Quality indicators in atrial fibrillation ablation (RIQAFA). A national registry from the Portuguese Association of Arrhythmology, Pacing and Electrophysiology (APAPE).

INTRODUCTION AND OBJECTIVES: Atrial fibrillation (AF) is the most common sustained arrhythmia, with significant burden for patients. Catheter ablation is safe and superior for symptom improvement. The purpose of this work was to assess how clinical practice compares with current scientific evidence and quality indicators for AF ablation. METHODS: The Portuguese Association of Arrhythmology, Pacing and Electrophysiology conducted a prospective registry among Portuguese centers to assess clinical practice regarding management of patients referred for ablation and the methodology used in the procedures and related outcomes. RESULTS: A total of 337 patients were referred for ablation, 102 (37.91%) female, age 65 (56-70.8) years. The median CHADS2-VaSC2 thromboembolic risk score was 2 (1-3), and 308 (92.49%) were on anticoagulants. AF was mainly paroxysmal (224, 66.97%) and symptomatic (mEHRA score 3; 2-3). Before ablation most patients (273, 81.49%) underwent cardiac computed tomography and only 24 (7.36%) procedures were performed with uninterrupted anticoagulation. For ablation, Carto® (194; 59.15%) and Ensite® (55; 16.77%) were mainly used, and the preferential strategy was pulmonary vein isolation (316; 94.61%). Acute complications occurred in five (1.49%) patients, while most had symptom improvement at one month (200; 86.21%), sustained at one year. There were 40 (12.6%) relapses within 30 days and 19 (26.39%) at one year. CONCLUSIONS: In a population of patients with AF referred for ablation in Portuguese centers, patient management is provided according to the best scientific evidence and there is a high standard of practice with respect to the quality of AF ablation practice.

Electrocardiographic imaging to guide ablation of ventricular arrhythmias and agreement between two different systems.

BACKGROUND AND AIM: A recent study using an epicardial-only electrocardiographic imaging (ECGI), suggests that the agreement of ECGI activation mapping and that of the contact mapping for ventricular arrhythmias (VA) is poor. The aim of this study was to assess the diagnostic value of two endo-epicardial ECGI systems using different cardiac sources and the agreement between them. METHODS: We performed 69 ECGI procedures in 52 patients referred for ablation of VA at our center. One system based on the extracellular potentials was used in 26 patients, the other based on the equivalent double layer model in 9, and both in 17 patients. The first uses up to 224 leads and the second just the 12­lead ECG. The localization of the VA was done using a segmental model of the ventricles. A perfect match (PM) was defined as a predicted location within the same anatomic segment, whereas a near match (NM) as a predicted location within the same segment or a contiguous one. RESULTS: 44 patients underwent ablation, corresponding to 58 ECGI procedures (37 with the first and 21 with the second system). The percentage of PMs and NMs was not significantly different between the two systems, respectively 76% and 95%, p = 0.077, and 97% and 100%, p = 1.000. In 14 patients that underwent ablation and had the ECGI performed with both systems, raw agreement for PMs was 79%, p = 0.250 for disagreement. CONCLUSIONS: ECGI systems were useful to identify the origin of the VAs, and the results were reproducible regardless the cardiac source.

Non-invasive three-dimensional electrical activation mapping to predict cardiac resynchronization therapy response: site of latest left ventricular activation relative to pacing site.

AIMS: Pacing remote from the latest electrically activated site (LEAS) in the left ventricle (LV) may diminish response to cardiac resynchronization therapy (CRT). We tested whether proximity of LV pacing site (LVPS) to LEAS, determined by non-invasive three-dimensional electrical activation mapping [electrocardiographic Imaging (ECGI)], increased likelihood of CRT response. METHODS AND RESULTS: Consecutive CRT patients underwent ECGI and chest/heart computed tomography 6-24 months of post-implant. Latest electrically activated site and the distance to LVPS (dp) were assessed. Left ventricular end-systolic volume (LVESV) reduction of ≥15% at clinical follow-up defined response. Logistic regression probabilistically modelled non-response; variables included demographics, heart failure classification, left bundle branch block (LBBB), ischaemic heart disease (IHD), atrial fibrillation, QRS duration, baseline ejection fraction (EF) and LVESV, comorbidities, use of CRT optimization algorithm, angiotensin-converting enzyme inhibitor(ACE)/angiotensin-receptor blocker (ARB), beta-blocker, diuretics, and dp. Of 111 studied patients [64 ± 11 years, EF 28 ± 6%, implant duration 12 ± 5 months (mean ± SD), 98% had LBBB, 38% IHD], 67% responded at 10 ± 3 months post CRT-implant. Latest electrically activated sites were outside the mid-to-basal lateral segments in 35% of the patients. dp was 42 ± 23 mm [31 ± 14 mm for responders vs. 63 ± 24 mm non-responders (P < 0.001)]. Longer dp and the lack of use of CRT optimization algorithm were the only independent predictors of non-response [area under the curve (AUC) 0.906]. dp of 47 mm delineated responders and non-responders (AUC 0.931). CONCLUSION: The distance between LV pacing site and latest electrical activation is a strong independent predictor for CRT response. Non-invasive electrical evaluation to characterize intrinsic activation and guide LV lead deployment may improve CRT efficacy.

