Characterization of conduction system activation in the postinfarct ventricle using ripple mapping

BACKGROUND

Three-dimensional (3D) mapping of the ventricular conduction system is challenging.

OBJECTIVE

The purpose of this study was to use ripple mapping to distinguish conduction system activation to that of adjacent myocardium in order to characterize the conduction system in the postinfarct left ventricle (LV).

METHODS

High-density mapping (PentaRay, CARTO) was performed during normal rhythm in patients undergoing ventricular tachycardia ablation. Ripple maps were viewed from the end of the P wave to QRS onset in 1-ms increments. Clusters of >3 ripple bars were interrogated for the presence of Purkinje potentials, which were tagged on the 3D geometry. Repeating this process allowed conduction system delineation.

RESULTS

Maps were reviewed in 24 patients (mean 3112 ± 613 points). There were 150.9 ± 24.5 Purkinje potentials per map, at the left posterior fascicle (LPF) in 22 patients (92%) and at the left anterior fascicle (LAF) in 15 patients (63%). The LAF was shorter (41.4 vs 68.8 mm; P = .0005) and activated for a shorter duration (40.6 vs 64.9 ms; P = .002) than the LPF. Fourteen of 24 patients had left bundle branch block (LBBB), with 11 of 14 (78%) having Purkinje potential-associated breakout. There were fewer breakouts from the conduction system during LBBB (1.8 vs 3.4; 1.6 ± 0.6; P = .039) and an inverse correlation between breakout sites and QRS duration (P = .0035).

CONCLUSION

We applied ripple mapping to present a detailed electroanatomic characterization of the conduction system in the postinfarct LV. Patients with broader QRS had fewer LV breakout sites from the conduction system. However, there was 3D mapping evidence of LV breakout from an intact conduction system in the majority of patients with LBBB.

Non-ischemic cardiomyopathy: what predicts survival and ICD shocks after ventricular tachycardia ablation?

Funding Acknowledgements

Type of funding sources: None.

Introduction

Patients (pts) with non-ischemic cardiomyopathy (NICM) present an increased morbidity and mortality from sustained monomorphic ventricular tachycardia (VT). Implantable cardiac defibrillators effectively terminate VT, but ablation is usually required to prevent recurrences and appropriate shocks. Although several risk factors have been pointed out, clear prognostic predictors need to be established and addressed.

Purpose

To evaluate risk factors associated with all-cause mortality and ICD shocks in NICM pts submitted to VT ablation.

Methods

Prospective, observational, single-centre study of pts with NICM submitted to VT ablation using high density mapping tools.The primary outcome was all-cause death or VT recurrence terminated with appropriate ICD shock during long-term follow up. Kaplan-Meier analysis was used to estimate the long-term event-free survival. Uni and multivariate Cox regression analyses were used to determine relevant prognostic predictors.

Results

A total of 27 consecutive pts with NICM were referred for a first-ever VT ablation procedure between June 2015 and June 2021 (males: 93%; mean age: 61±12 years). The mean left ventricular ejection fraction (LVEF) was 35±12% and 70% of pts had NYHA class I or II.

During a mean follow-up of 29 ± 19 months, VT recurrences requiring ICD shocks occurred in 25.9% of pts. VT ablation success and the risk of ICD shocks were not associated with any of the clinical characteristics. Long-term all-cause mortality was 37%. In univariate analysis, LVEF <30%, NT-proBNP, NYHA classification III-IV, chronic kidney disease (CKD), ICD for secondary prevention and prior VT ablation (p=0.08) were associated with reduced survival. On multivariate analysis, CKD was identified as the strongest independent survival predictor (HR 6.9; CI95%: 1.5-23-2, p=0.010)

Conclusions

In pts with NIDM, VT ablation may be successful even in pts with advanced heart disease. However, long-term survival will depend mostly on the stage of disease progression and is strongly associated with the clinical markers of end-stage heart failure. Therefore, a timely referral is crucial to derive the best clinical benefit from VT ablation in this population.

Epicardial mapping as first intention approach for structural ventricular tachycardia ablation

Funding Acknowledgements

Type of funding sources: None.

Introduction

In several structural arrhythmogenic diseases that comprise intricate endocardial, intramural and epicardial substrates, endocardial ablation of ventricular tachycardia (VT) is not sufficient and epicardial ablation has lately become a complementary and necessary tool.

Purpose

To evaluate the clinical characteristics of patients (pts) most suitable for first intention epicardial VT ablation.

Methods

Single-center prospective study of consecutive pts with structural heart disease undergoing first intention epicardial VT mapping between August 2015 and June 2021. Decision for epicardial approach was based on the etiology, VT electrocardiogram (ECG) and cardiac magnetic resonance (CMR) results. Under general anesthesia, subxiphoid access using a Tuhoy needle was done using fluoroscopic guidance and with high-density epicardial mapping was performed. Epicardial ablation was performed if relevant arrhythmogenic findings were locally confirmed.

Results

First intention epicardial VT ablation was attempted in 18 pts (mean age 59.8±12 years,94% male) of whom 16 had non-ischemic dilated cardiomyopathy (NICM,idiopathic:11; post-myocardis:4; hereditary:1) and 2 had right ventricular arrhythmogenic cardiomyopathy. Mean LVEF was 33% and 79% had a previous ICD (53% in primary prevenon). 69% were referred for ablation due to arrhythmic storm (1pt in cardiogenic shock). Epicardial access was achieved in 17 pts (94%), without acute complications. In 35% pts with NICM the decision for epicardial approach was based on the detection of subepicardial CMR delayed-hyperenhancement and relevant epicardial arrhythmic substrate was confirmed by mapping in all cases. In 3 pts radiofrequency (RF) applicaons were not performed at epicardium, as no abnormal electrograms were locally detected, and an addional endocardial approach was prosecuted. The mean overall procedure and fluoroscopic time were 123 and 28min, respectively, with a mean RF application me of 51min. After the procedure 1pt required pericardial drainage due to inflammatory pericardial effusion. No other acute complications occurred. During a mean follow-up of 2.8±1.8 years, only 3pts (17%) had VT recurrence; 5pts (28%) died due to end-stage heart failure and 2pts (11%) underwent heart transplantation.

Conclusion

In NICM a first intention epicardial VT ablation performed by experienced operators/centers is efficient, particularly if guided by CMR findings,and presents a safety profile.

Additional features in Brugada Syndrome stratification: frequent PVC and QRS duration

Funding Acknowledgements

Type of funding sources: None.

Introduction

Brugada syndrome (BrS) is a channelopathy with high prevalence of malignant arrhythmic events. The risk stratification in patients (pts) with Brugada electrocardiographic (ECG) pattern is of major importance, to prevent sudden cardiac death (SCD). A higher risk is evidenced in spontaneous type 1 pattern when compared with induced type-1 pattern, as so other electrocardiographic features have been explored aiming to detect additional prognostic factors.

Purpose

To evaluate the association of QRS duration and frequent premature ventricular contractions (PVC) with malignant arrhythmic events.

Methods

Prospective single-center study of consecutive pts with BrS, with spontaneous or induced type 1 pattern included from 2003 to 2021. All pts were enrolled in a protocol including annual non-invasive assessment with ECG and 24-hours Holter monitoring. Primary endpoints were defined as SCD or appropriate shocks in the context of ventricular tachycardia or fibrillation (VT/FV) during follow-up. Cox regression and Kaplan-Meier survival analyses were used to determine the association between the baseline ECG and Holter characteristics and the long-term risk of arrhythmic events.

Results

A total of 117 pts was included, 75 (65%) with a spontaneous type 1 pattern and 44 (33%) with an induced type 1 pattern. The mean age was 47±13years and 38 (32.5%) were male.

During a median follow-up of 4.1±0.3 years, the primary endpoint occurred in 8 (6.8%) pts, with sudden cardiac death in 3 (2.6%) and appropriate shocks due to VT/FV in 5 (4.3%). Pts who suffered arrhythmic events had presented at the study inclusion higher QRS duration (124±18 vs. 108±16ms, p= 0.014) and more frequent PVCs on 24-hour Holter (169±297 vs. 29±198; p = 0.001) - Figure 1. Indeed, the presence of QRS ≥119ms was associated with a 7-fold higher risk (HR: 7.250, 95% CI 1.619-32.461, p = 0.010) and the presence of more than 6 PVC on 24-hour Holter was also associated with a 5-fold higher risk of malignant arrhythmic events (HR 5.376, 95% 1.186-24.260, p = 0.029).

Conclusion

QRS duration and frequent PVC may established themselves as additional risk factors. In our cohort, they were both predictors of arrhythmic events during follow-up and thus can further complement BrS risk stratification.

Apical versus septal pacing - can we chose the localization of ventricular lead in order to prevent upgrade to cardiac resynchronization therapy?

