RESUMEN
BACKGROUND: Left bundle branch pacing (LBBP) is considered an alternative to cardiac resynchronization therapy (CRT). However, LBBP is not suitable for all patients with heart failure. OBJECTIVE: The aim of our study was to identify predictors of unsuccessful LBBP implantation in CRT candidates. METHODS: A cohort of consecutive patients with indications for CRT were included. Clinical, echocardiographic, and electrocardiographic variables were prospectively recorded. RESULTS: A total of 187 patients were included in the analysis. LBBP implantation was successful in 152 of 187 patients (81.2%) and failed in 35 of 187 patients (18.7%). The causes of unsuccessful implantation were unsatisfactory paced QRS morphology (28 of 35 [80%]), inability to screw the helix (4 of 35 [11.4%]), lead instability (2 of 35 [5.7%]), and high pacing thresholds (1 of 35 [2.8%]). The left ventricular end-diastolic diameter (LVEDD), non-LBBB (left bundle branch block) QRS morphology, and QRS width were predictors of failed implantation according to the univariate analysis. According to the multivariate regression analysis, LVEDD (odds ratio 1.31 per 5-mm increase; 95% confidence interval 1.05-1.63 per 5-mm increase; P = .02) and non-LBBB (odds ratio 3.07; 95% confidence interval 1.08-8.72; P = .03) were found to be independent predictors of unsuccessful LBBP implantation. An LVEDD of 60 mm has 60% sensitivity and 71% specificity for predicting LBBP implant failure. CONCLUSION: When LBBP was used as CRT, LVEDD and non-LBBB QRS morphology predicted unsuccessful implantation. Non-LBBB triples the likelihood of failed implantation independent of LVEDD. Caution should be taken when considering these parameters to plan the best pacing strategy for patients.
RESUMEN
BACKGROUND: A partial delineation of targets for ablation of ventricular tachycardia (VT) during a stable rhythm is likely responsible for a suboptimal success rate. The abnormal low-voltage near-field functional components may be hidden within the high-amplitude far-field signal. OBJECTIVES: The aim of this study was to evaluate the benefit and feasibility of functional substrate mapping using a full-ventricle S3 protocol and to assess its colocalization with arrhythmogenic conducting channels (CCs) on late gadolinium enhancement cardiac magnetic resonance. METHODS: An S3 mapping protocol with a drive train of S1 followed by S2 (effective refractory period + 30 ms) and S3 (effective refractory period + 50 ms) from the right ventricular apex was performed in 40 consecutive patients undergoing scar-related VT ablation. Deceleration zones (DZs) and areas of late potentials (LPs) were identified for all maps. A preprocedural noninvasive substrate assessment was done using late gadolinium enhancement cardiac magnetic resonance and postprocessing with automated CC identification. RESULTS: The S3 protocol was completed in 34 of the 40 procedures (85.0%). The S3 protocol enhanced the identification of VT isthmus on the basis of DZ (89% vs 62%; P < 0.01) and LP (93% vs 78%; P = 0.04) assessment. The percentage of CCs unmasked by DZs and LPs using S3 maps was significantly higher than the ones using S2 and S1 maps (78%, 65%, and 48% [P < 0.001] and 88%, 81%, and 68% [P < 0.01], respectively). The functional substrate identified during S3 activation mapping was significantly more extensive than the one identified using S2 and S1, including a greater number of DZs (2.94, 2.47, and 1.82, respectively; P < 0.001) and a wider area of LPs (44.1, 38.2, and 29.4 cm2, respectively; P < 0.001). After VT ablation, 77.9% of patients have been VT free during a median follow-up period of 13.6 months. CONCLUSIONS: The S3 protocol was feasible in 85% of patients, allows a better identification of targets for ablation, and might improve VT ablation results.
