Outcomes of ventricular tachycardia ablation in patients with ischemic and non-ischemic cardiomyopathy: A propensity-score matched analysis

INTRODUCTION AND OBJECTIVES

Catheter ablation (CA) is effective in the treatment of ventricular tachycardia (VT). Although some observational data suggest patients with non-ischemic cardiomyopathy (NICM) have less favorable outcomes when compared to those with an ischemic etiology (ICM), direct comparisons are rarely reported. We aimed to compare the outcomes of VT ablation in a propensity-score matched population of ICM or NICM patients.

METHODS

Single-center retrospective study of consecutive patients undergoing VT ablation from 2012 to 2023. A propensity score (PS) was used to match ICM and NICM patients in a 1:1 fashion according to age, sex, left ventricular ejection fraction (LVEF), NYHA class, electrical storm (ES) at presentation, and previous endocardial ablation. The outcomes of interest were VT-free survival and all-cause mortality.

RESULTS

The PS yielded two groups of 71 patients each (mean age 63±10 years, 92% male, mean LVEF 35±10%, 36% with ES at presentation, and 23% with previous ablation), well matched for baseline characteristics. During a median follow-up of 2.3 (interquartile range IQR 1.3-3.8) years, patients with NICM had a significantly lower VT-free survival (53.5% vs. 69.0%, log-rank p=0.037), although there were no differences regarding all-cause mortality (22.5% vs. 16.9%, log-rank p=0.245). Multivariate analysis identified NICM (HR 2.34 [95% CI 1.32-4.14], p=0.004), NYHA class III/IV (HR 2.11 [95% CI 1.11-4.04], p=0.024), and chronic kidney disease (HR 2.23 [95% CI 1.25-3.96], p=0.006), as independent predictors of VT recurrence.

CONCLUSION

Non-ischemic cardiomyopathy patients were at increased risk of VT recurrence after ablation, although long-term mortality did not differ.

Electrocardiographic imaging to guide ablation of ventricular arrhythmias and agreement between two different systems

BACKGROUND AND AIM

A recent study using an epicardial-only electrocardiographic imaging (ECGI), suggests that the agreement of ECGI activation mapping and that of the contact mapping for ventricular arrhythmias (VA) is poor. The aim of this study was to assess the diagnostic value of two endo-epicardial ECGI systems using different cardiac sources and the agreement between them.

METHODS

We performed 69 ECGI procedures in 52 patients referred for ablation of VA at our center. One system based on the extracellular potentials was used in 26 patients, the other based on the equivalent double layer model in 9, and both in 17 patients. The first uses up to 224 leads and the second just the 12‑lead ECG. The localization of the VA was done using a segmental model of the ventricles. A perfect match (PM) was defined as a predicted location within the same anatomic segment, whereas a near match (NM) as a predicted location within the same segment or a contiguous one.

RESULTS

44 patients underwent ablation, corresponding to 58 ECGI procedures (37 with the first and 21 with the second system). The percentage of PMs and NMs was not significantly different between the two systems, respectively 76% and 95%, p = 0.077, and 97% and 100%, p = 1.000. In 14 patients that underwent ablation and had the ECGI performed with both systems, raw agreement for PMs was 79%, p = 0.250 for disagreement.

CONCLUSIONS

ECGI systems were useful to identify the origin of the VAs, and the results were reproducible regardless the cardiac source.

Outcomes of a combined vs non-combined endo-epicardial ventricular tachycardia ablation strategy

BACKGROUND

Direct comparisons of combined (C-ABL) and non-combined (NC-ABL) endo-epicardial ventricular tachycardia (VT) ablation outcomes are scarce. We aimed to investigate the long-term clinical efficacy and safety of these 2 strategies in ischemic heart disease (IHD) and non-ischemic cardiomyopathy (NICM) populations.

METHODS

Multicentric observational registry included 316 consecutive patients who underwent catheter ablation for drug-resistant VT between January 2008 and July 2019. Primary and secondary efficacy endpoints were defined as VT-free survival and all-cause death after ablation. Safety outcomes were defined by 30-day mortality and procedure-related complications.

