Life-Threatening Arrhythmias in Patients With Takotsubo Syndrome: Insights Into Pathophysiology and Treatment Innovations.

Takotsubo syndrome (TTS) is a reversible form of acute myocardial injury due to a neurocardiogenic mechanism associated with a relevant risk for life-threatening ventricular arrhythmias, occurring in up to 25% of all patients and including both ventricular arrhythmias (especially) in the context of QT prolongation and atrial tachy- or bradyarrhythmias. The pathogenetic mechanisms of TTS-related arrhythmic complications are not completely understood, and there are no randomized clinical trials addressing the pharmacologic and nonpharmacologic management in this specific setting. In this narrative review, the authors provide an overview of the pathogenesis and the therapeutic management of arrhythmic complications in patients with TTS, along with the future perspectives and the remaining knowledge gaps in this field.

Anatomical Annulus Predictors of New Permanent Pacemaker Implantation Risk after Balloon-expandable Trans-catheter Aortic Valve Implantation.

New-generation transcatheter-heart-valves (THV) have significantly improved technical success and procedural safety of transcatheter-aortic-valve-implantation (TAVI) procedures, but incidence of permanent pacemaker implantation (PPI) remains a concern.The study aimed to assess the role of anatomical annulus features in determining peri-procedural conduction disturbances leading to new-PPI following TAVI with the last generation Edwards Sapien balloon-expandable valves (BEV). In the context of a prospective single-center registry, we integrated clinical and procedural predictors of PPI with anatomical data derived from multi-slice-computed-tomography (MSCT). A total of 210 consecutive patients treated with balloon expandable Edwards THV were included in the study from 2015 to 2023. Technical success was achieved in 197 (93.8%) procedures, and 26 patients (12.4%) required new-PPI at 30-day follow-up (median time-to-implantation 3 days). At the univariable logistic-regression analysis, pre-procedural right bundle branch block (RBBB; OR:2.24 [95%CI:1.01-4.97], p=0.047), annulus eccentricity ≥0.25 (OR:5.43 [95%CI:2.21-13.36], p<0.001), calcium volume at annulus of the right coronary cusp (RCC) >48 mm3 (OR:2.60 [95%CI:1.13-5.96], p=0.024) and prosthesis implantation depth greater than membranous septum length (OR:2.17 [95%CI: 1.10-4.28], p=0.026) were associated with new-PPI risk. At multivariable analysis pre-procedural RBBB (OR:2.81 [95%CI:1.01-7.85], p=0.049), annulus eccentricity ≥0.25 (OR:4.14 [95%CI:1.85-9.27], p<0.001), and annulusRCC calcium >48 mm3 (OR:2.89 [95%CI:1.07-7.82], p=0.037) were confirmed as independent predictors of new-PPI. In conclusion, specific anatomical features of the aortic valve annulus might have an additive role in determining the occurrence of conduction disturbances in patients undergoing TAVI with BEV. This suggests the possibility to use the MSCT to improve the prediction of post-TAVI new-PPI risk.

Italian Registry in the Setting of Atrial Fibrillation Ablation with Rivaroxaban - IRIS.

BACKGROUND: Catheter ablation (CA) of atrial fibrillation is routinely used to obtain rhythm control. Evidence suggest that catheter ablation should be done during uninterrupted oral anticoagulation. METHODS: Italian Registry in the setting of atrial fibrillation ablation with rivaroxaban (IRIS) is an Italian multicenter, non-interventional, prospective study which enrolled 250 consecutive atrial fibrillation patients eligible for catheter ablation on rivaroxaban. The decision for rivaroxaban management was left to the physician: uninterrupted or shortly interrupted prior to Catheter ablation. Patients received a follow-up visit at 1 month and 12 months after the procedure. RESULTS: The primary outcome, represented by all-cause death and systemic embolism at 1 month and 12 months was characterized by one transient ischemic attack and one myocardial infarction in the first 30 days. Both events happened in patients with shortly interrupted strategy (P=0.147), and both in patients who underwent radiofrequency ablation (P=0.737). In the primary safety outcome represented by major bleeding we did not register any event in the 12-month follow-up. The secondary outcome constituted by minor bleeding registered 1 event, after the first 30 days since CA. CONCLUSIONS: IRIS is the biggest real-life data registry regarding CA ablation on rivaroxaban in Italian setting, proving the safety and efficacy of rivaroxaban.

