Robert D. Schaller

Long-Term Outcome After Catheter Ablation of Ventricular Tachycardia in Patients With Nonischemic Dilated Cardiomyopathy

Background—Catheter ablation (CA) of ventricular tachycardia (VT) in patients with nonischemic dilated cardiomyopathy can be challenging because of the complexity of underlying substrates. We sought to determine the long-term outcomes of endocardial and adjuvant epicardial CA in nonischemic dilated cardiomyopathy. Methods and Results—We examined 282 consecutive patients (aged 59±15 years, 80% males) with nonischemic dilated cardiomyopathy who underwent CA. Ablation was guided by activation/entrainment mapping for tolerated VT and pacemapping/targeting of abnormal electrograms for unmappable VT. Adjuvant epicardial ablation was performed for recurrent VT or persistent inducibility after endocardial–only ablation. Epicardial ablation was performed in 90 (32%) patients. Before ablation, patients failed a median of 2 antiarrhythmic drugs), including amiodarone, in 166 (59%) patients. The median follow-up after the last procedure was 48 (19–67) months. Overall, VT-free survival was 69% at 60-month follow-up. Transplant-free survival was 76% and 68% at 60- and 120-month follow-up, respectively. Among the 58 (21%) patients with VT recurrence, CA still resulted in a significant reduction of VT burden, with 31 (53%) patients having only isolated (1–3) VT episodes in 12 (4–35) months after the procedure. At the last follow-up, 128 (45%) patients were only on &bgr;-blockers or no treatment, 41 (15%) were on sotalol or class I antiarrhythmic drugs, and 62 (22%) were on amiodarone. Conclusions—In patients with nonischemic dilated cardiomyopathy and VT, endocardial and adjuvant epicardial CA is effective in achieving long-term VT freedom in 69% of cases, with a substantial improvement in VT burden in many of the remaining patients.

Acute Hemodynamic Decompensation During Catheter Ablation of Scar-Related Ventricular Tachycardia Incidence, Predictors, and Impact on Mortality

Background—The occurrence of periprocedural acute hemodynamic decompensation (AHD) in patients undergoing radiofrequency catheter ablation of scar-related ventricular tachycardia (VT) has not been previously investigated. Methods and Results—We identified univariate predictors of periprocedural AHD in 193 consecutive patients undergoing radiofrequency catheter ablation of scar-related VT. AHD was defined as persistent hypotension despite vasopressors and requiring mechanical support or procedure discontinuation. AHD occurred in 22 (11%) patients. Compared with the rest of the population, patients with AHD were older (68.5±10.7 versus 61.6±15.0 years; P=0.037); had a higher prevalence of diabetes mellitus (36% versus 18%; P=0.045), ischemic cardiomyopathy (86% versus 52%; P=0.002), chronic obstructive pulmonary disease (41% versus 13%; P=0.001), and VT storm (77% versus 43%; P=0.002); had more severe heart failure (New York Heart Association class III/IV: 55% versus 15%, P<0.001; left ventricular ejection fraction: 26±10% versus 36±16%, P=0.003); and more often received periprocedural general anesthesia (59% versus 29%; P=0.004). At 21±7 months follow-up, the mortality rate was higher in the AHD group compared with the rest of the population (50% versus 11%, log-rank P<0.001). Conclusions—AHD occurs in 11% of patients undergoing radiofrequency catheter ablation of scar-related VT and is associated with increased risk of mortality over follow-up. AHD may be predicted by clinical factors, including advanced age, ischemic cardiomyopathy, more severe heart failure status (New York Heart Association class III/IV, lower ejection fraction), associated comorbidities (diabetes mellitus and chronic obstructive pulmonary disease), presentation with VT storm, and use of general anesthesia.

Early recurrence of atrial arrhythmias following pulmonary vein antral isolation: Timing and frequency of early recurrences predicts long-term ablation success

BACKGROUND Early recurrence of atrial arrhythmia (ERAA) is common after atrial fibrillation (AF) ablation and is associated with long-term recurrence. However, the association between timing or frequency of ERAA and long-term ablation success remains unclear. OBJECTIVE We aimed to examine whether timing or frequency of ERAA after pulmonary vein antral isolation (PVAI) affects long-term ablation success. METHODS Three hundred AF patients (100 paroxysmal, 100 persistent, 100 long-standing persistent; mean age 59.5 ± 9.6 years, 79% male) undergoing PVAI were included. All patients underwent 30-day monitoring with mobile continuous outpatient telemetry after PVAI and were followed for >1 year. ERAA was defined as AF or organized atrial tachycardia (OAT) in the first 6 weeks, and was categorized as early (weeks 1-2), intermediate (weeks 3-4), or late (weeks 5-6). Long-term ablation success was defined as the absence of AF/OAT lasting >30 seconds off antiarrhythmic drugs 1 year after a single ablation (excluding first 6 weeks). RESULTS ERAA occurred in 169 patients (53%); of those, 79 (46.7%) had single ERAA and 90 (53.3%) had multiple ERAAs. ERAA occurred less commonly with paroxysmal versus persistent or long-standing persistent AF (46% vs 57% and 66%; P = .017). ERAA was associated with worse ablation success at 1 year (38.1% vs 79.5% [no ERAA]; P < .001). Multiple (vs single) ERAA more strongly predicted long-term ablation failure (OR: 4.5; 95% CI [2.3-8.8]). CONCLUSIONS ERAA after PVAI is associated with decreased long-term ablation success. Patients experiencing multiple ERAA events are at greatest risk for long-term arrhythmia recurrence and represent a subgroup in whom early reablation may be considered.