Asunto(s)
Ablación por Catéter , Imagen por Resonancia Magnética , Taquicardia Ventricular , Humanos , Taquicardia Ventricular/cirugía , Taquicardia Ventricular/fisiopatología , Masculino , Femenino , Persona de Mediana Edad , Ablación por Catéter/métodos , Anciano , Ventrículos Cardíacos/fisiopatología , Ventrículos Cardíacos/diagnóstico por imagen , Ventrículos Cardíacos/cirugía , Adulto , Estudios de Factibilidad , Técnicas Electrofisiológicas Cardíacas/métodosRESUMEN
Longitudinal dyssynchrony correction and strain improvement by comparable cardiac resynchronization therapy techniques is unreported. AIMS: Our purpose was to compare echocardiographic dyssynchrony correction and strain improvement by conduction system pacing (CSP) vs. biventricular pacing (BiVP) as a marker of contractility improvement during one-year follow-up. METHODS AND RESULTS: A treatment-received analysis was performed in patients included in the LEVEL-AT trial (NCT04054895), randomized to CSP or BiVP, and evaluated at baseline (ON and OFF programming) and at 6 and 12 months (n = 69, 32% women). Analysis included intraventricular (septal flash), interventricular (difference between left and right ventricular outflow times), and atrioventricular (diastolic filling time) dyssynchrony and strain parameters (septal bounce, global longitudinal strain [GLS], left bundle branch block pattern and mechanical dispersion).Baseline left ventricular ejection fraction (LVEF) was 27.5 ± 7% and left ventricular end-systolic volume (LVESV) was 138 ± 77â ml, without differences between groups. Longitudinal analysis showed LVEF and LVESV improvement (p < 0.001), without between-group differences. At 12-month follow-up, adjusted mean LVEF was 46% with CSP (95%CI 42.2%, 49.3%) vs. 43% with BiVP (95%CI 39.6%, 45.8%) (p = 0.31) and LVESV was 80â ml (95%CI 55.3â ml, 104.5â ml) vs. 100â ml (95%CI 78.7â ml, 121.6â ml), respectively (p = 0.66).Longitudinal analysis showed a significative improvement of all dyssynchrony parameters and GLS over time (p < 0.001), without differences between groups. Baseline GLS significantly correlated with LVEF and LVESV at 12-month follow-up. CONCLUSION: CSP and BiVP provided similar dyssynchrony and strain correction over time. Baseline global longitudinal strain correction predicted ventricular remodeling at 12-month follow-up.
RESUMEN
BACKGROUND: Atrial arrhythmogenic substrate is a key determinant of atrial fibrillation (AF) recurrence after pulmonary vein isolation (PVI), and reduced conduction velocities have been linked to adverse outcome. However, a noninvasive method to assess such electrophysiologic substrate is not available to date. OBJECTIVE: This study aimed to noninvasively assess regional conduction velocities and their association with arrhythmia-free survival after PVI. METHODS: A consecutive 52 patients scheduled for AF ablation (PVI only) and 19 healthy controls were prospectively included and received electrocardiographic imaging (ECGi) to noninvasively determine regional atrial conduction velocities in sinus rhythm. A novel ECGi technology obviating the need of additional computed tomography or cardiac magnetic resonance imaging was applied and validated by invasive mapping. RESULTS: Mean ECGi-determined atrial conduction velocities were significantly lower in AF patients than in healthy controls (1.45 ± 0.15 m/s vs 1.64 ± 0.15 m/s; P < .0001). Differences were particularly pronounced in a regional analysis considering only the segment with the lowest average conduction velocity in each patient (0.8 ± 0.22 m/s vs 1.08 ± 0.26 m/s; P < .0001). This average conduction velocity of the "slowest" segment was independently associated with arrhythmia recurrence and better discriminated between PVI responders and nonresponders than previously proposed predictors, including left atrial size and late gadolinium enhancement (magnetic resonance imaging). Patients without slow-conduction areas (mean conduction velocity <0.78 m/s) showed significantly higher 12-month arrhythmia-free survival than those with 1 or more slow-conduction areas (88.9% vs 48.0%; P = .002). CONCLUSION: This is the first study to investigate regional atrial conduction velocities noninvasively. The absence of ECGi-determined slow-conduction areas well discriminates PVI responders from nonresponders. Such noninvasive assessment of electrical arrhythmogenic substrate may guide treatment strategies and be a step toward personalized AF therapy.
