Reassessing noninducibility as ablation endpoint of post-infarction ventricular tachycardia: the impact of left ventricular function

Prognostic value of non-invasive programmed ventricular stimulation after VT ablation to predict VT recurrences

BACKGROUND

The prognostic value of (non)-invasive programmed ventricular stimulation (NIPS) to predict recurrences of ventricular tachycardia (VT) is under discussion. Optimal endpoints of VT ablation are not well defined, and optimal timepoint of NIPS is unknown. The goal of this study was to evaluate the ability of programmed ventricular stimulation at the end of the VT ablation procedure (PVS) and NIPS after VT ablation to identify patients at high risk for VT recurrence.

METHODS

Between January 2016 and February 2022, consecutive patients with VT and structural heart disease undergoing first VT ablation and consecutive NIPS were included. In total, 138 patients were included. All patients underwent NIPS through their implanted ICDs after a median of 3 (1-5) days after ablation (at least 2 drive cycle lengths (500 and 400 ms) and up to four right ventricular extrastimuli until refractoriness). Clinical VT was defined by comparison with 12-lead electrocardiograms and stored ICD electrograms from spontaneous VT episodes. Patients were followed for a median of 37 (13-61) months.

RESULTS

Of the 138 patients, 104 were non-inducible (75%), 27 were inducible for non-clinical VTs (20%), and 7 for clinical VT (5%). In 107 patients (78%), concordant results of PVS and NIPS were observed. After 37 ± 20 months, the recurrence rate for any ventricular arrhythmia was 40% (normal NIPS 29% vs. inducible VT during NIPS 66%; log-rank p = 0.001) and for clinical VT was 3% (normal NIPS 1% vs. inducible VT during NIPS 9%; log-rank p = 0.045). Positive predictive value (PPV) and negative predictive value (NPV) of NIPS were higher compared to PVS (PPV: 65% vs. 46% and NPV: 68% vs. 61%). NIPS revealed the highest NPV among patients with ICM and LVEF > 35%. Patients with inducible VT during NIPS had the highest VT recurrences and overall mortality. Patients with both negative PVS and NIPS had the lowest any VT recurrence rates with 32%. Early re-ablation of patients with recurrent VTs during index hospitalization was feasible but did not reveal better long-term VT-free survival.

CONCLUSIONS

In patients after VT ablation and structural heart disease, NIPS is superior to post-ablation PVS to stratify the risk of VT recurrences. The PPV and NPV of NIPS at day 3 were superior compared to PVS at the end of the procedure to predict recurrent VT, especially in patients with ICM.

Excellent Outcomes After First-Line Ablation in Post-MI Patients With Tolerated VT and LVEF >35

BACKGROUND

Post-myocardial infarction (MI) patients with ventricular tachycardia (VT) are considered at risk for VT recurrence and sudden cardiac death (SCD). Recent guidelines indicate that in selected patients catheter ablation should be considered instead of an implantable cardioverter-defibrillator (ICD).

OBJECTIVES

This study aimed to analyze outcomes of patients referred for VT ablation according to left ventricular ejection fraction (LVEF), tolerance of VT, and acute ablation outcome.

METHODS

Post-MI patients without prior ICD undergoing VT ablation at a single center between 2009 and 2022 were included. Patients who presented with tolerated VT and who had an LVEF >35% were offered catheter ablation as first-line therapy. ICD implantation was offered to all patients but was subject to shared decision according to clinical presentation, LVEF, and ablation outcome.

RESULTS

Eighty-six patients (mean age 69 ± 9 years, 84% male, mean LVEF 41 ± 9%) underwent VT ablation. In 66 patients, LVEF was >35%, of whom 51 had tolerated VT. Of these 51 patients, 37 (73%) were rendered noninducible. In 5 of 37 noninducible and in 11 of 14 inducible patients, an ICD was implanted. During a median follow-up of 40 months (Q1-Q3: 24-70 months), 10 of 86 patients had VT recurrence. The overall mortality was 27%, and 1 patient with ICD died suddenly. Among the 37 patients (none on antiarrhythmic drugs) with LVEF >35%, tolerated VT, and noninducibility, no SCD or VT recurrence occurred. Among the 14 patients with LVEF >35%, tolerated VT, and inducibility after ablation, no SCD occurred, but VT recurred in 29%.

CONCLUSIONS

Post-MI patients with LVEF >35%, tolerated VT, and noninducibility after ablation have an excellent prognosis. Deferring ICD implantation seems to be safe in these patients.

