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Introduction and objectives: In December 2019, SARS-CoV-2, was discovered as the agent of COVID-19 disease. Cardiac arrhythmias have been reported as frequent but their incidence is unknown. The aim of this research was to assess the real incidence of cardiac arrhythmias among COVID-19 patients admitted to Portuguese hospitals and to understand the underlying prognostic implications. Methods: The Portuguese Association of Arrhythmology, Pacing and Electrophysiology (APAPE) conducted a survey in Portuguese hospitals to assess the occurrence of arrhythmias in COVID-19 patients, their clinical characteristics, the use of experimental therapies and the impact on QT interval. Results: Twenty hospitals participated, reporting 692 hospitalized patients. An arrhythmic episode occurred in 81 (11.7%) and 64 (79%) had detailed information on these episodes. New onset arrhythmias occurred in 41 (64%) patients, 45 (70.3%) male, median age 73.5 (61-80.3) years. There were 51 (79.7%) with associated comorbidities, mainly arterial hypertension (41, 64.1%). Of 53 patients (82.3%) on experimental therapy, 7 (10.9%) had an increased QTc interval. Regarding arrhythmias, two patients (3.1%) had ventricular tachycardia, 5 (7.8%) sinus bradycardia, 17 (26.6%) paroxysmal supraventricular tachycardia and 40 (62.5%) atrial fibrillation or flutter. At the time of reporting, there had been no deaths due to arrhythmic syndrome or related complications. Conclusions: In a population of COVID-19 patients. The incidence of cardiac arrhythmias is high but not associated with increased cardiac mortality although it does though occur frequently in extremely ill patients and with multiple organ failure. Regardless of the use of experimental drugs, the incidence of ventricular arrhythmias is low and atrial fibrillation and other supraventricular arrhythmias are the most prevalent arrythmias. Resumo: Introdução e objetivos: Em dezembro de 2019, o SARS-CoV-2 foi descoberto como agente da doença Covid-19. As arritmias cardíacas são reportadas como frequentes, mas a sua incidência é desconhecida. O objetivo deste trabalho foi entender a incidência de arritmias em doentes Covid-19 tratados em hospitais portugueses e entender as suas implicações prognósticas. Métodos: A Associação Portuguesa de Arritmologia, Pacing e Electrofisiologia (APAPE) conduziu um inquérito em hospitais portugueses, documentando a ocorrência de arritmias em doentes com Covid-19, as suas caraterísticas clínicas, o uso de terapêutica experimental e o seu impacto no intervalo QT. Resultados: Participaram 20 hospitais, reportando 692 doentes hospitalizados. Ocorreram episódios arrítmicos em 81 (11,7%), 64 (79%) com informação adicional. Documentaram-se arritmias de novo em 41 (64%) doentes, 45 (79%) do sexo masculino, idade mediana 73,5 (61-80,3) anos. Destes, 51 (79,7%) tinham comorbilidades associadas, maioritariamente hipertensão arterial (41, 64,1%). Dos 53 (82,3%) doentes sob terapêutica experimental, 7 (10,9%) tiveram aumento do intervalo QTc. Tiveram taquicardia ventricular 2 (3,1%) doentes, 5 (7,8%) bradicardia sinusal, 17 (26,6%) taquicardia paroxística supraventricular e 40 (7,8%) fibrilhação ou flutter auricular. Nenhum doente teve morte por causa arrítmica ou complicações associadas, à data do registo. Conclusões: Numa população de doentes com Covid-19, a incidência de arritmias é elevada, mas não associada a aumento de mortalidade cardíaca, apesar da ocorrência mais frequente em doentes graves e com falência multiorgânica. Independentemente do uso de terapêuticas experimentais, a incidência de arritmias ventriculares é baixa e a fibrilhação auricular e outras arritmias supraventriculares são as arritmias mais prevalentes.

Background CHA2DS2-VASc risk score is the main determinant for maintaining anticoagulation after atrial fibrillation (AF) ablation, irrespective of the procedure outcome. The presence of aortic plaques is included in the score, but isn't regularly assessed previously to AF ablation. This way, risk factors for coronary artery disease (CAD) other than arterial hypertension and diabetes mellitus may influence stroke risk in patients with AF, albeit not being included in the CHA2DS2-VASc score. Purpose We sought to evaluate the prevalence of aortic plaques diagnosed during transesophageal echocardiography (TOE) in patients submitted to AF ablation and to assess its determinants and clinical impact on the CHA2DS2-VASc score. Methods Retrospective study of patients submitted to AF ablation that performed TOE prior to the procedure, with assessment of aortic plaques. CHA2DS2-VASc risk score was evaluated in the pre-ablation patient evaluation and reassessed after TOE. Demographic, clinical and echocardiographic data, including cardiovascular risk factors, were analyzed. We assessed AF recurrence rate, cerebrovascular events and death during follow-up. Results 120 patients were submitted to TOE prior to AF ablation from November 2015 to December 2020, mean age 66.6 (±9.55) years, 48% male. In 30 (25%) patients aortic plaques were identified in TOE. Mean CHA2DS2-VASc was 2.2 (±1.47) in pre-ablation evaluation and 2.5 (±1.69) post-TOE, increasing in all patients with aortic plaques and prompting beginning of oral anticoagulation in 5 patients. AF was paroxysmal in 74% and persistent in 26% of patients, mean duration of 6.28 (±3.76) years. Arterial hypertension was present in 79 (66%) of patients, type 2 diabetes mellitus in 24 (20%) and dyslipidemia in 67 (56%). 17 (14%) patients had a prior stroke. During a mean follow-up of 30 (±18.3) months, 32 (27%) patients had AF recurrence and 10 (8%) were submitted to redo procedures. 107 (89%) patients remained under oral anticoagulation, stroke occurred in 1 patient and 2 patients died. In univariate analysis, age, type 2 diabetes mellitus and dyslipidemia predicted an increase in CHA2DS2-VASc score after TOE (respectively, OR 1.113, 95% CI 1.041–1.190, p-value 0.002; OR 2.907, 95% CI 1.145–7.379, p-value 0.025; and OR 2.442, 95% CI 1.016–5.868, p-value 0.046). In multivariate analysis, age is the only independent predictor of increased CHA2DS2-VASc score after TOE (OR 1.095, 95% CI 1.013–1.185, p-value 0.023). No risk factor for CAD was independently associated with the presence of aortic plaques (Table 1). Conclusion In this population, single CAD risk factors were not independent predictors of aortic plaques. If TOE had not been performed prior to AF ablation, 25% of patients would have had an underestimated CHA2DS2-VASc score and would be off anticoagulation after the procedure, unprotected from thromboembolic events. Funding Acknowledgement Type of funding sources: None. Table 1