Funding Acknowledgements

Type of funding sources: None.

Introduction

Right ventricular apical pacing (RVAp) may be deleterious to ventricular function and hemodynamics due to pacing induced dyssynchrony. In the last decades, some studies showed that RVAp has been associated with heart failure, deterioration of left ventricular function and high mortality. Some patients (pts) may need, during the follow up (FUP), an upgrade to cardiac resynchronizaon therapy (CRT). New techniques have emerged such as RV lead implantation in the high septum or outflow RV tract (RVOT) and, more recently, His bundle/LB pacing.

Purpose

To compare the need for upgrade to CRT in patients with RVAp versus septal/RVOT pacing.

Methods

Retrospective single-center study of consecutive pts that implanted pacemakers in a tertiary center between January 1995 and December 2020. We collected data regarding pacing indication, RV pacing site (apex versus septum/RVOT) and need for an upgrade to CRT during follow up (FUP).

Our primary endpoint was upgrade to CRT during the FU period. In the model, the impact of localization of the implanted lead on the survival free from upgrade was estimated assuming a neutral effect on mortality. Statistical analysis was performed using T-student test and logistic regression.

Results

We included 8761 pts, 60.2% (n=5275) were male, with a mean age of 76.5±10.7 years. The main indications for pacemaker implantation were (1) complete atrioventricular (AV) block (2239, 25.6%), (2) sick sinus syndrome (2211, 25.2%), (3) atrial fibrillation with AV block or bradycardia with significant pauses (17.4%) and (4) Mobitz II 2nd degree AV block (1467, 16.7%).

RVAp was performed in 1746 (20%) patients and RVOT/septal pacing in 6933 patients (80%; RVOT in 657 (9,5%)). During FUP, 26 (1,5%) RVAp pts and 52 (0,8%) RVOT/septal pacing pts underwent upgrade to CRT, in a total of 78 pts (CRT-P in 54 patients and CRT-D in 24 patients).

We observed that patients with RVAp had twice the risk of CRT upgrade during FUP (OR: 2,0 (IC 95% 1,25-3,21), p=0,004) when compared to patients with RVOT/septal pacing.

Conclusions

Patients with RVAp presented a 2-fold higher risk for upgrade to CRT when compared to patients with RVOT/septal pacing in our center. This retrospective analysis shows that lead implantation in the septum/RVOT should be preferred instead of the apex to reduce pacing induced dyssynchrony and need for CRT upgrade.

Is it possible to predict mortality and recurrence of VT afterablation? PAINESD risk score applicability vs new predictors

Funding Acknowledgements

Type of funding sources: None.

Introduction

Catheter ablation (CA) prevents ventricular tachycardia (VT) recurrences in patients (pts) with structural heart disease (SHD), and might have a favorable outcome, but is associated with severe short-term complications. Identification of pts at high risk of periprocedural acute haemodynamic decompensation has important implications at procedural planning.

The PAINESD risk score is a promising tool to predict VT ablation procedure-related mortality.

Aim

To evaluate the accuracy of the PAINESD risk score to predict short-term mortality after structural VT ablation and to compare it with other conventional clinical predictors.

Methods

Prospective, observational, single-centre study of consecutive pts with SHD (ischemic or nonischemic), referred for VT-CA. High-density substrate maps were collected, through endocardial, epicardial or combined endo-epicardial approaches according to clinical data and operator preference. The primary endpoint was 30-day mortality or hemodynamic decompensation. Univariate Cox regression analysis was used to identify relevant clinical predictors and to compare them with the PAINESD risk score. Multivariable Cox proportional hazards regression models were used to estimate predictors of 30-day mortality.

Results

A total of 102 pts with SHD referred for VT ablation were evaluated(mean age: 67±11 years, 94% male, 78.4% in NYHA class I-II; mean LVEF was 34±11%). The baseline PAINESD risk score was 12.39±5.8, 19.6% at low risk, 36.3% at intermediate risk and 27.5% at high risk of adverse events. Overall 30-day mortality was 4.9%. The PAINESD did not predict 30-days mortality or hemodynamic decompensation (p= 0.93). Indeed, a non- significant trend to higher short and long-term mortality was noticed in high-risk score pts – Figure 1. On univariate analysis age>65 years (p=0.019), LVEF <35% (p=0.049), body mass index<28kg/m2 (p=0.019), CKD (p=0.001) and previous VT ablation (p=0.022) were prognostic predictors. On multivariate analysis, only LVEF<35% (HR2.225; CI95% 1.004-4-774,p=0.038) and CKD (HR 3.35; CI95%: 1.31-8.51, p=0.011) were independent predictors of short-term prognosis.

Conclusions

In our population, LVEF<35% and CKD were the strongest predictors of short-term mortality. PAINESD risk score was not accurate in predicting adverse events. New score systems must be derived for prognostic stratification in this population, incorporating the reduction on the actual short-term event rates after VT ablation.

Predictors of survival in patients submitted to typical atrial flutter ablation

Introduction

Cavo-tricuspid isthmus ablation (CTA) is the first line procedure in patients with typical atrial flutter (AFL) for adequate rhythm and symptoms control with low complication rates and excellent results. Given its apparent simplicity, rarely do we take clinical factors in account before referral.

Aim

To identify predictors of survival after typical AFL ablation.

Methods

Single-center retrospective study of pts with typical AFL submitted to ablation between 2015 and 2019. Pts clinical characteristics were collected. Statistical analysis was performed using Cox regression (for multivariate analysis), Chi-square and Mann-Whitney (for univariate analysis) to identify predictors of survival.

Results

A total of 476 pts (66±12 years, 80% males) underwent CTA. Regarding global clinical characteristics, median body mass index (BMI) 27.3 (IQ 24.5–30.4), median CHA2DS2-VASc score 2 (IQ 1–3), 27.3% with diabetes, 53.9% with dyslipidemia, 69.5% with hypertension, 12% with current tobacco abuse, thyroid disfunction in 10.9%, ischaemic cardiomyopathy in 13.7%, heart failure in 27.8% (3.6% of pts with reduced ejection fraction), chronic kidney disease (CKD) stage 3 or more in 17.7%, obstructive sleep apnea (OSA) in 11.9% and chronic obstructive pulmonary disease (COPD) in 9.5% of pts. Before CTA ablation, 444 pts were under anticoagulation, which was stopped in 293 pts after the procedure. The follow up period was 2.8 years.

In this population, COPD (p=0.005), CKD (p<0.001), heart failure (p=0.0027) and BMI less than 25 (p=0.02) were associated with reduced survival on univariate analysis; patients with BMI between 25 and 30 had better prognosis. On multivariate analysis, CKD was the only independent predictor of reduced survival (HR 0.366; CI95%: 0.132–0.737, p=0.005). There was no difference between genders (p=NS).

A CHA2DS2-VASc score of ≥4 predicted higher mortality (HR: 3.0) in all three groups, although the anti-coagulation suspension had no impact on survival (p=NS).

Conclusion

In this subset of patients, the presence of COPD, heart failure, BMI less than 25 and CHA2DS2-VASc score ≥4 predicted reduced survival, being CKD stage 3 or more an independent predictor. The suspension of anti-coagulation didn't impact on survival. These results can help us to better select pts to the procedure and decide on whether to stop anti-coagulation, although larger studies are still needed.

Funding Acknowledgement

Type of funding sources: None. BMI impact on survivalCKD impact on survival

Real-world comparison of different periprocedural antithrombotic strategies for atrial fibrillation catheter ablation

Introduction

Atrial Fibrillation (AF) catheter ablation carries high bleeding and thromboembolic risks, requiring a detailed assessment of overall risk-benefit profile regarding antithrombotic strategy. Vitamin K Anticoagulant (VKA) and Non-Vitamin K Antagonist Oral Anticoagulant (NOAC) have been used in the latest years in this setting, and with different interruption protocols periprocedural. Our goal was to evaluate the rate of acute adverse events (AAE) and compare them according to antithrombotic strategy used periprocedural, in a real-world basis.

Methods

A single-center retrospective study, including adult patients admitted to first AF catheter ablation, from 2004 to 2020. Different antithrombotic strategies (anticoagulation with VKA uninterrupted, anticoagulation with NOAC uninterrupted, no therapy or antiaggregation/interrupted ACO) were compared concerning the rate of any clinically relevant AAE; the composite of major AAE (hemopericardium and stroke/transient ischemic attack [TIA]) and minor AAE associated with vascular access. Descriptive statistics and logistic regression were used to compare groups according to the antithrombotic strategy with an alpha level of 0.05.

