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1.
Artigo em Inglês | MEDLINE | ID: mdl-32628867

RESUMO

Background - Clinical factors associated with development of intravascular lead adherence (ILA) are unreliable predictors. Because vascular injury in the superior vena cava - right atrium (SVC-RA) during transvenous lead extraction (TLE) is more likely to occur in segments with higher degrees of ILA, reliable and accurate assessment of ILA is warranted. We hypothesized that intravascular ultrasound (IVUS) could accurately visualize and quantify ILA and degree of ILA correlates with TLE difficulty. Methods - Serial imaging of leads occurred prior to TLE using IVUS. ILA areas were classified as high or low grade. Degree of extraction difficulty was assessed using 2 metrics and correlated with ILA grade. Lead extraction difficulty (LED) was calculated for each patient and compared to IVUS findings. Results - 158 vascular segments in 60 patients were analyzed: 141 (89%) low grade versus 17 (11%) high grade. Median extraction time (low=0 versus high grade=97 seconds, p<0.001) and median laser pulsations delivered (low=0 versus high grade=5852, p<0.001) were significantly higher in high grade segments. Most patients with low LED score had low ILA grades. 86% of patients with high LED score had low IVUS grade and the degree of TLE difficulty was similar to patients with low IVUS grades and LED scores. Conclusions - IVUS is a feasible imaging modality that may be useful in characterizing ILA in the SVC-RA region. An ILA grading system using imaging correlates with extraction difficulty. Most patients with clinical factors associated with higher extraction difficulty may exhibit lower ILA and extraction difficulty based on IVUS imaging.

2.
Heart Rhythm ; 2020 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-32325198

RESUMO

BACKGROUND: The mechanisms for scar-related ventricular tachycardia (VT) originating from the periaortic region remain incompletely characterized. OBJECTIVE: The purpose of this study was to map the circuits responsible for periaortic VT in high resolution. METHODS: Cases with periaortic VT (2016-2020) were analyzed to characterize the substrate and mechanisms with multielectrode mapping. Periaortic VT was defined as low-voltage and/or deceleration zones within 2 cm of the left ventriculoaortic junction with a corresponding critical site during VT. RESULTS: Forty-nine periaortic monomorphic VTs were analyzed in 30 patients (25% of all patients with nonischemic cardiomyopathy). Isolated periaortic substrate was observed in 27% of patients, with 73% having concomitant scar, most commonly in the mid-septum (47%). Deceleration zones were equally prevalent on the septal and lateral portions of the periaortic region (87% vs 73%; P = .19). During activation mapping of VT (tachycardia cycle length 392 ± 105 ms), localized reentrant patterns of activation (14 mm [10-17 mm] × 10 mm [7-14 mm]) were demonstrated in 63% and 37% of VTs showed centrifugal activation, consistent with a focal breakout pattern. Ninety-six percent of VTs fulfilled criteria for a reentrant mechanism. Sixty-five percent of reentrant circuits had endocardial activation gaps within the tachycardia cycle length (3-dimensional circuitry), which were associated with higher rates of recurrence as compared with 2-dimensional complete circuits at 1 year (73% vs 37%; P = .028). CONCLUSION: Periaortic VTs were observed in 25% of patients with nonischemic cardiomyopathy and scar-related VT. For the first time, localized reentry confined to this anatomically challenging region was demonstrated as the predominant mechanism by high-resolution circuit activation mapping.

4.
Curr Opin Cardiol ; 35(3): 295-307, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32205478

RESUMO

PURPOSE OF REVIEW: His bundle pacing (HBP) has emerged as a novel method to achieve electrical resynchronization in bundle branch block and as an alternative means to deliver cardiac resynchronization therapy (CRT). There are now data on HBP in CRT-eligible patients from cohort studies and a single pilot randomized controlled trial (RCT). RECENT FINDINGS: Early clinical data regarding HBP in heart failure have demonstrated echocardiographic and functional improvement similar to traditional biventricular pacing (BiV), mostly when utilized as a bailout to traditional BiV-CRT. A single pilot RCT, His-SYNC, showed a trend toward greater echocardiographic response in an on-treatment analysis, but was underpowered. No large RCTs have reported long-term clinical outcomes. In order to realize any benefit from HBP, output-dependent morphology changes must be demonstrated to ensure the conduction system capture is present. There may be a role for corrective HBP in patients with right bundle branch block and after atrioventricular node ablation, which is theoretically more desirable than traditional BiV. Importantly, however, HBP is likely not to benefit patients with nonspecific intraventricular conduction delay. SUMMARY: HBP is emerging as an alternative strategy for CRT and may have a role in patients in whom traditional BiV is not achievable or ineffective.