Introduction Reflex syncope is the result of an imbalance between the sympathetic and parasympathetic nervous system. The autonomic nervous system has been associated to some forms of atrial fibrillation (AF). Objective The aim of this study was to assess the prevalence of AF in patients with reflex syncope and a positive tilt table test and to identify the type of tilt test response in patients with AF in comparison to patients without AF. Methods We retrospectively studied consecutive patients that underwent a tilt table test at our institution between 2016 and 2019. We selected those patients with a positive test. Patients with an implanted pacemaker at the time of the tilt test and patients followed in a different institution were excluded. Previous diagnoses of AF episodes were assessed. We analysed the clinical characteristics and the tilt table test results according to previous history of AF. Results We studied 49 patients with a positive tilt test. Seven (14.3%) patients had previously diagnosed paroxysmal AF at the time of the tilt table test. Patients with AF were older, had more frequently hypertension, and the tilt test response was more frequently a vasodepressor than mixed or cardioinhibitory response (71.4% vs. 28.6%) (Table). In univariate analysis, age and hypertension were associated with AF, respectively, OR 1.08 (95% CI 1.01–1.17), p=0.034 and OR 10.80 (95% CI 1.19–98.36), p=0.035. A vasodepressor response was also associated with AF (OR 6.25, 95% CI 1.06–36.74, p=0.043). Conclusions Patients with reflex syncope and a positive tilt table test had a higher prevalence of AF than the general population. A vasodepressor response was associated with AF as were age and hypertension, demonstrating the possible impact of the autonomic nervous system and the multifactorial nature of AF. Funding Acknowledgement Type of funding sources: None.

Introduction Left atrial volume (LAV) is an accepted predictor of atrial fibrillation (AF) recurrence after radiofrequency catheter ablation, stronger than AF duration. Objective The aim of this study was to assess the value of left atrial stiffness (LAS) index as a new parameter evaluated by echocardiography to the prediction of AF recurrence after radiofrequency catheter ablation. Methods We retrospectively studied consecutive patients with paroxysmal or persistent AF submitted to radiofrequency catheter ablation at our institution between 2017 and 2019. We used transthoracic echocardiography to measure the LAV indexed to body surface area and the LAS index, defined as the ratio between the mitral E/e' (obtained with pulsed Doppler at the tip of the mitral leaflets – E, and tissue Doppler imaging at the mitral annulus – e') and the left atrial strain during the reservoir phase (obtained by speckle tracking echocardiography) [LAS index = (E/e') / LA reservoir strain]. The left ventricular ejection fraction (LVEF) was also evaluated. Patients with poor quality echocardiographic images were excluded. We compared 2 groups of patients, according to the recurrence of AF after the blanking period. We analysed the clinical characteristics and echocardiographic findings. The effect of clinical and echocardiography parameters on AF recurrence was evaluated by univariate and multivariate Cox Regression analysis. Results We studied 33 patients, 27 with paroxysmal AF and 6 with persistent AF. Baseline patients' characteristics are presented in Table 1. During a mean follow-up time of 17.9±10.4 months, 7 patients (21%) had AF recurrence, and none died. Patients with AF recurrence had a higher LAS index. After adjusting for confounding variables, only LAS index and LAV were independently associated with AF recurrence (Table 2). Every one unit increase in LAS index was associated with an 11-fold increased risk of AF recurrence (HR 10.86, 95% CI 1.38–85.56; p=0.024), while every one unit increase in LAV index was only associated with a 6% increased risk of AF recurrence (HR 1.06, 95% CI 1.01–1.11, p=0.010). Conclusion LAS index evaluated by echocardiography was a much stronger predictor of AF recurrence after radiofrequency catheter ablation than left atrial volume. Funding Acknowledgement Type of funding sources: None.

Funding Acknowledgements Type of funding sources: None. Background The greatest benefit with cardiac resynchronization therapy (CRT) is achieved when biventricular pacing (BivP) percentage (%) is close to 100%. However, in some patients that goal can be challenging to obtain. Purpose Determine whether a lower BivP% could lead to similar CRT response and events, as compared with patients with BivP% >98%. Methods Patients with CRT followed up in a remote-monitoring network were retrospectively analyzed. BivP% was assessed and response to CRT was defined as an absolute increase in left ventricle ejection fraction (LVEF) >5% or a relative increase in LVEF >15%. Low BivP% was defined as Results 88 patients, 76% male, median age 73.5 (IQR 65.75-79.25) years were included. A CRT-D was implanted in 69%. Etiology was ischemic in 44%. 93% were under beta-blockers. Median LVEF before CRT was 27% (IQR 20.25-32). 44 patients (50%) had low BivP% (median 91%, IQR 96-99), 55% due to atrial fibrillation and 52% due to frequent premature ventricular complexes. After optimization of medical therapy, device programming and/or interventional procedures, we obtained a BivP >98% in 26 out of the 44 patients (59%). However, in 18 patients (20%) BivP% was Optimal cut-point value for predicting CRT response was 91% BivP% (AUC 0.644, p-value 0.047, 95% CI 0.496-0.792). The characteristics of the two groups didn’t differ significantly (Table). Survival was significantly higher in patients with BivP% >91% (Log-rank 3.667, p-value 0.050) – Figure. Conclusion In this population, BivP% >91% was sufficient to achieve CRT-response and was associated with a better survival. BivP% 91%(n = 84)p-valueAge in years, median (IQR)72.50 (70.50-73.75)74.00 (65.00-80.00)0.666CRT-D, n (%)3 (75.0)58 (69.0)0.999Ischemic cardiopathy, n (%)3 (75.0)35 (41.7)0.311LVEF before CRT, median (IQR)27 (19-39)27 (20-32)0.795Beta-blockers, n (%)4 (100.0)78 (95.1)0.999Abstract Figure.

