Antoni Bayés de Luna

Advanced Interatrial Block is Associated with Recurrence of Atrial Fibrillation Post Pharmacological Cardioversion

INTRODUCTIONnManagement of atrial fibrillation (AF) is hampered by frequent recurrences after restoration of sinus rhythm. Delayed interatrial conduction has been associated with the development of AF in different clinical settings. The aim of our study was to assess whether advanced interatrial block (aIAB) was associated with AF recurrence after pharmacological cardioversion with two different antiarrhythmic drugs.nnnMETHODSnWe included 61 patients with recent onset AF without structural heart disease that underwent successful pharmacological cardioversion. Thirty-one patients received a single oral dose of propafenone, and 30 patients received iv vernakalant. A 12-lead ECG (filter 150xa0Hz, 25xa0mm/s, 10xa0mm/mV) after conversion was evaluated for the presence of interatrial block (IAB); partial (pIAB): P-wave durationxa0>xa0120xa0ms, and advanced (aIAB): P-wavexa0>xa0120xa0ms and biphasic morphology (±) in inferior leads. Clinical follow-up and electrocardiographic recordings were performed for a 12-month period.nnnRESULTSnAge was 58xa0±xa010.4xa0years and 50.8% were male. aIAB was present in 11 patients (18%) and pIAB in 10 (16.4%). At 1-year follow-up, 22 patients (36%) had AF recurrence. The recurrence rate with aIAB was 90.9% versus 70% in those with pIAB and 12.5% in normal P-wave duration (Pxa0=xa00.001). The presence of aIAB was strongly associated with AF recurrence (odds ratio 18.4 in multivariable modeling). Recurrence was not affected by the drug used for cardioversion (Pxa0=xa00.92).nnnCONCLUSIONnAdvanced interatrial block is associated with higher risk of AF recurrence at 1xa0year after pharmacological cardioversion, independent of the drug used.

Obesity paradox and risk of sudden death in heart failure: Results from the MUerte Subita en Insuficiencia Cardiaca (MUSIC) Study

BACKGROUNDnamong patients with heart failure (HF), body mass index (BMI) has been inversely associated with mortality, giving rise to the so-called obesity paradox. The aim of this study was to examine the relationship between BMI and two modes of cardiac death: pump failure death and sudden death.nnnMETHODSnnine hundred seventy-nine patients with mild to moderate chronic symptomatic HF from the MUSIC (MUerte Subita en Insuficiencia Cardiaca) Study, a prospective, multicenter, and longitudinal study designed to assess risk predictors of cardiac mortality, were followed up during a median of 44 months. Independent predictors of death were identified by a multivariable Cox proportional hazards model.nnnRESULTSnhigher BMI emerged as an independent predictor of all-cause mortality (hazard ratio [HR] = 0.94, 95% confidence interval [CI] = 0.91-0.97, P = .0003) and pump failure death (HR = 0.93, 95% CI = 0.88-0.98, P = .004). Sudden death accounted for 45% of deaths in obese patients, 53% in overweight patients, and 37% in lean patients. No significant relationship between BMI and sudden death was observed (HR = 0.97, 95% CI = 0.92-1.02, P = .28). The only independent predictors of sudden death were prior history of myocardial infarction (HR = 1.89, 95% CI = 1.23-2.90, P = .004), hypertension (HR = 1.66, 95% CI = 1.05-2.63, P = .03), left ventricular ejection fraction (HR = 0.88, 95% CI = 0.79-0.96, P = .006), and N-terminal pro-B-type natriuretic peptide (HR = 1.01, 95% CI = 1.00-1.02, P = .048).nnnCONCLUSIONSnthe obesity paradox in HF affects all-cause mortality and pump failure death but not sudden death. The risk of dying suddenly was similar across BMI categories in this cohort of ambulatory patients with HF.

Bayés’ syndrome: the association between interatrial block and supraventricular arrhythmias

The past few years have given rise to extensive research on atrial conduction disorders and their clinical relevance. Most notably, an association between interatrial block and supraventricular arrhythmias has been discovered. This disorder, recently termed ‘Bayés’ syndrome’, has important clinical implications. In this article, the authors review normal atrial conduction and associated disorders. A particular focus is placed on Bayés’ syndrome and the relationship between interatrial block and supraventricular arrhythmias in different clinical scenarios. The report also outlines the current progress in the study of this syndrome and highlights areas requiring further investigation.

Expert cardiologists cannot distinguish between Brugada phenocopy and Brugada syndrome electrocardiogram patterns

AIMSnBrugada phenocopies (BrPs) are electrocardiogram (ECG) patterns that are identical to true Brugada syndrome (BrS) but are induced by various clinical conditions. The concept that both ECG patterns are visually identical has not been formally demonstrated. The aim of our study was to determine if experts on BrS were able to accurately distinguish between the BrS and BrP ECG patterns.nnnMETHODS AND RESULTSnSix ECGs from confirmed cases of BrS and six ECGs from previously published cases of BrP were included in the study. Surface 12-lead ECGs were scanned, saved in JPEG format, and sent to 10 international experts on BrS for evaluation (no clinical history provided). Evaluators were asked to label each case as a Brugada ECG pattern or non-Brugada ECG pattern by visual interpretation alone. The overall accuracy was 53 ± 33% for all cases. Within the BrS cases, the mean accuracy was 63 ± 34% and within the BrP cases, the mean accuracy was 43 ± 33%. Intra-observer repeatability was moderate (κ = 0.56) and inter-observer agreement was fair (κ = 0.36) while evaluator accuracy vs. the true diagnosis was only marginally better than chance (κ = 0.05). Similarly, diagnostic operating characteristics were poor (sensitivity 62%, specificity 43%, +LR 1.1, -LR 0.9).nnnCONCLUSIONnOur results provide strong evidence that BrP and BrS ECG patterns are visually identical and indistinguishable. These findings support the use of systematic diagnostic criteria for differentiating BrP vs. BrS as an erroneous diagnosis may have a negative impact on patient morbidity and mortality.