RESUMEN
BACKGROUND: Voltage mapping could identify the conducting channels potentially responsible for ventricular tachycardia (VT). Standard thresholds (0.5-1.5 mV) were established using bipolar catheters. No thresholds have been analyzed with high-density mapping catheters. In addition, channels identified by cardiac magnetic resonance (CMR) has been proven to be related with VT. OBJECTIVE: The purpose of this study was to analyze the diagnostic yield of a personalized voltage map using CMR to guide the adjustment of voltage thresholds. METHODS: All consecutive patients with scar-related VT undergoing ablation after CMR (from October 2018 to December 2020) were included. First, personalized CMR-guided voltage thresholds were defined systematically according to the distribution of the scar and channels. Second, to validate these new thresholds, a comparison with standard thresholds (0.5-1.5 mV) was performed. Tissue characteristics of areas identified as deceleration zones (DZs) were recorded for each pair of thresholds. In addition, the relation of VT circuits with voltage channels was analyzed for both maps. RESULTS: Thirty-two patients were included [mean age 66.6 ± 11.2 years; 25 (78.1%) ischemic cardiomyopathy]. Overall, 52 DZs were observed: 44.2% were identified as border zone tissue with standard cutoffs vs 75.0% using personalized voltage thresholds (P = .003). Of the 31 VT isthmuses detected, only 35.5% correlated with a voltage channel with standard thresholds vs 74.2% using adjusted thresholds (P = .005). Adjusted cutoff bipolar voltages that better matched CMR images were 0.51 ± 0.32 and 1.79 ± 0.71 mV with high interindividual variability (from 0.14-1.68 to 0.7-3.21 mV). CONCLUSION: Personalized voltage CMR-guided personalized voltage maps enable a better identification of the substrate with a higher correlation with both DZs and VT isthmuses than do conventional voltage maps using fixed thresholds.
RESUMEN
AIMS: Same-day discharge (SDD) after atrial fibrillation (AF) ablation is an effective means to spare healthcare resources. However, safety remains a concern, and besides structural adaptations, SDD requires more efficient logistics and coordination. Therefore, in this study, we implement a streamlined, nurse-coordinated SDD programme following a standardized protocol. METHODS AND RESULTS: As a dedicated SDD coordinator, a nurse specialized in ambulatory cardiac interventions was in charge of the full SDD protocol, including eligibility, patient flow, in-hospital logistics, patient education, and discharge as well as early post-discharge follow-up by smartphone-based virtual visits. Patients planned for AF ablation were considered eligible if they had a left ventricular ejection fraction (LVEF) ≥35%, with basic support at home and accessibility of the hospital within 60â min also forming a part of the eligibility criteria. A total of 420 consecutive patients were screened by the SDD coordinator, of whom 331 were eligible for SDD. The reasons for exclusion were living remotely (29, 6.9%), lack of support at home (19, 4.5%), or LVEF <35% (17, 4.0%). Of the eligible patients, 300 (91%) were successfully discharged the same day. There were no major post-SDD complications. Rates of unplanned medical attention (19, 6.3%) and 30-day readmission (5, 1.6%) were extremely low and driven by femoral access-site complications. These were significantly reduced upon the introduction of compulsory ultrasound-guided punctures after the initial 150 SDD patients (P = 0.0145). Standardized SDD coordination resulted in efficient workflows and reduced the total workload of the medical staff. CONCLUSION: Same-day discharge after AF ablation following a nurse-coordinated standardized protocol is safe and efficient. The concept of ambulatory cardiac intervention nurses functioning as dedicated coordinators may be key in the future transition of hospitals to SDD. Ultrasound-guided femoral puncture virtually eliminated relevant femoral access-site complications in our cohort and should therefore be a prerequisite for SDD.