Funding Acknowledgements Type of funding sources: None. Background Cardiac magnetic resonance (CMR) using late gadolinium enhancement (LGE) fails to detect scar tissue in patients with electroanatomical abnormalities and biopsy-proven structural heart disease. It has shown conflicting data regarding existence of structural abnormalities in patients with idiopathic premature ventricular contractions (PVCs) from the right ventricular outflow tract (RVOT). Three- dimensional (3D) LGE enables high-spatial resolution more appropriate to the thin-walled right ventricle than two-dimensional (2D) LGE. Objective Our aim was to evaluate if the use of 3D-LGE would improve the performance of CMR to detect low voltage areas in the RVOT of patients with PVCs. Methods Since May 2020 we performed 3D-LGE CMR in 11 consecutive patients that underwent ablation of frequent PVCs. A control group of 11 consecutive patients that underwent catheter ablation by the same operator and had a 2D-LGE CMR performed before ablation was also studied. All patients had normal 2D-LGE CMR. A 3D electroanatomical bipolar voltage map of the RVOT was performed in sinus rhythm (0.5 mV-1.5 mV colour display). Areas with electrograms Results The median number of points used for the voltage map was 344 (242-450). 18 patients (82%) displayed LVAs. The site of origin of the PVCs was the RVOT in 17 patients and the left ventricular outflow tract (LVOT) in 5. Comparison between groups is displayed in the table. 2D LGE CMR failed to demonstrate abnormalities of the RVOT in any of the patients that presented with LVAs. 3D CMR showed presence of fibrosis (Figure) in 3 out of 9 patients with LVAs (33%). Conclusion CMR using 3-D LGE techniques showed an increased power to diagnose structural abnormalities. This technique may be a better choice in initial stages of RVOT disease. All sampleN = 223D-LGE CMRN = 112D-LGE CMRN = 11p-valueAge in years, median (Q1-Q3)47 (35-68)62 (34-55)42 (34-55)0.243Male gender, n (%)8 (36)3 (27)5 (46)0.330PVCs RVOT/LVOT17/59/28/30.500Nº points in the map, median (Q1-Q3)344 (242-450)350 (259-450)300 (158-345)0.076Low voltage areas, n (%)18 (82)9 (82)9 (82)0.707Abstract Figure.

Funding Acknowledgements Type of funding sources: None. Background Since January 2018 the availability of high sensitivity Troponin I (hsTnI) has improved ischemia diagnosis. In patients with rapid atrial fibrillation (AF), the decision to undergo coronary angiography is usually due to elevated cardiac biomarkers. However, evidence to support the rentability of this approach is sparse. Purpose Evaluate if hsTnI in patients with rapid AF and elevated cardiac biomarkers has a good discriminative power to predict a positive coronary angiography. Methods We retrospectively studied consecutive patients admitted to the emergency department (ED) between January 2018 and December 2019 with rapid AF that underwent coronary angiography and had multiple hsTnI values obtained. We analysed risk factors, initial and peak hsTnI, time from ED admission to peak hsTnI and ST-T segment abnormalities (ST depression and/or T wave inversion). We evaluated the presence of significant coronary artery stenosis with the need of revascularization at coronary angiography. Univariable and multivariable analysis was performed to obtain the Odds Ratio (OR, 95% CI, p-value) for significant coronary artery disease (CAD). Receiver operator characteristics (ROC) curve and area under the curve (AUC) were obtained to determine the discriminative power of peak hsTnI as predictor of a positive coronary angiography. Optimal cut-point value was obtained (Youden index) and patients were divided according to this value. Results From 1407 patients admitted to the ED with rapid AF, 30 patients, 60% male, median age 74 (IQR 61.25-80.75) years, were submitted to coronary angiography. Significant coronary artery stenosis was present in 17 (57%) patients. Age, ST-T segment abnormalities and peak hsTnI were predictors of significant CAD, respectively 1.203, 1.064-1.361, 0.003; 25.00, 3.522-177.477, 0.001; and 1.000, 1.000-1.001, 0.015. Optimal cut-point value for predicting the presence of significant coronary artery stenosis at coronary angiography was a peak hsTnI of 359 pg/mL (AUC 0.869, p-value 0.001, 95% CI 0.742-0.995). The two groups with hsTnI 359 differed in age and ST-T segment abnormalities (see Table). After adjustment, peak hsTnI >359 pg/mL was the only independent predictor of significant CAD (23.894, 1.310-435.669, 0.032). Conclusion In this group of patients with rapid AF, peak hsTnI >359 pg/mL was the only independent predictor of significant coronary artery disease. Therefore, those patients should undergo coronary angiography. Abstract Figure.

Obstructive Sleep Apnea (OSA) is a prevalent condition thought to increase in the future. Being mostly undiagnosed, the most serious complications are cardiovascular diseases, among which are arrhythmias. Controversy remains as to whether OSA is a primary etiologic factor for ventricular arrhythmias, because of the high incidence of cardiovascular comorbidities in OSA patients. However, there is mostly a strong evidence of a relation between OSA and ventricular arrhythmias. A few mechanisms have been proposed to be responsible for this association and some electrocardiographic changes have also been demonstrated to be more frequent in OSA patients. Treatment of OSA with Continuous Positive Airway Pressure (CPAP) has the potential to reduce arrhythmias and confer a mortality benefit.

