Functional substrate mapping of atrium in patients with atrial scar: A novel method to predict critical isthmus of atrial tachycardia.

Atrial tachycardia (AT) is a common rhythm disorder, especially in patients with atrial structural abnormalities. Although voltage mapping can provide a general picture of structural alterations which are mainly secondary to prior ablations, surgery or pressure/volume overload, data is scarce regarding the functional characteristics of low voltage regions in the atrium to predict critical isthmus of ATs. Recently, functional substrate mapping (FSM) emerged as a potential tool to evaluate the functionality of structurally altered regions in the atrium to predict critical sites of reentry. Current evidence suggested a clear association between deceleration zones of isochronal late activation mapping (ILAM) during sinus/paced rhythm and critical isthmus of reentry in patients with left AT. Therefore, these areas seem to be potential ablation targets even not detected during AT. Furthermore, abnormal conduction detected by ILAM may also have a role to identify the potential substrate and predict atrial fibrillation outcome after pulmonary vein isolation. Despite these promising findings, the utility of such an approach needs to be evaluated in large-scale comparative studies. In this review, we aimed to share our experience and review the current literature regarding the use of FSM during sinus/paced rhythm in the prediction of re-entrant ATs and discuss future implications and potential use in patients with atrial low-voltage areas.

Quantitative comparison of the isolation lesions between conventional- and larger-sized visually guided laser balloon ablation.

BACKGROUND: The importance of a wider circumferential isolation of the pulmonary veins (PV), which includes a large portion of the left atrial posterior wall (LAPW), has been suggested in several studies. However, the extended isolation area using a larger inflated visually guided laser balloon (VGLB) ablation remains to be elucidated. METHODS: Seventy-eight patients with atrial fibrillation (AF) who underwent VGLB ablation were enrolled in this prospective study. An electroanatomic map of the left atrium was obtained before and after PV isolation (PVI) using a conventional-sized VGLB. The isolation areas were extended by the largest-sized VGLB ablation and remapped in the same manner. After the ablation, isolation areas were calculated with CARTO-3 system. The one-year atrial arrhythmia (Ata) recurrence was assessed.  RESULTS: The largest-sized VGLB ablation yielded statistically greater areas of isolation in left-sided PV antrum (PVA) (11.5 ± 2.3 cm2 vs. 15.9 ± 3.5 cm2, P < .001) and right-sided PVA (14.2 ± 3.3 cm2 vs. 20.6 ± 4.4 cm2, P < .001) than the conventional-sized VGLB. Further, non-ablated LAPW (12.3 ± 4.4 cm2 vs. 7.8 ± 3.9 cm2, P < .001) was significantly reduced after largest-sized VGLB ablation, compared to the conventional-sized VGLB ablation. The one-year Ata freedom was 83.7% in patients with paroxysmal AF and 96.4% in those with persistent AF. CONCLUSION: The largest-sized VGLB ablation technique can create a significantly wider isolation area of PVA and debulk a large amount of LAPW than the conventional-sized VGLB ablation. The one-year outcome was similarly high in paroxysmal and persistent AF.

Mapeo de superficie corporal gástrica (Alimetria®): una nueva forma de estudiar la función gastroduodenal / Body Surface Gastric Mapping (Alimetry®): a New Way to study the Gastroduodenal Function

Upper gastrointestinal symptoms affect 10% of the population, leading to significant costs and negatively impacting quality of life. Diagnosing disorders such as functional dyspepsia and gastroparesis is challenging due to overlapping symptoms. Gastric emptying scintigraphy (GES) has reproducibility issues. Body Surface Gastric Mapping (BSGM) is an advanced technique for precise and reliable electrophysiological mapping, overcoming the limitations of electrogastrography (EGG). Gastric Alimetry® measures gastric myoelectric potentials, providing valuable diagnostic data. BSGM uses an electrode array to capture gastric activity and requires a standardized protocol for comparable data. The metrics generated help identify specific gastric dysfunction phenotypes, improving diagnostic accuracy. These advancements promise to revolutionize the clinical management of chronic gastric symptoms, making this review essential reading for those interested in gastrointestinal research and treatment.