RIPPLE-VT study: Multicenter prospective evaluation of ventricular tachycardia substrate ablation by targeting scar channels to eliminate latest scar potentials without direct ablation

BACKGROUND

Recurrent ventricular tachycardia (VT) can be treated by substrate modification of the myocardial scar by catheter ablation during sinus rhythm without VT induction. Better defining this arrhythmic substrate could help improve outcome and reduce ablation burden.

OBJECTIVE

The study aimed to limit ablation within postinfarction scar to conduction channels within the scar to reduce VT recurrence.

METHODS

Patients undergoing catheter ablation for recurrent implantable cardioverter-defibrillator therapy for postinfarction VT were recruited at 5 centers. Left ventricular maps were collected on CARTO using a Pentaray catheter. Ripple mapping was used to categorize infarct scar potentials (SPs) by timing. Earliest SPs were ablated sequentially until there was loss of the terminal SPs without their direct ablation. The primary outcome measure was sustained VT episodes as documented by device interrogations at 1 year, which was compared with VT episodes in the year before ablation.

RESULTS

The study recruited 50 patients (mean left ventricular ejection fraction, 33% ± 9%), and 37 patients (74%) met the channel ablation end point with successful loss of latest SPs without direct ablation. There were 16 recurrences during 1-year follow-up. There was a 90% reduction in VT burden from 30.2 ± 53.9 to 3.1 ± 7.5 (P < .01) per patient, with a concomitant 88% reduction in appropriate shocks from 2.1 ± 2.7 to 0.2 ± 0.9 (P < .01). There were 8 deaths during follow-up. Those who met the channel ablation end point had no significant difference in mortality, recurrence, or VT burden but had a significantly lower ablation burden of 25.7 ± 4.2 minutes vs 39.9 ± 6.1 minutes (P = .001).

CONCLUSION

Scar channel ablation is feasible by ripple mapping and can be an alternative to more extensive substrate modification techniques.

Inducibility of Multiple Ventricular Tachycardia's during a Successful Ablation Procedure Is a Marker of Ventricular Tachycardia Recurrence

Even after a successful ventricular tachycardia ablation (VTA), some patients have recurrent ventricular tachycardia (VT) during their follow-up. We assessed the long-term predictors of recurrent VT after having a successful VTA. The patients who underwent a successful VTA (defined as the non-inducibility of any VT at the procedure's end) in 2014-2021 at our center in Israel were retrospectively analyzed. A total of 111 successful VTAs were evaluated. Out of them, 31 (27.9%) had a recurrent event of VT after the procedure during a median follow-up time of 264 days. The mean left ventricular ejection fraction (LVEF) was significantly lower among patients with recurrent VT events (28.9 ± 12.67 vs. 23.53 ± 12.224, p = 0.048). A high number of induced VTs (>two) during the procedure was found to be a significant predictor of VT recurrence (24.69% vs. 56.67%, 20 vs. 17, p = 0.002). In a multivariate analysis, a lower LVEF (HR, 0.964; p = 0.037) and a high number of induced VTs (HR, 2.15; p = 0.039) were independent predictors of arrhythmia recurrence. The inducibility of more than two VTs during a VTA procedure remains a predictor of VT recurrence even after a successful VT ablation. This group of patients remains at high risk for VT and should be followed up with and treated more vigorously.

Pleomorphic Ventricular Tachycardia in Dilated Cardiomyopathy Predicts Ventricular Tachycardia Recurrence After Ablation Independent From Cardiac Function: Comparison With Patients With Ischemic Heart Disease

BACKGROUND

In dilated cardiomyopathy (DCM), outcome after catheter ablation of ventricular tachycardia (VT) is modest, compared with ischemic heart disease (IHD). Pleomorphic VT (PL-VT) has been associated with fibrotic remodeling and end-stage heart failure in IHD. The prognostic role of PL-VT in DCM is unknown.

METHODS

Consecutive IHD (2009-2016) or DCM (2008-2018) patients undergoing ablation for monomorphic VT were included. PL-VT was defined as ≥1 spontaneous change of the 12-lead VT-morphology during the same induced VT episode. Patients were followed for VT recurrence and mortality.

