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Wide complex tachycardia is a common presentation in the Emergency Department. Although differentiating between supraventricular and ventricular tachycardia is critical for an appropriate treatment, it can still prove quite challenging. Clinicians usually make this distinction based on clinical context and several electrocardiographic criteria and algorithms. We report a case of wide complex tachycardia where these criteria were conflicting and where the correct diagnosis was only established through the careful analysis of serial electrocardiograms during the treatment of the arrhythmia. It therefore highlights the importance of performing electrocardiograms before and after treatment and of meticulously analysing them, beyond the diagnostic algorithms, before making a final diagnosis. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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 < .001) and free from the combined endpoint of death or ischemic stroke (Log‐rank, P = .010). Conclusion: A lower LAAV was associated with AF occurrence and the combined endpoint of death or ischemic stroke after an initial episode of cryptogenic stroke. Patients with this finding could eventually benefit from long‐term cardiac rhythm monitoring. [ABSTRACT FROM AUTHOR]

Background and aims: Discrete potentials, low voltage and fragmented electrograms, have been previously reported at ablation site, in patients with premature ventricular contractions (PVCs) originating in the right ventricular outflow tract (RVOT). The aim of this study was to review the electrograms at ablation site and assess the presence of diastolic potentials and their association with success. Methods: We retrospectively reviewed the electrograms obtained at the radiofrequency (RF) delivery sites of 48 patients subjected to ablation of RVOT frequent PVCs. We assessed the duration and amplitude of local electrogram, local activation time, and presence of diastolic potentials and fragmented electrograms. Results: We reviewed 134 electrograms, median 2 (1–4) per patient. Success was achieved in 40 patients (83%). At successful sites the local activation time was earlier– 54 (-35 to -77) ms vs -26 (-12 to -35) ms, p<0.0001; the local electrogram had lower amplitude 1 (0.45–1.15) vs 1.5 (0.5–2.1) mV, p = 0.006, and longer duration 106 (80–154) vs 74 (60–90) ms, p<0.0001. Diastolic potentials and fragmented electrograms were more frequently present, respectively 76% vs 9%, p <0.0001 and 54% vs 11%, p<0.0001. In univariable analysis these variables were all associated with success. In multivariable analysis only the presence of diastolic potentials [OR 15.5 (95% CI: 3.92–61.2; p<0.0001)], and the value of local activation time [OR 1.11 (95% CI: 1.049–1.172 p<0.0001)], were significantly associated with success. Conclusion: In this group of patients the presence of diastolic potentials at the ablation site was associated with success. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Introduction: There is considerable debate regarding the use of thrombolytic therapy in patients with pulmonary embolism, normal blood pressure and intermediate clinical risk, as defined by right ventricular dysfunction on transthoracic echocardiography or elevated serum markers of cardiac necrosis. Aims and objectives: A clinical audit of normotensive patients diagnosed with acute pulmonary embolism using multi- detector computerized tomography pulmonary angiography (MDCTPA) and intermediate risk, was conducted to determine clinical outcomes at 30 days. The specific role played by imaging findings and clinical severity, on the decision to thrombolyse, was assessed. Methods: The two cohorts who did ( n = 15) and did not receive thrombolysis ( n = 20) were compared for age, heart rate, blood pressure and oxyhemoglobin saturation at presentation, and the simplified PESI score was calculated in each patient. MDCTPA findings suggestive of adverse clinical outcome including central PE and an increased RV/LV diameter were determined for each patient. RV dysfunction on echocardiography was compared to clinical scoring, and findings on MDCTPA. Results: The patients who received thrombolytic therapy were younger (48.6 ± 19.11 years versus 64.2 ± 13.83 years) ( P < 0.01) and had a higher heart rate (107.6 ± 17.1/min versus 91.7 ± 17.8/min) ( P < 0.05). More patients with a higher clinical severity, as determined by the simplified PESI score (12/20) and a higher shock index (0.94 ± 0.23), were thrombolysed as compared to the proportion with a lower score (3/15) ( P < 0.05) or index (0.70 ± 0.20) ( P < 0.005). In-hospital mortality and hemorrhagic complications at 30 days were zero in both groups. RV dysfunction by echocardiography was not a strong determinant for choosing thrombolytic therapy while central PE on MDCTPA tilted the decision towards thrombolysis. Conclusion: Our clinical audit revealed a predilection to use thrombolysis in younger patients with clinical severity and imaging findings on MDCTPA being the key drivers. A perception of a fragile hemodynamic status, as implied by a higher heart rate and shock index, despite a normal BP probably inclined us to thrombolyse. [ABSTRACT FROM AUTHOR]

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., Competing Interests: None to declare., (Copyright 2019, Parreira et al.)

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., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.)