RESULTS

Most of the patients were male (85%), with IHD (67%) and mean age of 63 ± 13 years. During a mean follow-up of 3 ± 2 years, 117 (37%) patients had VT recurrence and 73 (23%) died. Multivariate survival analysis identified electrical storm (ES) at presentation, IHD, left ventricular ejection fraction (LVEF), New York Heart Association (NYHA) functional class III / IV, and C-ABL as independent predictors of VT recurrence. In 135 patients undergoing repeated procedures, only C-ABL and ES were independent predictors of relapse. The identified independent predictors of mortality were C-ABL, ES, LVEF, age, and NYHA class III / IV. C-ABL survival benefit was only seen in patients with a previous ablation (P for interaction = 0.04). Mortality at 30 days was similar between NC-ABL and C-ABL (4% vs. 2%, respectively, P = 0.777), as was complication rate (10.3% vs. 15.1%, respectively, P = 0.336).

CONCLUSION

A combined or sequential endo-epicardial VT ablation strategy was associated with lower VT recurrence and lower all-cause death in IHD and NICM patients undergoing repeated procedures. Both approaches seemed equally safe.

Epidemiology and impact of frailty in patients with atrial fibrillation in Europe

BACKGROUND

Frailty is a medical syndrome characterised by reduced physiological reserve and increased vulnerability to stressors. Data regarding the relationship between frailty and atrial fibrillation (AF) are still inconsistent.

OBJECTIVES

We aim to perform a comprehensive evaluation of frailty in a large European cohort of AF patients.

METHODS

A 40-item frailty index (FI) was built according to the accumulation of deficits model in the AF patients enrolled in the ESC-EHRA EORP-AF General Long-Term Registry. Association of baseline characteristics, clinical management, quality of life, healthcare resources use and risk of outcomes with frailty was examined.

RESULTS

Among 10,177 patients [mean age (standard deviation) 69.0 (11.4) years, 4,103 (40.3%) females], 6,066 (59.6%) were pre-frail and 2,172 (21.3%) were frail, whereas only 1,939 (19.1%) were considered robust. Baseline thromboembolic and bleeding risks were independently associated with increasing FI. Frail patients with AF were less likely to be treated with oral anticoagulants (OACs) (odds ratio 0.70, 95% confidence interval 0.55-0.89), especially with non-vitamin K antagonist OACs and managed with a rhythm control strategy, compared with robust patients. Increasing frailty was associated with a higher risk for all outcomes examined, with a non-linear exponential relationship. The use of OAC was associated with a lower risk of outcomes, except in patients with very/extremely high frailty.

CONCLUSIONS

In this large cohort of AF patients, there was a high burden of frailty, influencing clinical management and risk of adverse outcomes. The clinical benefit of OAC is maintained in patients with high frailty, but not in very high/extremely frail ones.

Assessment of wave front activation duration and speed across the right ventricular outflow tract using electrocardiographic imaging as predictors of the origin of the premature ventricular contractions: A validation study

AIMS

Evaluate right ventricular outflow tract (RVOT) activation duration (AD) and speed, invasively and with the electrocardiographic imaging (ECGI), as predictors of the origin of the PVCs, validating the ECGI.

METHODS

18 consecutive patients, 8 males, median age 55 (35-63) years that underwent ablation of PVCs with inferior axis and had ECGI performed before ablation. Isochronal activation maps of the RVOT in PVC were obtained with the ECGI and invasively. Total RVOT AD was measured as the time between earliest and latest activated region, and propagation speed by measuring the area of the first 10 ms of activation. Cut-off values for AD, activation speed and number of 10 ms isochrones to predict the origin of the PVCs, were obtained with the ROC curve analysis. Agreement between methods was done with Pearson correlation test and Bland-Altman plot.

RESULTS

PVCs originated from the RVOT in 11 (61%) patients. The stronger predictor of PVC origin was the AD. The median AD in PVCs from RVOT was significantly longer than from outside the RVOT, both with ECGI and invasively, respectively 62 (58-73) vs 37 (33-40) ms, p < 0.0001 and 68 (60-75) vs 35 (29-41) ms, p < 0.0001. Agreement between the two methods was good (r = 0.864, p < 0.0001). The cut-off value of 43 ms for AD measured with ECGI predicted the origin of the PVCs with a sensitivity and specificity of 100%.