Background: The aim of the study was to evaluate the impact of premature atrial contractions (PACs) burden, and the presence of non-sustained ventricular tachycardia (NSVT) on prognosis and type of major adverse cardiovascular events in patients with frequent premature ventricular contractions (PVCs). Methods: We retrospectively studied 285 consecutive patients with frequent PVCs defined as PVC count equal or higher than 1% of total beats assessed with 24-h Holter recording. Patients with atrial fibrillation (AF) were excluded. We evaluated the impact of PAC burden and the presence of NSVT on the primary end points of all-cause mortality, stroke and new-onset AF, and secondary end points; arrhythmic end point (arrhythmic death or hospitalizations for ventricular arrhythmias) or heart failure (HF)-related end point (death or hospitalizations due to HF). Results: The PAC number showed an adjusted hazard ratio (HR) (95% confidence interval (CI), P value) of 1.077 (1.014 - 1.145, P = 0.017) for all-cause mortality, 1.250 (1.080 - 1.447, P = 0.003) for stroke, 1.090 (1.006 - 1.181, P = 0.036) for new-onset AF and 1.376 (1.128 - 1.679, P = 0.002) for the HF end point. The presence of NSVT showed an adjusted HR (95% CI) of 3.644 (1.147 - 11.57, P = 0.028) for the arrhythmic end point. Conclusions: In patients with frequent PVCs a high PAC count was independently associated with increased mortality, higher rate of AF, stroke and HF adverse events, but not with arrhythmic adverse events. The presence of NSVT was independently associated with increased arrhythmic adverse events, but not with overall mortality, AF, stroke or HF events. Cardiol Res. 2019;10(5):268-277 doi: https://doi.org/10.14740/cr935

Background and AimsThe wavefront propagation velocity in the myocardium with fibrosis is characterized by the presence of deceleration zones and late activated zones, that are absent in the normal myocardium. Our aim was to study the right ventricular outflow tract (RVOT) endocardial activation duration in sinus rhythm, and assess the presence of deceleration zones, in patients with premature ventricular contractions (PVCs) and in controls.MethodsWe studied 29 patients with idiopathic PVCs from the outflow tract, subjected to catheter ablation that had an activation and voltage map of the RVOT in sinus rhythm. A control group of 15 patients without PVCs that underwent ablation of supraventricular arrhythmias was also studied. RVOT endocardial activation duration and number of 10 ms isochrones across the RVOT were assessed. Propagation speed was calculated at the zone with the higher number of isochrones per cm radius. Deceleration zones were defined as zones with >3 isochrones within 1 cm radius. Low voltage areas were defined as areas with local electrogram with amplitude ResultsThe two groups did not differ in relation to age, gender or number of points in the map. RVOT endocardial activation duration and number of 10 ms isochrones were higher in the PVC group; 56 (41–66) ms vs. 39 (35–41) ms, p = 0.001 and 5 (4–8) vs. 4 (4–5), p = 0.001. Presence of deceleration zones and low voltage areas were more frequent in the PVC group; 20 (69%) vs. 0 (0%), p < 0.0001 and 21 (72%) vs. 0 (0%), p < 0.0001. The wavefront propagation speed was significantly lower in patients with PVCs than in the control group, 0.35 (0.27–0.40) vs. 0.63 (0.56–0.66) m/s, p < 0.0001. Patients with low voltage areas had longer activation duration 60 (52–67) vs. 36 (32–40) ms, p < 0.0001, more deceleration zones, 20 (95%) vs. 0 (0%), p < 0.0001, and lower wavefront propagation speed, 0.30 (0.26–0.36) vs. 0.54 (0.36–0.66) m/s, p = 0.002, than patients without low voltage areas.ConclusionRight ventricular outflow tract endocardial activation duration was longer, propagation speed was lower and deceleration zones were more frequent in patients with PVCs than in controls and were associated with the presence of low voltage areas.

Introduction Cardiac autonomic system modulation by endocardial ablation targeting atrial ganglionated plexi (GP) is an alternative strategy in selected patients with severe functional bradyarrhythmias, although no consensus exists on the best ablation strategy. The aim of this study was to evaluate if a simplified approach by a purely anatomical guided ablation of just the atrial right GP is enough for the treatment of these patients. Methods We prospectively enrolled patients with significant functional bradyarrhythmias and performed endocardial ablation purely guided by 3D electroanatomic mapping directed at the atrial right GP and accessed parameters of parasympathetic modulation and recurrence of bradyarrhythmias. Results Thirteen patients enrolled (76.9% male, median age 51, 42–63 years). After ablation, a median RR interval shortening of 28.3 (25.6–40.3)% occurred (1111, 937.5–1395.4 ms to 722.9, 652.2–882.4 ms, p = 0.0002). The AH interval also shortened (19, 10.5–35.7%) significantly after the procedure (115, 105–122 ms to 85, 71–105 ms, p = 0.0023) as well as Wenckebach cycle length (11.1, 5.9–17.8% shortening) from 450, 440–510 ms to 430, 400–460 ms, p = 0.0127. On 24-h Holter monitoring there was significant increase in heart rates (HR) of patients after ablation (minimal HR increased from 34 (26–43)bpm to 49 (43–56)bpm, p = 0,0102 and mean HR from 65 (47–72)bpm to 78 (67–87)bpm, p = 0.0004). No patients had recurrence of symptoms or significant bradyarrhythmias during a median follow-up of 8.4 months. Conclusions A purely anatomic guided procedure directed only at the atrial right ganglionated plexi seems to be enough as a therapeutic approach for cardioneuroablation in selected patients with significant functional bradyarrhythmias.