Results

Among the 868 patients included (mean age 59±12 yo, 67,5% [n=586] men), pulmonary vein isolation was performed under uninterrupted anticoagulation in 640 (73,7%), of which 595 patients with NOAC (68,5%) and 45 with VKA (5,2%). AF was paroxysmal, persistent and long-standing persistent in 63,4% (n=550), 21,4% (n=185) and 15,4% (n=133) patients, respectively. Mean CHADS-VASc score was 1,86±1,48. Over time there was a shift in the distribution of the type of antithrombotic therapy used, consistent with changes in recommendations (Graph 1).

The composite outcome occurred in 6,8% (n=62), including hemopericardium in 1,8% (n=16), stroke/TIA in 0,7% (n=6) and events related to vascular access in 1,4% (n=13) [Table 1]. No anticoagulation therapy or antiaggregation/interrupted ACO was more associated to the outcome, driven by major AAE, although the difference did not meet statistical significance (p=0,06) [Table 1]. No difference was found between VKA and NOAC group. Additionally, there was no diference in the incidence of hemorrhagic AAE since the implementation of an uninterrupted anticoagulation strategy periprocedural.

Conclusion

In our population of patients submitted to AF catheter ablation, an uninterrupted anticoagulation strategy is associated with lower rate of AAE, either with VKA or NOAC. Our real-world results are reassuring of the benefit of an uninterrupted strategy, and consistent with recent controlled trials.

Funding Acknowledgement

Type of funding sources: None. Antithrombotic therapies over timeClinically relevant acute adverse events

Cryoablation: safety of same day discharge

Introduction

Discharge after overnight hospital stay is standard procedure in patients submitted to elective atrial fibrillation (AF) ablation. Taking into consideration the low rate of cryoablation procedure complications could the same day discharge be an option?

Purpose

To assess the safety of same day discharge of patients submitted to AF cryoablation.

Methods

Single-center retrospective study of consecutive patients admitted to elective AF cryoablation in a tertiary center between February 2017 and November 2020. Patients were divided into two groups: same day discharge and next day discharge. Only patients submitted to ablation until 4 p.m. were included. Complication rates were obtained up to six months after the procedure. Complications were defined as death, pericardial tamponade, hematoma requiring evaluation and/or intervention, major bleeding requiring transfusion, hospital admission related to the procedure.

Results

One hundred fifty-four patients were included, with a mean age of 61±10.9 years, 66.2% were males, 18.2% with diabetes, 65.6% with dyslipidemia, 77.9% with hypertension, 10.4% with chronic kidney disease KDIGO stage 3 or more. Median follow-up of 436 [178 – 729] days. Most of the patients had paroxysmal (73.4%) and persistent short duration AF (23.4%). Sixty-two patients (40.3%) were early discharged and there were no differences between the two groups regarding epidemiological and clinical characteristics (p=NS).

A very low rate of complications in both groups was observed, occurring in 6.5% of patients with early discharge and in 8.7% of patients in overnight stay, without statistical significance between the two groups (p=0.61). The most frequent complications were local hematoma (5 patients, 2 in early discharged group), pericardial effusion (3 patients, all in overnight stay), femoral pseudo-aneurism (2 patients, 1 in each group) and arteriovenous fistula (1 patient in overnight stay group). The type of complications did not differ between the two groups (p=0.51). Two patients died during follow up, and this was unrelated to the procedure. In addition, no difference in success rate and arrhythmic recurrence was observed between the two groups (p=NS).

Conclusion

Our study suggests that it is safe to early discharge patients submitted to AF ablation, reducing the hospital stay length in selected patients. Larger studies are needed to confirm this data before routine implementation of this strategy.

Funding Acknowledgement

Type of funding sources: None.

Risk stratification in patients with Brugada syndrome: the role of the late potentials evaluated by signal-averaged ECG

Introduction

Brugada syndrome (BS) is a relevant cause of sudden death in individuals without structural heart disease. The accuracy of the available methods for risk stratification is very limited and the investigation of new methodologies to improve the identification of patients at risk is under intensive investigation. Recently the pathophysiological relevance of anomalous, fragmented and prolonged electrograms on the epicardial surface of the right ventricular outflow tract (RVOT) has been described. Therefore, the study of signal-averaged ECG (SA-ECG) has become attractive since it may allow the non-invasive evaluation of these electrical anomalies. In order to maximize the detection capacity and to focus the evaluation in the RVOT, we developed an alternative methodology of electrode positioning directed to this area of interest.

Purpose

To characterize the study of late potentials (LP) by SA-ECG in patients with SB and to evaluate its association with the occurrence of arrhythmia events.

Methods

Prospective single centre study of patients (pts) with BS. LP were evaluated by SA-ECG with determination of the total filtered QRS duration (fQRS), root mean square voltage of the 40 ms terminal portion of the QRS (RMS40) and duration of the low amplitude electric potential component (40 microV) of the terminal portion of the QRS (LAS40) in conventional and modified leads (addressed to RVOT). The association of LP with the risk of definite malignant dysrhythmias due to sudden death, ventricular fibrillation, ventricular tachycardia or appropriate shock of the implantable cardioverter defibrillator (ICD) was evaluated and the acuity of the prognostic stratification was determined by the area under the receiver operator characteristic curve (ROC).

Results

A total of 76 pts (69.7% men, age 48±12 years) were studied, of which 33 had a spontaneous type 1 pattern and 43 had a type 1 pattern induced by flecainide. During a median follow-up of 1.6 years, 13 pts (17.1%) had symptoms potentially related to BS and 6 (10.5%) had malignant arrhythmias [including two pts who suffered sudden death (2.6%).

The pts who had malignant dysrhythmias presented higher values of fQRS (125±23 vs. 108±18, p=0.046) and LAS40 (54±13 vs. 40±11, p=0.014), and lower values of RMS40 only in the modified leads (11±5 vs. 22±19, p=0.041). The parameters of the SA-ECG were significant prognostic predictors.

The acuity of each of the parameteres alone was moderate and the parameters that were identified as more powerful predictors of risk were those derived from the modified leads (Figure).

Conclusion

The LP evaluated by SA-ECG may be relevant in the prognostic stratification of patients with BS, since it seems to be associated with the risk of malignant ventricular arrhythmias.

Funding Acknowledgement

Type of funding sources: None.

Predictors of survival and ICD shocks in a population submitted to ventricular tachycardia ablation

Introduction

Sustained monomorphic ventricular tachycardia (VT) is associated with an increased risk of mortality and morbidity in patients with ischemic heart disease (IHD). While implantable cardiac defibrillators (ICD) have been shown to reduce mortality in patients with IHD and are effective in terminating VT, they are unable to prevent recurrent VT. Also, recurrent ICD shocks have been associated with an increase in all-cause mortality, hospitalizations for heart failure and are painful, resulting in impaired quality of life. Therefore, strategies to prevent ICD shocks are needed.

Aim

To evaluate risk factors associated to all cause Mortality and ICD shocks

Methods

We conducted a prospective, observational, single-centre and single-arm study involving patients with IHD, referred for Radiofrequency catheter ablation (RCA) procedure for VT using high-density mapping catheters. Variables selected from the univariate analyses (p<0.10) were entered into multivariable Cox proportional hazards regression models to estimate predictors of ICD shocks recurrence and overall mortality. All analyses were 2-sided and a P-value <0.05 was considered statistically significant. Statistical analysis was performed by using IBM SPSS Statistics 26™.

Results

From June 2015 to June 2020, a total of 64 consecutive patients were referred to our centre for a first RCA procedure using high density mapping for VT. The mean age was 68±9 years, 95% were male. 83% of patients were in NYHA functional class II or I and mean LV ejection fraction was 33±11%. All-cause mortality was 23.4%, an age higher than 70 years (p=0.01) and chronic kidney disease (CKD) were associated with reduced survival on univariate analysis. On multivariate analysis, CKD shown a tendency to reduced survival (HR 0.22; CI95%: 0.41–1.22, p=0.08). No risk factors for ICD shocks were found (table 2).

Conclusions

In our population, age and chronic kidney disease were associated with reduced survival, however no risk factors were associated with ICD shocks.

Funding Acknowledgement

Type of funding sources: None.

Is balloon cryoablation effective in common pulmonary trunk?

Introduction

Common pulmonary trunk (CPT) accounts for the most frequent pulmonary vein anatomical variation. The most frequent technique used for pulmonary vein isolation (PVI) is point-by-point radiofrequency, using cryoablation (CB) is still debatable. Some few studies have shown the feasibility and safety of CB in CPT atrial fibrillation (AF) patients (pts), most of them performed angio-CT prior to ablation.

Purpose

To analyzed AF pts with and without CPT submitted to CB in regarding of success rate and safety.

