Abstract Impaired interatrial conduction or interatrial block is well documented but is not described as an individual electrocardiographic (ECG) pattern in most of ECG books, although the term ...atrial abnormalities to encompass both concepts, left atrial enlargement (LAE) and interatrial block, has been coined. In fact, LAE and interatrial block are often associated, similarly to what happens with ventricular enlargement and ventricular block. The interatrial blocks, that is, the presence of delay of conduction between the right and left atria, are the most frequent atrial blocks. These may be of first degree (P-wave duration > 120 milliseconds), third degree (longer P wave with biphasic ± morphology in inferior leads), and second degree when these patterns appear transiently in the same ECG recording (atrial aberrancy). There are evidences that these electrocardiographic P-wave patterns are due to a block because they may ( a ) appear transiently, ( b ) be without associated atrial enlargement, and ( c ) may be reproduced experimentally. The presence of interatrial blocks may be seen in the absence of atrial enlargement but often are present in case of LAE. The most important clinical implications of interatrial block are the following: ( a ) the first degree interatrial blocks are very common, and their relation with atrial fibrillation and an increased risk for global and cardiovascular mortality has been demonstrated; ( b ) the third degree interatrial blocks are less frequent but are strong markers of LAE and paroxysmal supraventricular tachyarrhythmias. Their presence has been considered a true arrhythmological syndrome.
Introduction
Advanced interatrial block (IAB) on a 12‐lead electrocardiogram (ECG) is a predictor of stroke, incident atrial fibrillation (AF), and AF recurrence after catheter ablation. The ...objective of this study was to determine which features of IAB structural remodeling is associated with left atrium (LA) magnetic resonance imaging structure and function.
Methods/Results
We included 152 consecutive patients (23% nonparoxysmal AF) who underwent preprocedural ECG and cardiac magnetic resonance (CMR) in sinus rhythm before catheter ablation of AF. IAB was defined as P‐wave duration ≥120 ms, and was considered partial if P‐wave was positive and advanced if P‐wave had a biphasic morphology in inferior leads. From cine CMR and late gadolinium enhancement, we derived LA maximum and minimum volume indices, strain, LA fibrosis, and LA dyssynchrony. A total of 77 patients (50.7% paroxysmal) had normal P‐wave, 52 (34.2%) partial IAB, and 23 (15.1%) advanced IAB. Patients with advanced IAB had significantly higher LA minimum volume index (25.7 vs 19.9 mL/m2, P = .010), more LA fibrosis (21.9% vs 13.1%, P = .020), and lower LA maximum strain rate (0.99 vs 1.18, P = .007) than those without. Advanced IAB was independently associated with LA (minimum P = .032 and fibrosis P = .009). P‐wave duration was also independently associated with LA fibrosis (β = .33; P = .049) and LA mechanical dyssynchrony (β = 2.01; P = .007).
Conclusion
Advanced IAB is associated with larger LA volumes, lower emptying fraction, and more fibrosis. Longer P‐wave duration is also associated with more LA fibrosis and higher LA mechanical dyssynchrony.
The prevalence of interatrial block (IAB) is high in the elderly, particularly in those with heart disease. Despite this high prevalence—and the association of IAB with the risk of atrial ...fibrillation (AF), stroke, and cognitive decline—little information exists about the prognosis of older patients with IAB. P‐wave duration and morphology are associated with risk of developing AF, stroke, and cognitive decline in elderly patients with structural heart disease. The aim of the Interatrial Block and Yearly Events (BAYES) registry is to assess the impact of IAB on the risk of AF and stroke during 3 years of follow‐up. A series of 654 ambulatory patients age ≥70 years with heart disease from 35 centers will be included in 3 similar‐size groups of patients. Group A: normal P‐wave duration (<120 ms); Group B: partial IAB (P‐wave duration ≥120 ms without biphasic plus/minus morphology in the inferior leads II, III, and aVF); and Group C: advanced IAB (P‐wave duration ≥120 ms with biphasic plus/minus morphology in the inferior leads II, III, and aVF). Patients will be managed according to current recommendations. The 2 primary endpoints are defined as (1) AF duration >5 minutes and documented in any form of electrocardiographic recording; and (2) stroke. Results from this study might significantly improve the knowledge of IAB and its impact on the outcome of elderly patients with heart disease and could open the door to the use of anticoagulation therapy in some elderly patients with IAB.
