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BACKGROUND: Multiple studies continue to evaluate the use of intracardiac echocardiography (ICE) and transesophageal echocardiography (TEE) for guiding left atrial appendage occlusion (LAAO). OBJECTIVE: To conduct an updated meta-analysis comparing the effectiveness and safety outcomes of both imaging modalities. METHODS: PubMed, Cochrane, and Embase were searched for studies comparing ICE vs TEE to guide LAAO. Odds ratios (OR) with 95% confidence intervals (CI) were pooled using a random-effects model. The primary effectiveness endpoint was procedural success. The primary safety endpoint included the overall complications rate. Additional safety outcomes were assessed as secondary endpoints. Subgroup analysis of primary endpoints was conducted according to device type (Amulet, LAmbre, Watchman, Watchman FLX) and study region (American, Asia, Europe). We used R version 4.3.1 for all statistical analyses. RESULTS: Our meta-analysis included 19 observational studies encompassing 42,474 patients, of whom 4,415 (10.4%) underwent ICE-guided LAAO. Compared with TEE, ICE was associated with a marginally higher procedural success (OR 1.33; 95% CI: 1.01-1.76; p=0.04; I2=0%). There was no significant difference in the overall complications rate (OR 1.02; 95% CI: 0.77-1.36; p=0.89; I2=5%). However, ICE showed higher rates of pericardial effusion (OR 2.11; 95% CI: 1.47-3.03; p<0.001; I2=0%) and residual iatrogenic atrial septal defect (iASD) (OR 1.52; 95% CI: 1.15-2.03; p<0.004; I2=0%). Subgroup analysis revealed variations in procedural success within the ICE group across study regions (p=0.02). CONCLUSION: In this updated meta-analysis, the increasing adoption of ICE-guided LAAO demonstrated higher procedural success rates compared to TEE, although with limited statistical significance. Overall complication rates were similar; however, ICE showed higher rates of pericardial effusion and residual iASD.
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BACKGROUND: The current standard of practice for cremating patients with cardiac implantable electronic devices (CIEDs) is surgical explantation prior to cremation to mitigate the risk of device explosion. This surgery may conflict with patient or family beliefs, whereas cremation of CIEDs may create occupational hazards. OBJECTIVES: This study sought to establish an ex-vivo model for screening CIED behavior during cremation. METHODS: Seven CIED underwent testing including projectile/sound testing, impact testing, and gas analysis. In the projectile test, devices were heated until thermal failure (explosion) and filmed with a high-speed camera and microphone. For impact testing, brick structures were built to assess damage after explosion. Gas chromatography-mass spectrometry identified released gases. Findings were compared with occupational health standards, where available. RESULTS: The implantable loop recorder and leadless pacemaker produced minimal kinetic energy and impact risk with thermal failure. The remaining devices demonstrated explosive disintegration at thermal temperatures <500°C. The pacemakers and implantable cardiac defibrillators produced sound levels >120 dB and resulted in damage to brick structures. Small quantities of benzene and hydrogren fluoride were produced but at quantities within acceptable occupational exposure limits in a cremation chamber. CONCLUSIONS: All tested CIEDs experienced explosion at temperatures below crematorium standards. The smallest devices produced minimal risk of damage or injury suggesting they may safely remain in situ during cremation, while the larger devices produced more kinetic energy, testing chamber damage, and louder explosions suggesting potential risk with cremation. Cadaveric testing in full-sized cremation chambers is required to determine real-world risk.
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With the expanding use of cardiac implantable electronic device (CIED) therapy, intravascular device infections are becoming more common. In the case of transvenous implantable cardioverter-defibrillator (ICD) infections requiring extraction for bacterial clearance, there remains no standard method to deliver temporary ICD therapy following device removal. We present a case of persistent bacteremia complicated by monomorphic ventricular tachycardia (VT) electrical storm where biventricular ICD system extraction was performed and a temporary transvenous dual-coil lead with an externalized ICD generator was used to treat VT episodes prior to the re-implantation of a new permanent system. This case demonstrates the utility of a temporary externalized transvenous ICD system in the successful detection and pace-termination of VT, thereby reducing episodes of painful and potentially harmful external defibrillator shocks during the treatment of CIED infection.