High-density mapping of Koch's triangle during sinus rhythm and typical atrioventricular nodal re-entrant tachycardia, integrated with direct recording of atrio-ventricular node structure potential.

BACKGROUND: The mechanism of typical slow-fast atrioventricular nodal re-entrant tachycardia (AVNRT) and its anatomical and electrophysiological circuit inside the right atrium (RA) and Koch's Triangle (KT) are not well known. OBJECTIVE: To identify the potentials of the compact AV node and inferior extensions and to perform accurate mapping of the RA and KT in sinus rhythm (SR) and during AVNRT, to define the tachycardia circuit. METHODS: Consecutive patients with typical AVNRT were enrolled in 12 Italian centers and underwent mapping and ablation by means of a basket catheter with small electrode spacing for ultrahigh-density mapping and a modified signal-filtering toolset to record the potentials of the AV nodal structures. RESULTS: Forty-five consecutive cases of successful ablation of typical slow-fast AVNRT were included. The mean SR cycle length (CL) was 784.1 ± 6 ms and the mean tachycardia CL was 361.2 ± 54 ms. The AV node potential had a significantly shorter duration and higher amplitude in sinus rhythm than during tachycardia (60 ± 40 ms vs. 160 ± 40 ms, p < .001 and 0.3 ± 0.2 mV vs. 0.09 ± 0.12 mV, p < .001, respectively). The nodal potential duration extension was 169.4 ± 31 ms, resulting in a time-window coverage of 47.6 ± 9%. The recording of AV nodal structure potentials enabled us to obtain 100% coverage of the tachycardia CL during slow-fast AVNRT. CONCLUSION: Detailed recording of the potentials of nodal structures is possible by means of multipolar catheters for ultrahigh-density mapping, allowing 100% of the AVNRT CL to be covered. These results also have clinical implications for the ablation of right-septal and para-septal arrhythmias.

Mechanisms, prevalence and management of cardiac arrhythmias in cancer patients: a comprehensive review.

Recently, prognosis and survival of cancer patients has improved due to progression and refinement of cancer therapies; however, cardiovascular sequelae in this population augmented and now represent the second cause of death in oncological patients. Initially, the main issue was represented by heart failure and coronary artery disease, but a growing body of evidence has now shed light on the increased arrhythmic risk of this population, atrial fibrillation being the most frequently encountered. Awareness of arrhythmic complications of cancer and its treatments may help oncologists and cardiologists to develop targeted approaches for the management of arrhythmias in this population. In this review, we provide an updated overview of the mechanisms triggering cardiac arrhythmias in cancer patients, their prevalence and management.

Pulmonary vein isolation by means of a novel cryoballoon technology in paroxysmal atrial fibrillation patients: 1-year outcome from a large Italian multicenter clinical registry.