Abstract Brugada syndrome is an inherited heart disease without structural abnormalities that is thought to arise as a result of accelerated inactivation of Na channels and predominance of transient ...outward K current ( Ito ) to generate a voltage gradient in the right ventricular layers. This gradient triggers ventricular tachycardia/ventricular fibrillation possibly through a phase 2 reentrant mechanism. The Brugada electrocardiographic (ECG) pattern, which can be dynamic and is sometimes concealed, being only recorded in upper precordial leads, is the hallmark of Brugada syndrome. Because of limitations of previous consensus documents describing the Brugada ECG pattern, especially in relation to the differences between types 2 and 3, a new consensus report to establish a set of new ECG criteria with higher accuracy has been considered necessary. In the new ECG criteria, only 2 ECG patterns are considered: pattern 1 identical to classic type 1 of other consensus (coved pattern) and pattern 2 that joins patterns 2 and 3 of previous consensus (saddle-back pattern). This consensus document describes the most important characteristics of 2 patterns and also the key points of differential diagnosis with different conditions that lead to Brugada-like pattern in the right precordial leads, especially right bundle-branch block, athletes, pectus excavatum, and arrhythmogenic right ventricular dysplasia/cardiomyopathy. Also discussed is the concept of Brugada phenocopies that are ECG patterns characteristic of Brugada pattern that may appear and disappear in relation with multiple causes but are not related with Brugada syndrome.
Sudden cardiac death (SCD) and pump failure death (PFD) are common endpoints in chronic heart failure (CHF) patients, but prevention strategies are different. Currently used tools to specifically ...predict these endpoints are limited. We developed risk models to specifically assess SCD and PFD risk in CHF by combining ECG markers and clinical variables.
The relation of clinical and ECG markers with SCD and PFD risk was assessed in 597 patients enrolled in the MUSIC (MUerte Súbita en Insuficiencia Cardiaca) study. ECG indices included: turbulence slope (TS), reflecting autonomic dysfunction; T-wave alternans (TWA), reflecting ventricular repolarization instability; and T-peak-to-end restitution (ΔαTpe) and T-wave morphology restitution (TMR), both reflecting changes in dispersion of repolarization due to heart rate changes. Standard clinical indices were also included.
The indices with the greatest SCD prognostic impact were gender, New York Heart Association (NYHA) class, left ventricular ejection fraction, TWA, ΔαTpe and TMR. For PFD, the indices were diabetes, NYHA class, ΔαTpe and TS. Using a model with only clinical variables, the hazard ratios (HRs) for SCD and PFD for patients in the high-risk group (fifth quintile of risk score) with respect to patients in the low-risk group (first and second quintiles of risk score) were both greater than 4. HRs for SCD and PFD increased to 9 and 11 when using a model including only ECG markers, and to 14 and 13, when combining clinical and ECG markers.
The inclusion of ECG markers capturing complementary pro-arrhythmic and pump failure mechanisms into risk models based only on standard clinical variables substantially improves prediction of SCD and PFD in CHF patients.
Abstract
Aims
Advanced interatrial block (IAB), is an unrecognized surrogate of atrial dysfunction and a trigger of atrial dysrhythmias, mainly atrial fibrillation (AF). Our aim was to prospectively ...assess whether advanced IAB in sinus rhythm is associated with AF and stroke in elderly outpatients with structural heart disease, a group not previously studied.
Methods and results
Prospective observational registry that included outpatients aged ≥70 years with structural heart disease and no previous diagnosis of AF. Patients were divided into three groups: normal P-wave duration (<120 ms), partial IAB (P-wave duration ≥120 ms, positive in the inferior leads), and advanced IAB P-wave duration ≥120 ms, biphasic (plus/minus) morphology in the inferior leads. Among 556 individuals, 223 had normal P-wave (40.1%), 196 partial IAB (35.3%), and 137 advanced IAB (24.6%). After a median follow-up of 694 days, 93 patients (16.7%) developed AF, 30 stroke (5.4%), and 34 died (6.1%). Advanced IAB was independently associated with AF –hazard ratio (HR) 2.9, 95% confidence interval (CI) 1.7–5.1; P < 0.001, stroke HR 3.8, 95% CI 1.4–10.7; P = 0.010), and AF/stroke (HR 2.6, 95% CI 1.5–4.4; P = 0.001). P-wave duration (ms) was independently associated with AF (HR 1.05, 95% CI 1.03–1.07; P < 0.001), AF/stroke (HR 1.04, 95% CI 1.02–1.06; P < 0.001), and mortality (HR 1.04, 95% CI 1.00–1.08; P = 0.021).
Conclusions
The presence of advanced IAB in sinus rhythm is independently associated with AF and stroke in an elderly population with structural heart disease and no previous diagnosis of AF. P-wave duration was also associated with all-cause mortality.
Electrocardiography is a simple investigation to perform, but accurate interpretation can be challenging. This book takes a logical and systematic approach to ECG interpretation, beginning with the ...basics of normal variations and dealing in turn with atrial abnormalities, ventricular enlargement, ventricular conduction defects and ischemic heart disease. Extensively illustrated with ECG tracings that complement the text, this book provides clear and concise explanations of traditional concepts of electrocardiography and combines them with updates on the most recent developments in the field. In 22 clinical cases, Professor Bayés de Luna illustrates the principles of the book by integrating electrocardiographic features with clinical findings for a thorough and methodical approach to cardiac disease. Regular self-assessments allow readers to evaluate their understanding of the ECG and reinforce key concepts. This book is an ideal introduction to normal and abnormal ECG patterns. It is particularly valuable for medical students, residents / junior doctors and nurses who wish to broaden their skills in electrocardiography.
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