Interatrial block to predict atrial fibrillation in myotonic dystrophy type 1

Advanced Interatrial Block across the Spectrum of Renal Function

Background and Objective: Interatrial block (IAB) is defined as a conduction delay between the right and left atria. No data are available about the prevalence of both partial IAB and advanced IAB among the different stages of chronic kidney disease. The aim of this study was to describe the prevalence and type of advanced IAB across the spectrum of renal function, including patients on dialysis and the clinical characteristics associated with advanced IAB. Materials and Methods: Retrospective, single-center study of 151 patients consecutively admitted to the Nephrology and Ophthalmology Unit for 3 months. The study population was divided into three groups according to stages of chronic kidney disease. We evaluated the prevalence and pattern of IAB among the groups and the clinical characteristics associated with advanced IAB. Results: The prevalence of partial IAB was significantly lower in end-stage kidney disease (ESKD) group compared to control group (36.7% vs. 59.6%; p = 0.02); in contrast the prevalence of advanced IAB was significantly higher in both chronic kidney disease (CKD) (17.8% vs. 5.3%, p = 0.04) and ESKD group (24.5% vs. 5.3%, p = 0.005) compared to control group. The atypical pattern of advanced IAB was more frequent in both the ESKD and CKD group than in the control group (100% and 75% vs. 33.3%; p = 0.02). Overall, among patients that showed advanced IAB, 17 (73.9%) showed an atypical pattern by morphology and 2 (8.7%) showed an atypical pattern by duration of advanced IAB. The ESKD group was younger than the control group (65.7 ± 12.3 years vs. 71.3 ± 9.9 years; p = 0.01) and showed a higher prevalence of beta blockers (42.9% vs. 19.3%; p = 0.009), as in the CKD group (37.8% vs. 19.3%; p= 0.04). Conclusions: The progressive worsening of renal function was associated with an increasing prevalence of advanced IAB. Advanced IAB may be a sign of uremic cardiomyopathy and may suggest further evaluation with long-term follow-up to investigate its prognostic significance in chronic kidney disease.

Interatrial block as a first clinical presentation of atrial cardiomyopathy related to a novel LMNA variant: a case report

Background

Interatrial block (IAB) is a conduction delay in Bachmann's bundle with a well-described association with structural heart disease, supraventricular arrhythmias, and cardiovascular events.

Case summary

We report the case of an asymptomatic 35-year-old man in whom the presence of IAB at electrocardiogram led to a comprehensive evaluation including speckle-tracking echocardiography, 24 h Holter monitoring, and genetic testing. Speckle-tracking echocardiography demonstrated a decrease in the longitudinal strain of interventricular septum, a typical feature of LMNA-related cardiomyopathy, and decreased indices of left atrial deformation. A diagnosis of cardiac laminopathy related to the frame shift variant c.1367 (p.Asn456Thrfs*24) of the LMNA gene was made. A dual-chamber implantable cardioverter defibrillator implantation was performed for the high risk of life-threatening ventricular tachyarrhythmias.

Discussion

This case demonstrates that IAB could be a rare presentation of a life-threatening laminopathy. Strain echocardiography is an essential tool to evaluate the deposition of fibrosis tissue in subclinical cardiomyopathies. Our report describes a novel variant of LMNA gene associated with a high risk of sudden cardiac death.

Electrocardiographic Predictors of Atrial Fibrillation

BACKGROUND

Atrial fibrillation (AF) is the most common pathological arrhythmia, and its complications lead to significant morbidity and mortality. However, patients with AF can often go undetected, especially if they are asymptomatic or have a low burden of paroxysms. Identification of those at high risk of AF development may help refine screening and management strategies.

METHODS

PubMed and Embase databases were systematically searched for studies looking at electrocardiographic predictors of AF from inception to August 2021.

RESULTS

A total of 115 studies were reported which examined a combination of atrial and ventricular parameters that could be electrocardiographic predictors of AF. Atrial predictors include conduction parameters, such as the PR interval, p-wave index and dispersion, and partial interatrial or advanced interatrial block, or morphological parameters, such as p-wave axis, amplitude and terminal force. Ventricular predictors include abnormalities in QRS amplitude, morphology or duration, QT interval duration, r-wave progression and ST segment, i.e., t-wave abnormalities.