Asunto(s)
Fibrilación Atrial , Humanos , Fibrilación Atrial/diagnóstico , Fibrilación Atrial/cirugía , Alta del Paciente , Volumen Sistólico , Cuidados Posteriores , Función Ventricular Izquierda , Estudios Retrospectivos , Resultado del TratamientoRESUMEN
AIMS: Non-invasive myocardial scar characterization with cardiac magnetic resonance (CMR) has been shown to accurately identify conduction channels and can be an important aid for ventricular tachycardia (VT) ablation. A new mapping method based on targeting deceleration zones (DZs) has become one of the most commonly used strategies for VT ablation procedures. The aim of the study was to analyse the capability of CMR to identify DZs and to find predictors of arrhythmogenicity in CMR channels. METHODS AND RESULTS: Forty-four consecutive patients with structural heart disease and VT undergoing ablation after CMR at a single centre (October 2018 to July 2021) were included (mean age, 64.8 ± 11.6 years; 95.5% male; 70.5% with ischaemic heart disease; a mean ejection fraction of 32.3 ± 7.8%). The characteristics of CMR channels were analysed, and correlations with DZs detected during isochronal late activation mapping in both baseline maps and remaps were determined. Overall, 109 automatically detected CMR channels were analysed (2.48 ± 1.15 per patient; length, 57.91 ± 63.07â mm; conducting channel mass, 2.06 ± 2.67â g; protectedness, 21.44 ± 25.39â mm). Overall, 76.1% of CMR channels were associated with a DZ. A univariate analysis showed that channels associated with DZs were longer [67.81 ± 68.45 vs. 26.31 ± 21.25â mm, odds ratio (OR) 1.03, P = 0.010], with a higher border zone (BZ) mass (2.41 ± 2.91 vs. 0.87 ± 0.86â g, OR 2.46, P = 0.011) and greater protectedness (24.97 ± 27.72 vs. 10.19 ± 9.52â mm, OR 1.08, P = 0.021). CONCLUSION: Non-invasive detection of targets for VT ablation is possible with CMR. Deceleration zones found during electroanatomical mapping accurately correlate with CMR channels, especially those with increased length, BZ mass, and protectedness.
Asunto(s)
Ablación por Catéter , Taquicardia Ventricular , Humanos , Masculino , Persona de Mediana Edad , Anciano , Femenino , Taquicardia Ventricular/diagnóstico por imagen , Taquicardia Ventricular/cirugía , Imagen por Resonancia Magnética/métodos , Miocardio/patología , Frecuencia Cardíaca/fisiología , Arritmias Cardíacas , Cicatriz/patología , Ablación por Catéter/métodosRESUMEN
AIMS: Conducting channels (CCs) detected by late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) are related to ventricular tachycardia (VT). The aim of this work was to study the ability of post-ablation LGE-CMR to evaluate ablation lesions. METHODS AND RESULTS: This is a prospective study of consecutive patients referred for a scar-related VT ablation. LGE-CMR was performed 6-12 months prior to ablation and 3-6 months after ablation. Scar characteristics of pre- and post-ablation LGE-CMR were compared. During the study period (March 2019-April 2021), 61 consecutive patients underwent scar-related VT ablation after LGE-CMR. Overall, 12 patients were excluded (4 had poor-quality LGE-CMR, 2 died before post-ablation LGE-CMR, and 6 underwent post-ablation LGE-CMR 12 months after ablation). Finally, 49 patients (age: 65.5 ± 9.8 years, 97.9% male, left ventricular ejection fraction: 34.8 ± 10.4%, 87.7% ischaemic cardiomyopathy) were included. Post-ablation LGE-CMR showed a decrease in the number (3.34 ± 1.03 vs. 1.6 ± 0.2; P < 0.0001) and mass (8.45 ± 1.3 vs. 3.5 ± 0.6 g; P < 0.001) of CCs. Arrhythmogenic CCs disappeared in 74.4% of patients. Dark core was detected in 75.5% of patients, and its presence was not related to CC reduction (52.2 ± 7.4% vs. 40.8 ± 10.6%, P = 0.57). VT recurrence after one year follow-up was 16.3%. The presence of two or more channels in the post-ablation LGE-CMR was a predictor of VT recurrence (31.82% vs. 0%, P = 0.0038) with a sensibility of 100% and specificity of 61% (area under the curve 0.82). In the same line, a reduction of CCs < 55% had sensibility of 100% and specificity of 61% (area under the curve 0.83) to predict VT recurrence. CONCLUSION: Post-ablation LGE-CMR is feasible, and a reduction in the number of CCs is related with lower risk of VT recurrence. The dark core was not present in all patients. A decrease in VT substrate was also observed in patients without a dark core area in the post-ablation LGE-CMR.