5.
J Am Coll Cardiol ; 75(8): 884-897, 2020 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-32130924

RESUMO

BACKGROUND: Mechanisms of scar-related ventricular tachycardia (VT) are largely based on computational and animal models that portray a 2-dimensional view. OBJECTIVES: The authors sought to delineate the human VT circuit with a 3-dimensional perspective from recordings obtained by simultaneous endocardial and epicardial mapping. METHODS: High-resolution mapping was performed during 97 procedures in 89 patients with structural heart disease. Circuits were characterized by systematic isochronal analysis to estimate the dimensions of the isthmus and extent of the exit region recorded on both myocardial surfaces. RESULTS: A total of 151 VT morphologies were mapped, of which 83 underwent simultaneous endocardial and epicardial mapping; 17% of circuits activated in a 2-dimensional plane, restricted to 1 myocardial surface. Three-dimensional activation patterns with nonuniform transmural propagation were observed in 61% of circuits with only 4% showing transmurally uniform activation, and 18% exhibiting focal activation patterns consistent with mid-myocardial reentry. The dimensions of the central isthmus were 17 mm (12 to 28 mm) × 10 mm (9 to 19 mm) with 55% exhibiting a minimal dimension of <1.5 cm. QRS activation was transmural in 63% and located 43 mm (34 to 52 mm) from the central isthmus. On the basis of 6 proposed definitions for epicardial VT, the prevalence of an epicardial circuit ranged from 21% to 80% in ischemic cardiomyopathy and 28% to 77% in nonischemic cardiomyopathy. CONCLUSIONS: A 2D perspective oversimplifies the electrophysiological circuit responsible for reentrant human VT and simultaneous endocardial and epicardial mapping facilitates inferences about mid-myocardial activation. Intricate activation patterns are frequently observed on both myocardial surfaces, and the epicardium is functionally involved in the majority of circuits. Human reentry may exist within isthmus dimensions smaller than 1 cm, whereas QRS activation is often transmural and remote from the critical isthmus target. A 3-dimensional perspective of the VT circuit may enhance the precision of ablative therapy and may support a greater role for adjunctive strategies and technology to address arrhythmogenic tissue harbored in the mid-myocardium and subepicardium.

6.
JACC Clin Electrophysiol ; 6(3): 311-323, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32192682

RESUMO

OBJECTIVES: This study aimed to evaluate the feasibility and accuracy of using a novel grid mapping catheter during scar-related ventricular tachycardia (VT) ablation. BACKGROUND: Ultra-high-density (UHD) mapping improves identification of local abnormal ventricular activities (LAVAs) and characterization of scar substrates. METHODS: Consecutive patients underwent endocardial and/or epicardial ablation guided by a HD grid mapping catheter. A linear duodecapolar catheter was used in the initial cases for systematic correlation. Isochronal late activation mapping was performed during sinus rhythm to identify deceleration zones, and activation mapping of VT was performed when tolerated. RESULTS: In 38 patients, 51 electroanatomic maps (left ventricle: 26, epicardium: 21, right ventricle: 4) were created using a grid catheter. LAVAs were identified in 98% of cases and deceleration zones were observed in 86%. High-frequency electrograms with diastolic activation were identified during 44 sustained monomorphic VTs, and the critical isthmus was colocalized to deceleration zones during sinus rhythm in 96% of cases. In 17 cases that underwent sequential mapping with both grid and linear catheters, the low voltage area detected using the grid (HD wave) was significantly smaller, with ratios of 0.61 (<0.5 mV) and 0.81 (<1.5 mV) relative to the duodecapolar catheter. CONCLUSIONS: VT ablation guided by a novel HD grid catheter is safe and feasible for clinical use in human scar-related VT via both endocardial and epicardial approaches. Automated selection of larger bipolar amplitudes among orthogonal pairs consistently displayed smaller low voltage areas than a previously validated linear catheter.