INTRODUCTION: Recently, a new cryoballoon (CB) technology (POLARx; Boston Scientific) has come onto the market. Preliminary data have shown that its acute safety and efficacy are similar to those of the first-generation CB. The aim of this study was to assess the medium-term outcome of pulmonary vein isolation (PVI) with the POLARxTM CB in a large multicenter registry. METHODS: We prospectively collected data on 125 consecutive patients with paroxysmal atrial fibrillation (AF) who underwent PVI by means of a novel CB system. Two cases of transient phrenic nerve palsy occurred, with full recovery in the 48h post procedure; no major procedure-related adverse events were reported. During the 90-day blanking period, 4 (3.2%) patients experienced an early recurrence. After the blanking period, over a mean follow-up of 411 ± 62 days, 19 patients (15.2%) suffered an AF/atrial tachycardia (AT) recurrence. The 1-year freedom from AF/AT recurrence was 86.4% (n = 17): 10 (8%) patients had an AF recurrence, 6 (4.8%) had an AT occurrence and 1 (0.8%) suffered both events. Patients with AF/AT recurrences had both a shorter deflation time and total deflation time. Moreover, CB ablations with measured TTI < 90 s and TTI < 60 s were more frequent in patients without AF/AT recurrence (88.5% and 77.4%, respectively) than in those who experienced at least one AF/AT recurrence (67.5% and 55.0%, p = .001 and p = .005, respectively). CONCLUSION: The novel POLARx cryo-balloon system is safe and effective for PV isolation, displaying a 1-year freedom from atrial arrhythmia recurrence of 86.4%, which is in line to that reported with AFA-Pro CB or RF ablation. CLINICAL TRIAL REGISTRATION: Catheter Ablation of Arrhythmias with a High-Density Mapping System in Real-World Practice (CHARISMA). URL: http://clinicaltrials.gov/ Identifier: NCT03793998. Registration date: January 4, 2019.

Takotsubo syndrome and its linkage to neuroendocrinological disorders: a case report.

Takotsubo syndrome (TTS) is an increasingly diagnosed entity, however the underlying pathophysiological mechanisms and their clinical implications are incompletely understood. An 82-year-old female, diagnosed with pituitary apoplexy, presented with ECG abnormalities and hsTnI levels consistent with an acute coronary syndrome and therefore underwent urgent coronary angiography that showed no significant stenosis and apical ballooning at left ventricle angiogram and therefore a TTS diagnosis was made. Moreover, during catheterization a 20 s torsade de pointes was registered. TTS is an entity that can be triggered by numerous conditions. This case of TTS was linked to many neuroendocrinological disorders.

Reversible Causes of Atrioventricular Block.

Atrioventricular blocks may be caused by a variety of potentially reversible conditions, such as ischemic heart disease, electrolyte imbalances, medications, and infectious diseases. Such causes must be always ruled out to avoid unnecessary pacemaker implantation. Patient management and reversibility rates depend on the underlying cause. Careful patient history taking, monitoring of vital signs, electrocardiogram, and arterial blood gas analysis are crucial elements of the diagnostic workflow during the acute phase. Atrioventricular block recurrence after the reversal of the underlying cause may pose an indication for pacemaker implantation, because reversible conditions may actually unmask a preexistent conduction disorder.

Incidence of ventricular arrhythmias related to COVID infection and vaccination in patients with Brugada syndrome: Insights from a large Italian multicenter registry based on continuous rhythm monitoring.

INTRODUCTION: Brugada syndrome (BrS) has a dynamic ECG pattern that might be revealed by certain conditions such as fever. We evaluated the incidence and management of ventricular arrhythmias (VAs) related to COVID-19 infection and vaccination among BrS patients carriers of an implantable loop recorder (ILR) or implantable cardioverter-defibrillator (ICD) and followed by remote monitoring. METHODS: This was a multicenter retrospective study. Patients were carriers of devices with remote monitoring follow-up. We recorded VAs 6 months before COVID-19 infection or vaccination, during infection, at each vaccination, and up to 6-month post-COVID-19 or 1 month after the last vaccination. In ICD carriers, we documented any device intervention. RESULTS: We included 326 patients, 202 with an ICD and 124 with an ILR. One hundred and nine patients (33.4%) had COVID-19, 55% of whom developed fever. Hospitalization rate due to COVID-19 infection was 2.76%. After infection, we recorded only two ventricular tachycardias (VTs). After the first, second, and third vaccines, the incidence of non-sustained ventricular tachycardia (NSVT) was 1.5%, 2%, and 1%, respectively. The incidence of VT was 1% after the second dose. Six-month post-COVID-19 healing or 1 month after the last vaccine, we documented NSVT in 3.4%, VT in 0.5%, and ventricular fibrillation in 0.5% of patients. Overall, one patient received anti-tachycardia pacing and one a shock. ILR carriers had no VAs. No differences were found in VT before and after infection and before and after each vaccination. CONCLUSIONS: From this large multicenter study conducted in BrS patients, followed by remote monitoring, the overall incidence of sustained VAs after COVID-19 infection and vaccination is relatively low.

