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Resumen Introduccion y objetivos La evaluacion del riesgo de arritmias ventriculares en pacientes con tetralogia de Fallot reparada (TFr) es compleja. Este estudio pretende identificar las caracteristicas electrofisiologicas del ventriculo derecho (VD) asociadas con un mayor riesgo de arritmias ventriculares en pacientes con TFr. Metodos Se incluyo a todos los pacientes consecutivos con TFr sometidos a mapeo electroanatomico del VD en un centro terciario. Mediante modelos de regresion logistica, se identificaron los factores asociados con mayor riesgo de taquicardia ventricular (TV) clinica o inducida y, secundariamente, solo de TV clinica. Resultados De los 56 pacientes incluidos, 21 presentaron TV clinica o inducida. Los factores asociados con TV clinica o inducida fueron: extrasistolia ventricular (EV) frecuente/TV no sostenida en el Holter de 24 h (OR = 11,34; IC95%, 1,50-85,97; p = 0,019), intervalo HV > 55 ms (OR = 21,20; IC95%, 3,12-144,14; p = 0,002) y tiempo de activacion del VD (por cada 10 ms, OR = 1,34; IC95%, 1,02-1,75; p = 0,035). El modelo que incluia dichas variables mostro una buena capacidad de discriminacion, con un area bajo la curva de 0,884 (IC95%, 0,79-0,97; p 55 ms (OR = 9,65; IC95%, 1,41-66,14; p = 0,021) y la EV frecuente/TV no sostenida (OR = 13,14; IC95%, 1,95-88,54; p = 0,008) (area bajo de la curva = 0,836; IC95%, 0,663-1,000; p = 0,002). Conclusiones La EV frecuente/TV no sostenida, el intervalo HV > 55 ms y el tiempo de activacion del VD son factores asociados con mayor riesgo de arritmias ventriculares en pacientes con TFr.

Introduction and objectives Risk stratification of ventricular arrhythmias in patients with repaired tetralogy of Fallot (rTOF) remains unresolved. We aimed to identify right ventricular (RV) electrophysiological parameters potentially associated with a higher risk of ventricular arrhythmias in patients with rTOF. Methods We included all consecutive patients with rTOF who underwent RV electroanatomical mapping at a single tertiary center. We used logistic regression modeling to identify those variables associated with an increased risk of clinical or induced ventricular tachycardia (VT), or clinical VT exclusively. Results Twenty-one of the 56 patients included had clinical or induced VT. A high-frequency of premature ventricular contractions/nonsustained VT (OR, 11.34; 95%CI, 1.50-85.97; P = .019), an HV interval > 55 ms (OR, 21.20; 95%CI, 3.12-144.14; P = .002), and RV activation time (ms) (OR [per 10 ms intervals], 1.34; 95%CI, 1.02-1.75; P = .035) proved to be associated with clinical or induced VT. The model including this information had good discrimination ability, with an area under the curve of 0.884 (95%CI, 0.79-0.97; P 55 ms (OR, 9.65; 95%CI, 1.41-66.14; P = .021) and high-frequency of premature ventricular contractions/nonsustained VT (OR, 13.14; 95%CI, 1.95-88.54; P = .008) were independently associated (area under the curve of 0.836 [95%CI, 0.663-1.000; P = .002]). Conclusions High-frequency of premature ventricular contractions/nonsustained VT, an HV interval > 55 ms and RV activation time are factors associated with an increased risk of ventricular arrhythmias in patients with rTOF.

The aim of this work was to study the association of potential biomarkers with fast aortic stenosis (AS) progression. Patients with moderate-to-severe AS were classified as very fast progressors (VFP) if exhibited an annualized change in peak velocity (aΔVmax) ≥0.45m/s/year and/or in aortic valve area (aΔAVA) ≥-0.2cm2/year. Respective cut-off values of ≥0.3m/s/year and ≥-0.1cm2/year defined fast progressors (FP), whereas the remaining patients were non-fast progressors (non-FP). Baseline markers of lipid metabolism, inflammation, and cardiac overload were determined. Two hundred and nine patients (97 non-FP, 38 FP, and 74 VFP) were included. PCSK9 levels were significantly associated with VFP (OR 1.014 [95%CI 1.005-1.024], for every 10 ng/mL), as were active smoking (OR 3.48) and body mass index (BMI, OR 1.09), with an AUC of 0.704 for the model. PCSK9 levels, active smoking, and BMI were associated with very fast AS progression in our series, suggesting that inflammation and calcification participate in disease progression.

Aim To assess the changes induced by the COVID-19 lockdown on cardiac biometric variables recorded using an implantable cardiac monitor (ICM) in a patient population monitored for syncope work-up, as well to assess whether there has been an effect on arrhythmic events among the patients. Methods Longitudinal cohort study. We included 245 adult patients monitored with an ICM indicated for the investigation of syncope. The records from days 1 to 12 March 2020 (prior to the institution of lockdown by the state government) with days 16 to 28 March 2020 were compared. Results Daily physical exercise reduced markedly after the imposition of lockdown (132 [55–233] minutes vs. 78 [21–154] minutes). The mean daytime HR prior to lockdown was 77 [69–85] bpm, whereas during lockdown it was 74 [66–81] bpm. During the lockdown period, a drop in the variability in heart rate (114 [94–136] ms vs. 111 [92–133] ms) was observed. Although the incidence of AF was similar over both periods, the daily AF burden was significantly higher post-lockdown (405 [391–425] minutes vs. 423 [423–537] minutes). No differences in the number of other arrhythmias were found. Conclusions The establishment of mandatory lockdown has led to a marked drop in daily physical activity in this population which probably explains changes observed in other cardiac biometric variables. Although, in the short term, we have not documented an increased risk of arrhythmia, we cannot rule out an effect in the medium to long term or in other populations of at-risk patients.

Background Syncope in patients with mid-range left ventricular ejection fraction (LVEF) can be due to potentially serious arrhythmic causes. However, there is no clear consensus on the best way to manage these patients. Objectives The objectives of this study were to determine the causes of syncope and assess the diagnostic yield and safety of a stepwise workup protocol in this population. Methods This was a prospective observational study. A stepwise workup protocol was applied to patients with LVEF 35%–50% and unexplained syncope after the initial assessment (step 1). Results One hundred four patients were included {median age 75.6 years; (interquartile range [IQR] 67.6–81.2 years); median LVEF 45% (IQR 40%–48%); median follow-up 2.0 years (IQR 0.7–3.3 years). In 71 patients (68.3%), a diagnosis was reached: 55 (77.5%) in step 2 (hospital admission and electrophysiology study) and 16 (36.5%) in step 3 (implantable cardiac monitor). Arrhythmic causes were the most common etiology (45.2% auriculoventricular block and 9.6% ventricular tachycardia). Sixty patients (57.7%) required the implantation of a cardiac device and 11 had a defibrillation function. Patients diagnosed in step 3 had a higher global risk of recurrence of syncope (hazard ratio 6.5; 95% confidence interval 2.3–18.0). The mortality rate was 8.1 per 100 person-years, and the sudden or unknown death rate was 0.9 per 100 person-years. Conclusion In patients with mid-range left ventricular dysfunction and syncope of unknown cause, a systematic diagnostic strategy based on electrophysiology study and/or implantable cardiac monitor implantation allows a diagnosis to be reached in a high proportion of cases and guides the treatment. Arrhythmia is the most common cause of syncope in this population, particularly auriculoventricular block.