9.
Circulation ; 140(17): 1383-1397, 2019 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-31533463

RESUMO

BACKGROUND: Accurate and expedited identification of scar regions most prone to reentry is needed to guide ventricular tachycardia (VT) ablation. We aimed to prospectively assess outcomes of VT ablation guided primarily by the targeting of deceleration zones (DZ) identified by propagational analysis of ventricular activation during sinus rhythm. METHODS: Patients with scar-related VT were prospectively enrolled in the University of Chicago VT Ablation Registry between 2016 and 2018. Isochronal late activation maps annotated to the latest local electrogram deflection were created with high-density multielectrode mapping catheters. Targeted ablation of DZ (>3 isochrones within 1cm radius) was performed, prioritizing later activated regions with maximal isochronal crowding. When possible, activation mapping of VT was performed, and successful ablation sites were compared with DZ locations for mechanistic correlation. Patients were prospectively followed for VT recurrence and mortality. RESULTS: One hundred twenty patients (median age 65 years [59-71], 15% female, 50% nonischemic, median ejection fraction 31%) underwent 144 ablation procedures for scar-related VT. 57% of patients had previous ablation and epicardial access was employed in 59% of cases. High-density mapping during baseline rhythm was performed (2518 points [1615-3752] endocardial, 5049±2580 points epicardial) and identified an average of 2±1 DZ, which colocalized to successful termination sites in 95% of cases. The median total radiofrequency application duration was 29 min (21-38 min) to target DZ, representing ablation of 18% of the low-voltage area. At 12±10 months, 70% freedom from VT recurrence (80% in ischemic cardiomyopathy and 63% in nonischemic cardiomyopathy) was achieved. The overall survival rate was 87%. CONCLUSIONS: A novel voltage-independent high-density mapping display can identify the functional substrate for VT during sinus rhythm and guide targeted ablation, obviating the need for extensive radiofrequency delivery. Regions with isochronal crowding during the baseline rhythm were predictive of VT termination sites, providing mechanistic evidence that deceleration zones are highly arrhythmogenic, functioning as niduses for reentry.

11.
Echocardiography ; 36(8): 1450-1458, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31424113

RESUMO

BACKGROUND: Secondary mitral regurgitation (MR) is common in patients with left bundle branch block (LBBB) undergoing cardiac resynchronization therapy (CRT). We aimed to define CRT effects on left ventricular (LV) and mitral valve (MV) geometry, and their correlation with MR severity. METHODS: Forty-one patients with LBBB and ≥mild secondary MR underwent CRT between 2009 and 2012, and had baseline and follow-up echocardiograms available. Repeated measure and linear regression analyses were performed to assess for changes in MV and LV geometry and MR severity, and associations with follow-up MR grade. RESULTS: The mean age and baseline QRS duration were 65.5 ± 14.9 years and 160 ± 24 ms. At a mean follow-up of 2.6 ± 1.8 years, there was an increase in LV ejection fraction and reductions in LV end-systolic volume index, MR grade, and end-systolic interpapillary muscle distance (P < .05 for all). Linear correlations were observed between follow-up MR grade and baseline MV tenting height (r = .44), left atrial volume index (r = .41), LV end-systolic volume index (r = .4), MV tenting area (r = .38), LV ejection fraction (r = -.34), and end-systolic interpapillary muscle distance (r = .34) (P < .05 for all). Multiple regression analysis revealed associations between follow-up MR grade and baseline MV tenting height (ß/mm = 0.42, P = .006) and left atrial volume index (ß/mL/m2  = 0.4, P = .008), independent of QRS duration (ß/ms=-0.07; P = 0.6) and nonischemic cardiomyopathy (ß = -0.34, P = .02). CONCLUSIONS: Cardiac resynchronization therapy in patients with LBBB and secondary MR results in LV and MV geometric reverse remodeling and decreases MR severity. Extent of baseline MV tethering is independently associated with persistent MR at follow-up.

12.
Heart Rhythm ; 16(12): 1797-1807, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31096064

RESUMO

BACKGROUND: The His-SYNC pilot trial was the first randomized comparison between His bundle pacing in lieu of a left ventricular lead for cardiac resynchronization therapy (His-CRT) and biventricular pacing (BiV-CRT), but was limited by high rates of crossover. OBJECTIVE: To evaluate the results of the His-SYNC pilot trial utilizing treatment-received (TR) and per-protocol (PP) analyses. METHODS: The His-SYNC pilot was a multicenter, prospective, single-blinded, randomized, controlled trial comparing His-CRT vs BiV-CRT in patients meeting standard indications for CRT (eg, NYHA II-IV patients with QRS >120 ms). Crossovers were required based on prespecified criteria. The primary endpoints analyzed included improvement in QRS duration, left ventricular ejection fraction (LVEF), and freedom from cardiovascular (CV) hospitalization and mortality. RESULTS: Among 41 patients enrolled (aged 64 ± 13 years, 38% female, LVEF 28%, QRS 168 ± 18 ms), 21 were randomized to His-CRT and 20 to BiV-CRT. Crossover occurred in 48% of His-CRT and 26% of BiV-CRT. The most common reason for crossover from His-CRT was inability to correct QRS owing to nonspecific intraventricular conduction delay (n = 5). Patients treated with His-CRT demonstrated greater QRS narrowing compared to BiV (125 ± 22 ms vs 164 ± 25 ms [TR], P < .001;124 ± 19 ms vs 162 ± 24 ms [PP], P < .001). A trend toward higher echocardiographic response was also observed (80 vs 57% [TR], P = .14; 91% vs 54% [PP], P = .078). No significant differences in CV hospitalization or mortality were observed. CONCLUSIONS: Patients receiving His-CRT on-treatment demonstrated superior electrical resynchronization and a trend toward higher echocardiographic response than BiV-CRT. Larger prospective studies may be justifiable with refinements in patient selection and implantation techniques to minimize crossovers.