Valor pronóstico del intervalo Tpeak-Tend en el desarrollo de arritmias ventriculares subagudas intrahospitalarias en el síndrome de tako-tsubo / Prognostic value of the Tpeak-Tend interval for in-hospital subacute ventricular arrhythmias in tako-tsubo syndrome

Introducción y objetivos El valor de los parámetros del electrocardiograma (ECG) de repolarización asociados al riesgo de arritmias ventriculares (AVs) en el síndrome de tako-tsubo es controvertido. Nuestro objetivo fue identificar predictores ECG de AVs subagudas, definidas como aquellas ocurridas después de las primeras 48 horas desde el ingreso. Métodos Estudio observacional unicéntrico de pacientes ingresados en el servicio de cardiología entre 2012 y 2018 con diagnóstico de síndrome de tako-tsubo. La recogida de datos incluyó el ECG de 12 derivaciones al ingreso y a las 48 horas, registros de telemetría continua, analíticas, ecocardiografía transtorácica y angiografía coronaria durante la hospitalización. Los eventos de AVs se definieron como: extrasístoles ventriculares ≥ 2.000 en registros de telemetría de 24 horas, fibrilación ventricular, taquicardia ventricular (TV) sostenida, TV polimórfica y TV no sostenida. Resultados Se incluyeron 87 pacientes (edad 72±12 años). Durante una hospitalización mediana de 8 días se registraron AVs subagudas en 22 pacientes (25%) tras una mediana de 91 horas desde el ingreso. Las AVs subagudas se asociaron a aumento de la mortalidad hospitalaria (p=0,030). El intervalo Tpeak-Tend corregido global (promedio de las 12 derivaciones del ECG) a las 48 horas del ingreso fue un predictor independiente de AVs subagudas, superior al intervalo QT corregido (p=0,040). Un valor de corte 108ms en el Tpeak-Tend corregido global mostró una sensibilidad del 71% y especificidad del 72% para AVs subagudas. Conclusiones En pacientes con síndrome de tako-tsubo, las AVs subagudas se asocian a alteraciones de la repolarización que pueden detectarse en el ECG convencional mediante el intervalo Tpeak-Tend (AU)

Introduction and objectives The clinical value of electrocardiogram (ECG) repolarization parameters associated with ventricular arrhythmias (VAs) in tako-tsubo syndrome is still under debate. We aimed to evaluate ECG predictors of subacute VAs, defined as those occurring after the first 48hours from admission. Methods This single-center observational study enrolled patients admitted to the cardiology department between 2012 and 2018 with a confirmed diagnosis of tako-tsubo syndrome. Data collection included a 12-lead ECG on admission and at 48hours, continuous telemetry monitoring, blood testing, transthoracic echocardiography, and coronary angiography during hospitalization. VAs events were defined as: premature ventricular contractions ≥ 2000 within a 24-hour window of telemetry monitoring, ventricular fibrillation, sustained ventricular tachycardia (VT), polymorphic VT, and non-sustained VT. Results A total of 87 patients (age 72±12 years) were enrolled. During a median of 8 days of hospitalization, subacute VAs were documented in 22 patients (25%) after a median of 91hours from admission. Subacute VAs were associated with an increase in mortality during hospitalization (P=.030). The corrected global (mean of the 12-lead ECG values) Tpeak-Tend interval at 48hours from admission was an independent predictor of subacute VAs and was statistically superior to the standard corrected QT interval (Z test, P=.040). A cut-off of 108 msec for the corrected global Tpeak-Tend yielded a 71% sensitivity and 72% specificity for subacute VAs. Conclusions In patients with tako-tsubo syndrome, subacute VAs are associated with repolarization alterations that can be identified on conventional ECG using the Tpeak-Tend interval (AU)

Clinical Impact of Cardiac Fibrosis on Arrhythmia Recurrence after Ablation in Adults with Congenital Heart Disease.