Los síntomas gastroduodenales afectan a más del 10% de la población, causando costos significativos e impac- tando negativamente la calidad de vida. Diagnosticar trastornos como la dispepsia funcional y la gastroparesia es complejo debido a la superposición de síntomas. El cintigrama de vaciamiento gástrico (CVG) y electrogas- trografía (EGG) tiene problemas de reproducibilidad. El Mapeo de superficie de Cuerpo Gástrico (MSCG) o conocida también como Alimetría gástrica, es una técnica avanzada que permite un mapeo electrofisiológico preciso y fiable, superando las limitaciones de la EGG. La Alimetría Gástrica mide los potenciales mioeléc - tricos gástricos, proporcionando datos útiles para el diagnóstico. El MGSC utiliza una matriz de electrodos para capturar la actividad gástrica y requiere un protocolo estandarizado para obtener datos comparables. Las métricas generadas ayudan a identificar fenotipos específicos de disfunción gástrica, mejorando la precisión diagnóstica. Estos avances prometen revolucionar el manejo clínico de los síntomas gástricos crónicos, ha - ciendo de esta revisión una lectura esencial para aquellos interesados en la investigación y tratamiento de problemas gastrointestinales

Body surface potential mapping detects early disease onset in plakophilin-2-pathogenic variant carriers.

AIMS: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a progressive inherited cardiac disease. Early detection of disease and risk stratification remain challenging due to heterogeneous phenotypic expression. The standard configuration of the 12 lead electrocardiogram (ECG) might be insensitive to identify subtle ECG abnormalities. We hypothesized that body surface potential mapping (BSPM) may be more sensitive to detect subtle ECG abnormalities. METHODS AND RESULTS: We obtained 67 electrode BSPM in plakophilin-2 (PKP2)-pathogenic variant carriers and control subjects. Subject-specific computed tomography/magnetic resonance imaging based models of the heart/torso and electrode positions were created. Cardiac activation and recovery patterns were visualized with QRS- and STT-isopotential map series on subject-specific geometries to relate QRS-/STT-patterns to cardiac anatomy and electrode positions. To detect early signs of functional/structural heart disease, we also obtained right ventricular (RV) echocardiographic deformation imaging. Body surface potential mapping was obtained in 25 controls and 42 PKP2-pathogenic variant carriers. We identified five distinct abnormal QRS-patterns and four distinct abnormal STT-patterns in the isopotential map series of 31/42 variant carriers. Of these 31 variant carriers, 17 showed no depolarization or repolarization abnormalities in the 12 lead ECG. Of the 19 pre-clinical variant carriers, 12 had normal RV-deformation patterns, while 7/12 showed abnormal QRS- and/or STT-patterns. CONCLUSION: Assessing depolarization and repolarization by BSPM may help in the quest for early detection of disease in variant carriers since abnormal QRS- and/or STT-patterns were found in variant carriers with a normal 12 lead ECG. Because electrical abnormalities were observed in subjects with normal RV-deformation patterns, we hypothesize that electrical abnormalities develop prior to functional/structural abnormalities in ARVC.

Repolarization abnormalities unmasked with a 252-lead BSM system in patients with ARVC and healthy gene carriers.

BACKGROUND: Diagnosing arrhythmogenic right ventricular cardiomyopathy (ARVC) at an early stage can be challenging even after ECG recording and a combination of several imaging techniques. The purpose of this study was to explore if a body surface mapping (BSM) system with 252-leads could identify repolarization abnormalities and thereby diagnose early stages of ARVC. METHODS: ARVC patients, gene carriers without signs of ARVC and controls underwent a 12-lead resting ECG, signal-averaged ECG, echocardiography, 24-hours Holter monitoring, and BSM with electrocardiographic imaging (ECGI). All 252-leads, divided into four quadrants of the vest, were analyzed regarding concordances between T wave polarity and QRS main vector. RESULTS: Of 40 patients included there were 12 ARVC patients, 20 gene carriers, and 8 controls. The ARVC patients had two different repolarization patterns, one with more pronounced negative T waves at the lower left panel and another with mixed changes that clearly differed from the controls, all of whom had a normal 12 lead ECGs and consistent repolarization patterns on their BSM recordings. The patterns observed in ARVC patients were also present in 5/20 (25%) gene carriers, three of whom had normal resting ECG. A novel repolarization index successfully detected all ARVC patients and 88% of gene carriers with pathologic repolarization pattern. CONCLUSIONS: The finding that abnormal repolarization patterns could be unmasked by BSM in 25% of healthy gene carriers, suggests that it may potentially be a useful tool for identifying early manifestations of ARVC. Further and larger studies are warranted to assess its diagnostic accuracy.