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AIMS: Prior case series showed promising results for cardioneuroablation in patients with vagally induced atrioventricular blocks (VAVBs). We aimed to examine the acute procedural characteristics and intermediate-term outcomes of electroanatomical-guided cardioneuroablation (EACNA) in patients with VAVB. METHODS AND RESULTS: This international multicentre retrospective registry included data collected from 20 centres. Patients presenting with symptomatic paroxysmal or persistent VAVB were included in the study. All patients underwent EACNA. Procedural success was defined by the acute reversal of atrioventricular blocks (AVBs) and complete abolition of atropine response. The primary outcome was occurrence of syncope and daytime second- or advanced-degree AVB on serial prolonged electrocardiogram monitoring during follow-up. A total of 130 patients underwent EACNA. Acute procedural success was achieved in 96.2% of the cases. During a median follow-up of 300 days (150, 496), the primary outcome occurred in 17/125 (14%) cases with acute procedural success (recurrence of AVB in 9 and new syncope in 8 cases). Operator experience and use of extracardiac vagal stimulation were similar for patients with and without primary outcomes. A history of atrial fibrillation, hypertension, and coronary artery disease was associated with a higher primary outcome occurrence. Only four patients with primary outcome required pacemaker placement during follow-up. CONCLUSION: This is the largest multicentre study demonstrating the feasibility of EACNA with encouraging intermediate-term outcomes in selected patients with VAVB. Studies investigating the effect on burden of daytime symptoms caused by the AVB are required to confirm these findings.
Subject(s)
Atrioventricular Block , Registries , Humans , Male , Female , Retrospective Studies , Aged , Middle Aged , Treatment Outcome , Atrioventricular Block/physiopathology , Atrioventricular Block/therapy , Atrioventricular Block/surgery , Catheter Ablation/methods , Time Factors , Vagus Nerve Stimulation/methods , Electrophysiologic Techniques, Cardiac , Syncope/etiology , Recurrence , Atrioventricular Node/surgery , Atrioventricular Node/physiopathologyABSTRACT
The efficacy and safety of hybrid ablation (HA) for patients with non-paroxysmal atrial fibrillation (AF) remain unclear. PubMed, Embase, Cochrane, and ClinicalTrials.gov were searched for randomized controlled trials (RCTs) comparing HA (endo-epicardial ablation) versus endocardial ablation (EA) for patients with persistent/long-standing persistent AF. Risk ratios (RRs) and 95% confidence intervals (CIs) were pooled. Our meta-analysis included 3 RCTs comprising 358 patients, of whom 233 (65.1%) were randomized to HA. Compared with EA, HA reduced the recurrence of atrial tachyarrhythmias (RR 0.53; 95% CI 0.41-0.69; p < 0.01) but had no subgroup interaction according to AF type (p = 0.90). There was no significant difference in major adverse events (RR 1.22; 95% CI 0.46-3.25; p = 0.68). Trial sequential analysis indicates that the observed effects can be deemed conclusive. In conclusion, in patients with persistent/long-standing persistent AF, HA substantially reduced the recurrence of atrial tachyarrhythmias. Notably, patients with long-standing persistent AF may benefit more from this ablation strategy.