BACKGROUND: Adults with congenital heart disease (ACHD) are often affected by cardiac arrhythmias requiring catheter ablation. Catheter ablation in this setting represents the treatment of choice but is flawed by frequent recurrencies. Predictors of arrhythmia relapse have been identified, but the role of cardiac fibrosis in this setting has not been investigated. The aim of this study was to determine the role of the extension of cardiac fibrosis, detected by electroanatomical mapping, in predicting arrhythmia recurrencies after ablation in ACHD. MATERIALS AND METHODS: Consecutive patients with congenital heart disease and atrial or ventricular arrhythmias undergoing catheter ablation were enrolled. An electroanatomical bipolar voltage map was performed during sinus rhythm in each patient and bipolar scar was assessed according to the current literature data. During follow-up, arrhythmia recurrences were recorded. The relationship between the extent of myocardial fibrosis and arrhythmia recurrence was assessed. RESULTS: Twenty patients underwent successful catheter ablation of atrial (14) or ventricular (6) arrhythmias, with no inducible arrhythmia at the end of the procedure. During a median follow-up period of 207 weeks (IQR 80 weeks), eight patients (40%; five atrial and three ventricular arrhythmias) had arrhythmia recurrence. Of the five patients undergoing a second ablation, four showed a new reentrant circuit, while one patient had a conduction gap across a previous ablation line. The extension of the bipolar scar area (HR 1.049, CI 1.011-1.089, p = 0.011) and the presence of a bipolar scar area >20 cm2 (HR 6.101, CI 1.147-32.442, p = 0.034) were identified as predictors of arrhythmia relapse. CONCLUSION: The extension of the bipolar scar area and the presence of a bipolar scar area >20 cm2 can predict arrhythmia relapse in ACHD undergoing catheter ablation of atrial and ventricular arrhythmias. Recurrent arrhythmias are often caused by circuits other than those previously ablated.

Ventricular tachycardia ablation through radiation therapy (VT-ART) consortium: Concept description of an observational multicentric trial via matched pair analysis.

Introduction: Monomorphic ventricular tachycardia (VT) is a life-threatening condition often observed in patients with structural heart disease. Ventricular tachycardia ablation through radiation therapy (VT-ART) for sustained monomorphic ventricular tachycardia seems promising, effective, and safe. VT-ART delivers focused, high-dose radiation, usually in a single fraction of 25 Gy, allowing ablation of VT by inducing myocardial scars. The procedure is fully non-invasive; therefore, it can be easily performed in patients with contraindications to invasive ablation procedures. Definitive data are lacking, and no direct comparison with standard procedures is available. Discussion: The aim of this multicenter observational study is to evaluate the efficacy and safety of VT-ART, comparing the clinical outcome of patients undergone to VT-ART to patients not having received such a procedure. The two groups will not be collected by direct, prospective accrual to avoid randomization among the innovative and traditional arm: A retrospective selection through matched pair analysis will collect patients presenting features similar to the ones undergone VT-ART within the consortium (in each center independently). Our trial will enroll patients with optimized medical therapy in whom endocardial and/or epicardial radiofrequency ablation (RFA), the gold standard for VT ablation, is either unfeasible or fails to control VT recurrence. Our primary outcome is investigating the difference in overall cardiovascular survival among the group undergoing VT-ART and the one not exposed to the innovative procedure. The secondary outcome is evaluating the difference in ventricular event-free survival after the last procedure (i.e., last RFA vs. VT-ART) between the two groups. An additional secondary aim is to evaluate the reduction in the number of VT episodes comparing the 3 months before the procedure to the ones recorded at 6 months (from the 4th to 6th month) following VT-ART and RFA, respectively. Other secondary objectives include identifying the benefits of VT-ART on cardiac function, as evaluated through an electrocardiogram, echocardiographic, biochemical variables, and on patient quality of life. We calculated the sample size (in a 2:1 ratio) upon enrolling 149 patients: 100 in the non-exposed control group and 49 in the VT-ART group. Progressively, on a multicentric basis supervised by the promoting center in the VT-ART consortium, for each VT-ART patient enrollment, a matched pair patient profile according to the predefined features will be shared with the consortium to enroll a patient that has not undergone VT-ART. Conclusion: Our trial will provide insight into the efficacy and safety of VT-ART through a matched pair analysis, via an observational, multicentric study of two groups of patients with or without VT-ART in the multicentric consortium (with subgroup stratification into dynamic cohorts).