Effects of Anatomical Variations of the Stomach on Body-Surface Gastric Mapping Investigated Using a Large Population-Based Multiscale Simulation Approach.

Body-surface gastric mapping (BSGM) measures the resultant body-surface potentials of gastric slow waves using an array of cutaneous electrodes. However, there is no established protocol to guide the placement of the mapping array and to account for the effects of biodiversity on the interpretation of BSGM data. This study aims to quantify the effect of anatomical variation of the stomach on body surface potentials. To this end, 93 subject specific models of the stomach and torso were developed, based on data obtained from the Cancer Imaging Archive. For each subject a set of points were created to model general anatomy the stomach and the torso, using a finite element mesh. A bidomain model was used to simulate the gastric slow waves in the antegrade wave (AW) direction and formation of colliding waves (CW). A forward modeling approach was employed to simulate body-surface potentials from the equivaelent dipoles. Simulated data were sampled from a 5 × 5 array of electrodes from the body-surface and compared between AW and CW cases. Anatomical parameters such as the Euclidean distance from the xiphoid process (8.6 ± 2.2 cm), orientation relative to the axial plane (195 ± 20.0°) were quantified. Electrophysiological simulations of AW and CW were both correlated to specific metrics derived from BSGM signals. In general, the maximum amplitude ( ∆ ϕ) and orientation ( θ) of the signals provided consistent separation of AW and CW. The findings of this study will aid gastric BSGM electrode array design and placement protocol in clinical practices.

Utilising electroanatomic mapping during ablation in patients with CHD to reduce radiation exposure.

BACKGROUND: Patients with CHD can be exposed to high levels of cumulative ionising radiation. Utilisation of electroanatomic mapping during catheter ablation leads to reduced radiation exposure in the general population but has not been well studied in patients with CHD. This study evaluated the radiation sparing benefit of using three-dimensional mapping in patients with CHD. METHODS: Data were retrospectively collected from the Catheter Ablation with Reduction or Elimination of Fluoroscopy multi-institutional registry. Patients with CHD were selected. Those with previous ablations, concurrent diagnostic or interventional catheterisation and unknown arrhythmogenic foci were excluded. The control cohort was matched for operating physician, arrhythmia mechanism, arrhythmia location, weight and age. The procedure time, rate of fluoroscopy use, fluoroscopy time, procedural success, complications, and distribution of procedures per year were compared between the two groups. RESULTS: Fifty-six patients with congenital heart disease and 56 matched patients without CHD were included. The mean total procedure time was significantly higher in patients with CHD (212.6 versus 169.5 minutes, p = 0.003). Their median total fluoroscopy time was 4.4 minutes (compared to 1.8 minutes), and their rate of fluoroscopy use was 23% (compared to 13%). The acute success and minor complication rates were similar and no major complications occurred. CONCLUSIONS: With the use of electroanatomic mapping during catheter ablation, fluoroscopy use can be reduced in patients with CHD. The majority of patients with CHD received zero fluoroscopy.

QRS dispersion detected in ARVC patients and healthy gene carriers using 252-leads body surface mapping: an explorative study of a potential diagnostic tool for arrhythmogenic right ventricular cardiomyopathy.

BACKGROUND: The diagnosis of ARVC remains complex requiring both imaging and electrocardiographic (ECG) techniques. The purpose was therefore to investigate whether QRS dispersion assessed by body surface mapping (BSM) could be used to detect early signs of ARVC, particularly in gene carriers. METHODS: ARVC patients, gene carriers without a history of arrhythmias or structural cardiac changes and healthy controls underwent 12-lead resting ECG, signal-averaged ECG, echocardiographic examination, 24-hours Holter monitoring, and BSM with electrocardiographic imaging. All 252-leads BSM recordings and 12-leads ECG recordings were manually analyzed for QRS durations and QRS dispersion. RESULTS: Eight controls, 12 ARVC patients with definite ARVC and 20 healthy gene carriers were included. The ECG-QRS dispersion was significantly greater in ARVC patients (42 vs. 25 ms, p < .05), but failed to fully differentiate them from controls. The BSM-derived QRS dispersion was also significantly greater in ARVC patients versus controls (65 vs. 29 ms, p < .05) and distinguished 11/12 cases from controls using the cut-off 40msec. The BSM derived QRS dispersion was abnormal (> 40 ms) in 4/20 healthy gene carriers without signs of ARVC, which may indicate early depolarization changes. CONCLUSIONS: QRS dispersion, when assessed by BSM versus 12-lead ECG, seem to better distinguish ARVC patients from controls, and could potentially be used to detect early ARVC in gene carriers. Further studies are required to confirm the value of BSM-QRS dispersion in this respect.