Background Ablation of premature ventricular contractions (PVCs) is currently based on activation mapping. This strategy is impaired by the absence or paucity of PVCs on the day of the procedure. Frequently, isolated diastolic potentials (DP) are present at the successful ablation site in sinus rhythm (SR), although their meaning is still a matter of debate. Objective Evaluate the feasibility and results of a substrate-based approach for ablation of idiopathic right ventricular outflow tract (RVOT) PVCs, in patients that present with a low PVC burden during the procedure. Methods We included 12 consecutive patients referred for ablation of frequent (>10000/24 hours) idiopathic PVCs from the RVOT that present with less than 2 PVCs/min in the beginning of the procedure. The ablation was based on fast mapping of the RVOT in SR looking for DPs, defined as isolated small amplitude potentials occurring after the T wave of the surface ECG in SR (Figure). The area with DPs was marked and a reduced activation mapping of the PVCs was done in that area. We evaluated the procedure time, mapping, fluoroscopy and radiofrequency (RF) application times. The number of points used for the maps, the area of DPs, local activation time and success rate. Values are presented as median (Q1-Q3). Electroanatomical mapping of the RVOT in SR was also performed in a control group of 10 subjects that underwent ablation of supraventricular arrhythmias, to evaluate the prevalence of DPs in subjects without PVCs. Results The number of PVCs during the procedure was 1 (0.1–1.6)/min. Both groups did not differ in relation to age or gender. Median age 45 (34–65) years, 6 males in the PVC group and 40 (33–65) years, 6 males in the control group, p=0.821 and p=0.231 respectively. The number of points sampled per RVOT map in SR was 400 (193–500) in the PVC group and 330 (277–425) in the control group, p=0.539. All patients in the study group had DPs in the RVOT. None of the control group subjects had DPs in the RVOT. Ablation data is presented in the Table. The acute success rate was 100%. After a median follow-up time of 4 (3–6) months one patient had recurrence. Conclusion In these group of patients with very low PVC burden during the procedure, this approach partially based on substrate mapping, made ablation of the PVCs feasible, in a fast and efficient way. Funding Acknowledgement Type of funding source: None

Introduction Premature ventricular contractions (PVC) have been associated with mortality and heart failure (HF) regardless the presence of structural heart disease (SHD). The aim of this study was assessing the impact of burden and complexity of PVCs on prognosis, according to presence of SHD. Methods 312 patients were retrospectively evaluated out of 1967 consecutive patients referred for 24‐hr Holter at a single hospital, with a PVC count >1% of total beats. Two groups with and without SHD. PVC burden (PVC%), presence of complex forms, incidence of all‐cause death, combined outcomes of all‐cause death and cardiovascular hospitalizations, HF death and HF hospitalizations and, sudden death (SD) or hospitalizations due to ventricular arrhythmias (VA)were assessed. Results Premature ventricular contraction burden was 2.7 (IQR: 1.6–6.7). SHD patients had more polymorphic PVCs, 77% versus 65%, p = .022, triplets and episodes of non‐sustained ventricular tachycardia (NSVT): 44% versus 27%, p = .002; 30% versus 12%, p

Background: Patients with premature ventricular contractions (PVCs) from the right ventricular outflow tract (RVOT) and apparently normal hearts, can have ST elevation similar to type 2 or type 3 Brugada pattern in the electrocardiographic (ECG) performed at a higher position. Cardiac magnetic resonance (CMR), has shown conflicting data regarding existence of structural abnormalities in patients with idiopathic PVCs from the RVOT.Objective: Our aim was to evaluate the prevalence of low voltage areas (LVAs) in the RVOT of patients with PVCS from the outflow tract, and in a control group. Secondly, assess for the presence of a non-invasive ECG marker.Methods: A 56 consecutive patients, 45 with frequent PVCs (>10000/24 h) LBBB, vertical axis, negative in aVL and 11 subjects without PVCs. Arrhythmogenic right ventricular cardiomyopathy was ruled out in all patients. An ECG was performed with V1–V2 at the level of the second intercostal space and the presence of ST-segment elevation with a Type 2 or 3 Brugada pattern (Type 2 BrP) was assessed. Bipolar voltage map of the RVOT was performed in sinus rhythm (0.5–1.5 mV color display). Areas with electrograms

Introduction Recently, the presence of right bundle brunch block (RBBB) in patients with persistent ischaemic symptoms has been suggested as an indication for emergent coronary angiography. Objective The aim of this study was to assess the prognostic impact of RBBB in patients with acute myocardial infarction (AMI) before the implementation of the recent recommendations. Methods We retrospectively studied consecutive patients admitted with AMI between 2011 and 2013. Patients with left bundle brunch block, pacemaker, or nonspecific intraventricular conduction delay were excluded. Patients with RBBB were compared with those without RBBB. Clinical characteristics, in-hospital evolution, and major adverse cardiovascular events (MACE) during follow-up, defined as cardiovascular death, sustained ventricular arrhythmias, acute heart failure syndromes, recurrent myocardial infarction, or acute stroke, were analysed. Results The analysis included 481 patients. Thirty two patients (6.7%) had RBBB. Patients with RBBB were older. During hospital admission, RBBB patients had a higher rate of sustained ventricular tachycardia and death. Survival curve analysis showed that patients with RBBB had a lower in-hospital survival rate (Log-rank, p = 0.004). After discharge, during a mean follow-up time of 24.3 ± 11.6 months, 53 patients (12%) died. Survival curve analysis showed a lower survival rate free of MACE for those patients with RBBB (Log-rank, p = 0.011). RBBB was independently associated with MACE occurrence (HR 2.17, 95% CI 1.07–4.43; p = 0.033), after adjusting for demographic data, coronary angiography findings, treatment performed, echocardiographic evaluation, and medical therapy. Conclusion Patients with RBBB had a higher rate of in-hospital mortality and arrhythmic events, and an increased risk of MACE during follow-up.