Mortality after transvenous lead extraction: A risk prediction model for sustainable care delivery.

BACKGROUND AND AIMS: Transvenous lead extraction (TLE) has become a pivotal part of a comprehensive lead management strategy, dealing with a continuously increasing demand. Nonetheless, the literature about the long-term impact of TLE on survivals is still lacking. Given these knowledge gaps, the aim of our study was to analyse very long-term mortality in patients undergoing TLE in public health perspective. METHODS: This prospective, single-centre, observational study enrolled consecutive patients with cardiac implantable electronic device (CIED) who underwent TLE, from January 2005 to January 2021. The main goal was to establish the independent predictors of very long-term mortality after TLE. We also aimed at assessing procedural and hospitalization-related costs. RESULTS: We enrolled 435 patients (mean age 70 ± 12 years, with mean lead dwelling time 6.8 ± 16.7 years), with prevalent infective indication to TLE (92%). Initial success of TLE was achieved in 98% of population. After a median follow-up of 4.5 years (range: 1 month-15.5 years), 150 of the 435 enrolled patients (34%) died. At multivariate analysis, death was predicted by: age (≥77 years, OR: 2.55, CI: 1.8-3.6, p < 0.001), chronic kidney disease (CKD) defined as severe reduction of estimated glomerular filtration rate (eGFR <30 mL/min/1.73 m2 , OR: 1.75, CI: 1.24-2.4, p = 0.001) and systolic dysfunction assessed before TLE defined as left ventricular ejection fraction (LVEF) <40%, OR: 1.78, CI 1.26-2.5, p = 0.001. Mean extraction cost was €5011 per patient without reimplantation and €6336 per patient with reimplantation respectively. CONCLUSIONS: Our study identified three predictors of long-term mortality in a high-risk cohort of patients with a cardiac device infection, undergoing successful TLE. The future development of a mortality risk score before might impact on public health strategy.

Different Phases of Disease in Lymphocytic Myocarditis: Clinical and Electrophysiological Characteristics.