Objective The use of implantable cardiac monitors (ICM) is highly useful in syncope workup. Latest-generation devices can detect asymptomatic episodes of atrial fibrillation. The main objective of this study was to determine the incidence of subclinical atrial fibrillation (AF) detected in a patient population undergoing prolonged electrocardiographic monitoring with an ICM for the etiological workup of syncope. Methods Prospective observational study carried out in a tertiary hospital from April 2014 to October 2019. All consecutive adult patients monitored with a latest-generation ICM for syncope with no prior history of AF were included in the analysis. Results Of a total of 509 ICMs implanted during the study period, 208 patients fulfilled the inclusion criteria. 42 patients (20.2%) were found to have AF on ICM. The incidence of AF was 11.7 cases per 100 person-years (95% CI: 8.7–15.9 per 100 person-years). The median burden of AF was 0.2% (IQR 0–0.8%). Age, the presence of hypertension, chronic kidney disease, the size of the septum and left atrium on electrocardiogram and the presence of broad QRS on baseline electrocardiogram were predictors for the appearance of AF in the univariate analysis. Conclusion The incidental finding of atrial fibrillation in patients with syncope monitored with ICM is common. The burden of AF is low, and it is generally subclinical. These findings create added value for the use of ICM in the workup for syncope, although further studies are needed to determine the clinical benefit of documenting subclinical AF.

Monitoreo cardíaco; Grabadora de bucle; Palpitación Cardiac monitoring; Loop recorder; Palpitation Monitorització cardíaca; Gravadora de bucle; Palpitació Palpitations are one of the most common reasons for medical consultation. They tend to worry patients and can affect their quality of life. They are often a symptom associated with cardiac rhythm disorders, although there are other etiologies. For diagnosis, it is essential to be able to reliably correlate the symptoms with an electrocardiographic record allowing the identification or ruling out of a possible rhythm disorder. However, reaching a diagnosis is not always simple, given that they tend to be transitory symptoms and the patient is frequently asymptomatic at the time of assessment. In recent years, electrocardiographic monitoring systems have incorporated many technical improvements that solve several of the 24-h Holter monitor limitations. The objective of this review is to provide an update on the different monitoring methods currently available, remarking their indications and limitations, to help healthcare professionals to appropriately select and use them in the work-up of patients with palpitations.

Background In the last years a substantial effort has been made to improve the understanding of the sex-differences in cardiovascular disease. However, no studies have examined differences in presentation and outcomes between men and women presenting with syncope and bundle branch block (BBB). Aim To determinate if there are sex-specific differences in the characteristics and outcomes of syncope in patients with BBB Methods Cohort study carried out in a tertiary hospital that is a reference center for syncope from January 2008 to February 2021. Patients (p.) with BBB and syncope of unknown origin after the initial evaluation without direct indication of an ICD were included. They were managed according to the current ESC guidelines. All patients underwent to an EPS and an ILR was implanted if it was not diagnostic. Results 374p. were included (75±1 y. o; 135 (36%) female). Mean follow up was 2.3±1.6 y.o. No differences in baseline characteristics where found comparing both groups, except that LBBB was more prevalent in female and RBBB in male (Figure 1A). EPS and ILR diagnostic yield was 44%/44% respectively in females and 50% /40% in males (p=ns). However, basal HV interval in EPS was significant shorter in females (Figure 2A). In the multivariate analyses female sex was associated with a significant lower risk of AV block (Figure 1B), and with a trend of less need of a pacemaker implantation (PM) (53% in females, 60% in males) (Log-rank 0.1) (Figure 2B). No significant differences in recurrences neither in mortality rate were found. Conclusions Female patients with syncope and BBB have lower risk of AV block compared to males, and only half of them required a pacemaker implantation. A strategy of direct PM implantation should be avoided, specially in woman. Funding Acknowledgement Type of funding sources: None. Figure 1Figure 2

HL-1 cells; L-type calcium channels; Calcium regulation Células HL-1; Canales de calcio tipo L; Regulación del calcio Cel·lules HL-1; Canals de calci tipus L; Regulació del calci MicroRNAs (miRNAs) participate in atrial remodeling and atrial fibrillation (AF) promotion. We determined the circulating miRNA profile in patients with AF and heart failure with reduced ejection fraction (HFrEF), and its potential role in promoting the arrhythmia. In plasma of 98 patients with HFrEF (49 with AF and 49 in sinus rhythm, SR), differential miRNA expression was determined by high-throughput microarray analysis followed by replication of selected candidates. Validated miRNAs were determined in human atrial samples, and potential arrhythmogenic mechanisms studied in HL-1 cells. Circulating miR-199a-5p and miR-22-5p were significantly increased in HFrEF patients with AF versus those with HFrEF in SR. Both miRNAs, but particularly miR-199a-5p, were increased in atrial samples of patients with AF. Overexpression of both miRNAs in HL-1 cells resulted in decreased protein levels of L-type Ca2+ channel, NCX and connexin-40, leading to lower basal intracellular Ca2+ levels, fewer inward currents, a moderate reduction in Ca2+ buffering post-caffeine exposure, and a deficient cell-to-cell communication. In conclusion, circulating miR-199a-5p and miR-22-5p are higher in HFrEF patients with AF, with similar findings in human atrial samples of AF patients. Cells exposed to both miRNAs exhibited altered Ca2+ handling and defective cell-to-cell communication, both findings being potential arrhythmogenic mechanisms. This work was funded by the following grants, awarded to B.B.: Sociedad Española de Cardiología, Sección de Arritmias y Electrofisiología 2012; Sociedad Española de Cardiología, Sección de Insuficiencia Cardíaca 2013; Fondo Investigación Sanitaria (FIS)—Instituto Carlos III 2013 (PI13/01830); and Societat Catalana de Cardiologia 2016. Awarded to K.W.A-A. and S.R.: British Heart Foundation (BHF) Intermediate Research Fellowship. Awarded to J.M.F.F.: grant from the Spanish Ministry of Science and Innovation (RTI2018-094809-B-I00). “María de Maeztu” Programme for Units of Excellence in R&D to the Departament de Ciències Experimentals i de la Salut (MDM-2014-0370) and FEDER (Fondo Europeo de Desarrollo Regional) also contributed to this work.