CONCLUSIONS

We found good agreement between ECGI and invasive map. The AD measured with ECGI was the best predictor of the origin of the PVCs.

Medication adherence to direct anticoagulants in patients with non-valvular atrial fibrillation - A real world analysis

INTRODUCTION

Direct oral anticoagulants (DOACs) changed the landscape of atrial fibrillation (AF) treatment, but also brought with them new challenges in terms of accessibility and compliance. The purpose of this study was to assess adherence to DOACs, and its determinants in a population of AF patients.

METHODS

Single-center retrospective study including all patients with non-valvular AF treated with a DOAC from the outpatient general cardiology list at a tertiary center, whose first DOAC prescription was between 1 April 2016 and August 2018. The number of pharmacy refills from the day of first prescription to 31 August 2018 was counted (by means of an electronic prescription platform). Medication refill adherence (MRA) was calculated by dividing the total days' supply by the number of days under therapy. Non-compliance was defined as MRA <90%.

RESULTS

A total of 264 patients (120 men, mean age 74 ± 12 years) met the inclusion criteria. The median CHA₂DS₂VAS_C score was 3 (interquartile range (IQR) 2-5) and the median HAS-BLED was 1 (IQR 1-2). Rivaroxaban, apixaban, dabigatran and edoxaban were prescribed in 45%, 41%, 24% and 13% of patients, respectively. During the study 51 patients (19%) used at least two DOACs .Patients took DOACs for a median period of 439 days (IQR 269-638), during which the included population adhered to therapy 90% of the time (IQR 75-100%). Half of the patients (51%) were classified as non-compliant; therapy duration (adjusted odds ratio 1.06 per month, 95% confidence interval (CI) 1.03-1.08, p<0.001), DOACs twice daily (adjusted OR 1.73, 95%CI 1.08-2.75, p=0.022), and higher out-of-pocket costs (adjusted OR 2.13, 95%CI 1.28-3.45, p=0.003) were independent predictors of non-compliance.

CONCLUSION

Half of the patients (51%) were classified as non-compliant (medication refill adherence <90%). Therapy duration, DOACs twice daily and higher out out-of-pocket costs were independent predictors of non-compliance, which could be targets to improve patient adherence.

Predictors of pacemaker implantation after TAVI in a registry including self, balloon and mechanical expandable valves

The need for permanent pacemaker implantation (PPMI) is a burdensome complication of transcatheter aortic valve implantation (TAVI). The aim of our study was to evaluate different anatomical, clinical, electrocardiographic, and procedural variables associated with the development of conduction abnormalities after TAVI across the entire device spectrum. Single-center prospective cohort of consecutive patients who underwent TAVI since March 2017. Final cohort was studied to detect areas of calcium within aortic valve characterized by leaflet sector and region. Membranous septum (MS) length was assessed throughout a modified coronal view. Device selection and positioning were performed according to the operator criteria. Device selection and positioning were performed according to the operator criteria. From the 273 patients included, 57 underwent PPMI (20.8%). Univariate analysis determined right bundle branch block (RBBB), QRS duration, MS length and calcium within LVOT of non-coronary cuspid as independent predictors. After multivariable logistic regression, both RBBB (OR 6.138; 95% CI 1.23-30.73, P = 0.027) and MS length (OR 0.259; 95% CI 0.164-0.399, P < 0.005) emerged as statistically significant. As a model, they could predict PPMI in 88.7%, independently of which valve used. Youden index analysis yielded 7.69 mm as the optimal cut-off with a negative and positive predictive value of 94.7 and 71.9%, respectively. In our experience, both RBBB pattern and short membranous septum (< 8 mm) were strongly and independently associated with new permanent pacemaker implantation, regardless of the device type. Our findings suggest that this simple evolved measure of MS length may guide device selection and implantation technique and facilitate early discharge.

Successful ablation of premature ventricular contractions exclusively guided by epicardial and endocardial non-invasive mapping (ECGI) and confirmed by substrate mapping

Ablation of premature ventricular contractions (PVCs), relies mostly on a detailed activation mapping. This can be impossible to achieve in case of paucity or even absence of PVCs during the procedure. Pacemapping as an alternative has many limitations. We present a case of a patient with very frequent symptomatic PVCs, that on the day of the procedure had total absence of PVCs. We performed successful ablation based exclusively on electrocardiographic imaging confirmed by substrate mapping.