Validation of an electrocardiographic marker of low voltage areas in the right ventricular outflow tract in patients with idiopathic ventricular arrhythmias.

BACKGROUND: Previous studies have reported the presence of subtle abnormalities in the right ventricular outflow tract (RVOT) in patients with apparently normal hearts and ventricular arrhythmias (VAs) from the RVOT, including the presence of low voltage areas (LVAs). This LVAs seem to be associated with the presence of ST-segment elevation in V1 or V2 leads at the level of the 2nd intercostal space (ICS). OBJECTIVE: Our aim was to validate an electrocardiographic marker of LVAs in the RVOT in patients with idiopathic outflow tract VAs. METHODS: A total of 120 patients were studied, 84 patients referred for ablation of idiopathic VAs with an inferior axis by the same operator, and a control group of 36 patients without VAs. Structural heart disease including arrhythmogenic right ventricular cardiomyopathy was ruled out in all patients. An electrocardiogram was performed with V1-V2 at the 2nd ICS, and ST-segment elevation ≥1 mm and T-wave inversion beyond V1 were assessed. Bipolar voltage map of the RVOT was performed in sinus rhythm (0.5-1.5 mV color display). Areas with electrograms <1.5 mV were considered LVAs, and their presence was assessed. We compared three groups, VAs from the RVOT (n = 66), VAs from the LVOT (n = 18) and Control group (n = 36). ST-elevation, T-wave inversion and left versus right side of the VAs were tested as predictors of LVAs, respective odds ratio (ORs) (95% confidence interval [CI]) and p values, were calculated with univariate logist regression. Variables with a p < .005 were included in the multivariate analysis. RESULTS: ST-segment elevation, T-wave inversion and LVAs were present in the RVOT group, LVOT group and Control group as follows: (62%, 17%, and 6%, p < .0001), (33%, 29%, and 0%, p = .001) and (62%, 25%, and 14%, p < .0001). The ST-segment elevation, T-wave inversion and right-sided VAs were all predictors of LVAs, respective unadjusted ORs (95% CI), p values were, 32.31 (11.33-92.13), p < .0001, 4.137 (1.615-10.60), p = .003 and 8.200 (3.309-20.32), p < .0001. After adjustment, the only independent predictor of LVAs was the ST-segment elevation, with an adjusted OR (95% CI) of 20.94 (6.787-64.61), p < .0001. CONCLUSION: LVAs were frequently present in patients with idiopathic VAs. ST-segment elevation was the only independent predictor of their presence.

A simplified approach to radiofrequency catheter ablation of idiopathic ventricular outflow tract premature ventricular contractions.

INTRODUCTION: Frequently, low voltage areas (LVAs) and diastolic potentials (DPs) are present at ablation sites in sinus rhythm in patients with idiopathic premature ventricular contractions (PVCs). OBJECTIVE: Validate these findings as substrates for PVCs and evaluate the feasibility of a simplified substrate approach based on LVAs and DPs for ablation of idiopathic outflow tract PVCs, in patients with a low PVC burden during the procedure. METHODS: Prospective single-arm clinical trial at two centers with comparison with a historical group, matched to age and gender. The study group consisted of consecutive patients referred for ablation of frequent idiopathic PVCs with inferior axis, that presented with less than two PVCs/min in first 5 min of the procedure. The ablation was based on fast mapping of the right ventricular outflow tract in sinus rhythm looking for LVAs and DPs, defined as isolated small amplitude potentials occurring after the T wave of the surface echocardiogram. The area with LVAs and DPs was tagged, and a simplified activation mapping of the PVCs was done in that area. The procedure time, success rate, and recurrence rate were compared with the historical group in whom ablation was performed based on activation and pace mapping only. A validation group without PVCs was also studied to assess the prevalence of LVAs and DPs in the general population. RESULTS: The study (n = 38), historical (n = 38), and validation (n = 38) groups did not differ in relation to age or gender. Prevalence of LVAs and DPs was significantly higher in the study group in comparison with the validation group, respectively, 71% versus 11%, p < 0.0001 and 87% versus 8%, p < 0.0001. Procedure time was significantly lower in the study group when comparing to the historical group, 130 (100-164) versus 183 (160-203) min, p < 0.0001 and the success rate was significantly higher, 90% versus 64%, p = 0.013. The recurrence rate in patients with a successful ablation was not significantly different between both groups, Log-rank = 0.125. CONCLUSION: The prevalence of LVAs and DPs was significantly higher in the study group than in the validation group. The proposed approach proved to be feasible, faster, and more efficient than the historical approach.