Purpose Patients undergoing cavotricuspid isthmus (CTI) ablation for typical flutter (AFL) have a high incidence of new onset atrial fibrillation (AF). We aimed to analyze the influence of PACE score to predict new onset AF in this subset of patients to stratify thromboembolic risk. Methods Between 2017 and 2019, patients undergoing CTI ablation for AFL and without history of AF were prospectively included. All patients were monitored continuously by implantable loop recorder and followed by remote monitoring. Results Overall 48 patients were included. New onset AF rate at 12 months was 56.3%. We observed two very strong independent predictors for new onset AF: a PACE score ≥ 30 (HR:6.9; 95% CI:1.71–27.91; p = 0.007) and an HV interval ≥ 55 (HR:11.86; 95% CI:2.57–54.8; p = 0.002). Conclusions The incidence of newly diagnosed AF is high in patients with AFL after CTI ablation, and can occur early. A high PACE score and/or long HV interval predict even higher risk, and may be useful in the decision for empiric long-term anticoagulation.

Silent atrial fibrillation (AF) may be the cause of some cryptogenic strokes (CrS). The aim of the study was to analyse atrial size and function by speckle tracking echocardiography in CrS patients to detect atrial disease. Patients admitted to the hospital due to CrS were included prospectively. Echocardiogram analysis included left atrial ejection fraction (LAEF) and atrial strain. Insertable cardiac monitor was implanted, and AF was defined as an episode of ≥1 min in the first year after stroke. Left atrial enlargement was defined as indexed volume &gt, 34 mL/m2. Seventy-five consecutive patients were included, aged 76 ± 9 years (arterial hypertension 75%). AF was diagnosed in 49% of cases. The AF group had higher atrial volume and worse atrial function: peak atrial longitudinal strain (PALs) 19.6 ± 5.7% vs. 29.5 ± 7.2%, peak atrial contraction strain (PACs) 8.9 ± 3.9% vs. 16.5 ± 6%, LAEF 46.8 ± 11.5% vs. 60.6 ± 5.2%, p &lt, 0.001. AF was diagnosed in 20 of 53 patients with non-enlarged atrium, and in 18 of them, atrial dysfunction was present. The multivariate logistic regression analysis demonstrated an independent association between detection of AF and atrial volume, LAEF, and strain. Cut-off values were obtained: LAEF &lt, 55%, PALs &lt, 21.4%, and PACs &lt, 12.9%. In conclusion, speckle tracking echocardiography in CrS patients improves silent atrial disease diagnosis, with or without atrial enlargement.

Introduction: Takotsubo syndrome is a complex entity that, although it usually has a good prognosis, can be life threatening. While recent advances have improved the knowledge of takotsubo syndrome, many aspects of its etiology still remain uncertain. Metabolomics, a hypothesis generating approach, could provide novel pathophysiology information about this disease. Methods and Results: Serum samples were obtained from takotsubo (n = 19) and acute myocardial infarction patients (n = 8) at the cath lab and, in the case of takotsubo, again once the patient had recovered, 3 months after the main event. 1H NMR spectra of the serum were acquired at 9.4T using a CPMG pulse sequence (32 ms effective delay). Supervised and unsupervised pattern recognition approaches where applied to the data. Pattern recognition was able to differentiate between takotsubo and acute myocardial infarction during the acute phase with 95% accuracy. Myocardial infarction patients showed an increase in lipid signals, a known risk factor for the disease while takotsubo patients showed a relative increase in acetate that could suggest a reduced turnover of the Krebs cycle. When comparing acute and recovered phases, we could detect an increase in alanine and creatine once patients recovered. Conclusions: Our results demonstrate that takotsubo syndrome is metabolically different than AMI, showing limited myocardial energy production capacity during the acute phase. We achieved high classification success against AMI, however, this study should be considered as a proof of concept regarding clinical application of metabolic profiling in takotsubo cardiomyopathy.

Purpose: Patients undergoing cavotricuspid isthmus (CTI) ablation for typical flutter (AFL) have a high incidence of new onset atrial fibrillation (AF). We aimed to analyze the incidence and predictors for new onset AF in this subset of patients to stratify thromboembolic risk. Methods: Between 2016 and 2019, 70 patients without history of AF but with high-risk for developing AF, based on a recent AFL ablation or a high PACE score for AF risk, were prospectively included. All patients were monitored continuously by implantable loop recorder and followed by remote monitoring.Results: Overall 48 patients were included after CTI ablation and 22 patients were included based on a high PACE score. New onset AF rate at 12 months was significantly higher in the AFL group compared to PACE group (56.3% vs 22.7%, p=0.011). History of AFL was the only independent predictor for new onset AF (HR:3.82; 95% CI:1.46-10.03; p=0.006) at a median follow-up of 12 months (Q1-Q3:4-19 months). In the AFL group, two very strong independent predictors for new onset AF were a PACE score ³30 (HR:6.9; 95% CI:1.71-27.91; p=0.007) and HV interval ³55 (HR:11.86; 95% CI:2.57-54.8; p=0.002).Conclusions: AFL is the most important predictor for new onset AF. In patients undergoing AFL ablation, a high PACE score and/or long HV interval predict even higher risk, and may be useful in decision for empiric long-term anticoagulation.

Background: Pulmonary veins isolation (PVI) is a standard treatment for recurrent atrial fibrillation (AF). Uninterrupted anticoagulation for minimum 3 weeks before the ablation and exclusion of left atrial (LA) thrombus with transesophageal echography (TEE) immediately before or during the procedure minimize peri-procedural risk. We aimed to demonstrate the utility of cardiac tomography (CT) and cardiac magnetic resonance (CMR) to rule out LA thrombus prior to PVI.Methods: Patients undergoing PVI for recurrent AF were retrospectively evaluated. Only patients that started anticoagulation at least 3 weeks prior to the CT/CMR and subsequently uninterrupted until the ablation procedure were selected. An intracardiac echo (ICE) catheter was used in all patients to evaluate LA thrombus. The results of CT/CMR were compared to ICE imaging.Results: We included 272 consecutive patients averaging 54.5 years (71% male; 30% persistent AF). Average CHA2DS2VASC Score was 0.9 and mean LA diameter was 43 mm, 111 patients on Acenocumarol and 161 on direct oral anticoagulants. Anticoagulation was started 227±392 days before the CT/CMR, and 291±416 days before the ablation procedure. CT/CMR diagnosed intracardiac thrombus in 2 cases, both in the LA appendage. A new CT/CMR revealed resolution of thrombus after 6 additional months of uninterrupted anticoagulation. No macroscopic thrombus was observed in any patients with ICE (negative predictive value of 100%; p