CONCLUSIONS

There has been significant interest in electrocardiographic prediction of AF, especially in populations at high risk of atrial AF, such as those with an embolic stroke of undetermined source. This review highlights the breadth of possible predictive parameters, and possible pathological bases for the predictive role of each parameter are proposed.

Echocardiographic Features of Cardiac Involvement in Myotonic Dystrophy 1: Prevalence and Prognostic Value

Myotonic dystrophy type 1 (DM1) is the most common muscular dystrophy in adults. Cardiac involvement is reported in 80% of cases and includes conduction disturbances, arrhythmias, subclinical diastolic and systolic dysfunction in the early stage of the disease; in contrast, severe ventricular systolic dysfunction occurs in the late stage of the disease. Echocardiography is recommended at the time of diagnosis with periodic revaluation in DM1 patients, regardless of the presence or absence of symptoms. Data regarding the echocardiographic findings in DM1 patients are few and conflicting. This narrative review aimed to describe the echocardiographic features of DM1 patients and their prognostic role as predictors of cardiac arrhythmias and sudden death.

Pneumonia and de novo atrial fibrillation in a patient with myotonic dystrophy type 1: A case report

INTRODUCTION

Myotonic dystrophy type 1 is a rare genetic disorder that mainly affects the musculoskeletal system; However, it may cause several complications in other body systems representing challenges for health care providers.

PATIENT CONCERNS

We present the case of a patient with a history of previously diagnosed type 1 myotonic dystrophy who presented to the emergency department with cough dyspnea, and thoracic pain.

DIAGNOSIS

Differential diagnoses included pulmonary embolism with a moderate probability according to the Wells score, acute coronary syndrome, acute heart failure, and pneumonia. Diagnostic workup involved chest radiography, EKG, and a CTPA which revealed pneumonia, posteriorly the patient presented de novo atrial fibrillation.

INTERVENTIONS

The patient was successfully treated with empiric antibiotic therapy and amiodarone, respiratory and physical therapy.

OUTCOMES

The patient was discharged on day 34, however oxygen weaning was not possible.

CONCLUSION

Treatment of MD1 patients is challenging due to the various mechanisms of the disease; patients with new-onset deterioration should be screened for the most common complications such as cardio-respiratory events.The authors suggest pneumonia as a risk factor for basal respiratory function deterioration and a contributing factor for triggering cardiac events for further research in prospective studies.

The prognostic role of interatrial block among COVID-19 patients hospitalized in medicine wards

INTRODUCTION

Some abnormal electrocardiographic findings were independently associated with increased mortality in patients admitted for COVID-19; however, no studies have focussed on the prognosis impact of the interatrial block (IAB) in this clinical setting. The aim of our study was to assess the prevalence and clinical implications of IAB, both partial and advanced, in hospitalized COVID-19 patients.

MATERIALS

We retrospectively evaluated 300 consecutive COVID-19 patients (63.22 ± 15.16 years; 70% males) admitted to eight Italian Hospitals from February 2020 to April 2020 who underwent twelve lead electrocardiographic recording at admission. The study population has been dichotomized into two groups according to the evidence of IAB at admission, both partial and advanced. The differences in terms of ARDS in need of intubation, in-hospital mortality and thromboembolic events (a composite of myocardial infarction, stroke and transient ischaemic attack) have been evaluated.

RESULTS

The presence of IAB was noticed in 64 patients (21%). In the adjusted logistic regression model, the partial interatrial block was found to be an independent predictor of ARDS in need of intubation (HR: 1.92; p: .04) and in-hospital mortality (HR: 2.65; p: .02); moreover, the advanced interatrial block was an independent predictor of thrombotic events (HR: 7.14; p < .001).

CONCLUSIONS

Among COVID-19 patients hospitalized in medical wards, the presence of interatrial block is more frequent than in the general population and it might be useful as an early predictor for increased risk of incident thrombotic events, ARDS in need of intubation and in-hospital mortality.