14.
Am J Med ; 132(4): e549-e550, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30935464
15.
J Cardiovasc Electrophysiol ; 30(8): 1380-1383, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30907486

RESUMO

We present an illustrative case of a patient with intermittent left bundle branch block (LBBB) that underwent electrophysiological study with detailed multielectrode recordings of the right and left septum. The case elucidates the nature and location of conduction block and provides further insight into the underlying mechanisms of LBBB.

16.
JACC Clin Electrophysiol ; 5(3): 330-339, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30898236

RESUMO

OBJECTIVES: This study assessed the impact of atrial fibrillation (AF) ablation on hospitalization and antiarrhythmic drug use in the community setting. BACKGROUND: Despite the widespread increase in the use of catheter ablation to treat AF in the United States, the impact of ablation on arrhythmic, cardiovascular, and noncardiovascular hospitalizations remains unclear. METHODS: The national prospectively acquired Truven Health MarketScan data set (January 1, 2008 to December 31, 2014) was used to identify patients who underwent first time AF ablation with uninterrupted enrollment for 24 months (12 months pre-ablation and 12 months post-ablation). Multivariate logistic regression was used to determine predictors of hospitalization. RESULTS: Of 5,238 patients who underwent AF ablation for the first time, 2,720 patients with uninterrupted enrollment were analyzed (age 60 ± 10 years; 29% were women, 79% had hypertension, and 23% had heart failure [HF]). AF ablation was associated with significantly reduced all-cause hospitalization from 1,669 hospitalizations in the year before ablation to 1,034 hospitalizations in the year after ablation, which was driven primarily by a 56% reduction in arrhythmic hospitalization. Nonarrhythmic cardiovascular hospitalizations also declined through a 43% drop off in HF hospitalizations. Noncardiovascular hospitalization rates did not significantly change. Age younger than 55 years (odds ratio [OR]: 1.43; p < 0.001), obstructive sleep apnea (OR: 1.38; p < 0.001), and HF (OR: 1.29; p = 0.024) were multivariate predictors for decreased arrhythmic hospitalization. Rates of antiarrhythmic drug use also significantly declined post-procedure by 37.5% (p < 0.001). CONCLUSIONS: In this nationwide cohort, AF ablation was associated with significant decreases in arrhythmic and nonarrhythmic cardiovascular hospitalizations, which was driven by reductions in hospitalization for AF and HF.


Assuntos
Fibrilação Atrial , Ablação por Cateter , Hospitalização/estatística & dados numéricos , Idoso , Antiarrítmicos/efeitos adversos , Antiarrítmicos/uso terapêutico , Fibrilação Atrial/tratamento farmacológico , Fibrilação Atrial/cirurgia , Ablação por Cateter/efeitos adversos , Ablação por Cateter/estatística & dados numéricos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
17.
Heart Rhythm ; 16(8): 1151-1159, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30776449

RESUMO

BACKGROUND: Recurrences of atrial fibrillation (AF) after ablation have been attributed to conduction gaps and nontransmural ablation lesions. OBJECTIVE: The purpose of this study was to assess the feasibility of adjunctive percutaneous mapping of the epicardial regions of the left atrium to characterize the transmural extent of substrate and ablation lesions. METHODS: Between 2014 and 2018, combined epicardial and endocardial mapping of AF was performed in 18 patients via an inferior subxiphoid percutaneous approach (16 with previously failed ablation procedures and 2 patients with long-standing persistent AF) at 2 centers. Epicardial substrate mapping was compared with endocardial mapping to assess transmural uniformity. RESULTS: Of 18 patients, 4 (22%) demonstrated nontransmural atrial low-voltage regions with relative epicardial sparing in the left atrial posterior wall. Transmural isolation of the posterior wall was achieved after an endocardial "box" lesion set in 6/9 (67%), guided by epicardial voltage data, while epicardial and endocardial dissociation during AF was observed in 1 patient. In 3 patients, epicardial capture along the endocardial pulmonary vein lesion set despite endocardial capture loss and bidirectional block was observed. Two cases of mitral flutter were terminated from the epicardium. A balloon was positioned in the pericardial space in 6 patients for esophageal protection during ablation. CONCLUSION: A percutaneous epicardial approach for mapping and ablation of the left atrium is feasible in the electrophysiology laboratory during endocardial catheter ablation for AF and may be useful as an adjunctive approach in refractory cases. High-density epicardial mapping can provide direct evidence of nonuniform lesion and substrate transmurality of the human left atrium before and after ablation.