Funding Acknowledgements Type of funding sources: Public hospital(s). Main funding source(s): Hospital Universitari Vall d"Hebron - Vall d"Hebron Institut de Recerca. CIBERCV BACKGROUND Patients with structural heart disease (SHD) or bundle branch block (BBB) are at high risk of having an arrhythmic syncope (AS). In patients with recurrent syncope episodes (RSE) complete work-up including electrophysiological study (EPS) and/or implantation of a loop recorder (ILR) is recommended, however patients with their first episode may also be at risk of an AS. AIM To determinate if the patients with SHD or BBB with a single syncope episode (SSE) are at high risk of having an AS and compare it with patients with recurrent episodes (RSE). METHODS Cohort study carried out in a tertiary hospital that is a reference centre for syncope. From January 2008 to August 2020 patients with SHD or BBB with syncope of unknown origin after the initial evaluation and without direct indication of an ICD were included. They were managed according the current ESC guidelines. RESULTS 417patients were included (74 ±11 y. o; 39% female). Mean follow up was 2.5 ±1 y. 223 patients were diagnosed from an AS [113 (53%) in SSE group and 110 (54%) in RSE group, p = 0.9], 210 were due to bradyarrhythmia (AV block or sinus arrest). No differences in baseline characteristics where found comparing both groups, except that BBB was slightly more prevalent in patients with RSE (81% vs 90%, p = 0.01) (FIGURE- PANEL A). Risk of AS was 53% in patients with SE and 54% (p = 0.9). RSE were not associated with an increased risk of AS in univariate analyses (OR 1.01 IC95% 0.7-1.5) neither in the multivariate (FIGURE- PANEL B). EPS and ILR diagnostic yield was 45% / 32% respectively in SSE group and 44% / 33% in RSE group (p = 0.8) (FIGURE - PANEL C). After appropriate treatment, recurrence syncope rate was 10% in SSE group and 9% in RSE group (p = 0.8). No significant differences in mortality rate were found. CONCLUSIONS Patients with SHD or BBB and single syncope episode are at a high risk of having AS, and similar to those with RSE. EPS and ILR offer a similar diagnostic yield in both groups. Complete syncope work-up must be recommended in these patients despite having had only a single episode. Abstract Figure

Background and Aims Sodium-glucose cotransporter 2 inhibitors (SGLT2i) and endothelin A receptor (ETA) antagonist have shown nephroprotective effects in diabetic kidney disease (DKD) through blood pressure and urinary albumin loss reduction. The protective impact and the pathways through which they exert this protection have not yet been elucidated. This study aimed to investigate the effects of the add-on therapy of SGLT2i and ETA antagonists on a type 2 diabetes murine model. Method 12 weeks-old db/db mice were treated for 8 weeks with different combinations of empagliflozin 10 mg/Kg/day (SGLT2i), atrasentan 7 mg/Kg/day (ETA antagonist) or ramipril 8 mg/Kg/day. A group of non-diabetic mice (db/m) was included as negative control. In vivo variables were recorded during treatment, including transdermal measured glomerular filtration rate (GFR) and urinary albumin-to-creatinine ratio (UACR). After treatment kidneys were preserved for histopathological studies. Results After 8 weeks of treatment empagliflozin decreased fasting blood glucose alone or in combination with atrasentan or ramipril (234.2 mg/dL mean reduction in three treated groups when compared to db/db). Ramipril decreased blood pressure (BP) in monotherapy or in add-on therapy. Empagliflozin or atrasentan alone did not have any effect on blood pressure, but combination of atrasentan and ramipril had a synergistic effect and reduced both systolic (9.0 mmHg, CI 95%: -16.3 to -1.1; P=0.028) and diastolic BP (11.9 mmHg, CI 95%: -17.7 to -3.1; P=0.005) when compared to ramipril alone. The combination of atrasentan and ramipril significantly reduced UACR (1002 ug/mg, CI 95%: -2312.0 to -32.4; P=0.043). Empagliflozin treatment alone or in combination also reduced UACR (686.0 ug/mg mean reduction in three treated groups), although this reduction was not statistically significant. In the kidney, empagliflozin in monotherapy or combination reduced glomerular mesangial matrix expansion (4.85% mean mesangial reduction in three treated groups). Treatments with atrasentan and ramipril also reduced measangial matrix expansion. Conclusion Both empagliflozin and atrasentan demonstrated possible beneficial effects in DKD by reducing BP, UACR, and mesangial matrix expansion. The add-on therapy did not show greater protective effects in the analysed variables. Further studies are needed to characterize these protective effects and pathways involved.

Background and Aims Angiotensin converting enzyme 2 (ACE2) is one of the components of the renin-angiotensin system (RAS) that mainly degrades angiotensin II to angiotensin-(1-7). ACE2 is predominantly expressed in the kidney and the heart, but it has been evidenced in type 2 alveolar lung cells, where it acts as a receptor for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In this context, a controversy arose as to whether the use of RAS blockers could increase ACE2 lung expression and the risk infection by COVID-19. This study aimed to investigate the effect of an ACE inhibitor (Ramipril) on ACE2 expression in experimental diabetes. Method 12 weeks old diabetic db/db mice (n=7) were given ramipril (8 mg/Kg/day) during 8 weeks or the respective vehicle. db/m (n=7) vehicle-treated non-diabetic mice were included as controls. ACE2 mRNA expression and enzymatic activity were studied in kidney, heart and lung samples of these animals to identify if the diabetic condition or treatment with ramipril modulated ACE2 expression. Results In vehicle-treated diabetic db/db animals, ACE2 mRNA expression was significantly increased in the kidney (p Conclusion ACE2 is increased in the kidney and the lung, and decreased in the heart of diabetic mice. Ramipril treatment restores ACE2 levels. The results suggest that ACE inhibitors do not increase ACE2 expression and the activity decrease exerted in the lung may be protective against COVID-19 infection.

Three-dimensional (3D) substrate characterization by high-resolution late gadolinium enhancement cardiac magnetic resonance (LE-CMR) is useful for guiding ventricular tachycardia ablation of the left ventricle in ischemic heart disease.The purpose of this study was to validate the substrate characterization and 3D reconstruction of LE-CMR images of the right ventricle (RV) in patients with repaired tetralogy of Fallot (rTOF) and to identify the algorithm that best fits with electroanatomic mapping (EAM).RV LE-CMR images were compared with RV EAM in 10 patients with rTOF. RV LE-CMR images were postprocessed and analyzed to identify fibrotic tissue on 3D color maps. The 3D RV substrate reconstructions were created using an adjustable percentage of the maximum voxel signal intensity (MSI) of the scar region to define the threshold between core, transitional zone (TZ), and healthy tissue. Extensions of the core and TZ areas were compared with the scar (0.5 mV) and low-voltage (0.5-1.5 mV) areas obtained by RV EAM. Agreement on anatomic isthmi identification was quantified.The best match between core and scar was obtained at 65% MSI cutoff (mean areas 17.4 ± 9.9 cmThis study demonstrates that characterization of the RV substrate by postprocessing LE-CMR images in rTOF patients is feasible and validates the technique against RV EAM, which could help in planning target ablation.