Idiopathic Premature Ventricular Contractions From the Outflow Tract Display an Underlying Substrate That Can Be Unmasked by a Type 2 Brugada Electrocardiographic Pattern at High Right Precordial Leads

Background: Patients with premature ventricular contractions (PVCs) from the right ventricular outflow tract (RVOT) and apparently normal hearts, can have ST elevation similar to type 2 or type 3 Brugada pattern in the electrocardiographic (ECG) performed at a higher position. Cardiac magnetic resonance (CMR), has shown conflicting data regarding existence of structural abnormalities in patients with idiopathic PVCs from the RVOT. Objective: Our aim was to evaluate the prevalence of low voltage areas (LVAs) in the RVOT of patients with PVCS from the outflow tract, and in a control group. Secondly, assess for the presence of a non-invasive ECG marker. Methods: A 56 consecutive patients, 45 with frequent PVCs (>10000/24 h) LBBB, vertical axis, negative in aVL and 11 subjects without PVCs. Arrhythmogenic right ventricular cardiomyopathy was ruled out in all patients. An ECG was performed with V1-V2 at the level of the second intercostal space and the presence of ST-segment elevation with a Type 2 or 3 Brugada pattern (Type 2 BrP) was assessed. Bipolar voltage map of the RVOT was performed in sinus rhythm (0.5-1.5 mV color display). Areas with electrograms <1.5 mV represented the LVA. The area adjacent to the pulmonary valve usually displays voltage between 0.5 and 1.5 mV and is classified as transitional-voltage zone. Presence of LVAs outside this transitional-voltage zone were estimated. We compared two groups with and without ST-segment elevation and tested for the association between ECG pattern and LVAs. Results: None of the patients in the control group had ST-segment elevation or LVAs. In the PVC group, no patient had type 1 Brugada pattern, 29 patients (64%) had type 2 or 3 ST-segment elevation (Type 2 BrP), and 28 (62%) had LVAs outside the transitional-voltage zone. LVAs were more frequent in patients with Type 2 BrP; 93% versus 4%, p < 0.0001. The ECG pattern was associated with the presence of LVAs, OR (95% CI): 202.50 (16.92-2423), p < 0.0001. Conclusion: Low voltage areas were frequently present in the RVOT of patients with idiopathic PVCs. They were absent in controls and can be unmasked by the presence of Type 2 BrP in high right precordial leads.

Analysis of a 10-year period of lead removal in a referral centre

OBJECTIVES

Our goal was to analyse all lead extraction procedures (transvenous or open surgery) performed in our centre and the short- and long-term follow-up data from these patients.

METHODS

All lead extractions performed from 2008 to 2017 were retrospectively reviewed for patient characteristics and indications for device implantation; indications for lead extraction; techniques used; peri- and postprocedural complications and short- and long-term follow-up data.

RESULTS

A total of 159 patients (282 leads) were included [age 70 (62-78) years; 72% men]. The median follow-up time was 57 (25-90) months. Patients with lead explants were excluded. The most common indication for lead removal was infection (77%). A surgical approach was necessary in 14 patients (9%) owing to unsuccessful transvenous removal (n = 3), large vegetation in the lead (n = 4), concomitant valvular endocarditis (n = 2), other indications for open surgery (n = 4) and complicated transvenous removal (n = 1). Removal was tried for 282 leads. Of those, 256 were completely removed. Clinical success was achieved in 155 individual patients (98%). Complications occurred in 6 patients: 3 persistent infections, 1 stroke and 2 blood vessel ruptures. The procedure-related mortality rate was 2% (n = 3).

CONCLUSIONS

Lead removal was associated with a high success rate and low all-cause complication and mortality rates. Emergency surgery because of acute complications was rare, and open-heart surgery was most frequently elective and not associated with a worse outcome.