Asunto(s)
Ablación por Catéter , Taquicardia Ventricular , Humanos , Masculino , Persona de Mediana Edad , Anciano , Femenino , Miocardio/patología , Medios de Contraste , Imagen por Resonancia Cinemagnética/métodos , Cicatriz/patología , Estudios Prospectivos , Gadolinio , Imagen por Resonancia Magnética/métodos , Taquicardia Ventricular/diagnóstico por imagen , Taquicardia Ventricular/cirugía , Taquicardia Ventricular/patología , Espectroscopía de Resonancia MagnéticaRESUMEN
AIMS: Recurrence of arrhythmia after catheter ablation of atrial fibrillation (AF) in the form of atypical atrial flutter (AFL) is common among a significant number of patients and often requires redo ablation with limited success rates. Identifying patients at high risk of AFL after AF ablation could aid in patient selection and personalized ablation approach. The study aims to assess the relationship between pre-existing atrial cardiomyopathy and the occurrence of AFL following AF ablation. METHODS AND RESULTS: We analysed a cohort of 1007 consecutive AF patients who underwent catheter ablation and were included in a prospective registry. Patients who did not have baseline cardiac magnetic resonance imaging and late gadolinium enhancement (LGE-CMR) or did not experience any recurrences were excluded. A total of 166 patients were included gathering 56 patients who underwent re-ablation due to AFL recurrences and 110 patients who underwent re-ablation due to AF recurrences (P = 0.11). A multiparametric assessment of atrial cardiomyopathy was based on basal LGE-CMR, including left atrial (LA) volume, LA sphericity, and global and segmental LA fibrosis using semiautomated post-processing software. Out of the initial cohort of 1007 patients, AFL and AF occurred in 56 and 110 patients, respectively. An age higher than 65 [odds ratio (OR) = 5.6, 95% confidence interval (CI): 2.2-14.4], the number of previous ablations (OR = 3.0, 95% CI: 1.2-7.8), and the management of ablation lines in the index procedure (OR = 2.5, 95% CI: 1.0-6.3) were independently associated with AFL occurrence. Furthermore, several characteristics assessed by LGE-CMR were identified as independent predictors of AFL recurrence after the index ablation for AF, such as enhanced LA sphericity (OR = 1.3, 95% CI: 1.1-1.6), LA global fibrosis (OR = 1.03, 95% CI: 1.01-1.07), and increased fibrosis in the lateral wall (OR = 1.03, 95% CI: 1.01-1.04). CONCLUSION: Advanced atrial cardiomyopathy assessed by LGE-CMR, such as increased LA sphericity, global LA fibrosis, and fibrosis in the lateral wall, is independently associated with arrhythmia recurrence in the form of AFL following AF ablation.
Asunto(s)
Fibrilación Atrial , Aleteo Atrial , Cardiomiopatías , Ablación por Catéter , Humanos , Fibrilación Atrial/diagnóstico por imagen , Fibrilación Atrial/cirugía , Aleteo Atrial/diagnóstico por imagen , Aleteo Atrial/cirugía , Medios de Contraste , Gadolinio , Imagen por Resonancia Magnética , Atrios Cardíacos/diagnóstico por imagen , Atrios Cardíacos/cirugía , Cardiomiopatías/complicaciones , Cardiomiopatías/diagnóstico por imagen , Ablación por Catéter/efectos adversos , Espectroscopía de Resonancia MagnéticaRESUMEN
INTRODUCTION: Prediction of recurrent ventricular arrhythmia (VA) in survivors of an out-of-hospital cardiac arrest (OHCA) is important, but currently difficult. Risk of recurrence may be related to presence of myocardial scarring assessed with late gadolinium enhancement cardiac magnetic resonance (LGE-CMR). Our study aims to characterize myocardial scarring as defined by LGE-CMR in survivors of a VA-OHCA and investigate its potential role in the risk of new VA events. METHODS: Between 2015 and 2022, a total of 230 VA-OHCA patients without ST-segment elevation myocardial infarction had CMR before implantable cardioverter-defibrillator implantation for secondary prevention at Copenhagen University Hospital, Rigshospitalet, and Hospital Clínic, University of Barcelona, of which n = 170 patients had a conventional (no LGE protocol) CMR and n = 60 patients had LGE-CMR (including LGE protocol). Scar tissue including core, border zone (BZ) and BZ channels were automatically detected by specialized investigational software in patients with LGE-CMR. The primary endpoint was recurrent VA. RESULTS: After exclusion, n = 52 VA-OHCA patients with LGE-CMR and a mean left ventricular ejection fraction of 49 ± 16% were included, of which 18 (32%) patients reached the primary endpoint of VA. Patients with recurrent VA in exhibited greater scar mass, core mass, BZ mass, and presence of BZ channels compared with patients without recurrent VA. The presence of BZ channels identified patients with recurrent VA with 67% sensitivity and 85% specificity (area under the ROC curve (AUC) 0.76; 95% CI: 0.63-0.89; p < .001) and was the strongest predictor of the primary endpoint. CONCLUSIONS: The presence of BZ channels was the strongest predictor of recurrent VA in patients with an out of-hospital cardiac arrest and LGE-CMR.