Individualized ablation strategy to treat persistent atrial fibrillation: Core-to-boundary approach guided by charge-density mapping.

BACKGROUND: Noncontact charge-density mapping allows rapid real-time global mapping of atrial fibrillation (AF), offering the opportunity for a personalized ablation strategy. OBJECTIVE: The purpose of this study was to compare the 2-year outcome of an individualized strategy consisting of pulmonary vein isolation (PVI) plus core-to-boundary ablation (targeting the conduction pattern core with an extension to the nearest nonconducting boundary) guided by charge-density mapping, with an empirical PVI plus posterior wall electrical isolation (PWI) strategy. METHODS: Forty patients (age 62 ± 12 years; 29 male) with persistent AF (10 ± 5 months) prospectively underwent charge-density mapping-guided PVI, followed by core-to-boundary stepwise ablation until termination of AF or depletion of identified cores. Freedom from AF/atrial tachycardia (AT) at 24 months was compared with a propensity score-matched control group of 80 patients with empirical PVI + PWI guided by conventional contact mapping. RESULTS: Acute AF termination occurred in 8 of 40 patients after charge-density mapping-guided PVI alone and in 21 of the remaining 32 patients after core-to-boundary ablation in the study cohort, compared with 8 of 80 (10%) in the control cohort (P <.001). On average, 2.2 ± 0.6 cores were ablated post-PVI before acute AF termination. At 24 months, freedom from AF/AT after a single procedure was 68% in the study group vs 46% in the control group (P = .043). CONCLUSION: An individualized ablation strategy consisting of PVI plus core-to-boundary ablation guided by noncontact charge-density mapping is a feasible and effective strategy for treating persistent AF, with a favorable 24-month outcome.

Discrepancy between CARTO and Rhythmia maps for defining the left atrial low-voltage areas in atrial fibrillation ablation.

Reported mapping procedures of left atrial (LA) low-voltage areas (LVAs) vary widely. This study aimed to compare the PentaRay®/CARTO®3 (PentaRay map) and Orion™/Rhythmia™ (Orion map) systems for LA voltage mapping. This study included 15 patients who underwent successful pulmonary vein isolation (PVI) for atrial fibrillation. After PVI, PentaRay and Orion maps created for all patients were compared. LVAs were defined as sites with ≥ 3 adjacent low-voltage points < 0.5 mV. LVAs were indicated in 8 (53%) among 15 patients, and the average values of the measured LVAs was comparable between the systems (PentaRay map = 5.4 ± 8.7 cm2; Orion map = 4.3 ± 6.4 cm2, p = 0.69). However, in 2 of 8 patients with LVAs, the Orion map indicated LVAs at the septum and posterolateral sites of the LA, respectively, whereas the PentaRay map indicated no LVAs. In those patients, sharp electrograms of > 0.5 mV were properly recorded at the septum and posterolateral sites during appropriate beats in the PentaRay map. The PentaRay map had a shorter procedure time than the Orion map (12 ± 3 min vs. 23 ± 8 min, respectively; p < 0.01). Our study results showed a discrepancy in the LVA evaluation between the PentaRay and Orion maps. In 2 of 15 patients, the Orion map indicated LVAs at the sites where > 0.5-mV electrograms were properly recorded in the PentaRay map.

Sex differences in mapping and rhythm outcomes of a repeat atrial fibrillation ablation.