18.
Circulation ; 139(16): 1876-1888, 2019 04 16.
Artigo em Inglês | MEDLINE | ID: mdl-30704273

RESUMO

BACKGROUND: Septal activation in patients with left bundle-branch block (LBBB) patterns has not been described previously. We performed detailed intracardiac mapping of left septal conduction to assess for the presence and level of complete conduction block (CCB) in the His-Purkinje system. Response to His bundle pacing was assessed in patients with and without CCB in the left bundle. METHODS: Left septal mapping was performed with a linear multielectrode catheter in consecutive patients with LBBB pattern referred for device implantation (n=38) or substrate mapping (n=47). QRS width, His duration, His-ventricular (HV) intervals, and septal conduction patterns were analyzed. The site of CCB was localized to the level of the left-sided His fibers (left intrahisian) or left bundle branch. Patients with ventricular activation preceded by Purkinje potentials were categorized as having intact Purkinje activation. RESULTS: A total of 88 left septal conduction recordings were analyzed in 85 patients: 72 LBBB block pattern and 16 controls (narrow QRS, n=11; right bundle-branch block, n=5). Among patients with LBB block pattern, CCB within the proximal left conduction system was observed in 64% (n=46) and intact Purkinje activation in the remaining 36% (n=26). Intact Purkinje activation was observed in all controls. The site of block in patients with CCB was at the level of the left His bundle in 72% and in the proximal left bundle branch in 28%. His bundle pacing corrected wide QRS in 54% of all patients with LBBB pattern and 85% of those with CCB (94% left intrahisian, 62% proximal left bundle-branch). No patients with intact Purkinje activation demonstrated correction of QRS with His bundle pacing. CCB showed better predictive value (positive predictive value 85%, negative predictive value 100%, sensitivity 100%) than surface ECG criteria for correction with His bundle pacing. CONCLUSIONS: Heterogeneous septal conduction was observed in patients with surface LBBB pattern, ranging from no discrete block to CCB. When block was present, we observed pathology localized within the left-sided His fibers (left intrahisian block), which was most amenable to corrective His bundle pacing by recruitment of latent Purkinje fibers. ECG criteria for LBBB incompletely predicted CCB, and intracardiac data might be useful in refining patient selection for resynchronization therapy.


Assuntos
Fascículo Atrioventricular/fisiologia , Bloqueio de Ramo/diagnóstico , Técnicas de Imagem Cardíaca/métodos , Eletrocardiografia/métodos , Septos Cardíacos/diagnóstico por imagem , Hipertrofia Ventricular Esquerda/diagnóstico , Ramos Subendocárdicos/fisiologia , Idoso , Fascículo Atrioventricular/diagnóstico por imagem , Cateteres Cardíacos , Terapia de Ressincronização Cardíaca , Estudos de Coortes , Feminino , Frequência Cardíaca , Septos Cardíacos/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Contração Miocárdica , Prognóstico
20.
Card Electrophysiol Clin ; 10(3): 511-517, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30172288

RESUMO

Cardiac resynchronization therapy with left ventricular coronary sinus or epicardial pacing is an established therapy for patients with systolic heart failure and intraventricular conduction system delay, particularly left bundle branch block. Despite large-scale randomized trials demonstrating the efficacy of this therapy, clinical and echocardiographic nonresponse rates remain as high as up to 40%. His bundle pacing (HBP) has reemerged as a means to provide physiologic resynchronization in patients with bundle branch block by correcting QRS by direct capture of the His-Purkinje system. This critical appraisal reviews early clinical data, evaluates possible mechanism, and identifies areas for future investigation for HBP in resynchronization.


Assuntos
Fascículo Atrioventricular/fisiopatologia , Bloqueio de Ramo/terapia , Terapia de Ressincronização Cardíaca/métodos , Eletrocardiografia , Ventrículos do Coração/fisiopatologia , Bloqueio de Ramo/fisiopatologia , Cateterismo Cardíaco/métodos , Humanos
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