inappropriate shock and lead failure were 37% and 29%, respectively. Inappropriate shock occurred in 91 patients (24%; 4±4 shocks per patient) because of lead failure (n=38), supraventricular tachycardia (n=20), T-wave oversensing (n=14), or sinus tachycardia (n=12). Importantly, introduction of remote monitoring, programming a high single ventricular fibrillation zone (>210–220 bpm), and a long detection time were associated with a reduced risk of inappropriate shock. Conclusions— Appropriate therapies are more prevalent in symptomatic Brugada syndrome patients but are not insignificant in asymptomatic patients (1%/y). Optimal implantable cardioverter-defibrillator programming and follow-up dramatically reduce inappropriate shock. However, lead failure remains a major problem in this population.

We present the case of a 38-year-old woman with no past medical history and structurally normal heart with recurrent drug-refractory septal ventricular tachycardia (VT). Despite treatment with flecainide, celiprolol, and sotalol, she experienced breakthrough episodes of VT (Figure 1B). She had undergone 5 failed attempts at VT ablation. She was therefore referred for a further attempt at ablation. Cardiac multidetector computed tomography and late gadolinium enhancement (LGE) MRI were performed before VT ablation. MRI demonstrated nontransmural subendocardial LGE on either side of the septum, which corresponded to previous ablation sites (Figure 2A, Movie I in the online-only Data Supplement). Figure 1. Twelve-lead ECG of sinus rhythm and clinical tachycardia. A , Sinus rhythm. B , Ventricular tachycardia with left superior axis, relatively small QRS, and a transition around V3. Figure 2. MRI data before and after sixth ablation procedure. A , LGE images acquired on the day before the procedure show subendocardial enhancement related to a nontransmural scar from previous ablations, on both sides of the interventricular septum and on the inferior RV wall (yellow arrows). B , LGE images acquired on day 1 after the procedure show an intramural hematoma in the septum at the site of …

Background— Specific noninvasive signal processing was applied to identify drivers in distinct categories of persistent atrial fibrillation (AF). Methods and Results— In 103 consecutive patients with persistent AF, accurate biatrial geometry relative to an array of 252 body surface electrodes was obtained from a noncontrast computed tomography scan. The reconstructed unipolar AF electrograms acquired at bedside from multiple windows (duration, 9±1 s) were signal processed to identify the drivers (focal or reentrant activity) and their cumulative density map. The driver domains were catheter ablated by using AF termination as the procedural end point in comparison with the stepwise-ablation control group. The maps showed incessantly changing beat-to-beat wave fronts and varying spatiotemporal behavior of driver activities. Reentries were not sustained (median, 2.6 rotations lasting 449±89 ms), meandered substantially but recurred repetitively in the same region. In total, 4720 drivers were identified in 103 patients: 3802 (80.5%) reentries and 918 (19.5%) focal breakthroughs; most of them colocalized. Of these, 69% reentries and 71% foci were in the left atrium. Driver ablation alone terminated 75% and 15% of persistent and long-lasting AF, respectively. The number of targeted driver regions increased with the duration of continuous AF: 2 in patients presenting in sinus rhythm, 3 in AF lasting 1 to 3 months, 4 in AF lasting 4 to 6 months, and 6 in AF lasting longer. The termination rate sharply declined after 6 months. The mean radiofrequency delivery to AF termination was 28±17 minutes versus 65±33 minutes in the control group ( P P =not significant. Conclusions— Persistent AF in early months is maintained predominantly by drivers clustered in a few regions, most of them being unstable reentries.