Methods

Single-center retrospective study of consecutive AF pts refractory to antiarrhythmics submitted to CB between 2017 and 2020. Before the procedure auriculography was performed in all pts to verify variations in pulmonary veins, however the procedure was not modify regarding the presence of CPT. Clinical records were analyzed to determine baseline characteristics, success rate and complications. Monitoring was performed with a 7-day event loop recorder at 3, 6 and 12 months and annually from the 2nd year. Success was defined by recurrence of AF (duration >30 seconds). Kaplan Meier survival curves were used to estimate the risk of events and the groups were compared using Chi-square and Mann-Whitney analysis.

Results

A total of 232 pts (60±12 years, 68% males) underwent CB. 29 pts had CPT (28 – common left pulmonary trunk and 2 – common right pulmonary trunk). Baseline characteristics were similar between groups, except for CHA2DS2VASc score and prior cerebrovascular disease history which were higher in CPT pts (3±2 vs 2±2, p=0.001; 24.1% vs 6.8%, p=0.007, respectively). The mean baseline CHA2DS2VASc was 2±2 and the median post-CB follow-up was 135 (IQ 32–249) days.

Both the 1 and 3 year arrhythmic recurrence after AF ablation was not significantly different when comparing CPT and non CPT group with a 3 year success rate of 95.8% in pts with CPV against 86.5% in pts without CPT (p=0.299).

There was no difference between groups (p=0.296; p=0,164, respectively) regarding the time of the procedure, radiation dose and rate of complications.

Conclusions

In our experience, balloon cryoablation for PVI is a safe and successful procedure in patients with CPT anatomical variation.

Funding Acknowledgement

Type of funding sources: None.

Long-Term outcome of ventricular tachycardia catheter ablation in ischemic heart disease patients using a high-density mapping substrate-based approach: a prospective cohort study

Funding Acknowledgements

Type of funding sources: None.

Introduction and objective

Radiofrequency catheter ablation (RCA) for ventricular tachycardia (VT) in patients with ischemic heart disease (IHD) is associated with a reduced risk of VT storm and implantable cardioverter defibrillator (ICD) shocks. We aim to report the long-term outcome after a single RCA procedure for VT in patients with IHD using a high-density substrate-based approach.

Methods

We conducted a prospective, observational, single-centre and single-arm study involving patients with IHD, referred for RCA procedure for VT using high-density mapping catheters. Substrate mapping was performed in all patients. Procedural endpoints were VT noninducibility and local abnormal ventricular activities (LAVAs) elimination. The primary end point was survival free from appropriate ICD shocks and secondary end points included VT storm and all-cause mortality.

Results

Sixty-four consecutive patients were included (68 ± 9 years, 95% male, mean ejection fraction 33 ± 11% , 39% VT storms, and 69% appropriate ICD shocks). LAVAs were identified in all patients and VT inducibility was found in 83%. LAVAs elimination and noninducibility were achieved in 93.8% and 60%, respectively. After a mean follow-up of 25 ± 18 months, 90% and 85% of patients are free from appropriate ICD shocks at 1 and 2 years, respectively. The proportion of patients experiencing VT storm decreased from 39% to 1.6%. Overall survival was 89% and 84% at 1 and 2 years, respectively.

Conclusions

RCA of VT in IHD using a high-density mapping substrate-based approach resulted in a long-term steady freedom of ICD shocks and VT storm. Abstract Figure. Appropriate shock & all cause mortality

Catheter ablation of long-standing persistent atrial fibrillation: the ugly type of AF?

Funding Acknowledgements

Type of funding sources: None.

Introduction

In atrial fibrillation (AF) patients (pts), catheter ablation (CA) by isolating pulmonary veins (PVI) is the most effective therapeutic option in order to maintain sinus rhythm. The success rate of CA relies on type and duration of AF, being more successful in pts with paroxysmal AF and presenting suboptimal success in pts with long-standing persistent AF (LSPAF, >12 months).

Purpose

To evaluate the success of AF ablation, particularly in LSPAF.

Methods

Single-center prospective study of pts submitted to CA between 2004 and 2020. The strategy, regardless of the type of AF, was based on PVI, complemented by cavo-tricuspid isthmus line (CTI) in pts with history of flutter. Additional CA strategies were selectively considered in pts with stable atypical flutter conversion, persistent triggers or no electrograms in the VPs. Pts were monitored with Holter/7-day event loop recorder (3, 6, 12 months and annually up to 5 years). Success was assessed from the 90th day after ablation, with the absence of recurrences of any sustained atrial arrhythmias (> 30 sec). Cox regression and Kaplan-Meier survival were used to compare the success of ablation as a function of the clinical type of AF.

Results

862 pts were submitted to AF ablation (67.3% male, mean age of 58 ± 0.41 years), including 130 pts (15.1%) with LSPAF, 63.3% with paroxysmal AF and 21.6% with short-duration persistent AF (SDPAF). In LSPAF, PVI was performed with irrigated catheter in 26.4%, PVAC in 39.5% and cryoablation in 34.1%. With a mean follow up period of 838 (IQ 159-1469) days, the 3-year success rate after a single procedure was 54.1% in LSPAF, compared to 72.4% in paroxysmal AF and 61.6% in SDPAF (LogRank - p < 0.0001 - figure 1). The risk of arrhythmic recurrence was 37% higher in patients with LSPAF comparing with other groups (HR 0.63 CI 95% 0.43-0.92, p 0.016).

However after a mean of 1.17 procedures/patients, the success difference between groups was not detect (LogRank – p = 0.112 – figure 2). With additional ablation procedures (REDO), the success rate at 3 years was 82.9% LSPAF pts, compared 88.2% in paroxysmal AF pts and 83.6% in SDPAF pts.

In LSPAF pts, different ablation techniques did not predict arrhythmic recurrence. Regarding comorbidities, higher prevalence of peripheral arterial disease (PAD, p = 0.005) a higher NT-proBNP (p = 0.006) and left auricular volume (p = 0.045) were associated with arrhythmic relapse.

Conclusions

AF ablation is more effective when performed earlier in the natural history of the disease. However, even in LSPAF pts, with additional procedures an acceptable rate of success can be achieve, independently from the ablation techniques. Abstract Figures 1 and 2: Success of AF ablation

Can we use the CHA2DS2VASc score in Atrial Flutter?

Funding Acknowledgements

Type of funding sources: None.

Introduction

CHA2DS2VASc score is a well stablished prognostic score in atrial fibrillation population. However, considering patients with isolated atrial flutter no prognostic score are defined, regarding the embolic risk of this population.

Purpose

To evaluate the capacity of CHA2DS2VASc score to predict cardiovascular death and major adverse cardiovascular events (MACE) in flutter patients (pts).

Methods

Single-center retrospective study of pts submitted to CTA between 2015 and 2019, comprising two groups: I – pts with lone AFL; II – patients with AFL and prior AF. Clinical records were analyzed to determine the occurrence of MACE during the long-term follow up, defined as death (of cardiovascular or unknown cause), stroke, clinically relevant bleed or hospitalization due to heart failure or arrhythmic events. CHA2DS2VASc score was categorized into 3 groups: 0-1; 2-3; >4. Kaplan Meier survival curves were used to estimate the risk of events and the groups were compared using uni- and multivariate Cox regression analyses.

Results

A total of 476 pts (66 ± 12 years, 80% males) underwent CTA: group I – 284 pts (60%), II – 192 pts (40%). Baseline characteristics were similar between groups, except for age with group I pts being older (68 ± 12, 64 ± 11, p < 0.01). The mean baseline CHA2DS2VASc was 2.3 ± 1.5 and the median post-CTA follow-up was 2.8 year. Considering global population, CHA2DS2VASc score was an independent predictor of cardiovascular death (OR: 1.49 95%CI 1.09-1.79, p = 0.08) and was a predictor of MACE even after adjustment for the diagnose of prior AF (OR 1.88, 95% IC 1.094-3.249, p = 0.022). Considering only the pts in group I CHA2DS2VASc score was a predictor of MACE (OR 3.03, 95% CI 1.112-8.278, p = 0.03) after adjustment for sex and age. Regarding the different MACE components, the score was a predictor of stroke (OR 4.45, IC 1.66-13.39, p = 0.04). In flutter pts CHA2DS2VASc score did not predict cardiovascular death.

Conclusions

 In our population CHA2DS2VASc score was able to predict MACE events and stroke in patients with isolated atrial flutter. This suggests that in the future CHA2DS2VASc score could be applied to establish embolic risk in atrial flutter. Abstract Figure.

The pacemaker ventricular lead position and outcomes in patients upgrading to crt

Funding Acknowledgements

Type of funding sources: None.

Introduction

 

Adverse hemodynamic effects of right ventricular pacing are known, and the optimal right ventricular lead position is still being a matter of debate. According to the guidelines, upgrade to cardiac resynchronization therapy (CRT) is recommended in patients with indication for pacemaker and left ventricular ejection fraction less than 50% or who need more than 40% of ventricular pacing.