Assessment of wave front activation duration and speed across the right ventricular outflow tract using electrocardiographic imaging as predictors of the origin of the premature ventricular contractions: A validation study.

AIMS: Evaluate right ventricular outflow tract (RVOT) activation duration (AD) and speed, invasively and with the electrocardiographic imaging (ECGI), as predictors of the origin of the PVCs, validating the ECGI. METHODS: 18 consecutive patients, 8 males, median age 55 (35-63) years that underwent ablation of PVCs with inferior axis and had ECGI performed before ablation. Isochronal activation maps of the RVOT in PVC were obtained with the ECGI and invasively. Total RVOT AD was measured as the time between earliest and latest activated region, and propagation speed by measuring the area of the first 10 ms of activation. Cut-off values for AD, activation speed and number of 10 ms isochrones to predict the origin of the PVCs, were obtained with the ROC curve analysis. Agreement between methods was done with Pearson correlation test and Bland-Altman plot. RESULTS: PVCs originated from the RVOT in 11 (61%) patients. The stronger predictor of PVC origin was the AD. The median AD in PVCs from RVOT was significantly longer than from outside the RVOT, both with ECGI and invasively, respectively 62 (58-73) vs 37 (33-40) ms, p < 0.0001 and 68 (60-75) vs 35 (29-41) ms, p < 0.0001. Agreement between the two methods was good (r = 0.864, p < 0.0001). The cut-off value of 43 ms for AD measured with ECGI predicted the origin of the PVCs with a sensitivity and specificity of 100%. CONCLUSIONS: We found good agreement between ECGI and invasive map. The AD measured with ECGI was the best predictor of the origin of the PVCs.

Cardiac arrhythmias in patients presenting with COVID-19 treated in Portuguese hospitals: A national registry from the Portuguese Association of Arrhythmology, Pacing and Electrophysiology.

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.

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.

Cardiac arrhythmias in patients presenting with COVID-19 treated in Portuguese hospitals: A national registry from the Portuguese Association of Arrhythmology, Pacing and Electrophysiology.

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.

Prolonged Right Ventricular Outflow Tract Endocardial Activation Duration and Presence of Deceleration Zones in Patients With Idiopathic Premature Ventricular Contractions. Association With Low Voltage Areas.

BACKGROUND AND AIMS: The 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. METHODS: We 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 <1.5 mV. RESULTS: The 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. CONCLUSION: Right 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.

Anatomic guided ablation of the atrial right ganglionated plexi is enough for cardiac autonomic modulation in patients with significant bradyarrhythmias.

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.

Premature ventricular contractions of the right ventricular outflow tract: is there an incipient underlying disease? New insights from a speckle tracking echocardiography study.

CONTEXT: Premature ventricular contractions (PVCs) originating in the right ventricular outflow tract (RVOT) are traditionally considered idiopathic and benign. Echocardiographic conventional measurements are typically normal. AIMS: To assess whether right ventricle longitudinal strain, determined by two-dimensional speckle tracking echocardiography, differ between RVOT PVCs patients (treated with catheter ablation) and healthy controls. METHODS: We retrospectively selected patients with PVCs from the RVOT who underwent electrophysiological study and catheter ablation between 2016 and 2019. Patients with documented structural heart disease were excluded. Transthoracic echocardiography was performed and right ventricle global longitudinal strain (RV-GLS), free wall longitudinal strain (RVFW-LS) and left ventricle global longitudinal strain (LV-GLS) were determined as well as conventional ultrasound measurements of RV and LV function. RESULTS: We studied 21 patients with RVOT PVCs and 13 controls. Patients with PVCs from the RVOT had lower values of RV-GLS and RVFW-LS compared with the control group (-19.4% versus -22.5%, P = 0.015 and -22.1% versus -25.5, P = 0.041, respectively). They also had lower values of LV-GLS, although still within the normal range (-19.1% versus -20.9%, P = 0.047). Regarding RVOT PVCs patients only, RV-GLS and RVFW-LS had no correlation with the PVCs burden prior to catheter ablation and they did not differ between the patients in whom the catheter ablation was successful and those in whom it was not. RV-GLS also had a positive correlation with RVOT proximal diameter (r = 0.487, P = 0.025). CONCLUSIONS: In this group of RVOT PVCs patients, we found worse RV longitudinal strain values (and therefore sub-clinical myocardial dysfunction) when compared to healthy controls.