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BACKGROUND: The ADVENT randomized trial revealed no significant difference in 1-year freedom from atrial arrhythmias (AA) between thermal (radiofrequency/cryoballoon) and pulsed field ablation (PFA). However, recent studies indicate that the postablation AA burden is a better predictor of clinical outcomes than the dichotomous endpoint of 30-second AA recurrence. OBJECTIVES: The goal of this study was to determine: 1) the impact of postablation AA burden on outcomes; and 2) the effect of ablation modality on AA burden. METHODS: In ADVENT, symptomatic drug-refractory patients with paroxysmal atrial fibrillation underwent PFA or thermal ablation. Postablation transtelephonic electrocardiogram monitor recordings were collected weekly or for symptoms, and 72-hour Holters were at 6 and 12 months. AA burden was calculated from percentage AA on Holters and transtelephonic electrocardiogram monitors. Quality-of-life assessments were at baseline and 12 months. RESULTS: From 593 randomized patients (299 PFA, 294 thermal), using aggregate PFA/thermal data, an AA burden exceeding 0.1% was associated with a significantly reduced quality of life and an increase in clinical interventions: redo ablation, cardioversion, and hospitalization. There were more patients with residual AA burden <0.1% with PFA than thermal ablation (OR: 1.5; 95% CI: 1.0-2.3; P = 0.04). Evaluation of outcomes by baseline demographics revealed that patients with prior failed class I/III antiarrhythmic drugs had less residual AA burden after PFA compared to thermal ablation (OR: 2.5; 95% CI: 1.4-4.3; P = 0.002); patients receiving only class II/IV antiarrhythmic drugs pre-ablation had no difference in AA burden between ablation groups. CONCLUSIONS: Compared with thermal ablation, PFA more often resulted in an AA burden less than the clinically significant threshold of 0.1% burden. (The FARAPULSE ADVENT PIVOTAL Trial PFA System vs SOC Ablation for Paroxysmal Atrial Fibrillation [ADVENT]; NCT04612244).
Subject(s)
Atrial Fibrillation , Catheter Ablation , Recurrence , Humans , Atrial Fibrillation/surgery , Atrial Fibrillation/therapy , Atrial Fibrillation/physiopathology , Male , Female , Middle Aged , Catheter Ablation/methods , Aged , Quality of Life , Treatment OutcomeABSTRACT
BACKGROUND: The boundaries of critical isthmuses for re-entrant ventricular tachycardia (VT) are formed by wavefront discontinuities (fixed lines of block, slow propagation, and rotational propagation) seen during baseline rhythm. It is unknown whether wavefront discontinuities can be automatically identified and targeted for ablation using electroanatomic mapping systems. OBJECTIVES: The purpose of this study was to assess the electrophysiologic characteristics of automatically projected wavefront discontinuity lines (WADLs) and outcomes of an ablation strategy targeting WADLs in a mixed cohort of VT patients. METHODS: Late activation substrate maps were analyzed from 1 or more baseline rhythm wavefronts. WADLs were identified using the Carto Extended Early Meets Late module. Number, total length, and distance to critical VT sites were measured. VT recurrence and VT-free survival were followed. RESULTS: In total, 49 patients underwent 52 ablations with 71 unique substrate maps analyzed (18.8% epicardial; 62.0% right ventricular paced, 28.2% sinus rhythm, 9.9% left ventricular paced). A total of 28 VT critical sites were identified in 24 patients. WADLs were present in 49 of 71 (69.0%) maps. WADLs were present regardless of cardiomyopathy etiology, mapping wavefront, or surface. At a WADL threshold of 30%, 73.9% of critical VT sites were in close proximity (≤15 mm) to a WADL. VT-free survival was 62% at 1 year, with a competing risk model estimating a 1-year risk of VT recurrence of 23%. CONCLUSIONS: WADLs can be automatically projected in a majority of patients in a mixed cohort of cardiomyopathy etiology, mapped wavefronts, and myocardial surfaces mapped. Targeting WADLs results in low rate of VT recurrence at 1 year.