RESULTS

A total of 247 patients (86% men; 63±13 years; IHD n=152; DCM n=95) underwent ablation for monomorphic VT. PL-VT was observed in 22 and 29 patients with IHD and DCM, respectively (14% versus 31%, P=0.003). In IHD, PL-VT was associated with lower LVEF (28±9% versus 34±12%, P=0.02) and only observed in those with LVEF<40%. In contrast, in DCM, PL-VT was not related to LVEF and induced in 27% of patients with LVEF>40%. During a median follow-up of 30 months, 79 (32%) patients died (IHD 48; DCM 31; P=0.88) and 120 (49%) had VT recurrence (IHD 59; DCM 61; P<0.001). PL-VT was associated with mortality in IHD but not in DCM. In IHD, VT recurrence was independently associated with LVEF, number of induced VTs, and procedural noncomplete success. Of note, in DCM, PL-VT (HR, 2.62 [95% CI, 1.47-4.69]), pathogenic mutation (HR, 2.13 [95% CI, 1.16-3.91]), and anteroseptal VT substrate (HR, 1.75 [95% CI, 1.00-3.07]) independently predicted VT recurrence.

CONCLUSIONS

In IHD, PL-VT was associated with low LVEF and mortality. In DCM, PL-VT was not associated with mortality but a predictor of VT recurrence independent from LVEF. PL-VT in DCM may indicate a specific arrhythmic substrate difficult to control by current ablation techniques.

Clinical Outcomes in Patients With Dilated Cardiomyopathy and Ventricular Tachycardia

BACKGROUND

Recurrent ventricular tachycardia (VT) due to dilated cardiomyopathy (DCM) is difficult to treat, and long-term outcome data are limited.

OBJECTIVES

The aim of this study was to identify predictors of mortality or heart transplantation (HTx) and VT recurrence.

METHODS

Consecutive patients with DCM accepted for radiofrequency catheter ablation (RFCA) of VT at 9 centers were prospectively enrolled and followed.

RESULTS

Of 281 consecutive patients (mean age 60 ± 13 years, 85% men, mean left ventricular ejection fraction [LVEF] 36% ± 12%), 35% had VT storm, 20% had incessant VT, and amiodarone was unsuccessful in 68%. During follow-up of 21 months (IQR: 6-30 months), 67 patients (24%) died or underwent HTx, and 138 (49%) had VT recurrence (45 within 30 days, defined as early); the 4-year rate of VT recurrence or mortality or HTx was 70%. Independent predictors of mortality or HTx were early VT recurrence (HR: 2.92; 95% CI: 1.37-6.21; P < 0.01), amiodarone at discharge (HR: 3.23; 95% CI: 1.43-7.33; P < 0.01), renal dysfunction (HR: 1.92; 95% CI: 1.01-3.64; P = 0.046), and LVEF (HR: 1.36; 95% CI: 1.0-1.84; P = 0.052). LVEF ≤32% identified patients at risk for mortality or HTx (area under the curve: 0.75). Mortality or HTx per 100 person-years was 40.4 events after early, compared with 14.2 events after later VT recurrence and 8.5 events with no VT recurrence after RFCA (P < 0.01 for both). Patients with early recurrence and LVEFs ≤32% had a 1-year rate of mortality or HTx of 55%. VT recurrence was predicted by prior implantable cardioverter-defibrillator shocks, basal anteroseptal VT origin, and procedural failure but not LVEF.

CONCLUSIONS

Patients with DCM needing RFCA for VT are a high-risk group. Following RFCA, approximately one-half remain free of VT recurrence. Early VT recurrence with LVEF ≤32% identifies those at very high risk for mortality or HTx, and screening for mechanical support or HTx should be considered. Late VT recurrence after RFCA does not predict worse outcome.

Development and Validation of a Risk Prediction Model for Ventricular Arrhythmia in Elderly Patients with Coronary Heart Disease

BACKGROUND

Sudden cardiac death is a leading cause of death from coronary heart disease (CHD). The risk of sudden cardiac death (SCD) increases with age, and sudden arrhythmic death remains a major cause of mortality in elderly individuals, especially ventricular arrhythmias (VA). We developed a risk prediction model by combining ECG and other clinical noninvasive indexes including biomarkers and echocardiology for VA in elderly patients with CHD.

METHOD

In the retrospective study, a total of 2231 consecutive elderly patients (≥60 years old) with CHD hospitalized were investigated, and finally 1983 patients were enrolled as the model group. The occurrence of VA within 12 months was mainly collected. Study parameters included clinical characteristics (age, gender, height, weight, BMI, and past medical history), ECG indexes (QTcd, Tp-e/QT, and HRV indexes), biomarker indexes (NT-proBNP, Myo, cTnT, CK-MB, CRP, K+, and Ca2+), and echocardiology indexes. In the respective study, 406 elderly patients (≥60 years old) with CHD were included as the verification group to verify the model in terms of differentiation and calibration.