OBJECTIVE: The risk of procedure-related complications and rhythm outcomes differ between men and women after atrial fibrillation catheter ablation (AFCA). We evaluated whether consistent sex differences existed in mapping and rhythm outcomes in repeat ablation procedures. METHODS: Among 3282 patients in the registry, we analysed 443 consecutive patients (24.6% female, 58.5±10.3 years old, 61.5% with paroxysmal atrial fibrillation) who underwent a second AFCA. We compared the clinical factors, mapping, left atrial (LA) pressure, complications and long-term clinical recurrences after propensity score matching. RESULTS: LA volume index (43.1±18.6 vs 35.8±11.6 mL/m2, p<0.001) was higher, but LA dimension (40.0±6.8 vs 41.6±6.3 mm, p=0.018), LA voltage (0.94±0.55 vs 1.20±0.68 mV, p=0.002) and pericardial fat volume (89.5±43.1 vs 122.1±53.9 cm3, p<0.001) were lower in women with repeat ablation than in their male counterparts. Pulmonary vein (PV) reconnections were lower (58.7% vs 74.9%, p=0.001), but the proportion of extra-PV triggers (27.5% vs 17.0%, p=0.026) and elevated LA pulse pressures (79.7% vs 63.7%, p=0.019) was significantly higher in women than in men. There was no significant sex difference in the rate of procedure-related complications (4.6% vs 4.2%, p=0.791). During a 31-month (8-60) median follow-up, clinical recurrences were significantly higher in women after both the de novo procedure (log-rank p=0.039, antiarrhythmic drug (AAD)-free log-rank p<0.001) and the second procedure (log-rank p=0.006, AAD-free log-rank p=0.093). Female sex (HR 1.51, 95% CI 1.06 to 2.15, p=0.023), non-paroxysmal atrial fibrillation (HR 1.78, 95% CI 1.30 to 2.34, p<0.010) and extra-PV triggers (HR 1.88, 95% CI 1.28 to 2.75, p=0.001) were independently associated with clinical recurrences after repeat procedures. CONCLUSIONS: During repeat AFCA procedures, PV reconnections were lower in women than in men, and the existence of extra-PV triggers and an LA pressure elevation were more significant, which resulted in poor rhythm outcomes. TRIAL REGISTRATION NUMBER: NCT02138695.

Right bundle branch block ventricular tachycardia in arrhythmogenic right ventricular cardiomyopathy more commonly originates from the right ventricle: Criteria for identifying chamber of origin.

BACKGROUND: Right bundle branch block (RBBB) ventricular tachycardia (VT) morphology is a criterion for left ventricular (LV) involvement in arrhythmogenic right ventricular cardiomyopathy (ARVC). OBJECTIVE: The purpose of this study was to determine the frequency and chamber of origin of RBBB VT in patients with ARVC and VT. METHODS: We studied 110 consecutive patients with VT who met the diagnostic International Task Force criteria for ARVC and underwent VT mapping/ablation. Patients with ≥1 RBBB VT were identified. Right ventricular (RV) origin of the RBBB VT was determined based on standard mapping criteria and elimination with ablation. RESULTS: Nineteen patients (17%) had 26 RBBB VTs. Eleven of these 19 patients (58%) had 16 RBBB VTs from the RV, and 9 patients (47%) had 10 RBBB VTs originating from the LV, with 1 patient demonstrating both. RBBB VT from RV most commonly (13/16 RBBB VTs) had an early precordial QRS transition (V2 or V3), with superiorly and typically leftward directed frontal plane axis, consistent with exit from dilated RV adjacent to inferior LV septum, whereas all 10 VTs from LV had RBBB morphology with positive R waves to V5 or V6 and rightward axis in 6 VTs characteristic of basal lateral origin. CONCLUSION: In patients with ARVC and VT presenting for VT ablation, RBBB VT occurs in 17% of cases, with most RBBB VTs (62%) originating from the RV and not indicative of LV origin. Precordial R-wave transition and frontal plane axis can be used to identify the anticipated chamber of origin of RBBB VT.

Effects of 60-Hertz notch filtering on local abnormal ventricular activities.