Intermittent bladder catheterization (IBC) involves regular urine draining using a catheter, which is removed immediately after urinary elimination. It allows for the patient’s urological health to be managed and their renal function to be preserved, and it promotes autonomy. Compliance with the prescribed number of daily catheterizations, which must be conducted by the patient, and infection prevention measures are crucial. To identify the patients requiring IBC, and to determine their adherence (whether they followed the prescribed guidelines and their difficulty in carrying out the procedure, as well as to assess how the IBC influences their quality of life and state of mind after receiving self-care training from a specialized nurse), we carried out a prospective, multicenter observational study in 24 Spanish hospitals with one month of monitoring and a sample of 99 patients. The sources of information were the patients’ clinical records, the King’s Health Questionnaire, the Mini-Mental State Examination (MMSE), and the hospital anxiety and depression scale (HADS). Descriptive and bivariate statistics were used to analyses the paired data. After recruitment (n = 99), 79 patients completed the questionnaire at a mean age of 35.2 years (SD = 20.5 years). In total, 53.5% (53) of the sample consisted of men and 32.3% (32) had neurological damage as the reason for prescription, 67% (67.7) performed self-catheterization and 86.7% adhered to the IBC. After one month of monitoring, a statistically significant improvement in quality of life was observed in all criteria, with the exception of personal relationships (p &lt, 0.005), as well as an improvement in anxiety and depression levels (p &lt, 0.001). Patients who require IBC show good adherence to the IBC with a significant percentage of self-catheterization. After one month of IBC, a significant improvement in the patients’ quality of life and mood was observed. These results could be attributed to adequate patient training and adequate personalization of the IBC materials by the specialized nurses.

Visual Abstract, Highlights • In patients with STEMI treated with primary percutaneous coronary intervention, iron deficiency is associated with larger infarcts, more extensive microvascular obstruction, and a higher frequency of adverse left ventricular remodeling. • An iron-deficient diet reduces the tolerance to ischemia/reperfusion in mice at least in part by interfering with the cardioprotective pathway eNOS/soluble guanylate cyclase/protein kinase G. • An iron-deficient diet reduces eNOS activity by increasing oxidative/nitrosative stress and its proteasome-dependent degradation. • Not only iron excess but also iron deficiency may have deleterious effects in the context of acute myocardial ischemia., Summary In patients with a first anterior ST-segment elevation myocardial infarction treated with primary percutaneous coronary intervention, iron deficiency (ID) was associated with larger infarcts, more extensive microvascular obstruction, and higher frequency of adverse left ventricular remodeling as assessed by cardiac magnetic resonance imaging. In mice, an ID diet reduced the activity of the endothelial nitric oxide synthase/soluble guanylate cyclase/protein kinase G pathway in association with oxidative/nitrosative stress and increased infarct size after transient coronary occlusion. Iron supplementation or administration of an sGC activator before ischemia prevented the effects of the ID diet in mice. Not only iron excess, but also ID, may have deleterious effects in the setting of ischemia and reperfusion.

Introduction Patients with D-transposition of the great arteries (TGA) treated with Senning or Mustard surgery develop supraventricular tachycardias (SVTs) that require treatment with ablation. The use of multipoint, high-density, wavefront-activation-orientation independent mapping catheters hasn’t been reported in literature. Purpose To describe the feasibility of using a specific mapping catheter in SVTs in this set of patients. Methods Prospective observational study in patients with history of SVT and atrial switch surgery, that underwent EP study and electroanatomic (EA) mapping with a new 8Fr deflectable, multipoint (16 equidistant electrodes along 4 splines), with magnetic sensor, wavefront-activation-orientation independent catheter, in a third level hospital since April 2018 until May 2019, with medium-term follow-up. Results A total of 8 EPS (electrophysiologic studies) were performed in 7 patients (clinical data in Table 1). One patient had a tachycardia recurrence, accounting for a second EPS. The pulmonary venous atrium (PVA) was mapped in all procedures, whereas the systemic venous atrium (SVA) was mapped only in 75% of them, A total of 15 EA maps were obtained, with a ratio of 1.9 maps/patient, and an average of 20 375 ± 13 045 total points per patient. In all cases, PVA mapping was performed via retrograde transaortic approach, without transbaffle puncture. Tachycardia was induced in 5 out of 8 procedures, obtaining 6 different tachycardias (4 CTI dependent macro-reentry: 3 w/anticlockwise activation; 1 localized re-entry in SVA; 1 focal AT in SVA). No arrhythmia was induced in the other 3 procedures, however, in a patient with a previous CTI ablation, evidence of a gap in the ablation line on the voltage map was found. Ablation was performed with an irrigated, contact force, 3.5 mm catheter in 6 of the 8 procedures (75%). A retrograde transaortic approach was used in 3 of CTI dependent macro-reentries (75%). In one patient (who underwent two procedures) ablation was performed through a baffle leak. We report an acute success rate of ablation of 100%, and a recurrence rate of 20% on medium-term follow up. There were no major complications; nonetheless, one patient with history of morbid obesity had a minor vascular complication on the femoral puncture site treated medically. Conclusions it’s feasible and safe to use this new mapping catheter in patients with history of atrial switch surgery, both via retrograde and anterograde approach on the PVA and SVA respectively. The most frequent tachycardia observed in this study was anticlockwise CTI-dependent atrial flutter. Abstract Figure. Patient characteristics

INTRODUCTION Patients with D- transposition of the great arteries (TGA) treated with Senning or Mustard surgeries have several atrial scars that predispose them to develop atrial tachycardias (AT). Identification of scar zones and possible arrhythmic isthmus in voltage mapping will help to guide the ablation. AIM To describe the feasibility of using a specific mapping catheter to identify possible arrhythmic isthmus in this set of patients. METHODS Prospective observational study in patients with history of SVT and atrial switch surgery, that underwent electrophysiologic study (EP) and electroanatomic (EA) mapping with a new 8Fr deflectable, multipoint wavefront-activation-orientation independent Grid catheter, in a third level hospital since April 2018 until May 2019, with medium-term follow-up. RESULTS A total of 8 EPs were performed in 7 patients (3 (57%) Female, median age 35 ± 6,3 y.o.). Figure 1A shows the localization and percentage of scar identified in both atria. A total of 6 AT were induced. In this, an arrhythmogenic isthmus was identified and, in all patients, at least one non-arrhytmogenic isthmus was documented. Figure 1B shows anatomical and electrophysiological characteristics of the isthmus. Arrhythmogenic isthmus had slower conduction velocity than non-arrhytmogenic ( mean 0,44m/s (IQI 0,17-0,62) vs 1,05 m/s (IQI 0,86-1,39) p = 0.008) and fractionated potentials were detected more frequently (100% vs 50% p = 0.089) CONCLUSION EA mapping with a new a multipoint, high-definition, Grid Cather is feasible and allows the identification and electrophysiological characterization of arrhythmogenic and non-arrhytmogenic isthmus in patients with TGA treated with atrial switch surgery. Abstract Figure 1