Subject(s)
Catheter Ablation , Cicatrix , Electrophysiologic Techniques, Cardiac , Tachycardia, Ventricular , Humans , Tachycardia, Ventricular/surgery , Tachycardia, Ventricular/physiopathology , Female , Male , Catheter Ablation/methods , Middle Aged , Aged , Cicatrix/physiopathology , Electrophysiologic Techniques, Cardiac/methods , RecurrenceABSTRACT
BACKGROUND: Pulmonary vein isolation (PVI) is increasingly recommended as first-line therapy for atrial fibrillation. Recent data suggest growing PVI volumes but rising complication rates, although comprehensive real-world outcomes including both inpatient and outpatient encounters remain unclear. OBJECTIVES: The purpose of this study was to evaluate patient characteristics, population rates, and 30-day outcomes of PVI in a nationwide sample of U.S. adults aged >65 years. METHODS: First-time PVIs were identified among U.S. Medicare fee-for-service beneficiaries using Current Procedural Terminology procedural codes. Comorbidities were ascertained using International Classification of Diseases-10th Revision diagnosis codes associated with each procedural claim. Outcomes included periprocedural complications, all-cause hospitalizations, and mortality at 30 days. RESULTS: From January 2017 through December 2021, a total of 227,133 patients underwent PVI (mean age 72.5 years, 42% women, 92.7% White) with an increasing comorbidity burden over time. PVI volume increased from 83.8 (2017) to 111.6 per 100,000 patient-years (2021), which was driven by outpatient procedures (87.8% of all PVIs). Concurrently, there was a significant decrease in complication rates (3.9% in 2017 vs 3.1% in 2021; P < 0.001) and hospitalizations (8.8% vs 7.0%; P < 0.001), with no significant change in mortality (0.4%; P = 0.08). The most common periprocedural complications were bleeding (1.8%), pericardial effusion (1.4%), and vascular access damage (0.8%). CONCLUSIONS: The use of PVI has steadily increased among older patients in contemporary U.S. clinical practice; yet, cumulative complication and hospitalization rates at 30 days have decreased over time, with stably low rates of short-term mortality despite rising comorbidity burden among treated patients. These data may reassure patients and providers on the safety of PVI as an increasingly common first-line procedure for atrial fibrillation.
Subject(s)
Atrial Fibrillation , Catheter Ablation , Humans , Atrial Fibrillation/surgery , Atrial Fibrillation/epidemiology , Aged , Female , Male , United States/epidemiology , Catheter Ablation/statistics & numerical data , Catheter Ablation/adverse effects , Aged, 80 and over , Postoperative Complications/epidemiology , Hospitalization/statistics & numerical data , Treatment Outcome , Medicare/statistics & numerical data , Pulmonary Veins/surgery , ComorbidityABSTRACT
Chagas cardiomyopathy caused by infection with the intracellular parasite Trypanosoma cruzi is the most common and severe expression of human Chagas disease. Heart failure, systemic and pulmonary thromboembolism, arrhythmia, and sudden cardiac death are the principal clinical manifestations of Chagas cardiomyopathy. Ventricular arrhythmias contribute significantly to morbidity and mortality and are the major cause of sudden cardiac death. Significant gaps still exist in the understanding of the pathogenesis mechanisms underlying the arrhythmogenic manifestations of Chagas cardiomyopathy. This article will review the data from experimental studies and translate those findings to draw hypotheses about clinical observations. Human- and animal-based studies at molecular, cellular, tissue, and organ levels suggest 5 main pillars of remodeling caused by the interaction of host and parasite: immunologic, electrical, autonomic, microvascular, and contractile. Integrating these 5 remodeling processes will bring insights into the current knowledge in the field, highlighting some key features for future management of this arrhythmogenic disease.