BACKGROUND: Endomyocardial biopsy (EMB) is required to make a definite diagnosis of lymphocytic myocarditis (LM), to identify its etiology, and to classify LM into different phases. OBJECTIVES: This study aims to characterize and compare clinical and electrophysiological characteristics of different biopsy-proven LM phases, namely acute myocarditis (AM), chronic active myocarditis (CAM), and healed myocarditis (HM). METHODS: All patients with a diagnosis of LM at 3 Italian referral centers were prospectively enrolled. According to EMB findings, LM was classified as AM, CAM, or HM; per-group comparisons of clinical presentations, noninvasive, and invasive findings are reported. RESULTS: Among the 122 enrolled patients (AM, n = 44; CAM, n = 42; HM, n = 36), complex ventricular arrhythmias were very common overall (n = 109, 89%), but ventricular fibrillation was slightly more prevalent in AM (P = 0.028). Cardiac magnetic resonance imaging showed late gadolinium enhancement in more patients with HM and CAM than AM (94.4% vs 92.9% vs 50%; P < 0.001), whereas edema was more common in AM than in CAM, being absent in HM (90.9% vs 50% vs 0%; P < 0.001). Accordingly, edema was the strongest independent clinical predictor of EMB-proven active inflammation. Electroanatomical mapping revealed a lower prevalence of low-voltage areas in AM than in CAM or HM. We observed a strong association between edema at a specific myocardial segment and normal voltages at that site (odds ratio: 0.24; 95% CI: 0.10-0.54; P < 0.01), as well as between late gadolinium enhancement and low-voltage areas (odds ratio: 2.86; 95% CI: 1.19-6.97; P = 0.019). CONCLUSIONS: LM is a highly heterogeneous disease, and its different phases are characterized by diverse clinical, morphological, and electrophysiological features. Further research is required to identify electroanatomical markers of inflammation.

Prognostic value of the Tpeak-Tend interval for in-hospital subacute ventricular arrhythmias in tako-tsubo syndrome.

INTRODUCTION AND OBJECTIVES: The clinical value of electrocardiogram (ECG) repolarization parameters associated with ventricular arrhythmias (VAs) in tako-tsubo syndrome is still under debate. We aimed to evaluate ECG predictors of subacute VAs, defined as those occurring after the first 48hours from admission. METHODS: This single-center observational study enrolled patients admitted to the cardiology department between 2012 and 2018 with a confirmed diagnosis of tako-tsubo syndrome. Data collection included a 12-lead ECG on admission and at 48hours, continuous telemetry monitoring, blood testing, transthoracic echocardiography, and coronary angiography during hospitalization. VAs events were defined as: premature ventricular contractions ≥ 2000 within a 24-hour window of telemetry monitoring, ventricular fibrillation, sustained ventricular tachycardia (VT), polymorphic VT, and non-sustained VT. RESULTS: A total of 87 patients (age 72±12 years) were enrolled. During a median of 8 days of hospitalization, subacute VAs were documented in 22 patients (25%) after a median of 91hours from admission. Subacute VAs were associated with an increase in mortality during hospitalization (P=.030). The corrected global (mean of the 12-lead ECG values) Tpeak-Tend interval at 48hours from admission was an independent predictor of subacute VAs and was statistically superior to the standard corrected QT interval (Z test, P=.040). A cut-off of 108 msec for the corrected global Tpeak-Tend yielded a 71% sensitivity and 72% specificity for subacute VAs. CONCLUSIONS: In patients with tako-tsubo syndrome, subacute VAs are associated with repolarization alterations that can be identified on conventional ECG using the Tpeak-Tend interval.

Automated conduction velocity estimation based on isochronal activation of heart chambers.

BACKGROUND: Spatial differences in conduction velocity (CV) are critical for cardiac arrhythmias induction. We propose a method for an automated CV calculation to identify areas of slower conduction during cardiac arrhythmias and sinus rhythm. METHODS: Color-coded representations of the isochronal activation map using data coming from the RHYTHMIA™ Mapping System were reproduced by applying a temporal isochronal window at 20 ms. Geodesic distances of the 3D mesh were calculated using an algorithm selecting the minimum distance pathway (MDP). The CV estimation was performed considering points on the boundary of two spatially and temporally adjacent isochrones. For each of the boundary points of a given isochrone, the nearest boundary point of the consecutive isochrone was chosen, the MDP was evaluated, and a map of CV was created. The proposed method has been applied to a population of 29 patients. RESULTS: In all cases of perimitral atrial flutter (16 pts out of 29 (55%)), areas with significantly low CV (< 30 cm/s) were found. Half of the cases present regions with low CV located in the anterior wall. No case with low CV at the so-called LA isthmus was observed. Right atrial maps during common atrial flutters showed low CV areas mainly located in the inferior inter-atrial septum. No areas of low CV were observed in subjects without a history of atrial arrhythmia while pts affected by paroxysmal AF showed areas with a limited extension of low CV. CONCLUSIONS: The proposed software for automated CV estimation allows the identification of low CV areas, potentially helping electrophysiologists to plan the ablation strategy.