Previous studies demonstrated a reduction in myocardial scar size in heterozygous Cx43+/- mice subjected to permanent coronary occlusion. However, patients presenting with ST segment elevation myocardial infarction often undergo rapid coronary revascularization leading to prompt restoration of coronary flow. Therefore, we aimed to assess changes in scar size and left ventricular remodeling following transient myocardial ischemia (45 min) followed by 14 days of reperfusion using Cx43fl/fl (controls) and Cx43Cre-ER(T)/fl inducible knock-out (Cx43 content: 50%) mice treated with vehicle or 4-hydroxytamoxifen (4-OHT) to induce a Cre-ER(T)-mediated global deletion of the Cx43 floxed allele. The scar area (picrosirius red), measured 14 days after transient coronary occlusion, was similarly reduced in both vehicle and 4-OHT-treated Cx43Cre-ER(T)/fl mice, compared to Cx43fl/fl animals, having normal Cx43 levels (15.78% &plusmn, 3.42% and 16.54% &plusmn, 2.31% vs. 25.40% &plusmn, 3.14% and 22.43% &plusmn, 3.88% in vehicle and 4-OHT-treated mice, respectively, p = 0.027). Left ventricular dilatation was significantly attenuated in both Cx43-deficient groups (p = 0.037 for left ventricular end-diastolic diameter). These protective effects were correlated with an attenuated enhancement in pro-transforming growth factor beta 1 (TGF&beta, 1) expression after reperfusion. In conclusion, our data demonstrate that Cx43 deficiency induces a protective effect on scar formation after transient coronary occlusion in mice, an effect associated with reduced left ventricular remodeling and attenuated enhancement in pro-TGF&beta, 1 expression.

Background Severe aortic stenosis (AoS) is considered a primary cause of syncope. However, other mechanisms may be present in these patients and accurate diagnosis can have important clinical implications. The aim of this study is to assess the different etiologies of syncope in patients with severe AoS and the impact on prognosis of attaining a certain or highly probable diagnosis for the syncope. Methods Out of a cohort of 331 patients with AoS and syncope, 61 had severe AoS and were included in the study. Main cause of syncope and adverse cardiac events were assessed. Results In 40 patients (65.6%), we reached a certain or highly probable diagnosis of the main cause of the syncope. AoS was considered the primary cause of the syncope in only 7 patients (17.5% of the patients with known etiology). Atrioventricular block (14 patients, 35.0%) and vasovagal syncope (6 patients, 15.0%) were the most frequently diagnosed causes. The presence of a known cause for syncope during the admission was not associated with a lower incidence of recurrence during follow-up (hazard ratio [HR] 0.69, 95% confidence interval [CI] 0.20-2.40). Syncope of unknown etiology was independently associated with greater mortality during 1-year follow-up (HR 5.4, 95% CI 1.3-21.6) and 3-year follow-up (HR 3.5, 95% CI 1.2-10.3). Conclusions In a high proportion of patients with severe AoS admitted for syncope, the valvulopathy was not the main cause of the syncope. Syncope in two-thirds of this population was caused by either bradyarrhythmia or reflex causes. Syncope of unknown cause was associated with increased short- and medium-term mortality, independently from treatment of the valve disease. An exhaustive work-up should be conducted to determine the main cause for syncope.

Aims: Obstructive sleep apnea (OSA) has been associated with heart failure (HF). Sleep fragmentation (SF), one of the main hallmarks of OSA, induces systemic inflammation, oxidative stress and sympathetic activation, hence potentially participating in OSA-induced cardiovascular consequences. However, whether SF per se is deleterious to heart function is unknown. The aim of this study was to non-invasively evaluate the effect of SF mimicking OSA on heart function in healthy mice and in mice with HF. Methods and Results: Forty C57BL/6J male mice were randomized into 4 groups: control sleep (C), sleep fragmentation (SF), isoproterenol-induced heart failure (HF), and mice subjected to both SF+HF. Echocardiography was performed at baseline and after 30 days to evaluate left ventricular end-diastolic (LVEDD) and end-systolic (LVESD) diameters, left ventricular ejection fraction (LVEF) and fraction shortening (FS). The effects of SF and HF on these parameters were assessed by two-way ANOVA. Mice with isoproterenol-induced HF had significant increases in LVEDD and LVESD, as well as a decreases in LVEF and FS (p = 0.013, p = 0.006, p = 0.027, and p = 0.047, respectively). However, no significant effects emerged with SF (p = 0.480, p = 0.542, p = 0.188, and p = 0.289, respectively). Conclusion: Chronic SF mimicking OSA did not induce echocardiographic changes in cardiac structure and function in both healthy and HF mice. Thus, the deleterious cardiac consequences of OSA are likely induced by other perturbations associated with this prevalent condition, or result from interactions with underlying comorbidities in OSA patients. Funding. This work was supported in part by the Spanish Ministry of Economy and Competitiveness (SAF2017-85574-R). IC-A was supported by CONICYT PFCHA—Chilean Doctorate Fellowship 2017; Grant No. 72180089. DG was supported in part by National Institutes of Health grants HL130984 and HL140548.

Cryoballoon ablation (CBA) has become a standard treatment for recurrent atrial fibrillation (AF). There is need for improved CBA protocols. We aimed to demonstrate that a new protocol including minimum temperature (minT) reached could reduce procedure times and complications. A new double factor protocol (DFP), based on the performance of one single shot per vein with variable duration, and conditional bonus shot, determined by time-to-effect (TTE) and minT, was compared with the conventional protocol (CP), with at least two shots per vein. Procedure parameters, complications, and efficacy were compared. We prospectively included 88 consecutive patients treated with the DFP. These were compared to the previous consecutive 69 patients treated with CP. All procedures were performed with 28-mm second-generation balloon. Acute pulmonary vein (PV) isolation was similar (98.6% vs. 98.9% in CP vs. DFP, p = 0.687). Procedure and ablation times favored DFP over CP (120 vs. 134 min, p = 0.003; and 1051 vs. 1475 s, p

Background The diagnostic accuracy of incremental atrial pacing (IP) to determine complete cavo-tricuspid isthmus (CTI) block during typical atrial flutter (AFL) ablation is limited by both an extensive/nonlinear ablation and/or the presence of intra-atrial conduction delay elsewhere in the right atrium. We examined the diagnostic performance of an IP variant based on the assessment of the atrial potentials adjacent to the ablation line which aims at overcoming both limitations. Methods From a prospective population of 108 consecutive patients, 15 were excluded due to observation of inconclusive CTI ablation potentials precluding for a straight comparison between the IP maneuver and its variant. In the remaining 93, IP was performed from the low lateral right atrium and the coronary sinus ostium, with the ablation catheter positioned both at the CTI line and adjacent (

Background Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the current coronavirus disease 2019 (COVID-19). The main organ affected in this infection is the lung and the virus uses the angiotensin-converting enzyme 2 (ACE2) as a receptor to enter the target cells. In this context, a controversy raised regarding the use of renin-angiotensin system (RAAS) blockers, as these drugs might increase ACE2 expression in some tissues and potentially increase the risk for SARS-CoV-2 infection. This is specially concerning in diabetic patients as diabetes is a risk factor for COVID-19. Methods 12-week old diabetic mice (db/db) were treated with ramipril, or vehicle control for 8 weeks. Non-diabetic db/m mice were included as controls. ACE2 expression and activity were studied in lung, kidney and heart of these animals. Results Kidney ACE2 activity was increased in the db/db mice as compared to the db/m (143.2% ± 23% vs 100% ± 22.3%, p = 0.004), whereas ramipril had no significant effect. In the lung, no differences were found in ACE2 when comparing db/db mice to db/m and ramipril also had no significant effect. In the heart, diabetes decreased ACE2 activity (83% ± 16.8%, vs 100% ± 23.1% p = 0.02), and ramipril increased ACE2 significantly (83% ± 16.8% vs 98.2% ± 15%, p = 0.04). Conclusions In a mouse model of type 2 diabetes, ramipril had no significant effect on ACE2 activity in either kidneys or in the lungs. Therefore, it is unlikely that RAAS blockers or at least angiotensin-converting enzyme inhibitors increase the risk of SARS-CoV-2 infection through increasing ACE2.