Subject(s)
Arrhythmias, Cardiac , Chagas Cardiomyopathy , Humans , Animals , Arrhythmias, Cardiac/etiology , Arrhythmias, Cardiac/parasitology , Arrhythmias, Cardiac/physiopathology , Chagas Cardiomyopathy/parasitology , Trypanosoma cruzi/pathogenicity , Chagas Disease/complications , Chagas Disease/parasitology , Chagas Disease/immunologyABSTRACT
INTRODUCTION: Numerous P-wave indices have been explored as biomarkers to assess atrial fibrillation (AF) risk and the impact of therapy with variable success. OBJECTIVE: We investigated the utility of P-wave alternans (PWA) to track the effects of pulmonary vein isolation (PVI) and to predict atrial arrhythmia recurrence. METHODS: This medical records study included patients who underwent PVI for AF ablation at our institution, along with 20 control subjects without AF or overt cardiovascular disease. PWA was assessed using novel artificial intelligence-enabled modified moving average (AI-MMA) algorithms. PWA was monitored from the 12-lead ECG at ~1 h before and ~16 h after PVI (n = 45) and at the 4- to 17-week clinically indicated follow-up visit (n = 30). The arrhythmia follow-up period was 955 ± 112 days. RESULTS: PVI acutely reduced PWA by 48%-63% (p < .05) to control ranges in leads II, III, aVF, the leads with the greatest sensitivity in monitoring PWA. Pre-ablation PWA was ~6 µV and decreased to ~3 µV following ablation. Patients who exhibited a rebound in PWA to pre-ablation levels at 4- to 17-week follow-up (p < .01) experienced recurrent atrial arrhythmias, whereas patients whose PWA remained reduced (p = .85) did not, resulting in a significant difference (p < .001) at follow-up. The AUC for PWA's prediction of first recurrence of atrial arrhythmia was 0.81 (p < .01) with 88% sensitivity and 82% specificity. Kaplan-Meier analysis estimated atrial arrhythmia-free survival (p < .01) with an adjusted hazard ratio of 3.4 (95% CI: 1.47-5.24, p < .02). CONCLUSION: A rebound in PWA to pre-ablation levels detected by AI-MMA in the 12-lead ECG at standard clinical follow-up predicts atrial arrhythmia recurrence.
Subject(s)
Action Potentials , Atrial Fibrillation , Catheter Ablation , Electrocardiography , Heart Rate , Predictive Value of Tests , Pulmonary Veins , Recurrence , Humans , Pulmonary Veins/surgery , Pulmonary Veins/physiopathology , Atrial Fibrillation/physiopathology , Atrial Fibrillation/surgery , Atrial Fibrillation/diagnosis , Male , Female , Catheter Ablation/adverse effects , Middle Aged , Aged , Time Factors , Treatment Outcome , Risk Factors , Retrospective Studies , Case-Control StudiesABSTRACT
BACKGROUND: The optimal treatment of atrial fibrillation (AF) in patients with heart failure with reduced ejection fraction (HFrEF) remains unsettled. OBJECTIVE: The purpose of this study was to assess the efficacy of catheter ablation (CA) and medical therapy compared to medical therapy alone in patients with AF and HFrEF. METHODS: We performed a systematic review of randomized controlled trials (RCTs) comparing CA with guideline-directed medical therapy for AF in patients with HFrEF (left ventricular ejection fraction [LVEF] ≤ 40%). We systematically searched PubMed, Embase, and Cochrane for eligible trials. A random effects model was used to calculate the risk ratios (RRs) and mean differences (MDs), with 95% confidence intervals (CIs). RESULTS: Six RCTs comprising 1055 patients were included, of whom 530 (50.2%) were randomized to CA. Compared with medical therapy, CA was associated with a significant reduction in heart failure (HF) hospitalization (RR 0.57; 95% CI 0.45-0.72; P < .01), cardiovascular mortality (RR 0.46; 95% CI 0.31-0.70; P < .01), all-cause mortality (RR 0.53; 95% CI 0.36-0.78; P < .01), and AF burden (MD -29.8%; 95% CI -43.73% to -15.90%; P < .01). Also, there was a significant improvement in LVEF (MD 3.8%; 95% CI 1.6%-6.0%; P < .01) and quality of life (Minnesota Living with Heart Failure Questionnaire; MD -4.92 points; 95% CI -8.61 to -1.22 points; P < .01) in the ablation group. CONCLUSION: In this meta-analysis of RCTs of patients with AF and HFrEF, CA was associated with a reduction in HF hospitalization, cardiovascular mortality, and all-cause mortality as well as a significant improvement in LVEF and quality of life.