RESULTS

In the multiparameter model, seven independent predictors were selected: LVEF, LAV, HLP, QTcd, sex, Tp-e/QT, and age. Increased HLP, Tp-e/QT, QTcd, age, and LAV were risk factors (RR > 1), while female and increased LVEF were protective factors (RR < 1). This model can well predict the occurrence of VA in elderly patients with CHD (for model group, AUC: 0.721, 95% CI: 0.669∼0.772; for verification group, AUC: 0.73, 95% CI: 0.648∼0.818; Hosmer-Lemeshow χ 2 = 13.541, P=0.095). After adjusting the predictors, it was found that the combination of clinical indexes and ECG indexes could predict VA more efficiently than using clinical indexes alone.

CONCLUSIONS

LVEF, LAV, QTcd, Tp-e/QT, gender, age, and HLP were independent predictors of VA risk in elderly patients with CHD. Among these factors, the echocardiology indexes LVEF and LAV had the greatest influence on the predictive efficiency of the model, followed by ECG indexes, QTcd and Tp-e/QT. After verification, the model had a good degree of differentiation and calibration, which can provide a certain reference for clinical prediction of the VA occurrence in elderly patients with CHD.

The prognostic value of J-wave pattern for recurrence of ventricular tachycardia after catheter ablation in patients with myocardial infarction

BACKGROUND

J-waves and fragmented QRS (fQRS) on surface ECGs have been associated with the occurrence of ventricular tachyarrhythmias. Whether these non-invasive parameters can also predict ventricular tachycardia (VT) recurrence after radiofrequency catheter ablation (RFCA) is unknown. Of interest, patients with a wide QRS-complex have been excluded from clinical studies on J-waves, although a J-wave like pattern has been described for wide QRS.

METHODS

We retrospectively included 168 patients (67 ± 10 years; 146 men) who underwent RFCA of post-infarct VT. J-wave pattern were defined as J-point elevation ≥ 0.1 mV in at least two leads irrespective of QRS width. fQRS was defined as various RSR` pattern in patients with narrow QRS and more than two R wave in those with wide QRS. The primary endpoint was VT recurrence after RFCA up to 24 months.

RESULTS

J-wave pattern and fQRS were present in 27 and 28 patients, respectively. Overlap of J-wave pattern and fQRS was observed in nine. During a median follow-up of 20 (interquartile range 9-24) months, 46 (27%) patients had VT recurrence. Kaplan-Meier curves revealed that both J-wave pattern and fQRS were associated with VT recurrence. Multivariate Cox regression analysis demonstrated that the presence of J-wave pattern (hazard ratio [HR] 2.84; 95% confidence interval [CI] 1.45-5.58; P = .002) and greater number of induced VT (HR 1.29; 95% CI 1.15-1.45; P < .001) were the independent predictors of VT recurrence.

CONCLUSIONS

A J-wave pattern-but not fQRS-is independently associated with an increased risk of post-infarct VT recurrence after RFCA irrespective of QRS width. This simple non-invasive parameter may identify patients who require additional treatment.

2019 HRS/EHRA/APHRS/LAHRS expert consensus statement on catheter ablation of ventricular arrhythmias

Ventricular arrhythmias are an important cause of morbidity and mortality and come in a variety of forms, from single premature ventricular complexes to sustained ventricular tachycardia and fibrillation. Rapid developments have taken place over the past decade in our understanding of these arrhythmias and in our ability to diagnose and treat them. The field of catheter ablation has progressed with the development of new methods and tools, and with the publication of large clinical trials. Therefore, global cardiac electrophysiology professional societies undertook to outline recommendations and best practices for these procedures in a document that will update and replace the 2009 EHRA/HRS Expert Consensus on Catheter Ablation of Ventricular Arrhythmias. An expert writing group, after reviewing and discussing the literature, including a systematic review and meta-analysis published in conjunction with this document, and drawing on their own experience, drafted and voted on recommendations and summarized current knowledge and practice in the field. Each recommendation is presented in knowledge byte format and is accompanied by supportive text and references. Further sections provide a practical synopsis of the various techniques and of the specific ventricular arrhythmia sites and substrates encountered in the electrophysiology lab. The purpose of this document is to help electrophysiologists around the world to appropriately select patients for catheter ablation, to perform procedures in a safe and efficacious manner, and to provide follow-up and adjunctive care in order to obtain the best possible outcomes for patients with ventricular arrhythmias.