Purpose

 

To compare clinical outcomes and ejection fraction in patients with previous pacemaker (apical versus septal right ventricular pacing) who are upgrated to CRT. 

Methods

 

Single-center retrospective study of 94 consecutive patients who had previous pacemaker and upgraded to CRT over a 4-year period. Of these patients, 64 had previous apical lead pacemaker and 30 had previous septal lead pacemaker. Data on comorbidities, New York Heart Association (NYHA), left ventricular ejection fraction and hospitalizations due to heart failure were collected.

The results were obtained using Chi-square, Mann-Whitney and t-test.

Results

Patients with septal pacemaker had significantly more diabetes (p = 0.04) and chronic obstructive pulmonary disease (p = 0.01), tended to be more symptomatic (p = 0.198) and had more days of hospitalization before and after pacemaker implantation (12 ± 3 versus 7 ± 2 days and 8 ± 4 versus 3 ± 1 days, respectively), mostly due heart failure decompensation. 

Although there were no significant differences in the initial ejection fraction in patients with apical or septal pacemaker implantation (31.2 ± 1.2% and 29.1 ± 1.5%, respectively, p = 0.323), the time to upgrade to CRT was significantly shorter in patients with septal pacemaker implantation (1999 ± 227 days versus 3005 ± 279 days, p = 0.005). 

After upgrading to CRT, patients with apical lead had a significant increase in ejection fraction (8.2%, p = 0.011), while patients with septal lead had a non-significant improvement of ejection fraction (4.5%, p = 0.448). In both, apical and septal lead patients, there was a significant improvement in NYHA class after upgrade to CRT (p = 0.03 and p = 0.02, respectively).

Conclusion

 

Although patients with septal lead had more comorbidities and hospitalizations due to heart failure, they do not benefit from the upgrade to CRT, unlike what happens in patients with apical lead. These findings can be explained by the fact that the septal lead minimizes ventricular desynchrony induced by right ventricular pacing.

Comparing single approaches success in index atrial fibrillation ablation

Funding Acknowledgements

Type of funding sources: None.

Introduction

Atrial Fibrillation (AF) ablation can be performed by inducing pulmonary vein electrical isolation. There are two widely used approaches: point-by-point and single-shot.  Catheter AF ablation is effective in restoring and maintaining sinus rhythm. However, efficacy is limited by high rate of AF recurrence, after an initially successful procedure.

Purpose

To evaluate AF index ablation successfulness using single-shot techniques and compare them to conventional one (point-by-point using irrigated- tip ablation catheter).

Methods

We analyzed, from a single center, all patients submitted to an index AF ablation procedure and its successfulness. The last was defined as AF, atrial tachycardia or flutter recurrence (with a duration superior to 30seconds) event- free survival, determined by holter and/or event recorder. These exams were performed after 6 and 12months and then annually, until 5years post procedure were accomplished.

Results

From November 2004 to November 2020, 821patients were submitted to first AF ablation (male patients 67,2%(N = 552), mean age of 59 ± 12years old). Paroxysmal AF(PAF) was present in 62,9%(N = 516), with short-duration persistent AF in 21,8%(N = 179) and long-standing persistent in 15,3%(N = 126). Ablation techniques were irrigated tip catheter point-by-point (PbP)ablation in 266 patients (32,4%) and single-shot (SS)techniques on the remaining 555(67,6%), including PVAC in 294(35,8%),225(27,4%) submitted to cryoablation and 36(4,4%) to nMARQ.

Globally, AF ablation had one-year success rate of 72,5%, and 56,2% at 3 years. A significant difference between AF duration type was found: Arrhythmic recurrence risk was 58% higher in persistent AF(PeAF) (HR 1.58;95%IC 1,22-2,04; p < 0.001). In patients presenting with PAF prior to the procedure, success was significantly higher in those submitted to SS technique(HR:0.69;95%CI 0,47-0,90;p = 0.046), while those with PeAF had similar results.

Conclusion

In this single center analysis almost three-quarters had achieved one-year event-free survival, and more than a half reached long-term freedom from atrial arrhythmia. Patients with paroxysmal atrial fibrillation submitted to single-shot procedure presented with a higher success-rate. Moreover, our study confirmed previous data on the importance of atrial fibrillation classification to postprocedural outcomes. Abstract Figure. Survival Curves

Long-term risk of major cardiovascular events after cavotricuspid isthmus ablation: when and in whom to discontinue oral anticoagulation?

Funding Acknowledgements

Type of funding sources: None.

Introduction

Cavotricuspid isthmus ablation (CTA) is the 1st line therapy to accomplish rhythm control in typical atrial flutter (AFL). Several studies have shown that AFL is frequently associated with AF, which may be silent, posing the patient at risk of systemic embolism. Nowadays, there are no formal recommendations for OAC after CTA in patients with isolated AFL.

Aim

To determine the risk of MACE after CTA and compare: 1) the presence of concomitant AF, 2) concomitantly performing PVI and 3) persistence on OAC.

Methods

Single-center retrospective study of  pts submitted to CTA between 2015 and 2019, comprising 3 groups: I – pts with lone AFL; II – patients with AFL and prior AF submitted to CTA only; and III – patients with AFL and prior AF submitted to PVI and CTA. Clinical records were analyzed to determine the occurrence of MACE - death (of CV or unknown cause), stroke, clinically relevant bleed or hospitalization due to HF or arrhythmic events. Long-term OAC was defined as its persistence over 18 months after CTA. Kaplan Meier survival curves were used to estimate the risk of events and the groups were compared using uni- and multivariate Cox regression analyses.

Results

A total of 476 pts (66 ± 12 years, 80% males) underwent CTA: group I – 284 pts (60%), II – 109 pts (23%) and III – 83 pts (17%). Baseline characteristics were similar between groups, except for age with group I pts being older (68 ± 12, 67 ± 11, 61 ± 11, p < 0.03). The mean baseline CHA2DS2VASc was 2.3 ± 1.5 and the median post-CTA follow-up was 2.8 year. The 1-, 3- and 5-years MACE risk was 7%, 21% and 32%, respectively and did not differ significantly between groups. OAC was suspended on the long-term in 105 pts (23%), at a mean of 241 days post-CTA. Suspension of OAC was significantly associated with lower MACE risk (HR: 0.26, 95%CI 0.12-0.56, p = 0.001). This effect was independent of the age and CHA2DS2VASc. The prognostic benefit of OAC suspension was driven by the group I and was not verified in patients with concomitant AF. In group I, withdraw of OAC (56 pts - 27%) was associated with a 70% relative risk reduction in the 5-year MACE risk (16% vs 43%, HR: 0.30, 95%CI 0.13-0.69, p = 0.005). In group I, OAC was suspended in patient who were younger (65 ± 11 vs. 69 ± 12, p = 0.002), had lower CHA2DS2VASc (1.9 ± 1.6 vs. 2.7 ± 1.4, p < 0.001) and less often had cerebral vascular disease (1% vs. 8%, p = 0.036), HF (14% vs. 38%, p = 0.001), ischemic cardiomyopathy (9% vs. 19%, p = 0.04) and HTN(61% vs. 75%, p = 0.019).

Conclusions

In pts with AFL submitted to CTA, the long-term risk of MACE is frighteningly high, even in the ones without prior documentation of concomitant AF. Pts with prior AF presenting at the electrophysiological procedure in typical AFL and submitted just to CTA were not significantly harmed, from a prognostic perspective. In pts with lone AFL submitted to successful CTA, it may be reasonable to suspend OAC within 18 months provided that the concomitant AF is carefully excluded. Abstract Figure.

Early discharge after cryoablation procedure: is it safe?

Funding Acknowledgements

Type of funding sources: None.

Introduction

Discharge after overnight hospital stay is standard procedure in patients submitted to elective atrial fibrillation (AF) ablation. Taking into consideration the low rate of cryoablation procedure complications could the same day discharge be an option?

Purpose

To access the safety of same day discharge of patients submitted to AF cryoablation.

Methods

Single-center retrospective study of consecutive pts admitted to elective AF cryoablation in a tertiary center between February 2017 and November 2020. Patients were divided into two groups: same day discharge and next day discharge. Only patients submitted to ablation until 4 p.m. were included. Complication rates were obtained up to six months after the procedure. Complications were defined as death, pericardial tamponade, hematoma requiring evaluation and/or intervention, major bleeding requiring transfusion, hospital admission related to the procedure.

Results

One hundred fifty-four pts were included, with a mean age of 61 ± 10.9 years, 66.2% were males, 18.2% with diabetes, 65.6% with dyslipidemia, 77.9% with hypertension, 10.4% with chronic kidney disease KDIGO stage 3 or more. Median follow-up of 436 (IQ 178 – 729) days. Most of the pts had paroxysmal (73.4%) and persistent short duration AF (23.4%). Sixty-two pts (40.3%) were early discharged and there were no differences between the two groups regarding epidemiological and clinical characteristics (p = NS).