Subject(s)
Atrial Fibrillation , Catheter Ablation , Heart Failure , Stroke Volume , Humans , Atrial Fibrillation/surgery , Atrial Fibrillation/physiopathology , Atrial Fibrillation/complications , Atrial Fibrillation/therapy , Catheter Ablation/methods , Heart Failure/physiopathology , Heart Failure/complications , Stroke Volume/physiology , Ventricular Function, Left/physiology , Quality of Life , Treatment Outcome , Randomized Controlled Trials as TopicABSTRACT
BACKGROUND: Myocardial electrical heterogeneity is critical for normal cardiac electromechanical function, but abnormal or excessive electrical heterogeneity is proarrhythmic. The spatial ventricular gradient (SVG), a vectorcardiographic measure of electrical heterogeneity, has been associated with arrhythmic events during long-term follow-up, but its relationship with short-term inducibility of ventricular arrhythmias (VAs) is unclear. OBJECTIVE: This study was designed to determine associations between SVG and inducible VAs during electrophysiology study. METHODS: A retrospective study was conducted of adults without prior sustained VA, cardiac arrest, or implantable cardioverter-defibrillator who underwent ventricular stimulation for evaluation of syncope and nonsustained ventricular tachycardia or for risk stratification before primary prevention implantable cardioverter-defibrillator implantation. The 12-lead electrocardiograms were converted into vectorcardiograms, and SVG magnitude (SVGmag) and direction (azimuth and elevation) were calculated. Odds of inducible VA were regressed by logistic models. RESULTS: Of 143 patients (median age, 69 years; 80% male; median left ventricular ejection fraction [LVEF], 47%; 52% myocardial infarction), 34 (23.8%) had inducible VAs. Inducible patients had lower median LVEF (38% vs 50%; P < .0001), smaller SVGmag (29.5 vs 39.4 mV·ms; P = .0099), and smaller cosine SVG azimuth (cosSVGaz; 0.64 vs 0.89; P = .0007). When LVEF, SVGmag, and cosSVGaz were dichotomized at their medians, there was a 39-fold increase in adjusted odds (P = .002) between patients with all low LVEF, SVGmag, and cosSVGaz (65% inducible) compared with patients with all high LVEF, SVGmag, and cosSVGaz (4% [n = 1] inducible). After multivariable adjustment, SVGmag, cosSVGaz, and sex but not LVEF or other characteristics remained associated with inducible VAs. CONCLUSION: Assessment of electrical heterogeneity by SVG, which reflects abnormal electrophysiologic substrate, adds to LVEF and identifies patients at high and low risk of inducible VA at electrophysiology study.
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BACKGROUND: The efficacy and safety of adjunctive low-voltage area (LVA) ablation on outcomes of catheter ablation (CA) for atrial fibrillation (AF) remains uncertain. METHODS: PubMed, Embase, Cochrane Library, and ClinicalTrials.gov were searched for randomized controlled trials (RCTs) comparing CA with versus without LVA ablation for patients with AF. Risk ratios (RR) with 95% confidence intervals (CI) were pooled with a random-effects model. Our primary endpoint was recurrence of atrial tachyarrhythmia (ATA), including AF, atrial flutter, or atrial tachycardia. We used R version 4.3.1 for all statistical analyses. RESULTS: Our meta-analysis included 10 RCTs encompassing 1780 patients, of whom 890 (50%) were randomized to LVA ablation. Adjunctive LVA ablation significantly reduced recurrence of ATA (RR 0.76; 95% CI 0.67-0.88; p < .01) and reduced the number of redo ablation procedures (RR 0.54; 95% CI 0.35-0.85; p < .01), as compared with conventional ablation. Among 691 (43%) patients with documented LVAs on baseline substrate mapping, adjunctive LVA ablation substantially reduced ATA recurrences (RR 0.57; 95% CI 0.38-0.86; p < .01). There was no significant difference between groups in terms of periprocedural adverse events (RR 0.78; 95% CI 0.39-1.56; p = .49). CONCLUSIONS: Adjunctive LVA ablation is an effective and safe strategy for reducing recurrences of ATA among patients who undergo CA for AF.