Asunto(s)
Cicatriz , Paro Cardíaco Extrahospitalario , Humanos , Cicatriz/diagnóstico por imagen , Cicatriz/etiología , Medios de Contraste , Volumen Sistólico , Paro Cardíaco Extrahospitalario/diagnóstico , Paro Cardíaco Extrahospitalario/terapia , Función Ventricular Izquierda , Gadolinio , Arritmias Cardíacas , Imagen por Resonancia Magnética/métodos , Imagen por Resonancia Cinemagnética/métodos , Valor Predictivo de las PruebasRESUMEN
BACKGROUND: Atrial myopathy may underlie the progression of atrial fibrillation (AF) from a treatable disease to an irreversible condition with poor ablation outcomes. Electrophysiological methods to unmask areas prone to re-entry initiation could be key to defining latent atrial myopathy. METHODS: Consecutive patients referred for AF ablation were prospectively included at four institutions. Decrement evoked potential mapping (DEEP) was performed in eight left atrial sites and five right atrial sites, from two different pacing locations (endocardially from the left atrial appendage, epicardially from the proximal coronary sinus). The electrograms (EGMs) during S1 600 ms drive and after an extra stimulus (S2 at +30 ms above atrial refractoriness) were studied at each location and assessed for decremental properties. Follow-up was 12 months. RESULTS: Seventy-four patients were included and 85% had persistent AF. A total of 17,614 EGMs were individually analysed and measured. Nine percent of the EGMs showed DEEP properties (local delay of >10 ms after S2) with a mean decrement of 33±26 ms. DEEPs were more frequent in the left atrium than the right atrium (9.4% vs 8.0%; p<0.001) and more prevalent in persistent AF patients than paroxysmal AF patients (9.8% vs 4.6% p=0.001). Atrial DEEPs were more frequently unmasked in normal bipolar voltage areas and by epicardial pacing than endocardial pacing (9.6% vs 8.4%, respectively; p=0.004). Within the left atrium, the roof had the highest prevalence of DEEP EGMs. CONCLUSIONS: DEEP mapping of both atria is useful for highlighting areas with a tendency for unidirectional block and re-entry initiation. Those areas are more easily unmasked by epicardial pacing from the coronary sinus and more prevalent in persistent AF patients than in paroxysmal AF patients.
Asunto(s)
Apéndice Atrial , Fibrilación Atrial , Ablación por Catéter , Enfermedades Musculares , Humanos , Atrios Cardíacos , Apéndice Atrial/cirugía , Enfermedades Musculares/cirugía , Potenciales EvocadosRESUMEN
BACKGROUND: A new functional mapping strategy based on targeting deceleration zones (DZs) has become one of the most commonly used strategies within the armamentarium of substrate-based ablation methods for ventricular tachycardia (VT) in patients with structural heart disease. The classic conduction channels detected by voltage mapping can be accurately determined by cardiac magnetic resonance (CMR). OBJECTIVES: The purpose of this study was to analyze the evolution of DZs during ablation and their correlation with CMR. METHODS: Forty-two consecutive patients with scar-related VT undergoing ablation after CMR in Hospital Clinic (October 2018-December 2020) were included (median age 65.3 ± 11.8 years; 94.7% male; 73.7% ischemic heart disease). Baseline DZs and their evolution in isochronal late activation remaps were analyzed. A comparison between DZs and CMR conducting channels (CMR-CCs) was realized. Patients were prospectively followed for VT recurrence for 1 year. RESULTS: Overall, 95 DZs were analyzed, 93.68% of which were correlated with CMR-CCs: 44.8% located in the middle segment and 55.2% located in the entrance/exit of the channel. Remapping was performed in 91.7% of patients (1 remap: 33.3%, 2 remaps: 55.6%, and 3 remaps: 2.8%). Regarding the evolution of DZs, 72.2% disappeared after the first ablation set, with 14.13% not ablated at the end of the procedure. A total of 32.5% of DZs in remaps correlated with a CMR-CCs already detected, and 17.5% were associated with an unmasked CMR-CCs. One-year VT recurrence was 22.9%. CONCLUSIONS: DZs are highly correlated with CMR-CCs. In addition, remapping can lead to the identification of hidden substrate initially not identified by electroanatomic mapping but detected by CMR.