Frequent premature ventricular contractions. Association of burden and complexity with prognosis according to the presence of structural heart disease.

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 < .0001. In idiopathic patients, a PVC% in the third quartile was independently associated with all-cause mortality hazard ratio (HR) 2.288 (1.042-5.026) p = .039, but not in SHD. The complexity of the PVCs was not independently associated with outcomes in both groups. In SHD group, NSVT was associated with lower survival free from SD and VA hospitalizations, p = .028; after multivariable, there was a trend for a higher arrhythmic outcome with NSVT, HR 3.896 (0.903-16.81) p = .068. CONCLUSION: Premature ventricular contractions in SHD showed more complex patterns. In idiopathic patients, a higher PVC count was associated with higher mortality but not is SHD patients. Complexity was not independently associated with worse prognosis.

Right bundle brunch block in patients with acute myocardial infarction is associated with a higher in-hospital arrhythmic risk and mortality, and a worse prognosis after discharge.

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.

Idiopathic Premature Ventricular Contractions From the Outflow Tract Display an Underlying Substrate That Can Be Unmasked by a Type 2 Brugada Electrocardiographic Pattern at High Right Precordial Leads.

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 <1.5 mV represented the LVA. The area adjacent to the pulmonary valve usually displays voltage between 0.5 and 1.5 mV and is classified as transitional-voltage zone. Presence of LVAs outside this transitional-voltage zone were estimated. We compared two groups with and without ST-segment elevation and tested for the association between ECG pattern and LVAs. Results: None of the patients in the control group had ST-segment elevation or LVAs. In the PVC group, no patient had type 1 Brugada pattern, 29 patients (64%) had type 2 or 3 ST-segment elevation (Type 2 BrP), and 28 (62%) had LVAs outside the transitional-voltage zone. LVAs were more frequent in patients with Type 2 BrP; 93% versus 4%, p < 0.0001. The ECG pattern was associated with the presence of LVAs, OR (95% CI): 202.50 (16.92-2423), p < 0.0001. Conclusion: Low voltage areas were frequently present in the RVOT of patients with idiopathic PVCs. They were absent in controls and can be unmasked by the presence of Type 2 BrP in high right precordial leads.

Successful ablation of premature ventricular contractions exclusively guided by epicardial and endocardial non-invasive mapping (ECGI) and confirmed by substrate mapping.

Ablation of premature ventricular contractions (PVCs), relies mostly on a detailed activation mapping. This can be impossible to achieve in case of paucity or even absence of PVCs during the procedure. Pacemapping as an alternative has many limitations. We present a case of a patient with very frequent symptomatic PVCs, that on the day of the procedure had total absence of PVCs. We performed successful ablation based exclusively on electrocardiographic imaging confirmed by substrate mapping.

Electrocardiographic imaging (ECGI): What is the minimal number of leads needed to obtain a good spatial resolution?

AIMS: Assess the minimal number of ECGI leads needed to obtain a good spatial resolution. METHODS: We enrolled 20 patients that underwent ablation of premature ventricular or atrial contractions using Carto and ECGI with AMYCARD. We evaluated the agreement regarding the site of origin of the arrhythmia between the ECGI and Carto, the area and diameter of the earliest activation site obtained with the ECGI (EASa and EASd). Based on previous studies with pacemapping, we considered a good spatial resolution of the ECGI when the EASd measured on the isopotential map was less than 18 mm. In presence of agreement the ECGI was reprocessed: a) with half the number of electrode bands (8 leads per electrode band) and b) with 6 electrode bands. RESULTS: The initial map was obtained with 23 (22-23) electrode bands per patient, corresponding to 143 (130-170) leads. Agreement rate was 85%, the median EASa and EASd were: 0.7 (0.5-1.3) cm2 and 9 (8-13) mm. With half the number of electrode bands including 73 (60-79) leads, agreement rate was 80%, the EASa and EASd were: 2.1 (1.5-6.2) cm2 and 16 (14 -28) mm. With only six electrode bands using 38 (30-42) leads, agreement rate was 55%, EASa and EASd were: 4.0 (3.3-5.0) cm2 and 23 (21-25) mm. The number of leads was a predictor of agreement with a good spatial resolution, OR (95% CI) of 1.138 (1.050-1.234), p = .002. According to the ROC curve, the minimal number of leads was 74 (AUC 0.981; 95% CI: 0.949-1.00, p < .0001). CONCLUSION: Reducing the number of leads was associated with a lower agreement rate and a significant reduction of spatial resolution. However, the number of leads needed to achieve a good spatial resolution was less than the maximal available.

Excessive Atrial Ectopic Activity Worsens Prognosis and Predicts the Type of Major Adverse Cardiac Events in Patients With Frequent Premature Ventricular Contractions.

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.