Subject(s)
Action Potentials , Atrial Fibrillation , Catheter Ablation , Randomized Controlled Trials as Topic , Recurrence , Humans , Atrial Fibrillation/surgery , Atrial Fibrillation/physiopathology , Atrial Fibrillation/diagnosis , Catheter Ablation/adverse effects , Treatment Outcome , Male , Risk Factors , Female , Middle Aged , Heart Rate , Aged , Time FactorsABSTRACT
BACKGROUND: Cardioneuroablation has been emerging as a potential treatment alternative in appropriately selected patients with cardioinhibitory vasovagal syncope (VVS) and functional AV block (AVB). However the majority of available evidence has been derived from retrospective cohort studies performed by experienced operators. METHODS: The Cardioneuroablation for the Management of Patients with Recurrent Vasovagal Syncope and Symptomatic Bradyarrhythmias (CNA-FWRD) Registry is a multicenter prospective registry with cross-over design evaluating acute and long-term outcomes of VVS and AVB patients treated by conservative therapy and CNA. RESULTS: The study is a prospective observational registry with cross-over design for analysis of outcomes between a control group (i.e., behavioral and medical therapy only) and intervention group (Cardioneuroablation). Primary and secondary outcomes will only be assessed after enrollment in the registry. The follow-up period will be 3 years after enrollment. CONCLUSIONS: There remains a lack of prospective multicentered data for long-term outcomes comparing conservative therapy to radiofrequency CNA procedures particularly for key outcomes including recurrence of syncope, AV block, durable impact of disruption of the autonomic nervous system, and long-term complications after CNA. The CNA-FWRD registry has the potential to help fill this information gap.
Subject(s)
Catheter Ablation , Heart Septal Defects, Ventricular , Tachycardia, Ventricular , Humans , Tachycardia, Ventricular/surgery , Tachycardia, Ventricular/etiology , Tachycardia, Ventricular/physiopathology , Catheter Ablation/adverse effects , Catheter Ablation/methods , Heart Septal Defects, Ventricular/surgery , Male , Electrocardiography , Female , Middle AgedABSTRACT
BACKGROUND: Activation mapping is often used to differentiate focal from re-entrant arrhythmias. This can be challenging but is critical to ablation success. The local activation time (LAT) histogram, which depicts point distribution over isochronal segments, may help characterize arrhythmia mechanisms and identify an optimal ablation strategy. OBJECTIVES: This study aimed to investigate features of the LAT histogram associated with the focal vs re-entrant mechanism of atrial tachycardias (ATs) and the use of the LAT histogram in the identification of target ablation sites. METHODS: We retrospectively evaluated cases of focal and re-entrant ATs performed at a single academic tertiary care center for which activation mapping was performed using CARTO 3 version 7 software (Biosense Webster). Baseline patient, arrhythmia, and procedural characteristics as well as LAT histogram features were evaluated for each case. LAT histogram-guided ablation targets were also compared against actual ablation sites. RESULTS: Among 52 ATs assessed, 17 were focal, and 35 were re-entrant. Tachycardia cycle length was significantly shorter in re-entrant than in focal ATs (288.2 milliseconds [Q1-Q3: 250-306.5 milliseconds] vs 370 milliseconds [Q1-Q3: 285-400 milliseconds], respectively; P = 0.006). LAT histograms contained more "valleys" in re-entrant than in focal ATs (3 [Q1-Q3: 2-4] vs 1 [Q1-Q3: 1-1]; P < 0.001). No focal ATs contained >2 and no re-entrant ATs contained <1 LAT valley(s). All successful ablation sites correlated with LAT histogram-suggested sites. CONCLUSIONS: LAT histograms can help distinguish focal from re-entrant Ats and identify effective ablation sites.