BACKGROUND: It is known that electrical signals can be affected by notch filtering. OBJECTIVE: We sought to investigate the effect of 60-Hz notch filtering on local abnormal ventricular activities (LAVA) in patients undergoing ventricular tachycardia ablation. METHODS: To ensure catheter stability, only patients undergoing ablation using Stereotaxis mapping catheters were enrolled. Catheter stability was judged by the display on the electroanatomic map and the morphology of the bipolar and unipolar electrograms of the ablation catheter. At sites recording stable LAVA, 60-Hz notch filtering was applied. The duration, amplitude, and morphology of LAVA were compared before and after filtering. The area under LAVA was used to analyze the amplitude of continuous LAVA. RESULTS: A total of 110 LAVA potentials recorded from 13 patients were analyzed. Notch filtering significantly affected the LAVA morphology and reduced their amplitude (the sum of the absolute value of the largest positive and negative voltages before filtering: 0.267 mV [0.191-0.395 mV]; after filtering: 0.172 mV [0.112-0.266 mV]; P < .001). At least 2 high-frequency components were introduced into the LAVA by filtering at 33 sites. The area under continuous LAVA was reduced by 28% from 24.64 cm2 (16.20-33.45 cm2) to 17.53 cm2 (10.52-23.82 cm2) (P < .001). The duration of continuous LAVA was reduced by 12% from 79.2 ms (55.0-93.0 ms) to 69.5 ms (53.0-88.5 ms) (P < .001). CONCLUSION: Notch filtering can distort LAVA by reducing their amplitude, changing their morphology, and shortening their duration, leading to potential false positives and negatives. Mitigating the 60-Hz noise should focus on eliminating the source of noise, not applying notch filtering.

Mapping and ablation of clinical spontaneous perimitral atrial tachycardias using an ultra-high-resolution mapping system.

BACKGROUND: Perimitral atrial tachycardias (PMATs) are common atrial tachycardias (ATs), yet their mechanisms vary. OBJECTIVE: The purpose of this study was to characterize clinical spontaneous PMATs using an ultra-high-resolution (UHR) mapping system. METHODS: The study included 32 consecutive PMATs in 31 patients who had undergone AT mapping/ablation using a UHR mapping system. RESULTS: Six, 10, 11, and 5 PMATs occurred in cardiac intervention-naïve (group A), post-lateral/posterior mitral isthmus linear ablation (group B), post-atrial fibrillation ablation without mitral isthmus linear ablation (group C), and post-cardiac surgery (group D) patients, respectively. Group A patients tended to be older, more likely were female, and had sinus node or atrioventricular conduction disturbances more frequently. A 12-lead synchronous isoelectric interval was observed in 15 PMATs (46.9%). Coronary sinus activation was proximal to distal or distal to proximal except in 3 PMATs with straight patterns due to epicardial gaps. Left atrial anterior/septal wall (LAASW) low-voltage areas were smallest in group B. Slow conduction areas (SCAs) were identified in 26 PMATs (81.2%) and were located on the LAASW in all group A and group D patients. Conduction velocity in the SCAs was slowest in group B. In group B, all PMATs were terminated by single applications, and the gaps were located epicardially in 5 of 10 (50%). Anterior (n = 23) or lateral/posterior (n = 9) mitral isthmus linear block was successfully created without any complications in all. Twenty-five concomitant ATs among 18 patients (58.1%) also were eliminated. During a median of 20.0 (11.0-40.0) months of follow-up, 28 patients (90.3%) were free from any atrial tachyarrhythmias. CONCLUSION: An UHR mapping-guided approach with identification of the individual tachycardia mechanism should be the preferred strategy given the distinct and complex arrhythmia mechanisms.

Safety of conscious sedation in electroanatomical mapping procedures and cryoballoon pulmonary vein isolation.

