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.
Lyme carditis and atrioventricular block Wan, Douglas, MD; Baranchuk, Adrian, MD
Canadian Medical Association journal (CMAJ),
05/2018, Letnik:
190, Številka:
20
Journal Article
Recenzirano
Odprti dostop
Lyme disease is a tick-borne bacterial infection (mainly Borrelia burgdorferi) with endemic regions predominantly along the Canada-US border. In 2016, 987 cases of Lyme disease were reported in ...Canada. The heart is involved in up to 10% of Lyme disease cases, with the development of cardiac tissue inflammation or Lyme carditis. Nearly all patients with Lyme carditis (90%) will have atrioventricular block, which commonly presents with breathlessness, palpitations, dizziness or syncope. Cardiac monitoring is critical, and temporary pacing may be needed to manage unstable atrioventricular block until adequate response to antibiotic treatment. An earlier diagnosis of Lyme disease provides a better chance of reducing or preventing lasting complications. Failure to treat Lyme disease in the early stages may increase the need for implantation of a permanent pacemaker. High-degree atrioventricular block usually resolves within one week of starting antibiotics.
Abstract Interatrial block (IAB) represents delay or block of conduction between the atria. IAB has been shown to predict the development or recurrence of atrial fibrillation (AF) in various clinical ...scenarios. Few studies have examined the correlation between coronary artery disease and the prevalence of IAB and its impact on AF. The aim of this study was to determine if specific coronary artery lesions (location and number) are associated with the presence of IAB and development of new-onset AF. Retrospective analysis of patients presenting with NSTEMI to our institution. Data were recorded for clinical, echocardiographic, angiographic, electrocardiographic and outcome variables. Semiautomatic calipers and scanned ECGs at 300 DPI maximized x 8 were used to measure P-wave duration. Follow-up for a minimum of one year. Chi-square tests and independent samples t-tests, which were done using IBM SPSS. A total of 322 patients were included in the analysis. Men 72.3%, mean age 65.4 ± 11.9 years, mean ejection fraction of 55.2 ± 12.7% and mean left atrial diameter of 38.7 ± 6mm. The prevalence of partial IAB was 31.9%, and advanced IAB was 6.5%. Patients with IAB were significantly older (<0.001) and had a greater prevalence of hypertension (0.014). The presence of diffuse coronary artery disease defined as more than one significant coronary artery lesion was associated with IAB (0.026). No specific coronary artery lesion location was found to be associated with IAB nor increased P-wave duration. Patients who developed AF during the follow-up had a significantly higher prevalence of IAB (p=0.021) and also higher prevalence of diffuse coronary artery disease (0.001). IAB is significantly associated with diffuse coronary artery disease in patients with NSTEMI. IAB is significantly associated with the development of new-onset AF within 12-months following NSTEMI.
Patients with obstructive sleep apnea (OSA) have intermittent hypoxia leading to atrial remodeling and this has been associated with the development of atrial fibrillation (AF). Postoperative AF is a ...common complication of coronary artery bypass grafting (CABG). The aim of this prospective study was to determine whether the presence of OSA predicts the occurrence of post-CABG AF (PCAF). This was a prospective single-center study. Patients undergoing elective CABG were evaluated and categorized as confirmed, high-risk, or low-risk OSA according to a modified Berlin questionnaire. PCAF was evaluated by 24-hour cardiac monitoring strip or 12-lead electrocardiography during the postoperative period, and validated by an electrophysiologist. We included 277 patients. OSA prevalence was 47.7%, with body mass index (31.0 vs 26.9 kg/m2 , p ≤0.001), advanced age (63.7 vs 66.4 years, p = 0.031), hypertension (78.0% vs 64.8%, p = 0.015), and diabetes (45.5% vs 28.3%, p = 0.003) more prevalent in the OSA group. PCAF was found to occur in 37.2% of all patients and OSA was found to be a strong predictor of PCAF (45.5% vs 29.7%, p = 0.007). PCAF was also associated with continuous positive airway pressure use (12.6% vs 5.2%, p = 0.027). Increased length of stay was associated with PCAF (6.5 vs 5.3 days, p = 0.006), as was longer time from surgery to occurrence of PCAF (p = 0.001). In conclusion, OSA was found to be a strong predictor of PCAF, which in turn was found to be associated with increased length of stay.
Atrial fibrillation (AF) is prevalent in cardiac channelopathies and may be the presenting feature in some patients. The pathogenesis is related to the primary ion channel dysfunction in atrial ...myocytes that affects atrial conduction or repolarization. The development of AF is associated with adverse outcomes, and its management is challenging in these patients. In this article we review the current information on the prevalence, risk factors, pathophysiology, and treatment of AF in specific cardiac channelopathies.
Atrial fibrillation (AF) can induce a hypercoagulable state in both the left and right atria. Thrombus in the right side of the heart (RHT) may lead to acute pulmonary embolism (APE). The aim of the ...study was to determine the prevalence of RHT and AF and to assess their impact on outcomes in patients with APE. The retrospective cohort included 1,006 patients (598 female), with a mean age of 66 ± 15 years. The primary end point was all-cause mortality. The secondary end point was incidence of complications (death, cardiogenic shock, cardiac arrest, vasopressor/inotrope treatment, or ventilatory support). Atrial fibrillation was detected in 231 patients (24%). RHT was observed in 50 patients (5%). The combination of AF and RHT was observed in 16 patients (2%). The overall mortality rate was significantly higher in patients with RHT compared with those without (32% vs 14%, respectively, odds ratio OR 3.0, 95% confidence interval CI 1.6 to 5.6, p = 0.001). The rate of complications was significantly higher in patients with RHT in comparison to those without (40% vs 22%, respectively, OR 2.4, 95% CI 1.3 to 4.4, p = 0.004). The mortality rate in patients with both AF and RHT was significantly higher in comparison to those with AF but without RHT (50% vs 20%, respectively, OR 3.86, 95% CI 1.3 to 11.2, p = 0.01). In multivariate analysis, RHT (p = 0.03) was an independent predictor of death. In conclusion, AF is a frequent co-morbidity in patients with APE, and the presence of RHT is not uncommon. Among patients with APE, the presence of RHT increases the mortality approximately threefold regardless of the presence of known AF.
Abstract Sleep apnea (SA) is a common breathing disorder. It is associated with a myriad of medical conditions including increased cardiovascular morbidity and mortality. Recent studies have shown ...that cardiac arrhythmias and conduction disorders are common in patients with SA. Sleep apnea has also been also linked to heart failure, hypertension, coronary artery disease, and stroke. The purpose of this brief review is to analyze the available information that links SA with different cardiac arrhythmias and conduction disorders and the role of intracardiac devices for the diagnosis and management of this condition.
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