A very low rate of complications in both groups was observed, occurring in 6.5% of pts with early discharge and in 8.7% of pts in overnight stay, without statistical significance between the two groups (p = 0.61). The most frequent complications were local hematoma (5 pts, 2 in early discharged group), pericardial effusion (3 pts, all in overnight stay), femoral pseudo-aneurism (2 pts, 1 in each group) and arteriovenous fistula (1 pt in overnight stay group). The type of complications did not differ between the two groups (p = 0.51). Two pts died during the follow up, unrelated with the procedure.

In addition, no difference in success rate and arrhythmic recurrence was observed between the two groups. (p = NS)

Conclusion

Our study suggests that is safe to early discharge pts submitted to AF ablation, reducing the hospital stay length in selected pts. Larger studies are needed to confirm this data before routine implementation of this strategy.

Typical atrial flutter ablation and predictors of events in the follow-up

Funding Acknowledgements

Type of funding sources: None.

Introduction

Cavotricuspid isthmus ablation (CTA) is considered the main treatment for rhythm control in patients (pts) with typical atrial flutter (AFL). Although there is an established risk for embolic events in atrial fibrillation (AF), the results are not standardized for typical AFL. Currently, anticoagulation in AFL pts submitted to ablation is not consensual.

Purpose

To determine the incidence and predictors of major cardiovascular events (MACE) of pts submitted to CTA of typical AFL.

Methods

Single-center retrospective study of patients (pts) submitted to CTA between 2015 and 2019, comprising three groups: I – pts with lone AFL; II – patients with AFL and prior AF submitted to CTA only; and III – patients with AFL and prior AF submitted to IVP and CTA. Clinical records were analyzed to determine the occurrence of MACE during the long-term follow up, defined as death (of cardiovascular or unknown cause), stroke, clinically relevant bleed or hospitalization due to heart failure or arrhythmic events. Kaplan Meier survival curves were used to estimate the risk of events and the groups were compared using uni- and multivariate Cox regression analyses

Results

A total of 476 pts (66 ± 12 years, 80% males) underwent CTA: group I – 284 pts (60%), II – 109 pts (23%) and III – 83 pts (17%). Baseline characteristics were similar between groups, except for age with group I pts being older (68 ± 12, 67 ± 11, 61 ± 11, p < 0.03).

At presentation, the majority of the pts had palpitations (70.4%) and mild symptoms (70.8%). HTN and dyslipidemia were the most frequent cardiovascular risk factors, 69.5% and 53.9%, respectively, and heart failure was not frequent (27.7%) with only 5.4% of pts with LVEF < 30% and 12.4% with left atrium > 50ml/m2.

During a mean follow-up of 2.8 years, the incidence of MACE events was 102 (21,4%). Regarding MACE components: 54 pts (11.5%) died from cardiovascular death, 20 pts had stroke (4.5%), 13 (3.8%) had a clinically relevant bleeding event, and 51 pts (11.4%) were hospitalized due to heart failure or arrhythmic events.

On univariate analysis, arterial peripheric disease (p = 0.018), HTN (p = 0.046), chronic kidney disease (p <0.001), chronic pulmonary disease (p = 0.0024), heart failure (p <0.001), cerebrovascular disease (p 0.029), body mass index (p = 0.01), age (p <0.001), CHADsVASc score (p < 0.001) and left atrial diameter (p= 0.01) were associated with the occurrence of MACE.

However only age (HR 1.073; 95%CI 1.03-1.06, p < 0.001) and chronic kidney disease (HR 0.37; 95%CI 0.186-0.765, p = 0.007) were independent predictors of major events.

Conclusions

In our cohort of pts with AFL, stroke and bleeding occurred in a minority of pts. Age and chronic kidney disease predicted MACE events during follow-up. Abstract Figure. CKD as FLA predictor

P1457Does high density mapping increase the efficacy of ischemic ventricular tachycardia ablation?

Introduction

 The treatment of ventricular tachycardia (VT) in patients (pts) with ischemic heart disease (IHD) represents a challenge because of its high morbidity and mortality rates and low long-term success rates. In the VANISH clinical trial, 51% of pts undergoing the conventional ablation technique developed within 2 years the combined outcome of mortality or electrical storm (ES) or appropriate CDI shock. The use of high-density substrate maps can lead to greater precision in substrate evaluation and ideally to improved ablation success.

Objectives

 To assess the efficacy of substrate-guided ischemic VT ablation using high-density mapping.

Methods

 Single-center prospective study of consecutive IHD pts submitted to endocardial ablation of substrate-guided VT using multipolar catheters (PentaRayTM or HDGridTM) and three-dimensional mapping systems with automatic annotation software. The maps were evaluated in order to identify the intra-cicatricial channels (areas of bipolar voltage <1.5mV) in which sequential propagation of local abnormal ventricular activities (LAVAs) were observed, during or after QRS. The ablation strategy aimed at the abolition of all intra-cicatricial LAVAs, directing the radiofrequency applications primarily to the entrances of the channels. The success of ablation was assessed by the primary outcome (death by any cause or ES or appropriate CDI shock) at 2 years and compared to the population of the VANISH study undergoing conventional ablation, using Cox regression and Kaplan- Meier survival analysis.

Results

 We included 40 patients, 95% males, 70 ± 8 years, mean ejection fraction 34 ± 10%. 82% on previous amiodarone therapy and 72% were ICD carriers. 32% underwent ablation during hospitalization for ES and 20% had previously undergone VT ablation. The median duration of substrate mapping was 74 minutes, with a mean of 2290 collected points. Major complications were seen in 1 patient (aortic dissection). During a mean follow-up time of 17.3 ± 12.9 months, the long-term success rate of VT ablation was 75%. Additionally, there was a reduction in the proportion of patients receiving amiodarone before vs after ablation (82% vs. 45% respectively). The rate of events observed during follow-up was lower than expected, namely by comparison with the population of the VANISH study undergoing conventional ablation (25% vs 51% at 24 months, HR 0.42 CI 95% 0.2-0.88, p = 0.022), reflecting a relative risk reduction of 58%.

Conclusions

 High density mapping allows a detailed characterization of the dysrhythmic substrate in patients with VT in an IHD context. Our results suggest that these technological innovations may be improving the clinical success of VT ablation.

Abstract Figure.

P945What is the role of late-potentials determined by signal-averaged ECG in predicting flecainide provocative test in brugada pattern?

Introduction

The sudden cardiac death risk in Brugada Syndrome (BrS) is higher in patients with spontaneous type 1 pattern. Brugada diagnosis is also established in patients with induced type 1 morphology after provocative test with intravenous administration with a sodium blocker channel. Nevertheless, this group of patients is known to be at a lower risk of SCD, and their risk stratification is still a matter of discussion.  Late potentials (LP) detected on signal-averaged ECG (SAECG) on the RVOT have been previously proposed as a predictor factor for BrS, even though data is lacking on its value.

Purpose

To evaluate the association between positive LP (LMS40> 38ms) on SAECG with modified Brugada leads and a positive flecainide test in patients with non-type 1 BrS.

Methods

Retrospective single-center study of non-type 1 BrS patients referred for the performance of a flecainide provocative test. Patients presenting with spontaneous type 1 morphology were excluded from the study. Study of LP on SAECG with modified leads for Brugada were evaluated before administration of flecainide [2mg/kg (maximum150mg), for 10minutes] with determination of filtered QRS duration (fQRS), root mean square voltage of the last 40ms of the QRS complex (RMS40) and duration of low amplitude signals <40μV of the terminal QRS complex (LMS40).

Results

126 patients (47.3 ± 14.1 years, 61.9% males) underwent study with LP SAECG and flecainide test. Among these patients, 7.9% were symptomatic and 16.7% had familiar history of BrS. Flecainide test was positive in 46.8% of patients.

In patients with a positive flecainide test, 64.4% presented LMS40 > 38ms whereas LMS40 > 38ms was present in only 46% of those with a negative flecainide test (p = 0.031). The presence of positive LMS40 was a positive predictor for a positive flecainide test, associated with a two-fold increase likelihood in the induction of a Brugada pattern (OR: 2,12; IC95% 1,025-4,392; P = 0,043).

There was no association between fQRS or RMS40 and a positive flecainide test (p = NS). fQRS > 114ms and RMS40 <20uV was present in 22% and 61% of patients with a positive flecainide test, respectively.

Conclusion

In patient with non-type 1 Brugada syndrome, LMS40 > 38ms in SAECG was a predictor for a positive flecainide test, suggesting that this finding could be helpful on the risk stratification of patients undergoing diagnostic study for Brugada syndrome.