Immobilization of patients during electrophysiological procedures, to avoid complications by patients' unexpected bodily motion, is achieved by moderate to deep conscious sedation using benzodiazepines and propofol for sedation and opioids for analgesia. Our aim was to compare respiratory and hemodynamic safety endpoints of cryoballoon pulmonary vein isolation (PVI) and electroanatomical mapping (EAM) procedures. Included patients underwent either cryoballoon PVI or EAM procedures. Sedation monitoring included non-invasive blood pressure measurements, transcutaneous oxygen saturation (tSpO2) and transcutaneous carbon-dioxide (tpCO2) measurements. We enrolled 125 consecutive patients, 67 patients underwent cryoballoon atrial fibrillation ablation and 58 patients had an EAM and radiofrequency ablation procedure. Mean procedure duration of EAM procedures was significantly longer (p < 0.001) and propofol doses as well as morphine equivalent doses of administered opioids were significantly higher in EAM patients compared to cryoballoon patients (p < 0.001). Cryoballoon patients display higher tpCO2 levels compared to EAM patients at 30 min (cryoballoon: 51.1 ± 7.0 mmHg vs. EAM: 48.6 ± 6.2 mmHg, p = 0.009) and at 60 min (cryoballoon: 51.4 ± 7.3 mmHg vs. EAM: 48.9 ± 6.6 mmHg, p = 0.07) procedure duration. Mean arterial pressure was significantly higher after 60 min (cryoballoon: 84.7 ± 16.7 mmHg vs. EAM: 76.7 ± 13.3 mmHg, p = 0.017) in cryoballoon PVI compared to EAM procedures. Regarding respiratory and hemodynamic safety endpoints, no significant difference was detected regarding hypercapnia, hypoxia and episodes of hypotension. Despite longer procedure duration and deeper sedation requirement, conscious sedation in EAM procedures appears to be as safe as conscious sedation in cryoballoon ablation procedures regarding hemodynamic and respiratory safety endpoints.

Surgical Endoepicardial Linear Ablation for Ventricular Tachycardia With Postinfarction Left Ventricular Aneurysm.

This retrospective study evaluated the feasibility of surgical endoepicardial linear ablation for ventricular tachycardia in patients with postinfarction left ventricular aneurysm. Sixty-four patients with multivessel coronary artery disease and left ventricular aneurysm but no mural thrombosis of the aneurysm or valve disease were treated at our institution from March 2012 through July 2015. All underwent off-pump coronary artery bypass grafting and left ventricular aneurysm repair by linear plication. Twenty-three patients (35.9%) had ventricular tachycardia and underwent surgical endoepicardial linear ablation on the beating heart guided by epicardial substrate mapping with the Carto 3 system. The remaining 41 patients (64.1%) composed the no-ablation group. The effectiveness of surgical linear ablation in the ablation group was evaluated. Safety and clinical outcomes were evaluated and compared between the groups. The ventricular tachycardia recurrence rate in the ablation group was 17.4% in the immediate postoperative period and 23.8% at last follow-up (39 ± 21 mo). Early (<30-d) mortality rates were 8.7% in the ablation group and 4.9% in the no-ablation group (P=0.41); the respective late mortality rates were 19.1% and 18% (P=0.70). Multivariate Cox regression analysis indicated that preoperatively poor left ventricular function was an independent risk factor for early and late death in both groups. The groups were similar in terms of the need for postoperative mechanical circulatory support, intensive care unit stay, and cumulative survival rate. We conclude that, for carefully selected candidates, surgical endoepicardial linear ablation combined with off-pump coronary artery bypass grafting and left ventricular aneurysm linear plication is a feasible treatment for ventricular tachycardia with postinfarction left ventricular aneurysm.

Macroreentrant biatrial tachycardia relevant to interatrial septal incisions after mitral valve surgery: Electrophysiological characteristics and ablation strategy.

BACKGROUND: Macroreentrant biatrial tachycardia (BiAT) associated with interatrial septal incisions after mitral valve (MV) surgery has been rarely reported. OBJECTIVE: The purpose of this study was to assess the mapping and ablation strategy of this special category of atrial tachycardia (AT). METHODS: We identified 10 BiATs from a total of 84 ATs after MV surgery performed at 3 institutions. Activation maps for both the right atrium (RA) and left atrium (LA) were obtained using an ultrahigh-density mapping system. We also performed entrainment pacing from multiple LA and RA site within the speculative circuit. RESULTS: By analyzing activation and propagation maps of both atria, we classified the circuit into 3 distinct types. In all types, posteroinferior interatrial connections act as a critical limb that, combined with other interatrial connections (Bachmann bundle, fossa ovalis, and coronary sinus ostium in 3 types, respectively), complete the circuit of BiATs. Most ATs (8/10) were terminated targeting the RA and LA end of posteroinferior interatrial connection sites. CONCLUSION: Ultrahigh-density mapping provides a detailed description of the macroreentrant circuit of BiAT associated with interatrial septal incisions. Posteroinferior interatrial connections were essential for the circuit and should be the preferred target for ablation.