Cardiac arrhythmias are a frequent complication related to seizures [1]. Most are benign although some, such as high-grade atrioventricular block, asystole, atrial fibrillation (AF), and ventricular fibrillation are potentially harmful. Indeed, several studies suggest that cardiac dysfunction may be the primary underlying cause of sudden unexpected death in epilepsy (SUDEP). Post-ictal atrial fibrillation (PIAF) is a very rare cardiac arrhythmia associated with seizures, and its relevance is currently unknown. AF characteristics include: 1) irregular R-R intervals, 2) absence of distinct repeating P waves, and 3) erratic atrial activity [2]. Atrial flutter is differentiated from AF because of the characteristic “saw tooth” waves on the ECG instead of the chaotic atrial rhythm of the AF. In fact, there are only four reported cases of PIAF diagnosed during video-EEG monitoring (VEM) [1], [3], [4]. We report a case of PIAF identified during long-term VEM, with recurrent episodes corroborated by Holter-ECG monitoring

Background: Obstructive sleep apnea (OSA) has been associated with worsening heart failure. Sleep fragmentation (SF), one of the major hallmarks of OSA, induces inflammation, oxidative stress and sympathetic activation, and could potentially contribute to OSA-induced cardiovascular consequences. However, it remains unclear whether SF per se is deleterious to cardiac function. Aim: To evaluate the effect of SF mimicking OSA on echocardiographically-measured cardiac function (ECHO) in otherwise healthy mice and in a murine model of heart failure. Methods: Forty C57BL/6J male mice were randomized into 4 treatment groups: control sleep, sleep fragmentation (SF), isoproterenol-induced heart failure (HF), and SF+HF. ECHO was measured at baseline and after 30 days. Left ventricular end-diastolic diameter, end-systolic diameter, shortening fraction and left ventricular ejection fraction were recorded by a blinded investigator. Results: Isoproterenol treatment promoted significant left ventricular dilatation and reduced systolic function in HF and SF+HF groups (in all cases p Conclusion: SF, as occurs in OSA, does not appear to induce ECHO-detectable deleterious changes in heart structure and function.

INTRODUCTION The incremental pacing (IP) maneuver is a highly specific technique that improves the ability to confirm complete CTI conduction block during typical atrial flutter (AFL) ablation, and reduces long-term AFL recurrences. The purpose of this study is to assess the performance of new catheters equipped with additional high precision bipoles (AHPB) to allow the visualization of the cavotricuspid isthmus (CTI) conduction gap and to compare them with the IP maneuver. METHODS AND RESULTS Twenty consecutive patients undergoing catheter ablation of the CTI for AFL were included. The IP maneuver confirmed functional versus complete CTI block. Local electrogram analysis using AHPB was then used to assess the presence or absence of gaps across the CTI line. Mean age was 67 years and 80% were male. At the end of the procedure CTI block was achieved in all patients. A transient stage of functional CTI block was observed in 40%. In all cases a continuous fragmented electrogram was present between the double potentials in the CTI in the AHPB channels. In contrast, no electrogram was observed between the CTI double potentials in any of the 20 patients once complete block was confirmed by the IP maneuver. When both techniques were compared a significant association and correlation were observed (chi-square

Resumen Introduccion La disfuncion del sistema nervioso autonomico produce alteraciones en la variabilidad de la frecuencia cardiaca y aumenta la incidencia de arritmias. Analizamos este fenomeno fisiopatologico en pacientes con sindrome de apnea/hipoapnea del sueno severo y el impacto sobre el mismo del tratamiento con presion positiva continua en la via aerea (CPAP). Metodos Pacientes consecutivos con sindrome de apnea/hipoapnea del sueno severo de reciente diagnostico fueron prospectivamente considerados para inclusion. Se analizo la incidencia de arritmias y la variabilidad de la frecuencia cardiaca (obtenidos mediante registro Holter de 24 horas) antes de iniciarse tratamiento con CPAP y tras un ano del mismo. Resultados Se incluyeron 26 pacientes. El tiempo de uso de CPAP durante el registro Holter fue de 6,6 ± 1,8 horas. Tras inicio de CPAP, se aprecio una reduccion marginalmente significativa en la FC media (80 ± 9 a 77 ± 11 lpm, p = 0,05). El uso de CPAP se asocio a una modulacion parcial y exclusivamente en horas de vigilia de los parametros de modulacion parasimpatica r-MSSD (p = 0,047) y HF (p = 0,025) y de modulacion simpatica LF (p = 0,049). Ninguno de estos revirtio completamente a la normalidad (p Conclusiones El tratamiento con CPAP se asocia a una mejora solo parcial y diurna de la variabilidad de la frecuencia cardiaca y disminuye la incidencia de taquicardia auricular. Ambos efectos podrian influir en la morbimortalidad cardiovascular de los pacientes con sindrome de apnea/hipoapnea del sueno.

Long QT syndrome, short QT syndrome, Brugada syndrome and catecholaminergic polymorphic ventricular tachycardia are inherited primary electrical disorders that predispose to sudden cardiac death in the absence of structural heart disease. Also known as cardiac channelopathies, primary electrical disorders respond to mutations in genes encoding cardiac ion channels and/or their regulatory proteins, which result in modifications in the cardiac action potential or in the intracellular calcium handling that lead to electrical instability and life-threatening ventricular arrhythmias. These disorders may have low penetrance and expressivity, making clinical diagnosis often challenging. However, because sudden cardiac death might be the first presenting symptom of the disease, early diagnosis becomes essential. Genetic testing might be helpful in this regard, providing a definite diagnosis in some patients. Yet important limitations still exist, with a significant proportion of patients remaining with no causative mutation identifiable after genetic testing. This review aims to provide the latest knowledge on the genetic basis of cardiac channelopathies and discuss the role of the affected proteins in the pathophysiology of each one of these diseases.