Implantable Cardioverter-Defibrillators in Trials of Drug Therapy for Heart Failure: A Systematic Review and Meta-Analysis

BACKGROUND

Medical therapy for heart failure with reduced ejection fraction evolved since trials validated the use of implantable cardioverter–defibrillators (ICDs). We sought to evaluate the performance of ICDs in reducing mortality in the era of modern medical therapy by means of a systematic review and meta‐analysis of contemporary randomized clinical trials of drug therapy for heart failure with reduced ejection fraction.

METHODS AND RESULTS

We systematically identified randomized clinical trials that evaluated drug therapy in patients with heart failure with reduced ejection fraction that reported mortality. Studies that enrolled <1000 patients, patients with left ventricular ejection fraction >40%, or patients in the acute phase of heart failure and study treatment with devices were excluded. We identified 8 randomized clinical trials, including 31 701 patients of whom 3631 (11.5%) had an ICD. ICDs were associated with a lower risk of all‐cause mortality (relative risk [RR], 0.85; 95% CI, 0.78–0.94) and sudden cardiac death (RR, 0.49; 95% CI, 0.40–0.61). Results were consistent among studies published before and after 2010. In meta‐regression analysis, the proportion of nonischemic etiology did not affect the associated benefit of ICD.

CONCLUSIONS

In our meta‐analysis of contemporary randomized trials of drug therapy for heart failure with reduced ejection fraction, the rate of ICD use was low and associated with a decreased risk in both all‐cause mortality and sudden cardiac death. This benefit was still present in trials with new medical therapy.

Impact of Type-2 Diabetes Mellitus on the Outcomes of Catheter Ablation of Atrial Fibrillation (European Observational Multicentre Study)

Type-2 diabetes mellitus (DM) is associated with an increased risk of atrial fibrillation (AF). It is unclear whether DM is a risk factor for arrhythmia recurrence following catheter ablation of AF. We performed a nonrandomised, observational study in 7 high-volume European centres. A total of 2,504 patients who underwent catheter ablation of AF were included, and procedural outcomes were compared among patients with or without DM. Patients with DM (234) accounted for 9.3% of the sample, and were significantly older, had a higher BMI and suffered more frequently from persistent AF. Arrhythmia relapses at 12 months after AF ablation occurred more frequently in the DM group (32.0% vs 25.3%, p = 0.031). After adjusting for type of AF (i.e., paroxysmal vs persistent), during a median follow-up of 17 ± 16 months, atrial arrhythmia free-survival was lower in the diabetics with persistent AF (log-rank p = 0.003), and comparable for paroxysmal AF (log-rank p = 0.554). These results were confirmed in a propensity-matched analysis, and DM was also an independent predictor of AF recurrence on the multivariate analysis (hazard ratio 1.39; 95% confidence interval _95%1.07 to 1.88; p = 0.016). There was no significant difference in the rate of periprocedural complications among DM and non-DM patients (3.8% vs 6.3%, p = 0.128). Efficacy and safety of cryoballoon ablation were comparable to radiofrequency ablation in both DM and no-DM groups. In conclusion, catheter ablation of AF appears to be safe in patients with DM. However, DM is associated with higher rate of atrial arrhythmia relapse, particularly for patients with persistent AF.

Epicardial ablation of ventricular tachycardia using a new high-density mapping system

We report the case of a 44-year-old woman who was referred for ablation of recurrent ventricular tachycardia (VT) in the setting of dilated cardiomyopathy secondary to myocarditis. The ECG displayed a right bundle branch block morphology and superior axis in the frontal plane, associated with a pseudo delta wave in the precordial leads that suggested an epicardial origin. Cardiac magnetic resonance performed prior to the procedure showed late gadolinium enhancement at the lateral wall of the left ventricle (LV) and excluded subendocardial fibrosis in either ventricle. This information was crucial and influenced the ablation strategy, identifying the target area as exclusively epicardial, thus avoiding unnecessary mapping of the endocardial surface of the LV. Epicardial activation mapping and ablation during VT were performed using the Orion® high-density catheter (Boston Scientific Inc.) and the Rhythmia® mapping system (Boston Scientific Inc.). Applications near the exit site immediately terminated the tachycardia, which was no longer inducible. One year after the procedure the patient was still in sinus rhythm with no episodes of VT or non-sustained VT recorded by continuous monitoring via an implanted cardioverter-defibrillator.