2019 HRS/EHRA/APHRS/LAHRS expert consensus statement on catheter ablation of ventricular arrhythmias

Ventricular arrhythmias are an important cause of morbidity and mortality and come in a variety of forms, from single premature ventricular complexes to sustained ventricular tachycardia and fibrillation. Rapid developments have taken place over the past decade in our understanding of these arrhythmias and in our ability to diagnose and treat them. The field of catheter ablation has progressed with the development of new methods and tools, and with the publication of large clinical trials. Therefore, global cardiac electrophysiology professional societies undertook to outline recommendations and best practices for these procedures in a document that will update and replace the 2009 EHRA/HRS Expert Consensus on Catheter Ablation of Ventricular Arrhythmias. An expert writing group, after reviewing and discussing the literature, including a systematic review and meta-analysis published in conjunction with this document, and drawing on their own experience, drafted and voted on recommendations and summarized current knowledge and practice in the field. Each recommendation is presented in knowledge byte format and is accompanied by supportive text and references. Further sections provide a practical synopsis of the various techniques and of the specific ventricular arrhythmia sites and substrates encountered in the electrophysiology lab. The purpose of this document is to help electrophysiologists around the world to appropriately select patients for catheter ablation, to perform procedures in a safe and efficacious manner, and to provide follow-up and adjunctive care in order to obtain the best possible outcomes for patients with ventricular arrhythmias.

Factors associated with recurrent postinfarction ventricular tachycardia following ablation

INTRODUCTION

Ablation of ventricular tachycardia is the main therapy for patients with drug-refractory ventricular tachycardia (VT). Although evidence suggests that VT ablation could lower the incidence of recurrent VT, many cases still develop VT in follow-up. In this study, we performed a systematic review and meta-analysis to examine risk factors for recurrent VT in patients with postinfarction VT who underwent VT ablation.

EVIDENCE ACQUISITION

We comprehensively searched the databases of MEDLINE and EMBASE from inception to March 2020. Included studies were cohort studies, experimental trials, or randomized controlled trials that evaluate the risk of recurrent VT in postinfarction VT patients who underwent VT ablation. Data from each study were combined using random-effects.

EVIDENCE SYNTHESIS

Thirteen studies involving 1803 postinfarction patients who underwent VT ablation were included. Inducibility after the procedure (pooled HR=1.71, P<0.001), lower baseline left ventricular ejection fraction (LVEF) (pooled HR=0.98, P<0.001) and higher baseline New York Heart Association (NYHA) classification (pooled HR=1.34, P=0.003) were significantly associated with VT recurrence during the follow-up. There was no significant association between age, gender or diabetes mellitus and VT recurrence.

CONCLUSIONS

Our meta-analysis demonstrated that inducibility after the procedure, lower baseline LVEF and higher baseline NYHA classification were associated with an increased risk of VT recurrence in postinfarction VT patients who underwent VT ablation.

Pre-procedural image-guided versus non-image-guided ventricular tachycardia ablation-a review

BACKGROUND

Magnetic resonance imaging and computed tomography in patients with ventricular tachycardia (VT) after myocardial infarction (MI) helps to delineate scar from healthy tissue. Image-guided VT ablation has not yet been studied on a large scale.

OBJECTIVE

The aim of the meta-analysis was to compare the long-term outcome of image-guided VT ablation with a conventional approach for VT after MI.

METHODS

Eight electronic bibliographic databases were searched to identify all relevant studies from 2012 until 2018. The search for scientific literature was performed for studies that described the outcome of VT ablation in patients with an ischaemic substrate. The outcome of image-guided ablation was compared with the outcome of conventional ablations.

RESULTS

Of the 2990 citations reviewed for eligibility, 38 articles-enrolling a total of 7748 patients-were included into the meta-analysis. Five articles included patients with image-guided ablation. VT-free survival was 82% [74-90] in the image-guided VT ablation versus 59% [54-64] in the conventional ablation group (p < 0.001) during a mean follow-up of 35 months. Overall survival was 94% [90-98] in the image-guided versus 82% [76-88] in the conventional VT ablation group (p < 0.001).