Introduccion y objetivos La ablacion de via lenta nodular es el tratamiento de eleccion de la taquicardia por reentrada nodular. No hay descritas variables demograficas, anatomicas ni electrofisiologicas que predigan una localizacion exacta de la via lenta dentro del nodulo auriculoventricular ni su proximidad a la via rapida. El objetivo es estudiar estas variables. Metodos Se incluyo prospectivamente a 54 pacientes (17 varones; media de edad, 55 ± 16 anos) sometidos a ablacion efectiva de via lenta. Se midieron los periodos refractarios de ambas vias y su tiempo de conduccion diferencial. Se calculo las distancias desde la region hisiana (correspondiente a la localizacion de la via rapida) hasta el ostium del seno coronario (con lo que se obtuvo una estimacion de la longitud anteroposterior del triangulo de Koch) y tambien hasta la zona de la via lenta. Resultados El tiempo de conduccion diferencial (139 ± 98 ms) no se correlaciono con las distancias His-seno coronario (19 ± 6 mm; p = 0,6) ni His-via lenta (14 ± 4 mm; p = 0,4). A mayor distancia His-seno coronario, se establecio mayor distancia His-via lenta (r = 0,652; p < 0,01) y se confirmo la correlacion anatomica entre las dimensiones del triangulo y la separacion entre ambas vias. En los pacientes mayores de 70 anos, se observaron menor tamano del triangulo y menor distancia entre ambas vias (p < 0,001). Conclusiones Una mayor dimension anteroposterior del triangulo de Koch se asocia a una localizacion de via lenta mas alejada de la rapida, encontrandose ambas mas proximas entre si (mayor riesgo de bloqueo auriculoventricular) en los pacientes de edad avanzada.

Nodal slow pathway ablation is the treatment of choice for nodal reentrant tachycardia. No demographic, anatomic, or electrophysiologic variables have been reported to predict an exact location of the slow pathway in the atrioventricular node or its proximity to the fast pathway. The purpose of this study was to analyze these variables.The study prospectively included 54 patients (17 men; mean age, 55 [16] years) who had undergone successful slow pathway ablation. The refractory periods of both pathways and their differential conduction time were measured, and calculations were performed to obtain the distance from the His-bundle region (location of the fast pathway) to the coronary sinus ostium (to estimate the anteroposterior length of the triangle of Koch) and to the slow pathway area.The differential conduction time (139 [98] ms) did not correlate with the His-coronary sinus distance (19 [6] mm; P=.6) or the His-slow pathway distance (14 [4] mm; P=.4). When the His-coronary sinus distance was larger, the His-slow pathway distance was also larger (r=0.652; P.01) and the anatomic correlation between the triangle dimensions and the separation between the two pathways was confirmed. In patients older than 70 years, smaller triangle sizes and a shorter distance between both pathways were observed (P.001).A greater anteroposterior dimension of the triangle of Koch is associated with a slow-pathway location farther from the fast pathway. In elderly patients the two pathways are closer together (higher risk of atrioventricular block).

Background A Methods One hundred and thirty-four patients (age 67 ± 13 years, 78% males) undergoing successful CTI ablation were included and divided into 2 groups: Group 1 (n = 68), in which ablation was performed before the IP maneuver was incorporated, with CTI block confirmed by at least 1 non-local and 1 local electrogram-based previously established criteria; and Group 2 (n = 66), in which IP maneuver was used to confirm complete CTI block. Results No intergroup differences were noted in baseline characteristics, ablation settings and fluoroscopy/radiofrequency times. Long-term AFL recurrences were observed in 14 out of 134 patients (10.4%), and were more common in Group 1 (19%, vs 1.5% among Group 2 patients, p Conclusions The addition of the IP maneuver for the diagnosis of complete CTI block reduces AFL long-term recurrences after ablation.

Objectives: The goal of this study was to assess mechanisms underlying atrial fibrillation (AF) promotion by exercise training in an animal model.Background: High-level exercise training promotes A...

Background The clinical yield of cavotricuspid isthmus (CTI) radiofrequency ablation of atrial flutter (AF) is limited by a high incidence of atrial fibrillation (AFib) in the long term. Among other acknowledged variables, the association of obstructive sleep apnea (OSA) could favor incomplete arrhythmia control in this setting. We assessed the impact of CPAP in reducing the occurrence of AFib after CTI ablation. Methods Consecutive patients with AF who were undergoing CTI ablation were screened for OSA. Relationship of the following variables with the occurrence of AFib during follow-up (12 months) was investigated: CPAP initiation, hypertension, BMI, underlying structural heart disease, left atrial diameter, and AFib documentation prior to ablation. Results We prospectively included 56 patients (mean age: 66 (± 11) years; 12 female patients), of whom 46 (82%) had OSA and 25 (45%) had severe OSA. Twenty-one patients (38%) had AFib during follow-up after CTI ablation. Both freedom from AFib prior to ablation and CPAP initiation in those patients without previously documented AFib at inclusion were associated with a reduction of AFib episodes during follow-up (P = .019 and P = .025, respectively). Inversely, CPAP was not protective from AFib recurrence when this arrhythmia was documented prior to ablation (P = .25). Conclusions OSA is a prevalent condition in patients with AF. Treatment with CPAP is associated with a lower incidence of newly diagnosed AFib after CTI ablation. Screening for OSA in patients with AF appears to be a reasonable clinical strategy.

El tratamiento antiarritmico cronico de la fibrilacion auricular ha experimentado pocos cambios en los ultimos anos hasta la irrupcion de la dronedarona. Su papel probablemente quedara restringido a pacientes con fibrilacion auricular paroxistica o persistente sin clinica de insuficiencia cardiaca asociada. La decision mas importante que debe adoptar el cardiologo sigue siendo si luchar por mantener el ritmo cardiaco o simplemente mantener una frecuencia cardiaca adecuada. La primera opcion es mas recomendable para pacientes sintomaticos sin demasiada cardiopatia estructural; la segunda, para pacientes poco sintomaticos o asintomaticos, de edad avanzada y con cardiopatia estructural asociada que haga previsible que el ritmo sinusal no se mantenga. La combinacion con tratamientos no farmacologicos, como la ablacion, actualmente es una realidad que probablemente sera mas notable aun en un futuro cercano.

Resumen El sindrome de QT largo, el sindrome de QT corto, el sindrome de Brugada y la taquicardia ventricular polimorfica catecolaminergica son trastornos electricos primarios que predisponen a muerte subita en ausencia de cardiopatia estructural. La estratificacion del riesgo en estas enfermedades es fundamental para identificar a los pacientes con peor pronostico. En el sindrome de QT largo y el sindrome de Brugada, numerosos estudios han establecido que los principales factores pronosticos son clinicos y se basan en la presencia de sintomas previos, los hallazgos del ECG, el sexo y, en el caso del sindrome de Brugada, la inducibilidad de arritmias en el estudio electrofisiologico. Por el escaso numero de casos descritos, actualmente disponemos de poca informacion acerca de las variables implicadas en el pronostico del sindrome de QT corto y la taquicardia ventricular polimorfica catecolaminergica. Esta revision resume nuestro conocimiento actual sobre la estratificacion del riesgo en estos cuatro trastornos hereditarios arritmogenicos.