Mid-Term Outcome of Ventricular Arrhythmias Catheter Ablation in Patients with Chronic Coronary Total Occlusion Compared to Ischemic and Non-Ischemic Patients.

Chronic coronary total occlusions (CTO) are considered an emerging predictor of ventricular arrhythmias (VAs), but currently there are few data on arrhythmic outcomes in patients affected by CTO undergoing radiofrequency catheter ablation of VAs. This study sought to evaluate the impact of unrevascularized CTO on the recurrence of VAs after catheter ablation. This was a single-center retrospective study enrolling 120 patients between 2015 and 2020. All patients were admitted for ventricular tachycardia (VT) or high premature ventricular contractions burden (>25% detected by Holter ECG), without evidence of acute coronary syndrome; they underwent coronary angiography, electrophysiology (EP) study, and three-dimensional electroanatomic mapping (3D-EAM) followed by VAs ablation. Twenty-eight patients (23%) of 120 patients showed CTO at coronary angiography. At baseline, the CTO group presented with higher prevalence of hypertension, chronic renal disease, systolic ventricular dysfunction, secondary prevention ICD implantation, and higher rate of LAVA by 3D-EAM compared with the non-CTO group. At a median follow-up of 15 months (range 1−96 months) after catheter ablation, the only independent predictor of VAs recurrence was the presence of moderate to severe left ventricular (LV) dysfunction. Therefore, the presence of CTO does not predict VAs recurrence after catheter ablation, which is instead predicted by LV dysfunction.

Ultra-high-resolution assessment of lesion extension after cryoballoon ablation for pulmonary vein isolation.

Introduction: Unrecognized incomplete pulmonary vein (PV) isolation during the index procedure, can be a major cause of clinical recurrences of atrial fibrillation (AF) after cryoballoon (CB) ablation. We aimed to characterize the extension of the lesions produced by CB ablation and to assess the value of using an ultra-high resolution electroanatomic mapping (UHDM) system to detect incomplete CB lesions. Materials and methods: Twenty-nine consecutive patients from the CHARISMA registry undergoing AF ablation at four Italian centers were prospectively evaluated. The Rhythmia™ mapping system and the Orion™ (Boston Scientific) mapping catheter were used to systematically map the left atrium and PVs before and after cryoablation. Results: A total of 116 PVs were targeted and isolated. Quantitative assessment of the lesions revealed a significant reduction of the antral surface area of the PV, resulting in an ablated area of 5.7 ± 0.7 cm2 and 5.1 ± 0.8 cm2 for the left PV pair and right PV pair, respectively (p = 0.0068). The mean posterior wall (PW) area was 22.9 ± 2 cm2 and, following PV isolation, 44.8 ± 6% of the PW area was ablated. After CB ablation, complete isolation of each PV was documented by the POLARMap™ catheter in all patients. By contrast, confirmatory UHDM and the Lumipoint™ tool unveiled PV signals in 1 out of 114 of the PVs (0.9%). Over 30-day follow-up, no major procedure-related adverse events were reported. After a mean follow-up of 333 days, 89.7% of patients were free from arrhythmia recurrence. Conclusion: The lesion extension achieved by the new CB ablation system involved the PV antrum, with less than 50% of the PW remaining untouched. The new system, with short tip and circular mapping catheter, failed to achieve PV isolation in only 0.9% of all PVs treated. Clinical trial registration: [http://clinicaltrials.gov/], identifier [NCT03793998].