Impact of Body Mass Index on the Outcomes of Catheter Ablation of Atrial Fibrillation: A European Observational Multicenter Study

Background Outcomes of catheter ablation of atrial fibrillation (AF) are variable and the predictors of success require further elucidation since the identification of correctable risk factors could help to optimize therapy. We aimed to assess the impact of body mass index (BMI) in the overall safety and efficacy of catheter ablation of AF, with emphasis on the use of cryoballoon ablation and novel oral anticoagulants. Methods and Results There were 2497 consecutive patients undergoing catheter ablation of AF in 7 European high volume centers were stratified according to BMI (normal weight <25 kg/m2, pre-obese 25-30 kg/m2, obesity 30-35 kg/m2, and morbid obesity ≥35 kg/m2) and comparisons of procedural outcomes evaluated. Pre-obese and obese patients presented more comorbidities (hypertension, diabetes mellitus, and sleep apnea), and had higher rates of non-paroxysmal AF ablation procedures. The rate of atrial 12-month arrhythmia relapse increased alongside with BMI (35.2%, 35.7%, 43.6%, and 48.0% P<0.001). During a median follow-up of 18.8 months (interquartile range 11-28), after adjusting for all baseline differences, BMI was an independent predictor of relapse (hazard ratio=1.01 per kg/m2; 95% CI 1.01-1.02; P=0.002), adding incremental predictive value to obstructive sleep apnea. BMI was not a predictor for any of the reported complications. Using novel oral anticoagulants and cryoballoon ablation was safe and efficacy was comparable with vitamin-K antagonists and radiofrequency ablation. Conclusions Obese patients present with a more adverse comorbidity profile, more advanced forms of AF, and have lower chances of being free from AF relapse after ablation. Use of novel oral anticoagulants and cryoballoon ablation may be an option in this patient group.

Non-invasive electrocardiographic imaging in patients with idiopathic premature ventricular contractions from the right ventricular outflow tract: New insights into arrhythmia substrate

AIMS

The aim of this study was to use non-invasive electrocardiographic imaging (ECGI) to study the electrophysiological properties of right ventricular outflow tract (RVOT) in patients with frequent premature ventricular contractions (PVCs) from the RVOT and in controls.

METHODS

ECGI is a combined application of body surface electrocardiograms and computed tomography or magnetic resonance imaging data. Unipolar electrograms are reconstructed on the epicardial and endocardial surfaces. Activation time (AT) was defined as the time of maximal negative slope of the electrogram (EGM) during QRS, recovery time (RT) as the time of maximal positive slope of the EGM during T wave, Activation recovery interval (ARI) was defined as the difference between RT and AT. ARI dispersion (Δ ARI) and RT dispersion (Δ RT) were calculated as the difference between maximal and minimal ARI and RT respectively. We evaluated those parameters in patients with frequent PVCs from the RVOT, defined as >10.000 per 24 h, and in a control group.

RESULTS

We studied 7 patients with frequent RVOT PVCs and 17 controls. Patients with PVCs from the RVOT had shorter median RT than controls, in the endocardium and in the epicardium, respectively 380 (239-397) vs 414 (372-448) ms, p = 0.047 and 275 (236-301) vs 330 (263-418) ms, p = 0.047. The dispersion of ARI and of RT in the epicardium was higher than in controls, Δ ARI of 145 (68-216) vs 17 (3-48) ms, p = 0.001 and Δ RT of 201 (160-235) vs 115 (65-177), p = 0.019.

CONCLUSION

In this group of patients we found a shorter median RT in the endocardium and in the epicardium of the RVOT and a higher dispersion of the ARI and RT across the epicardium in patients with PVCs from the RVOT when comparing to controls.

Premature ventricular contractions of the right ventricular outflow tract: Upward displacement of the ECG unmasks ST elevation in V1 associated with the presence of low voltage areas

INTRODUCTION AND AIMS

Frequent premature ventricular contractions (PVCs) originating from the right ventricular outflow tract (RVOT) are usually considered a benign entity and the ECG is typically normal. The aim of this study was to assess whether upward displacement of the ECG to the second intercostal space (ICS) would reveal any abnormal pattern.