CONCLUSIONS

Image-guided VT ablation in ischaemic VT was associated with a significant benefit in VT-free and overall survival as compared with conventional VT ablation. Visualising myocardial scar facilitates substrate-guided ablation procedures, pre-procedurally and by integrating imaging during the procedure, and may consequently improve long-term outcome.

Prognostic significance of extensive versus limited induction protocol during catheter ablation of scar-related ventricular tachycardia

INTRODUCTION

Testing for inducible ventricular tachycardia (VT) pre- and postablation forms the cornerstone of contemporary scar-related VT ablation procedures. There is significant heterogeneity in reported VT induction protocols. We examined the utility of an extensive induction protocol (up to 4 extra-stimuli [ES] ± burst ventricular pacing) compared to the current guideline-recommended protocol (up to 3ES, defined as limited induction protocol) in patients with scar-related VT.

METHODS AND RESULTS

Sixty-two patients (age: 64 ± 14 years; left ventricular ejection fraction: 37 ± 13%, ischemic cardiomyopathy: 31, nonischemic cardiomyopathy: 31) with at least one inducible VT were included. An extensive testing protocol induced 11%-17% more VTs, compared to the limited induction protocol before, and after the final ablation. VT recurred in 48% of patients during a mean follow up of 566 ± 428 days. Patients who were noninducible for any VT using the limited induction protocol had worse ventricular arrhythmia (VA)-free survival (12 months, 43% vs. 82%; p = .03) and worse survival free of VA, transplantation and mortality (12 months 46% vs. 82%; p = .02), compared to patients who were noninducible for any VT using the extensive induction protocol.

CONCLUSIONS

Between 11% and 17% of inducible VTs may be missed if 4ES and burst pacing are not performed in induction protocols before and after ablation. Noninducibility for any VT after an extensive induction protocol after the final ablation portends more favorable prognostic outcomes when compared with the current guideline-recommended induction protocol of up to 3ES. This data suggests that the adoption of an extensive induction protocol is of prognostic benefit after VT ablation.

Complete Electroanatomic Imaging of the Diastolic Pathway Is Associated With Improved Freedom From Ventricular Tachycardia Recurrence

Supplemental Digital Content is available in the text.

The development of multielectrode mapping catheters has expanded the spectrum of mappable ventricular tachycardias (VTs). Full diastolic pathway recording has been associated with a high rate of VT termination during radiofrequency ablation as well as noninducibility at study end. However, the role of diastolic pathway mapping on VT recurrence has yet to be clearly elucidated. We aimed to explore the role of complete diastolic pathway activation mapping on VT recurrence.

Catheter ablation of ventricular arrhythmia guided by a high-density grid catheter

INTRODUCTION

Minimal data exist on the Advisor HD Grid (HDG) catheter and the Precision electroanatomic mapping (EAM) system for ventricular arrhythmia (VA) procedures. Using the HDG catheter, the EAM uses the high-density (HD) wave mapping and best duplicate software to compare the maximum peak-to-peak bipolar voltages within a small zone independent of wavefront direction and catheter orientation. This study aimed to summarize the procedural experience for VAs using the HDG catheter.

METHODS

Clinical and procedural characteristics of VA ablation procedures were retrospectively reviewed that used the HDG catheter and the Precision EAM over a 12-month period.

RESULTS

A total of 22 patients, 18 with sustained ventricular tachycardia and 4 with premature ventricular contractions were included. Clinically indicated left and/or right ventricular (LV, RV, respectively), and aortic maps were created. LV substrate maps (n = 13) used a median 1700 points (interquartile range [IQR]_25%-75% , 1427-2412) out of a median 18 573 (IQR_25%-75% , 15 713-41 067) total points collected. RV substrate maps (n = 11) used a median 1435 points (IQR_25%-75% , 1114-1871) out of a median 16 005 (IQR_25%-75% , 11 063-21 405) total points collected. Total point utilization, used vs collected, was 9%. Mean mapping time was 43 ± 17 minutes (substrate, 34 ± 18 minutes; activation/pace mapping, 9 ± 13 minutes). Acute success was achieved in 56 (86%) and short-term success achieved in 16 patients (73%) at a median follow-up of 145 days (IQR_25%-75% , 62-273 days). There were no procedural complications.

CONCLUSION

HD wave mapping using the novel HDG catheter integrated with the Precision EAM is safe and feasible in VA procedures in the LV, RV, and aorta. Mapping times are consistent with other multielectrode mapping catheters.