Introduction Data suggest inappropriate defibrillator shocks are associated with a higher risk of all-cause mortality, particularly those delivered for atrial fibrillation (AF). However, the impact of inappropriate shocks has not been studied specifically in a population with AF. Aims to determine if AF-triggered inappropriate shocks are associated with long- term mortality in patients with AF and defibrillators implanted for primary prevention. Methods Retrospective single-center study. We analyzed all patients with defibrillators implanted for primary prevention in whom AF was diagnosed until the end of 2017. The cause of inappropriate shocks was evaluated by analysis of the stored intracardiac electrogram. Basal characteristics, cardiovascular risk factors, left ventricle ejection fraction, heart failure etiology (ischemic and non-ischemic), kidney function (creatinine) and medication were evaluated. Death was assessed during the follow-up. Results We studied 177 patients [median age 66 years (IQR 59-71); 82% male], with defibrillators and AF. AF was diagnosed before defibrillator implantation in 131 patients (74%) and after the implantation in the remaining 46 (26%). Inappropriate shocks occurred in 31 patients and 24 (14%) were caused by AF with rapid ventricular response: 13 patients with previously diagnosed AF and 11 with new-onset AF. During a median follow-up of 65 (IQR: 36-104) months, 74 patients died. Multivariate Cox-regression analysis demonstrated inappropriate shocks caused by AF were not independently related with death (adjusted HR 0.53; CI 0.23-1.23, p = 0.14). Kaplan-Meier survival curve demonstrated patients with AF-triggered inappropriate shocks had a better survival comparing to those with AF but without inappropriate shocks (logrank, p = 0.03) (figure). Conclusions In this group of AF patients, inappropriate shocks caused by AF did not increase the risk of death. Instead, these patients had a better survival comparing to those with AF but no shocks, probably due to a re-evaluation of the patient´s status and subsequent closer medical monitoring, strictly control of symptoms and optimization of drug treatment. These results demonstrate that inappropriate shocks are probably not deleterious per si through a direct mechanism. Abstract Figure. Kaplan-Meier survival curve

BACKGROUND Patients (pts) with atrioventricular nodal reentrant tachycardia (AVNRT) have a higher incidence of atrial fibrillation (AF) during follow-up. Conventional risk factors can play a role in AF development, however atrial electrical conduction properties may be implicated in AF pathogenesis. AIMS to evaluate atrial conduction times and assess its effect on AF development during follow-up. METHODS We studied AVNRT pts who performed EPS and catheter ablation of the slow pathway between 2013 and 2016 in a single center. Pts with AF or valvular disease were excluded. We evaluated duration of symptoms due to AVNRT, conventional risk factors for AF (age, gender, obesity, hypertension, diabetes and structural heart disease (SHD)), left atrium (LA) enlargement and electrophysiologic study (EPS) time intervals related with atrial electrical conduction properties. We measured the time interval between: (1) the beginning of the P wave on the ECG to the A deflection in His-bundle electrogram (P-AHis); (2) the beginning of the P wave to the mid-distal coronary sinus (CS) atrial electrogram (P-CS) and (3) the beginning of the P wave to the H deflection in His-bundle electrogram (P-HHis). RESULTS Fifty-two pts were evaluated during a median follow-up of 63 months (IQR 51-69): 22% male, median age 55 years (IQR 42-67). AF occurred in 9 patients (17%) (39 cases per 1000 person-years). Patients with AF were older (67 vs 53 years, p= 0.005) and had more frequently LA enlargement (33% vs 7%, p= 0.024) but they did not differ in hypertension, obesity, diabetes, SHD and duration of symptoms. EPS measured intervals P-AHis and P-HHis interval were not different between the groups (26.0 vs 22.8 ms, p = 0.89 and 151 vs 106 ms, p= 0.56, respectively) but P-CS were prolonged in patients with AF (70 vs 55 ms, p = 0.02) (figure 1). Univariate logistic analysis for AF is presented in table 1. There was no interaction between P-CS and LA enlargement (p = 0.87). In multiavariate analysis, only P-CS was independently associated with AF (table). CONCLUSIONS In this group of patients with AVNRT, P-CS, but not other atrial conduction intervals, was independently associated with AF development. The possible role of LA electrical conduction impairment in AVNRT pts for AF development needs further studies. Univariate and multivariate analysis Univariate analysis Multivariate analysis OR 95% CI p-value OR 95% CI p-value Age (years) 1.10 1.02-1.19 0.016 1.10 1.00-1.21 0.051 LA enlargement 7.00 1.10-44.71 0.040 3.42 0.41-28.03 0.255 P-CS 1.07 1.021.14 0.013 1.06 1.01-1.12 0.044 OR Odds ratio. CI: confidence interval Abstract Figure. Box-plot for the studied intervals

Background As the use of Cardiac Implantable Electronic Devices (CIED) is expanding, the burden of device-related infections, particularly infectious endocarditis, is also increasing. Furthermore, with the increase in life expectancy, these devices are being implanted in patients who are older, with more serious co-morbidities and who are frequently hospitalized. Purpose To assess incidence and predisposing factors for infective endocarditis (IE) in hospitalized patients with CIED and nosocomial bacteraemia. Methods We performed a retrospective analysis of all hospitalized patients with CIED and positive blood cultures admitted to the Cardiology department between January 2012 and February 2019. Endocarditis was defined according to modified Duke criteria. We analyzed clinical parameters, device- and procedure-related characteristics, length of hospital stay and hospitalizations in the previous year. Results 25 patients had positive blood cultures, 4 patients (16.0%) were diagnosed with infective endocarditis (median age 59.25 years, 75.0% male). Patients characteristics are displayed in the Table. In univariable analysis, the number and presence of hospitalizations in the previous year and the length of hospital stay was significantly associated with the possibility of endocarditis (respectively, OR 3.411, 95% CI 1.164-9.998, p-value 0.025; OR 18.000, 95% CI 1.375-235.686, p-value 0.028; and OR 1.047, 95% IC 1.001-1.096, p-value 0.046). Conclusion In this group of patients with positive blood cultures during hospitalization, the possibility of CIED infection was predicted by the length of hospital stay and the presence and number of hospitalizations in the previous year. With CIED-IE Without CIED-IE p-value Age in years, median (IQR) 63 (16) 76 (16) 0.002 Heart failure, n (%) 4 (100%) 10 (47.6%) 0.105 LVEF in %, median (IQR) 21 (9) 51 (30) 0.008 LV dilation, n (%) 4 (100%) 8 (38.1%) 0.039 Device revision/upgrade/substitution, n (%) 2 (50.0%) 6 (28.57%) 0.570 LOS in days, median (IQR) 58.5 (83) 20 (15) 0.004 Hospital admissions in the previous year, n (%) 3 (75.0%) 3 (14.3%) 0.031 No. of hospital admissions in the previous year, mean (standard deviation) 1.67 (1.528) 0.29 (0.784) 0.005 Use of central venous access, n (%) 4 (100%) 4 (19.05%) 0.008 LOS – Length of Stay; LV – Left Ventricle; LVEF – Left Ventricle Ejection Fraction