Acute Hemodynamic Decompensation during Catheter Ablation of Scar-Related VT: Incidence, Predictors and Impact on Mortality

Background—The occurrence of periprocedural acute hemodynamic decompensation (AHD) in patients undergoing radiofrequency catheter ablation of scar-related ventricular tachycardia (VT) has not been previously investigated. Methods and Results—We identified univariate predictors of periprocedural AHD in 193 consecutive patients undergoing radiofrequency catheter ablation of scar-related VT. AHD was defined as persistent hypotension despite vasopressors and requiring mechanical support or procedure discontinuation. AHD occurred in 22 (11%) patients. Compared with the rest of the population, patients with AHD were older (68.5±10.7 versus 61.6±15.0 years; P=0.037); had a higher prevalence of diabetes mellitus (36% versus 18%; P=0.045), ischemic cardiomyopathy (86% versus 52%; P=0.002), chronic obstructive pulmonary disease (41% versus 13%; P=0.001), and VT storm (77% versus 43%; P=0.002); had more severe heart failure (New York Heart Association class III/IV: 55% versus 15%, P<0.001; left ventricular ejection fraction: 26±10% versus 36±16%, P=0.003); and more often received periprocedural general anesthesia (59% versus 29%; P=0.004). At 21±7 months follow-up, the mortality rate was higher in the AHD group compared with the rest of the population (50% versus 11%, log-rank P<0.001). Conclusions—AHD occurs in 11% of patients undergoing radiofrequency catheter ablation of scar-related VT and is associated with increased risk of mortality over follow-up. AHD may be predicted by clinical factors, including advanced age, ischemic cardiomyopathy, more severe heart failure status (New York Heart Association class III/IV, lower ejection fraction), associated comorbidities (diabetes mellitus and chronic obstructive pulmonary disease), presentation with VT storm, and use of general anesthesia.

Pulmonary Vein Antral Isolation and Nonpulmonary Vein Trigger Ablation Are Sufficient to Achieve Favorable Long-Term Outcomes Including Transformation to Paroxysmal Arrhythmias in Patients With Persistent and Long-Standing Persistent Atrial Fibrillation

Background—Transformation from persistent to paroxysmal atrial fibrillation (AF) after ablation suggests modification of the underlying substrate. We examined the nature of initial arrhythmia recurrence in patients with nonparoxysmal AF undergoing antral pulmonary vein isolation and nonpulmonary vein trigger ablation and correlated recurrence type with long-term ablation efficacy after the last procedure. Methods and Results—Three hundred and seventeen consecutive patients with persistent (n=200) and long-standing persistent (n=117) AF undergoing first ablation were included. AF recurrence was defined as early (⩽6 weeks) or late (>6 weeks after ablation) and paroxysmal (either spontaneous conversion or treated with cardioversion ⩽7 days) or persistent (lasting >7 days). During median follow-up of 29.8 (interquartile range: 14.8–49.9) months, 221 patients had ≥1 recurrence. Initial recurrence was paroxysmal in 169 patients (76%) and persistent in 52 patients (24%). Patients experiencing paroxysmal (versus persistent) initial recurrence were more likely to achieve long-term freedom off antiarrhythmic drugs (hazard ratio, 2.2; 95% confidence interval, 1.5–3.2; P<0.0001), freedom on/off antiarrhythmic drugs (hazard ratio, 2.5; 95% confidence interval, 1.6–3.8; P<0.0001), and arrhythmia control (hazard ratio, 5.2; 95% confidence interval, 2.9–9.2; P<0.0001) after last ablation. Conclusions—In patients with persistent and long-standing persistent AF, limited ablation targeting pulmonary veins and documented nonpulmonary vein triggers improves the maintenance of sinus rhythm and reverses disease progression. Transformation to paroxysmal AF after initial ablation may be a step toward long-term freedom from recurrent arrhythmia.