Focal Ventricular Tachycardias in Structural Heart Disease: Prevalence, Characteristics, and Clinical Outcomes After Catheter Ablation

OBJECTIVES

This study sought to summarize the procedural characteristics and outcomes of patients with structural heart disease (SHD) who have focal ventricular tachycardia (VT).

BACKGROUND

Scar-mediated re-entry is the predominant mechanism of VT in SHD. Some SHD patients may have a focal VT mechanism that remains poorly described.

METHODS

An extended induction protocol incorporating programmed electrical stimulation, right ventricular burst pacing and isoprenaline was used to elucidate both re-entrant and focal VT mechanisms.

RESULTS

Eighteen of 112 patients (16%) with SHD undergoing VT ablation over 2 years had a focal VT mechanism elucidated (mean age 66±13 years; ejection fraction 46±14%; nonischemic cardiomyopathy 10). Repetitive failure of termination with antitachycardia pacing (ATP) (69% of patients) or defibrillator shocks (56%) was a common feature of focal VTs. A median of 3 VTs per patient were inducible (28 focal VTs, 34 re-entrant VTs; 53% of patients had both focal and re-entrant VT mechanism). Focal VTs more commonly originated from the right ventricle (RV) than the left ventricle (LV) (67% vs. 33%, respectively). In the RV, the RV outflow tract was the most common site (33% of all focal VTs), followed by the RV moderator band (22%), apical septal RV (6%), and lateral tricuspid annulus (6%). The lateral LV (non-Purkinje) was the most common LV focal VT site (16%), followed by the papillary muscles (17%). After median follow-up of 289 days, 78% of patients remained arrhythmia-free; no patients had recurrence of focal VT at repeat procedure. In patients with recurrence, defibrillator therapies were significantly reduced from a median of 53 ATP episodes pre-ablation to 10 ATP episodes post-ablation. During follow-up, 2 patients (11%) underwent repeat VT ablation; none had recurrence of focal VT.

CONCLUSIONS

Focal VTs are common in patients with SHD and often coexist with re-entrant forms of VT. High failure rate of defibrillator therapies was a common feature of focal VT mechanisms. Uncovering and abolishing focal VT may further improve outcomes of catheter ablation in SHD.

2019 HRS/EHRA/APHRS/LAHRS expert consensus statement on catheter ablation of ventricular arrhythmias

Ventricular arrhythmias are an important cause of morbidity and mortality and come in a variety of forms, from single premature ventricular complexes to sustained ventricular tachycardia and fibrillation. Rapid developments have taken place over the past decade in our understanding of these arrhythmias and in our ability to diagnose and treat them. The field of catheter ablation has progressed with the development of new methods and tools, and with the publication of large clinical trials. Therefore, global cardiac electrophysiology professional societies undertook to outline recommendations and best practices for these procedures in a document that will update and replace the 2009 EHRA/HRS Expert Consensus on Catheter Ablation of Ventricular Arrhythmias. An expert writing group, after reviewing and discussing the literature, including a systematic review and meta-analysis published in conjunction with this document, and drawing on their own experience, drafted and voted on recommendations and summarized current knowledge and practice in the field. Each recommendation is presented in knowledge byte format and is accompanied by supportive text and references. Further sections provide a practical synopsis of the various techniques and of the specific ventricular arrhythmia sites and substrates encountered in the electrophysiology lab. The purpose of this document is to help electrophysiologists around the world to appropriately select patients for catheter ablation, to perform procedures in a safe and efficacious manner, and to provide follow-up and adjunctive care in order to obtain the best possible outcomes for patients with ventricular arrhythmias.

Noninvasive Programmed Ventricular Stimulation-Guided Management Following Ventricular Tachycardia Ablation

OBJECTIVES

This study sought to determine the impact of repeat catheter ablation (CA) prior to hospital discharge based on inducibility of clinical ventricular tachycardia (VT) during noninvasive programmed ventricular stimulation (NIPS).

BACKGROUND

Inducibility of clinical VT during NIPS performed several days after CA identifies patients at high risk of recurrence. The impact of NIPS-guided repeat CA has not been reported.

METHODS

Consecutive patients with structural heart disease undergoing CA of VT followed by NIPS were studied. Clinical VT was defined by comparison with 12-lead electrocardiograms and stored implantable cardioverter-defibrillator electrograms from spontaneous VT episodes. Among those with inducible clinical VT at NIPS, VT-free survival was compared between those in whom ablation was repeated (group 1) versus those in whom ablation was not repeated (group 2) prior to hospital discharge.