A patient with an implantable cardioverter‐defibrillator (ICD) (Abbott®) had episodes of slow monomorphic ventricular tachycardia (VT) and his ICD was programmed with three tachycardia zones. During the follow‐up, he received an inappropriate shock. Upon interrogation (of the device), trigeminal pattern binned as ventricular sensing (VS)—VS—ventricular fibrillation (VF) was detected. VF was assumed according to binning system. When VF is present, discrimination algorithms are not available and five consecutive sinus beats are necessary to reset binning system. Catheter ablation was performed to treat VT in order to reprogram tachycardia zones.

Introduction There is growing evidence suggesting hypertension is related to the occurrence of arrhythmias. When occurring predominantly during the night, two potential entities commonly present in hypertensive patients could be related with increased arrhythmogenesis: (1) the lack of normal nocturnal dipping of blood pressure (BP) (non-dipping pattern of hypertension) or (2) obstructive sleep apnea (OSA). Thus, nocturnal arrhythmias (NAs) can identify hypertensive patients with OSA and/or non-dipping pattern, both related with adverse outcomes. Aims To determine if NAs are related with non-dipping hypertension, OSA or both. Methods We studied hypertensive patients who performed ambulatory blood pressure monitoring (ABPM) and also polysomnography and 24-hour Holter monitoring. Non-dipping pattern was considered when nocturnal BP reduction was inferior to 10%. Based on Holter monitoring, NAs were present when atrial fibrillation, frequent premature atrial contractions (PACs) (>30 PACs/hour), runs of >4 consecutive PACs, frequent premature ventricular contractions (PVCs) (>30PVCs/hour) or runs of >4 consecutive PVCs were present predominantly during sleeping hours. During polyssonography, apnoea/hypopnoea index (AHI) and oxygen saturation (SaO2) were analysed. Moderate to severe OSA was considered when AHI >15. Results We studied 104 patients [median age 62 (54–70) years, 65% male): 42 (40%) had moderate to severe OSA (median AHI=11 (6–26), mean SaO2=94% (92–95)] and 64 (61%) were non-dippers. NAs occurred in 18 patients (17%) and they were independently associated with AHI (Odds Ratio (OR) for a one unit increase 1.04, 95% confidence interval (CI) 1.01–1.07, p=0.03) but not with SaO2 (OR 0.96, CI 0.78–1.19, p=0.73) nor non-dipping pattern (OR 1.23, CI 0.38–3.98, p=0.72). No interaction was found between OSA and non-dipping hypertension (p=0.35). In patients with dipping pattern (n=40), AHI was higher in NAs patients comparing with no NAs patients (median AHI 29 versus 10, p=0.04), while in those with non-dipping pattern (n=64), AHI was not statistically different between patients with and without NAs (21 versus 11, p=0.12) (figure). Figure 1 Conclusion In this population of hypertensive patients, the presence of NAs was associated with OSA severity (i.e AHI), but not with the non-dipping pattern of hypertension. The importance of obstructive events in arrhythmogenesis seemed to be more pronounced in dipping patients, suggesting the abnormal high blood pressure during the night may also have some impact on NAs in non-dipping patients. Overall, our results suggest that OSA screening should be considered when nocturnal arrhythmias are detected in hypertensive patients, but ABPM should not be forgotten since multiple mechanisms can be involved in nocturnal arrhythmogenesis.

Background It is recommended to consider obstructive sleep apnoea (OSA) screening in atrial fibrillation (AF) patients with risk factors, due to the strong evidence of an association between these two entities. Excessive supraventricular ectopic activity (ESVEA) has been proposed to be a risk factor for AF. However, strong evidence between ESVEA and OSA has not been established. Objective We aimed to determine if ESVEA is associated with moderate to severe OSA since its treatment may prevent AF. Methods We studied patients who performed polysomnography and 24-hour Holter monitoring. Patients with atrial fibrillation were excluded. ESVEA was defined as more than 30 PACs per hour (frequent PACs) or runs of >4 consecutive PACs. The circadian pattern of PACs was also evaluated. Sleeping hours were used to define “nocturnal”. Moderate to severe OSA was defined when polyssonography demonstrated a apnoea/hypopnoea index (AHI) >15. We examined the association between ESVEA and moderate to severe OSA during wakefulness and sleep. Results We studied 290 patients [median age 65 (55–72) years, 62% males, body mass index (BMI) 30 (27–34)]. 112 (38%) had moderate to severe OSA. Median AHI was 11 (5–24) and mean oxygen saturation was 94% (92–95). Median PACs was 35 (9–117) and 29 patients (10%) had frequent PACs. Runs of >4PACs occurred in 114 patients (39%). Forty-three patients (15%) had predominant nocturnal PACs and 42 (14%) had nocturnal runs of PACs. Multivariate logistic regression analysis demonstrated only nocturnal PACs were associated with moderate to severe OSA (p=0.027) (table 1). Multivariate logistic regression Odds Ratio 95% Confidence Interval p-value Male gender 4.49 2.48–8.17 30 PAcs/hour), runs of PACs (>4 consecutive PACs), nocturnal frequent PACs and nocturnal runs of PACs. Conclusion OSA screening in patients presenting with nocturnal PACs should be routinely considered, especially in male and obese. Treating moderate to severe OSA patients with CPAP has a potential benefit in preventing ESVEA and consequently AF.