Comparison of Left Atrial Bipolar Voltage and Scar Using Multielectrode Fast Automated Mapping versus Point‐by‐Point Contact Electroanatomic Mapping in Patients With Atrial Fibrillation Undergoing Repeat Ablation

Bipolar voltage criteria to delineate left atrial (LA) scar have been derived using point‐by‐point (PBP) contact electroanatomical mapping. It remains unclear how PBP‐derived LA scar correlates with multielectrode fast automated mapping (ME‐FAM) derived scar. We aimed to correlate scar and bipolar voltages from LA maps created using PBP versus ME‐FAM.

Recurrent atrial arrhythmias in the setting of chronic pulmonary vein isolation

BACKGROUND Atrial arrhythmias may still occur in patients after durable pulmonary vein isolation (PVI). OBJECTIVE The purpose of this study was to examine the incidence of patients undergoing ablation for recurrent arrhythmia despite chronic PVI and their clinical outcomes. METHODS Patients undergoing repeat left atrial ablation procedures were selected from a prospective registry. From this population, we identified patients with chronic PVI. Clinical characteristics, ablation strategies, and outcomes were analyzed. RESULTS Between January 2003 and December 2013, 1045 patients underwent 1298 repeat left atrial procedures. Of these, 900 patients had atrial fibrillation (AF) and 145 had atrial flutter (AFL)/atrial tachycardia (AT). Fifty-two patients (5.0%; 27 with AF and 25 with AFL/AT) had chronic PVI and were included in the study. Patients were followed for 19.7 ± 5.6 months. In patients with AF, 11 (41%) had a non-PV trigger identified. Ablation strategies included non-PV trigger ablation (n = 11), empiric trigger-site ablation (n = 3), provoked arrhythmia ablation (n = 9), complex fractionated atrial electrogram ablation (n = 2), and linear ablation (n = 2). During follow-up, 9 (33%) had no recurrence, 7 (26%) had rare AF (≤2 episodes during follow-up ≥1 year), and 11 (41%) had AF recurrence. In patients with AFL/AT, 12 (48%) had no recurrence, 4 (16%) had rare recurrence (≤2 episodes during follow-up ≥1 year), and 9 (36%) had recurrence. CONCLUSION In patients with PVI undergoing a repeat procedure during the time period studied, only a small portion had chronic PVI. A strategy of targeting non-PV triggers for AF and linear/focal ablation for AFL/AT may achieve long-term arrhythmia control in the majority of patients.

Outcomes of Catheter Ablation of Idiopathic Outflow Tract Ventricular Arrhythmias With an R Wave Pattern Break in Lead V2: A Distinct Clinical Entity

In outflow tract ventricular arrhythmias (OT‐VAs), an abrupt loss of the R wave in lead V2 compared to V1 and V3 (pattern break in V2–PBV2) suggests an origin close to the anterior interventricular sulcus (anatomically opposite to lead V2) and adjacent to proximal coronaries. We studied the outcome of catheter ablation of OT‐VAs with a PBV2.

Imaging characteristics of papillary muscle site of origin of ventricular arrhythmias in patients with mitral valve prolapse

Mitral valve prolapse has been associated with increased risk of ventricular arrhythmias. We aimed to examine whether certain cardiac imaging characteristics are associated with papillary muscle origin of ventricular arrhythmias in these patients.

Utility of intracardiac echocardiography during transvenous lead extraction

BACKGROUND Transvenous lead extraction (TLE) carries a significant risk of intraprocedural complications. Phased-array intracardiac echocardiography (ICE) is widely used during cardiac procedures; however, its utility during TLE has not been well described. OBJECTIVE We sought to define the utility of ICE imaging during TLE. METHODS Fifty patients referred for TLE were included. Patients underwent ICE imaging before and throughout TLE. Clinical characteristics of the patients, ICE findings, and procedural outcomes were collected and analyzed. RESULTS Of the 50 patients, 18 (36%) were found to have visible binding sites in the ICE field of view; 13 (26%) had intracardiac binding sites only, and 5 (10%) had both superior vena cava (SVC) and intracardiac binding sites. Lead-adherent echodensities (LAEs) were found in 36 patients (72%), of whom 7 (14%) had bacteremia. Patients with SVC and/or intracardiac binding sites were more likely to have a complex extraction, defined as that requiring the use of internal jugular or femoral venous access, advancement of extraction apparatus beyond the SVC, disruption of lead structure during the procedure, or resulting in major complications (56% vs 0%; P ≤ .0001). CONCLUSION ICE imaging during TLE can be used to assess the presence of lead binding sites, LAEs, and procedural complications. LAEs were found in the majority of patients, mostly in the absence of bacteremia. The presence of ICE-detected lead binding sites is predictive of a more complex extraction procedure.