Abstract Figure. Effect of LMS 40 in flecainide test

P1402Isolation of pulmonary veins with duty-cycled circular multi-polar catheter: randomized controlled clinical trial

Introduction

Pulmonary vein isolation (PVI) is the central element in the ablation of atrial fibrillation (AF), and can be obtained with different ablation modalities. The duty-cycled circular multi-pole catheter PVAC® (Medtronic) allows linear application of radiofrequency energy, with the production of circumferential lesions. Conceptually, it can make ablation simpler and faster in patients with favorable anatomy.

Objectives

To evaluate the safety and efficacy of ablation with a PVAC® catheter and to compare it with the conventional technique point-by-point (PbP) with irrigated catheter.

Methods

Clinical trial with single-blinded patients with AF refractory to antiarrhythmic therapy, randomized (1: 1) for ablation with PVAC® or PbP. The ablation strategy consisted of PVI, complemented with ablation of the cavo-tricuspid isthmus in patients with history of concomitant flutter. Monitoring was performed with a 7-day event loop recorder at 3, 6 and 12 months and annually from the 2nd year. Success was defined by AF-free survival or any maintained supraventricular tachycardia (duration > 30seconds).

Results

354 patients (67.5% males, 58 ± 12 years, PbP: 175, PVAC: 179) were included, of which 59.1% had paroxysmal, 26.2% short-standing persistent and 14.7% had long-standing persistent AF. Baseline characteristics were similar between groups. Among patients treated with PVAC, 93.1% of the pulmonary veins were isolated (620/666), similar to the 98.3% immediate success of the PbP group (697/709). Although the complication rate was similar in both groups (PVAC: 4.9% vs. PbP: 7.8%; P = NS), the risk of hemopericardium was lower with PVAC (0% vs. 4.6%; P = 0.013). Two patients treated with PVAC developed stroke (1.13% vs. 0%; P = NS). The duration of the procedure was lower among the patients treated with PVAC [136 (100-180) vs. 230 (188-270) min; P <0.001], with no difference in fluoroscopy time [24.4 (14.5-36.8) vs. 27.1 (17.0-45.0) min]. The success rate after 1st ablation at 36 months was 68%, with no differences between groups. The success rate after multiple ablations increased to 85.8%, with no differences between groups.

Conclusion

The multipolar PVAC catheter can represent an added value in AF ablation, making the procedure simpler and faster, ensuring similar efficacy to the conventional technique and with a lower risk of cardiac tamponade. The present trial suggests the need for clinically manifested stroke risk surveillance, which may be increased with this technique.

Abstract Figure.

P1059Recurrence of AF after pulmonary vein isolation: how many times?

Introduction

Ablation of atrial fibrillation (AF) by catheter is an effective therapy, particularly in cases of refractoriness to medical therapy. Pulmonary vein isolation (PVI) has a significative long-term recurrence rate of AF, but the recurrence factors after this procedure are poorly defined.

Purpose

To characterize the causes of AF recurrence after PVI and to evaluate complementary strategies that can optimize the therapeutic efficacy.

Methods

A single centre prospective study of patients (pts) with AF submitted consecutively to PVI since September 2004. The variables responsible for the recurrence of AF, the complementary strategies of optimization of AF ablation and the occurrence of other dysrhythmias were evaluated.

Results

A population of 521 pts were submitted to PVI as a primary strategy for AF treatment - 36.1% for paroxysmal AF, 32.5% for persistent AF <1 year, 14.5% persistent AF> 1 year.

Eighty-three pts needed to perform 2 ablations and 10 pts performed 3 ablations. The higher the number of AF ablations, the higher the incidence of atypical atrial flutter (2% in the 1st AF ablation, 17% in the 2nd and 44% after 3 ablations).

In the pts with recurrence of AF undergoing the 2nd ablation, it was verified that most of the pulmonary veins (PV) were not isolated, with an isolation rate of only 34.1% for the right inferior PV; 29.4% for superior PV right, 29.4% lower left VP, 28.2% upper left PV. In this group, in addition to a new PVI in the pts with re-conduction of PV, 45% performed complementary ablation strategies such as: ablation of the cavo-tricuspid isthmus (52.6%); ablation of the left atrium roof line (29%); mitral isthmus ablation line (26%); applications in the scar zone (26%); posterior atrial left line (8%), atrioventricular nodal reentrant atrioventricular ablation (5%), atrial tachycardia ablation (2.6%).

In the pts submitted to the 3rd ablation, again a low PV isolation rate was confirmed: only 44.4% for the both left PV and upper right PV, and 55.6% for the right lower VP. 33.3% also performed cavo-tricuspid isthmus ablation, 22.2% lower mitral isthmus isolation and 22.2% re-isolation of gaps in the roof or intracicritricial line.

Conclusion

This prospective study demonstrates a high rate of PV re-conduction after PVI and its role in AF recurrence. Therefore, the need for a more effective and definitive IVP technique is evident.

P5689First intention epicardial VT ablation: what are the results?

Introduction

Ventricular tachycardia (VT) endocardial mapping and ablation may not be sufficient in several arrhythmogenic contexts, because ventricular myocardium may comprise intricate endocardial, intramural and epicardial substract. Thus, epicardial ablation has lately become a complementary and necessary tool to approach some VTs in different types of cardiomyopathies.

Purposes

To evaluate the clinical characteristics of patient most suitable for first intention epicardial VT ablation and to describe our centre experience.

Methods

Single-centre prospective study of consecutive patients (pts) undergoing isolated first intention epicardial VT mapping and ablation since August 2015. All pts had clinical assessment, electrocardiogram (ECG), echocardiogram and cardiac magnetic resonance when feasible. Pts with a previous endocardial ablation were excluded. Epicardial subxiphoid access utilizing a tuhoy needle was performed under fluoroscopic guidance. High-density mapping was performed using CARTO® V4 and EnSite PrecisionTM systems and multipolar catheters. Radiofrequency energy was applied with an irrigated-tip catheter.

Results

First intention epicardial VT ablation was attempted in 12 pts (mean age 57.6±14.6 years, 91% male). The majority had non-ischemic dilated cardiomyopathy, of unknown aetiology in 59%, hereditary dilated cardiomyopathy in 17% ethanolic origin in 8% and post-myocarditis in 8%. Right Ventricular Arrhythmogenic Cardiomyopathy was present in 1 patient. As expected, our population presented a mean ejection fraction of 29% and 11 pts (92%) had an implantable cardioverter defibrillator - ICD (55% as primary prevention, 45% as secondary prevention). All pts had experienced symptomatic VT, with all ICD carriers receiving appropriate shocks. Only 4 pts had an available 12 lead ECG of the VT, and all of them had a QS pattern in lead aVL and a slurred initial QRS complex. The majority of patients presented low voltage areas and local abnormal ventricular activities at the epicardial surface, with the exception of 2 pts in whom ablation was not performed (one non-ischemic cardiomyopathy of ethanolic aetiology and the other of unknown origin). Mean ablation application time was 68 minutes, with an average maximum power of 39.9 watts. Mean overall procedure and fluoroscopic time was 132 and 24 minutes, respectively, with no major intraprocedural complications. During a mean follow-up of 307±328 days, 3 pts died (mean 121 days after procedure), 3 had recurrent VT episodes and ICD shocks, and 2 received heart transplant.

Conclusion

In selected pts, with non-ischemic dilated cardiomyopathy and ECG with QS pattern in aVL and slurred QRS, epicardial VT mapping and ablation may be used as first approach, preventing unnecessary endocardial mapping. This procedure demonstrated to be safe.

P983Long-standing persistent atrial fibrillation: what can we achieve with ablation?

Introduction

Atrial fibrillation (AF) ablation presents suboptimal results in patients (pts) with persistent long-lasting forms (LSPAF, AF ≥12 months). Recently, the STAR AF-II trial has shown that in these pts complex additional strategies do not improve success compared to only performing pulmonary vein isolation (PVI).

Objectives

To evaluate the success of AF ablation, particularly in long-standing persistent AF

Methods

Single-center prospective study of pts with AF submitted to ablation. The strategy, regardless of the type of AF, was based on PVI, complemented by cavo-tricuspid isthmus line (CTI) in pts with history of flutter. Additional ablation strategies were selectively considered in pts with stable atypical flutter conversion, persistent triggers or no electrograms in the VPs. Pts were monitored with Holter/7-day event loop recorder (3, 6, 12 months and annually up to 5 years). Success was assessed from the 90th day after ablation, with the absence of recurrences of any sustained atrial arrhythmias (>30 sec). Cox regression and Kaplan-Meier survival were used to compare the success of ablation as a function of the clinical type of AF in our population and with pts included in STAR-II AF trial.