Asunto(s)
Desaceleración , Taquicardia Ventricular , Humanos , Masculino , Persona de Mediana Edad , Anciano , Femenino , Imagen por Resonancia Magnética , Corazón , Taquicardia Ventricular/diagnóstico por imagen , Taquicardia Ventricular/cirugía , Espectroscopía de Resonancia MagnéticaRESUMEN
AIMS: To define a stepwise application of left bundle branch pacing (LBBP) criteria that will simplify implantation and guarantee electrical resynchronization. Left bundle branch pacing has emerged as an alternative to biventricular pacing. However, a systematic stepwise criterion to ensure electrical resynchronization is lacking. METHODS AND RESULTS: A cohort of 24 patients from the LEVEL-AT trial (NCT04054895) who received LBBP and had electrocardiographic imaging (ECGI) at 45 days post-implant were included. The usefulness of ECG- and electrogram-based criteria to predict accurate electrical resynchronization with LBBP were analyzed. A two-step approach was developed. The gold standard used to confirm resynchronization was the change in ventricular activation pattern and shortening in left ventricular activation time, assessed by ECGI. Twenty-two (91.6%) patients showed electrical resynchronization on ECGI. All patients fulfilled pre-screwing requisites: lead in septal position in left-oblique projection and W paced morphology in V1. In the first step, presence of either right bundle branch conduction delay pattern (qR or rSR in V1) or left bundle branch capture Plus (QRS ≤120â ms) resulted in 95% sensitivity and 100% specificity to predict LBBP resynchronization, with an accuracy of 95.8%. In the second step, the presence of selective capture (100% specificity, only 41% sensitivity) or a spike-R <80â ms in non-selective capture (100% specificity, sensitivity 46%) ensured 100% accuracy to predict resynchronization with LBBP. CONCLUSION: Stepwise application of ECG and electrogram criteria may provide an accurate assessment of electrical resynchronization with LBBP (Graphical abstract).
Asunto(s)
Fascículo Atrioventricular , Terapia de Resincronización Cardíaca , Humanos , Bloqueo de Rama/diagnóstico , Bloqueo de Rama/terapia , Estimulación Cardíaca Artificial/métodos , Terapia de Resincronización Cardíaca/métodos , Electrocardiografía/métodos , Sistema de Conducción Cardíaco , Resultado del TratamientoRESUMEN
The peculiar electrophysiological properties of the sinoatrial node and the cardiac conduction system are key components of the normal physiology of cardiac impulse generation and propagation. Multiple genes and transcription factors and metabolic proteins are involved in their development and regulation. In this review, we have summarized the genetic underlying causes, key clinical findings, and the latest available clinical evidence. We will discuss clinical diagnosis and management of the genetic conditions associated with conduction disorders that are more prevalent in clinical practice, for this reason, very rare genetic diseases presenting sinus node or cardiac conduction system abnormalities are not discussed.