RESULTS

Among 469 patients (64 ± 12 years of age; 85% males; 60% ischemic), 216 patients (46%) underwent NIPS 3 days (interquartile range: 2 to 4 days) after CA. Clinical VT was induced in 45 patients (21%). Among those 45, CA was repeated in 11 patients (24%). There were no significant differences in baseline clinical or index CA characteristics between groups 1 and 2. Over a median 36-month follow-up, only 1 patient (9%) in group 1 experienced VT recurrence compared to 24 patients (71%) in group 2 (p < 0.01). In univariate Cox regression, repeat CA guided by NIPS (hazard ratio: 0.07; 95% confidence interval: 0.01 to 0.58; p = 0.01) was the only predictor of VT-free survival.

CONCLUSIONS

In patients with inducible clinical VT during post-ablation NIPS, repeat CA was associated with significantly lower risk of subsequent recurrence.

Prediction and prognosis of ventricular tachycardia recurrence after catheter ablation with remote magnetic navigation for electrical storm in patients with ischemic cardiomyopathy

BACKGROUND

Ventricular tachycardia (VT) recurrence after catheter ablation for electrical storm is commonly seen in patients with ischemic cardiomyopathy (ICM).

HYPOTHESIS

We hypothesized that VT recurrence can be predicted and be related to the all-cause death after VT storm ablation guided by remote magnetic navigation (RMN) in patients with ICM.

METHODS

A total of 54 ICM patients (87% male; mean age, 65 ± 7.1 years) presenting with VT storm undergoing acute ablation using RMN were enrolled. Acute complete ablation success was defined as noninducibility of any sustained monomorphic VT at the end of the procedure. Early VT recurrence was defined as the occurrence of sustained VT within 1 month after the first ablation.

RESULTS

After a mean follow-up of 17.1 months, 27 patients (50%) had freedom from VT recurrence. Sustained VT recurred in 12 patients (22%) within 1 month following the first ablation. In univariate analysis, VT recurrence was associated with incomplete procedural success (hazard ratio [HR]: 6.25, 95% confidence interval [CI]: 1.20-32.47, P = 0.029), lack of amiodarone usage before ablation (HR: 4.71, 95% CI: 1.12-19.7, P = 0.034), and a longer procedural time (HR: 1.023, 95% CI: 1.00-1.05, P = 0.05). The mortality of patients with early VT recurrence was higher than that of patients without recurrence (P < 0.01).

CONCLUSIONS

Inducibility of any VT at the end of procedure for VT storm guided by RMN is the strongest predictor of VT recurrence. ICM patients who have early recurrences after VT storm ablation are at high risk of all-cause death.

Multicenter Experience With Catheter Ablation for Ventricular Tachycardia in Lamin A/C Cardiomyopathy

Background—

Lamin A/C ( LMNA ) cardiomyopathy is a genetic disease with a proclivity for ventricular arrhythmias. We describe the multicenter experience with percutaneous catheter ablation of sustained monomorphic ventricular tachycardia (VT) in LMNA cardiomyopathy.

Methods and Results—

Twenty-five consecutive LMNA mutation patients from 4 centers were included (mean age, 55±9 years; ejection fraction, 34±12%; VT storm in 36%). Complete atrioventricular block was present in 11 patients; 3 patients were on mechanical circulatory support for severe heart failure. A median of 3 VTs were inducible per patient; in 82%, mapping was consistent with origin from scar in the basal left ventricle, particularly the septum, but also basal inferior wall and subaortic mitral continuity. After multiple procedures (median 2/patient; transcoronary alcohol in 6 and surgical cryoablation in 2 patients), acute success (noninducibility of any VT) was achieved in only 25% of patients. Partial success (inducibility of a nonclinical VT only: 50%) and failure (persistent inducibility of clinical VT: 12.5%) was attributed to intramural septal substrate in 13 of 18 patients (72%). Complications occurred in 25% of patients. After a median follow-up of 7 months after the last procedure, 91% experienced ≥1 VT recurrence, 44% received or were awaiting mechanical circulatory support or transplant for end-stage heart failure, and 26% died.

Conclusions—

Catheter ablation of VT associated with LMNA cardiomyopathy is associated with poor outcomes including high rate of arrhythmia recurrence, progression to end-stage heart failure, and high mortality. Basal septal scar and intramural VT origin makes VT ablation challenging in this population.