Prevalence of atrial fibrillation in myotonic dystrophy type 1: A systematic review

Cardiac involvement is recorded in about 80% of patients affected by myotonic dystrophy type 1 (DM1). The prevalence of cardiac conduction abnormalities is well described. Data regarding the prevalence of atrial fibrillation (AF) are still conflicting. The primary objective of this review was to assess the prevalence of AF in DM1. The secondary aim was to examine the association of clinical features with AF, to detect predisposing and/or influencing prognosis factors. A systematic search was developed in MEDLINE, EMBASE, Cochrane Register of Controlled Trials and Web of Science databases, to identify original reports between January 1, 2002 and January 30, 2020, assessing the prevalence of AF in DM1 population. Retrospective/prospective cohort studies and case series describing the prevalence of atrial fibrillation evaluated by periodic electrocardiogram (ECG) and/or ECG Holter 24 h, external loop recording (ELR) and implantable devices interrogation in DM1 patients were included. Case reports, simple reviews, commentaries and editorials were excluded. Thirteen reports fulfilled eligibility criteria and were included in our systematic review. According to the results from all the evaluated studies, the mean prevalence of AF in DM1 patients was 10.9% (n = 404) in 3677 DM1 patients. Male sex, conduction defects, echocardiographic findings of prolonged atrial electromechanical delay seem to be strongly associated with atrial fibrillation, representing factors favoring its onset. DM1 patients who develop AF seem to have a higher risk of cardiovascular and non-cardiovascular death. Further studies are needed to assess the prevalence of AF in DM1 patients and to investigate ECG abnormalities and other clinical features associated with this condition.

Prevalence of Left Ventricular Systolic Dysfunction in Myotonic Dystrophy Type 1: A Systematic Review

Cardiac involvement is recorded in about 80% of patients affected by myotonic dystrophy type 1 (DM1). The prevalence of cardiac conduction abnormalities and arrhythmias has been well described. Data regarding the prevalence of left ventricle systolic dysfunction (LVSD) and heart failure (HF) are still conflicting. The primary objective of this review was to assess the prevalence of LVSD and HF in DM1. The secondary aim was to examine the association of clinical features with LVSD and to detect predisposing and influencing prognosis factors. A systematic search was developed in MEDLINE, EMBASE, Cochrane Register of Controlled Trials, and Web of Science databases to identify original reports between January 1, 2009, and September 30, 2017, assessing the prevalence of LVSD and HF in populations with DM1. Retrospective and prospective cohort studies and case series describing the prevalence of LVSD, as evaluated by echocardiography, and HF in patients with DM1 were included. Case reports, simple reviews, commentaries and editorials were excluded. Seven studies were identified as eligible, of which 1 was a retrospective population-based cohort study, and 6 were retrospective single-center-based cohort studies. Echocardiographic data concerning LV function were available for 647 of the 876 patients with DM1 who were included in the analysis. The prevalence of LVSD in patients with DM1, defined as LVEF < 55%, was 13.8%, 4.5-fold higher than in general population. Patients with DM1 and LVSD were older, were more likely to be male, had longer baseline atrioventricular and intraventricular conduction-time durations, had higher incidences of atrial arrhythmias, and were more likely to have undergone device implantation. Also, symptomatic HF is more prevalent in patients with DM1 despite their limited levels of physical activity. Further studies are needed to evaluate the prevalence of LVSD and HF in patients with DM1 and to investigate electrocardiographic abnormalities and other clinical features associated with this condition.

Update on Bayés' syndrome: the association between an interatrial block and supraventricular arrhythmias

INTRODUCTION

The past few years have given rise to extensive research on an interatrial block and its clinical relevance, mainly its association with supraventricular arrhythmias. In 2015, the authors of this article reviewed the Bayes syndrome for the first time and after three years there has been so much evidence accumulated that it seems reasonable to rewrite an update, based fundamentally on the new findings. Focused on its relationship with cardioembolic strokes, today efforts are being targeted at understanding its pathophysiology, its diagnosis, and its prognostic implications, in order to learn if it should be treated. Areas covered: A non-systematic review of the literature was developed using the Pubmed and Cochrane databases, focusing on randomized clinical trials and large observational studies that evaluated new physiopathological and epidemiological aspects, new clinical scenarios in which it has been assessed and its association with dementia. Finally, those studies that proposed new possible treatments were reviewed. Expert commentary: Interatrial block is not only a predictor of supraventricular arrhythmias, is a subclinical disease that might be considered as a marker of risk for adverse outcomes. Although there is some evidence to suggest that early treatment may be beneficial, potential therapies have yet to be investigated.