Introduction Atrioventricular nodal reentry tachycardia (AVNRT) is the most common type of supraventricular tachycardia. Most of the patients experience recurrent symptoms for years before electrocardiographic documentation and AVNRT ablation. The effects of these ongoing episodes of AVNRT on atrial structure and function, and their influence on new-onset atrial fibrillation (AF) in patients with delayed AVNRT ablation are unknown. Purpose To assess if delayed ablation of AVNRT was associated with the development of AF. Methods We retrospectively evaluated patients subjected to AVNRT ablation between 2009 and 2016. Patients with history of AF previous to ablation were excluded. We evaluated age at the time of AVNRT ablation, the presence of cardiovascular risk factors, left atrial (LA) dilatation and the presence of frequent premature atrial contractions (PACs) (by 24-hour holter monitoring, defined as >30/h). During follow-up we assessed the occurrence of sustained AF episodes and age at the time of the first AF episode. Results We studied 130 patients that underwent AVNRT ablation. Mean follow-up time was 75±27 months and seventeen patients (13%) had new-onset AF during follow-up. Patients who developed AF were more often males (35% vs. 22%, p=0,015), older at the time of AVNRT ablation (60±16 vs. 50±15, p=0,01), had a higher prevalence of hypertension (64% vs. 35%, p=0,03), diabetes mellitus (35% vs. 6%, p=0,02), LA dilation (41% vs. 7%, p=0,01) and frequent PACs (24% vs. 2%, p=0,03). In Univariable Cox regression analysis all these available variables were associated with AF occurrence during follow-up. However, in Multivariable Cox regression analysis, only age at the time of the ablation procedure was independently associated with AF occurrence (Table 1). Multivariable Analysis HR 95% CI P value Age at ablation 8.762 3.308–23.20 Conclusion In this group of patients the occurrence of new-onset AF during follow-up was independently associated with delayed AVNRT ablation. These findings suggest that longer atrial exposure to AVNRT episodes before ablation may be associated with LA structural and functional changes leading to higher occurrence of AF.

BACKGROUND Silent atrial fibrillation is a frequent etiology of cryptogenic stroke. Spontaneous conversion of atrial fibrillation to sinus rhythm results in atrial stunning. OBJECTIVE To evaluate if the presence of a lower left atrial appendage peak emptying velocity (LAAV) after a cryptogenic stroke is associated with the occurrence of atrial fibrillation (AF). METHODS We retrospectively selected consecutive patients with an acute ischemic stroke that had a transoesophageal echocardiogram (TEE) performed in the first 30 days of the acute event. Documented AF or potential cardioembolic sources in the TEE were considered exclusion criteria. We assessed the LAAV. During follow-up, we evaluated the occurrence of new-onset AF and the combined endpoint of death or new ischemic stroke. RESULTS We studied 73 consecutive patients, during a mean follow-up period of 54.9 ± 19.3 months. Seven developed AF, and 13 had the combined endpoint. LAAV was independently associated with AF occurrence (HR: 0.93, 95% CI: 0.88-0.99; P = .016). Patients with a LAAV ≤ 46.5 cm/s (AUC: 0.766, 95% CI: 0.579-0.954; P = .021) had a lower survival rate free from AF occurrence (Log-rank, P

Background: Atrial high-rate episodes (AHREs) are common in pacemaker patients. Our aims were to compare patients with AHREs to those without them and to assess if, in those with AHREs, the initiation of oral anticoagulation (OAC) has any clinical impact on the occurrence of ischemic and hemorrhagic events. Methods: From 2014-2017 we selected patients with pacemaker in whom AHREs were detected. AHREs were defined as episodes lasting more than 6 minutes if the electrogram was available or more than 6 hours if not. We used an age- and gender-matched population with pacemaker but no AHRE as a control group (observational study). Those with AHRE were referred to their assistant physician to decide OAC initiation, based on individual circumstances (interventional study). In interventional study, the primary outcome was a composite of systemic thromboembolism or major bleeding. Secondary outcomes were clinical relevant nonmajor bleeding, major and nonmajor bleeding, CV death, and death from all causes. Results: AHREs were detected in 86 patients: 69 patients initiated OAC and the remaining 17 patients did not. When comparing patients with and without AHRE, baseline characteristics were not different between the groups, except for indexed left atrium volume—40 mL (IQR: 34-50) in AHRE group versus 35 mL (IQR: 34-40) in control group (P = .014). AHREs were associated with future development of atrial fibrillation (AF) and the risk was higher if AHRE duration was superior to 6 hours. Death and cardiovascular (CV) death were not significantly different between the groups with and without AHRE. Primary outcome occurred in 4.9 per 100 person-year in OAC group versus 3.4 per 100 person-year in non-OAC group (HR 1.4, 95% CI .2-11.3, P = .78). Secondary outcomes were not significantly different in the groups. Conclusions: In this group of patients with pacemakers, the presence of AHREs was useful for predicting the future development of AF and the risk of AF was higher in those with a longer duration of AHRE. In the AHRE group, OAC therapy was not associated with a significant difference in the risk of thromboembolism or major bleeding.

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i p a t a m s r Late gadolinium enhancement (LGE) cardiac magnetic resonance imaging (MRI) is very useful in distinguishing between myocardial infarction, in which the enhancement is typically subendocardial, and myocarditis, in which it is subepicardial (Figure 1). In addition, various patterns have been described with different cardiomyopathies, in some cases enabling a specific diagnosis without invasive workup and risk stratification.1 Cardiac amyloidosis was previously thought to be present only when systemic amyloidosis was patently manifest. This has proved not to be the case, with cardiac MRI detecting increasing numbers of cases in patients with diastolic heart failure in whom cardiac