METHODS

A total of 18 consecutive patients with apparently normal hearts were studied, mean age 44±16 years, 12 women, who underwent catheter ablation of the RVOT due to frequent PVCs. A 12-lead ECG was performed in the standard position and repeated in a higher position, at the level of the second ICS. Three-dimensional bipolar electroanatomical voltage mapping (EVM) was performed in all patients and low voltage areas (LVAs) were defined as areas with amplitude <1.5 mV.

RESULTS

The ECG in the second ICS was normal in eleven patients but in seven (39%) it revealed a pattern of ST-segment elevation in V1. EVM revealed the presence of LVAs in six patients (33%) which included the earliest activation site (EAS) in five. The ST elevation was associated with the presence of LVAs (p<0.0001) and with the LVAs at the EAS (p=0.002).

CONCLUSION

In this group of patients with apparently normal hearts and with frequent PVCs of the RVOT, upward displacement of the ECG revealed the presence of ST elevation in more than one third of patients, and the ST elevation was associated with the presence of LVAs in the RVOT.

Isolated diastolic potentials as predictors of success in ablation of right ventricular outflow tract idiopathic premature ventricular contractions

Background and aims

Discrete potentials, low voltage and fragmented electrograms, have been previously reported at ablation site, in patients with premature ventricular contractions (PVCs) originating in the right ventricular outflow tract (RVOT). The aim of this study was to review the electrograms at ablation site and assess the presence of diastolic potentials and their association with success.

Methods

We retrospectively reviewed the electrograms obtained at the radiofrequency (RF) delivery sites of 48 patients subjected to ablation of RVOT frequent PVCs. We assessed the duration and amplitude of local electrogram, local activation time, and presence of diastolic potentials and fragmented electrograms.

Results

We reviewed 134 electrograms, median 2 (1–4) per patient. Success was achieved in 40 patients (83%). At successful sites the local activation time was earlier– 54 (-35 to -77) ms vs -26 (-12 to -35) ms, p<0.0001; the local electrogram had lower amplitude 1 (0.45–1.15) vs 1.5 (0.5–2.1) mV, p = 0.006, and longer duration 106 (80–154) vs 74 (60–90) ms, p<0.0001. Diastolic potentials and fragmented electrograms were more frequently present, respectively 76% vs 9%, p <0.0001 and 54% vs 11%, p<0.0001. In univariable analysis these variables were all associated with success. In multivariable analysis only the presence of diastolic potentials [OR 15.5 (95% CI: 3.92–61.2; p<0.0001)], and the value of local activation time [OR 1.11 (95% CI: 1.049–1.172 p<0.0001)], were significantly associated with success.

Conclusion

In this group of patients the presence of diastolic potentials at the ablation site was associated with success.

Cardiac computed tomography previous to atrial fibrillation ablation - effects of technological improvements and protocol optimization

BACKGROUND

Cardiac computed tomography (CT) can provide a precise tridimentional anatomic map and exclude intra-cardiac thrombus. We aimed to access the impact of CT protocol optimization and technological evolution on the contrast and radiation dose as well as on image quality previous to atrial fibrillation (AF) ablation.

METHODS

From a prospective registry of consecutive patients who underwent cardiac CT in a single center, we selected 270 patients in whom the CT was done for evaluation prior to AF ablation and they were distributed in 3 groups: Group1: the first 150 patients included; Group2: the last 60 patients performed with the same CT scanner; Group3: the first 60 exams performed with the new CT scanner. Quality of the protocol was access based on radiation dose, contrast volume used, the use of a second (delayed) acquisition, and on quantitative image quality analisis (signal to noise and contrast to noise ratios; density homogeneity racio between LA and LAA).

RESULTS

We found a significant radiation dose as well as contrast dose reduction between the first and last subgroups (G1: 5,6mSv and 100ml; G2: 1,3mSv and 90ml; G3: 0,6mSv and 65ml). Even though group 3 had less radiation and contrast used it still had better quantitative image quality (signal/noise of 13,5; contrast/noise 14,8; density homogeneity racio of 0,92).

CONCLUSION

Protocol optimization and technology both contributed to significant lower radiation dose and contrast volume used on cardiac CTs prior to AF ablation, without compromising image quality.