Asunto(s)
Sistema de Conducción Cardíaco , Nodo Sinoatrial , Humanos , Frecuencia Cardíaca , ElectrocardiografíaRESUMEN
Aims: With recurrence rates up to 50% after pulmonary vein isolation (PVI) in persistent atrial fibrillation (AF), predictive tools to improve patient selection are needed. Patient selection based on left atrial late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) has been proposed previously (UTAH-classification). However, this approach has not been widely established, in part owed to the lack of standardization of the LGE quantification method. We have recently established a standardized LGE-CMR method enabling reproducible LGE-quantification. Here, the ability of this method to predict outcome after PVI was evaluated. Methods and results: This dual-centre study (n = 219) consists of a prospective derivation cohort (n = 37, all persistent AF) and an external validation cohort (n = 182; 66 persistent, 116 paroxysmal AF). All patients received an LGE-CMR prior to first-time PVI-only ablation. LGE was quantified based on the signal-intensity-ratio relative to the blood pool, applying a uniform LGE-defining threshold of >1.2. In patients with persistent AF in the derivation cohort, left atrial LGE-extent above a cut-off value of 12% was found to best predict relevant low-voltage substrate (≥2â cm two with <0.5â mV during sinus rhythm) and arrhythmia-free survival 12 months post-PVI. When applied to the external validation cohort, this cut-off value was also predictive of arrhythmia-free survival for both, the total cohort and the subgroup with persistent AF (LGE < 12%: 80% and 76%; LGE > 12%: 55% and 44%; P = 0.007 and P = 0.029, respectively). Conclusion: This dual-centre study established and validated a standardized, reproducible LGE-CMR method discriminating PVI responders from non-responders, which may improve choice of therapeutic approach or ablation strategy for patients with persistent AF.
RESUMEN
AIMS: Electrical reconnection of pulmonary veins (PVs) is considered an important determinant of recurrent atrial fibrillation (AF) after pulmonary vein isolation (PVI). To date, AF recurrences almost automatically trigger invasive repeat procedures, required to assess PVI durability. With recent technical advances, it is becoming increasingly common to find all PVs isolated in those repeat procedures. Thus, as ablation of extra-PV targets has failed to show benefit in randomized trials, more and more often these highly invasive procedures are performed only to rule out PV reconnection. Here we aim to define the ability of late gadolinium enhancement (LGE)-magnetic resonance imaging (MRI) to rule out PV reconnection non-invasively. METHODS AND RESULTS: This study is based on a prospective registry in which all patients receive an LGE-MRI after AF ablation. Included were all patients that-after an initial PVI and post-ablation LGE-MRI-underwent an invasive repeat procedure, which served as a reference to determine the predictive value of non-invasive lesion assessment by LGE-MRI.: 152 patients and 304 PV pairs were analysed. LGE-MRI predicted electrical PV reconnection with high sensitivity (98.9%) but rather low specificity (55.6%). Of note, LGE lesions without discontinuation ruled out reconnection of the respective PV pair with a negative predictive value of 96.9%, and patients with complete LGE lesion sets encircling all PVs were highly unlikely to show any PV reconnection (negative predictive value: 94.4%). CONCLUSION: LGE-MRI has the potential to guide selection of appropriate candidates and planning of the ablation strategy for repeat procedures and may help to identify patients that will not benefit from a redo-procedure if no ablation of extra-PV targets is intended.
Asunto(s)
Fibrilación Atrial , Ablación por Catéter , Venas Pulmonares , Humanos , Medios de Contraste , Venas Pulmonares/diagnóstico por imagen , Venas Pulmonares/cirugía , Gadolinio , Resultado del Tratamiento , Fibrilación Atrial/diagnóstico por imagen , Fibrilación Atrial/cirugía , Imagen por Resonancia Magnética , Ablación por Catéter/efectos adversos , Ablación por Catéter/métodos , RecurrenciaRESUMEN
Timothy syndrome 1 (TS1) is a multi-organ form of long QT syndrome associated with life-threatening cardiac arrhythmias, the organ-level dynamics of which remain unclear. In this study, we developed and characterized a novel porcine model of TS1 carrying the causative p.Gly406Arg mutation in CACNA1C, known to impair CaV1.2 channel inactivation. Our model fully recapitulated the human disease with prolonged QT interval and arrhythmic mortality. Electroanatomical mapping revealed the presence of a functional substrate vulnerable to reentry, stemming from an unforeseen constitutional slowing of cardiac activation. This signature substrate of TS1 was reliably identified using the reentry vulnerability index, which, we further demonstrate, can be used as a benchmark for assessing treatment efficacy, as shown by testing of multiple clinical and preclinical anti-arrhythmic compounds. Notably, in vitro experiments showed that TS1 cardiomyocytes display Ca2+ overload and decreased peak INa current, providing a rationale for the arrhythmogenic slowing of impulse propagation in vivo.