Results

620 patients were submitted to AF ablation, 67% male, 58±12 years, including 78 pts (13%) with LSPAF - pts with paroxysmal and persistent short duration AF represented 61% and 26% of the population. In LSPAF, VPI was performed with irrigated catheter (N=33), PVAC (N=44) or nMARQ (N=1), complemented by CTI ablation in 15, linear left atrial lesions in 3, ablation of areas of low voltage in 3 and elimination of fractionated electrograms in 1 patient.

With a median follow-up of 426 days (94–989), the 3-year success rate after a single procedure was 53% in LSPAF, lower than that observed in patients with paroxysmal AF (69%) or short-duration persistent AF (61%) - LogRank P=0.002. The risk of arrhythmias was double in LSPAF vs paroxysmal AF (HR: 2.0; P=0.001). However, after an average of 1.2 procedures/patient, the success rate in LSPAF was 80% at 3 years, comparable to that observed for other types of AF (Log Rank 2.5, p=0.29). Effectively, the long-term success rate of our LSPAF pts treated with PVI and very selective additional strategies was higher than that observed in the STAR-II AF pts treated with PVI and indiscriminate complex ablations (80% vs. 69%, t-test p<0.001, with similar mean follow-up).

Conclusions

AF ablation is more effective if it is performed earlier in the natural history of the disease. However, even in LSPAF, high success rates are achieved through PVI-based ablation strategies, although more procedures are required.

Triple-site pacing for cardiac resynchronization in permanent atrial fibrillation: follow-up results from a prospective observational study

Aims

Cardiac Resynchronization Therapy (CRT) is associated with a particularly high non-response rate in patients with atrial fibrillation (AF). We aimed to assess the effectiveness of triple-site (Tri-V) pacing CRT in this population.

Methods and results

Prospective observational study of patients with permanent AF who underwent CRT implantation with an additional right ventricle lead in the outflow tract septal wall. After implantation, programming mode (Tri-V or biventricular pacing) was selected based on cardiac output determination. Patients were classified as responders if NYHA class was reduced by at least one level and echocardiographic ejection fraction (EF) increased ≥ 10%, and as super-responders if in NYHA class I and EF ≥ 50%. Forty patients (93% male, mean age 72 ± 10 years) were included. Thirty-three were programmed in Tri-V. The following results pertain to this subgroup. At baseline, 58% were in NYHA class III and 36% NYHA class II. At 1 year follow-up, Minnesota QoL score was reduced (36 ± 23 vs. 8 ± 6; P = 0.001) and the 6MWT distance improved (384 ± 120 m to 462 ± 87 m, P = 0.003). Mean EF increased (26% ± 8 vs. 39 ± 10; P < 0.001 at 6 months and 41 ± 10; P < 0.001 at 12 months). Responder rate was 59% at 6 months and 79% at 12 months. Super-responder rate was 9% at 6 months and 16% at 12 months. One year survival free from heart failure hospitalization was 87.9%.

Conclusion

Tri-V CRT yielded higher response and super-response rates than usually reported for CRT in patients with permanent AF using clinical and remodeling criteria.

[Case report of serious cardiac insufficiency complicated by syncope]

The authors describe a case of a patient with congestive heart failure complicated by syncope, hypotension and a transitory state of vigil coma. The transthoracic and transesophageal echocardiogram showed a huge mass that occupied almost totally the right ventricle causing sever obstruction. The patient was submitted to surgery and a resection of the mass with reconstruction of the free right ventricle wall was done. The histopathology revealed to be a leiomyosarcoma. There was a previous history of an uterine surgery.

[Treatment of malignant ventricular arrhythmia guided by electrophysiologic study]

The purpose of this study was to assess the results of the treatment of malignant ventricular tachyarrhythmias guided by electrophysiologic studies. Thirty patients with ventricular arrhythmias, aged 56.6 +/- 14.1 years, were submitted to EP testing. The clinical presentation of arrhythmia was sustained monomorphic ventricular tachycardia in 24 (80%), non-sustained ventricular tachycardia in three and another three were survivors of sudden cardiac death. Twenty five patients (83%) had evidence of structural heart disease and left ventricular ejection fraction was less than 40% in 16 (53%). Antiarrhythmic drugs were considered effective when sustained monomorphic ventricular tachycardia was noninducible or significantly slowed in serial EP testing. Sustained monomorphic VT was induced in 19 patients (63%) and an effective drug therapy was found in 13 (68%). In the other 11 patients sustained arrhythmias were not induced, although in six of them the study was done already under antiarrhythmic drugs, that were continued in the follow-up. In the six patients in which an effective drug regimen could not be found and in two sudden death survivors with primary ventricular fibrillation and negative EP testing, an Implantable Cardioverter-Defibrillator was implanted. After 17.8 +/- 10.5 months, there was recurrence of the arrhythmia in 4 (18%) of the 22 patients on antiarrhythmic drugs and half of the patients with ICDs received appropriate therapy from the device. Three patients (10%) died in the follow-up, of which only one due to sudden death. We conclude that selection of optimal antiarrhythmic treatment based on the results of EP testing, is associated with decreased episode recurrence and sudden death.

[The catheter ablation of atrioventricular nodal reentry tachycardia: the results of a mixed electrophysiological/anatomical technic]

OBJECTIVE

To describe the results of radiofrequency catheter ablation of atrioventricular nodal reentrant tachycardia (AVNRT) by using a mixed electrophysiologic/anatomic mapping technique.

DESIGN

Consecutive patients with AVNRT, submitted to AV node modification between November 1992 and March 1995.

SETTING

Cardiology Department at an University Hospital.

INTERVENTIONS

Twenty consecutive patients with AVNRT were submitted to AV node modification. The ablation technique included two sequential steps. Initially, a detailed electrophysiologic mapping was performed with the ablation catheter, positioned near the coronary sinus ostium, looking for a specific recording: fractionated atrial electrogram, suggestive "slow pathway" potential and a ratio of atrial: ventricular electrogram amplitude > 1. In case of failure, after 5 applications of radiofrequency energy, an anatomic technique was used. The fluoroscopic image, in left anterior oblique projection, was used to guide catheter progression, and the radiofrequency energy applied sequentially in the posterior (P), followed by medium (M) and anterior (A) septal areas if needed. Radiofrequency energy was applied a power of 16-36 watts for 30-60 sec. If a His bundle deflection > 0.0025 mV was recorded, energy was not applied.

MEASUREMENTS AND RESULTS

Suppression of a AVNRT was initially obtained in 19 patients (95%). A mean of 8.3 +/- 6.1 energy application were required. Mean during of the entire procedure was 142 +/- 45 min and the fluoroscopy duration was 22 +/- 12 min. There were no complications. The location of successful ablation areas was: P in 15 patients, M in three and A in one. After a mean follow up of 10 +/- 6 months, two patients had recurrence of AVNRT. A second procedure was successful in the initially failed patient and in these two recurrences.

CONCLUSIONS

A mixed electrophysiologic/anatomic mapping technique to perform radiofrequency catheter ablation of AVNRT was associated with high efficacy and no complications.

[The diagnosis and ablation of accessory atrioventricular pathways in the initial electrophysiological exam: a new therapeutic modality in pre-excitation syndromes]

OBJECTIVE

To describe the experience and results in the diagnosis and catheter ablation of atrioventricular accessory (AP) pathways during the initial electrophysiologic study.

DESIGN

We performed catheter ablation at the time of an initial electrophysiologic study in 22 consecutive patients (12 W and 10 M, mean age 42 +/- 15) with Wolff-Parkinson-White syndrome or supraventricular tachycardia.

SETTING

Cardiology Department at University Hospital.

INTERVENTIONS

The precise AP mapping was performed with the ablation catheter (4 mm distal electrode and deflectable tip) according to the earlier ventricular activation during sinus rhythm or the earlier atrial activation during ventricular pacing or orthodromic reentrant tachycardia. For left-sided pathways the ablation catheter was positioned on the mitral annulus retrogradely across the aortic valve, while for right-sided pathways it was positioned on the tricuspid annulus or near the coronary sinus os. Radiofrequency energy was applied for 20-60 segs with 55-65 Volts.

MEASUREMENTS AND RESULTS

Seventeen AP were manifest and five were concealed. AP were left lateral in 11 patients (50%), left posterior in 5, and right postero-septal, right posterior or antero-septal in 2 patients each. The ablation was initially successful in 18/22 (82%), with 9 +/- 8 radiofrequency applications. Mean duration of the entire procedure was 145 +/- 59 min and the fluoroscopy duration was 39 +/- min. There were no major complications. During 2-9 months of follow-up AP conduction returned in two patients.

CONCLUSIONS

Radiofrequency catheter ablation of AP is effective and safe and can be performed at the time of an initial electrophysiologic test, avoiding the need for long-term antiarrhythmic drug therapy or surgical ablation.