Relation of Interatrial Block to New-Onset Atrial Fibrillation in Patients With Chagas Cardiomyopathy and Implantable Cardioverter-Defibrillators

Chagas cardiomyopathy is an endemic disease in Latin America. A significant proportion of patients develop atrial fibrillation (AF), which may result in stroke and increased morbidity or mortality. Interatrial block (IAB) has been associated with the development of AF in different clinical scenarios. The aim of our study was to determine whether IAB can predict new-onset AF in patients with Chagas cardiomyopathy and implantable cardioverter-defibrillators (ICDs). We conducted a retrospective study of patients with Chagas cardiomyopathy and ICDs from 14 centers in Latin America. Demographics, clinical, and device follow-up were collected. Surface electrocardiograms were scanned at 300 dpi and maximized ×8. Semiautomatic calipers were used to determine P-wave onset and offset. Partial IAB was defined as a P wave of >120 ms and advanced IAB as a P wave of >120 ms with biphasic morphology (±) in inferior leads. AF events and ICD therapies were reviewed during follow-up by 2 independent investigators. A total of 80 patients were analyzed. Mean age was 54.6 ± 10.4 years, and 52 (65%) were male. Mean left ventricular ejection fraction was 40 ± 12%. IAB was detected in 15 patients (18.8%), with 8 (10.0%) partial and 7 (8.8%) advanced. During a follow-up of 33 ± 20 months, 11 patients (13.8%) presented with new AF. IAB (partial + advanced) was strongly associated with new AF (p <0.0001) and inappropriate therapy by the ICD (p = 0.014). In conclusion, IAB (partial + advanced) predicted new-onset AF in patients with Chagas cardiomyopathy and ICDs.

New methodologies for measuring Brugada ECG patterns cannot differentiate the ECG pattern of Brugada syndrome from Brugada phenocopy.

BACKGROUNDnBrugada phenocopies (BrP) are clinical entities characterized by ECG patterns that are identical to true Brugada syndrome (BrS), but are elicited by various clinical circumstances. A recent study demonstrated that the patterns of BrP and BrS are indistinguishable under the naked eye, thereby validating the concept that the patterns are identical.nnnOBJECTIVEnThe aim of our study was to determine whether recently developed ECG criteria would allow for discrimination between type-2 BrS ECG pattern and type-2 BrP ECG pattern.nnnMETHODSnTen ECGs from confirmed BrS (aborted sudden death, transformation into type 1 upon sodium channel blocking test and/or ventricular arrhythmias, positive genetics) cases and 9 ECGs from confirmed BrP were included in the study. Surface 12-lead ECGs were scanned, saved in JPEG format for blind measurement of two values: (i) β-angle; and (ii) the base of the triangle. Cut-off values of ≥58° for the β-angle and ≥4mm for the base of the triangle were used to determine the BrS ECG pattern.nnnRESULTSnMean values for the β-angle in leads V1 and V2 were 66.7±25.5 and 55.4±28.1 for BrS and 54.1±26.5 and 43.1±16.1 for BrP respectively (p=NS). Mean values for the base of the triangle in V1 and V2 were 7.5±3.9 and 5.7±3.9 for BrS and 5.6±3.2 and 4.7±2.7 for BrP respectively (p=NS). The β-angle had a sensitivity of 60%, specificity of 78% (LR+ 2.7, LR- 0.5). The base of the triangle had a sensitivity of 80%, specificity of 40% (LR+ 1.4, LR- 0.5).nnnCONCLUSIONSnNew ECG criteria presented relatively low sensitivity and specificity, positive and negative predictive values to discriminate between BrS and BrP ECG patterns, providing further evidence that the two patterns are identical.

P-Wave Duration or P-Wave Morphology? Interatrial Block: Seeking for the Holy Grail to Predict AF Recurrence

P-Wave Duration or P-Wave Morphology? Interatrial Block: Seeking for the Holy Grail to Predict AF Recurrence Adrian Baranchuk, M.D., F.A.C.C., F.R.C.P.C.,∗ Diego Conde, M.D.,† Andres Enriquez, M.D.,∗ and Antoni Bayés de Luna, M.D.‡ From the ∗Division of Cardiology, Queen’s University, Kingston, Ontario, Canada; †Cardiovascular Institute of Buenos Aires. Buenos Aires, Argentina; and ‡Cardiovascular Research Center, CSIC-ICCC, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain

The Rsr′ Pattern in Leads V1-V2: Algorithm and Differential Diagnosis

Abstract This chapter reviews the ECG characteristics that allow, along with a detailed clinical history, to perform the differential diagnosis of ECG pattern with r′ in leads V1-V2. We make a distinction of the benign patterns: high precordial placement of electrodes, pectus excavatum, partial RBBB and athletes ECG, and the pathological patterns including: type-2 Brugada ECG pattern, RV enlargement, preexcitation and hyperkalemia. We discuss the clues for this differential diagnosis, and propose an algorithm that allows navigating this differential diagnosis. Finally, we comment the cases that present r′ pattern in lead V1 associated with supraventricular arrhythmias.