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JACC. Clinical Electrophysiology Jan 2023
Topics: Humans; Child; Cardiomyopathies; Heart Atria; Heart Block
PubMed: 36697202
DOI: 10.1016/j.jacep.2022.11.025 -
JACC. Clinical Electrophysiology Jan 2023Atrial standstill (AS) is a rare condition characterized by absence of electrical activity within the atria. Studies to date have been limited.
BACKGROUND
Atrial standstill (AS) is a rare condition characterized by absence of electrical activity within the atria. Studies to date have been limited.
OBJECTIVES
The authors sought to describe the clinical characteristics, genetics, and outcomes of patients with AS.
METHODS
This was a retrospective multicenter study of patients <18 years at AS diagnosis, defined as absence of atrial activity documented during an electrophysiology study, device placement, or noninvasive rhythm tracings and confirmed by echocardiogram. Patients with acquired disorders were excluded. Clinical details and genetic variants were recorded and analyzed.
RESULTS
Twenty patients were diagnosed at a median age of 6.6 years (IQR: 2.9-10.8 years). Arrhythmias included 16 (80%) with atrial/supraventricular arrhythmias and 8 (40%) with ventricular tachycardia, including 4 with cardiac arrests. A type 1 Brugada pattern was documented in 4. Pacemakers were implanted in 18 (90%). Although atrial leads were attempted in 15, only 4 achieved pacing at implantation. During a median follow-up of 6.9 years (IQR: 1.2-13.3 years), 7 (35%) had thromboembolic events. Of these, none had atrial pacing, 6 were not on anticoagulation, and 1 was on aspirin. Genetic testing identified SCN5A variants in 13 patients (65%). Analyses suggest SCN5A loss-of-function may be one mechanism driving AS. Ventricular arrhythmias and cardiac arrest were more commonly seen in patients with biallelic SCN5A variants.
CONCLUSIONS
AS may be associated with loss-of-function SCN5A variants. Patients demonstrate atrial and ventricular arrhythmias, and may present challenges during device placement. Patients without the capacity for atrial pacing are at risk for thromboembolic events and warrant anticoagulation.
Topics: Humans; Child; Child, Preschool; Atrial Fibrillation; Heart Atria; Heart Block; Heart Arrest; Anticoagulants
PubMed: 36435694
DOI: 10.1016/j.jacep.2022.08.022 -
JFMS Open Reports 2022In this report, we provide detailed clinical, laboratory, electrocardiographic and echocardiographic descriptions of two -positive cats diagnosed with transient...
CASE SERIES SUMMARY
In this report, we provide detailed clinical, laboratory, electrocardiographic and echocardiographic descriptions of two -positive cats diagnosed with transient myocardial thickening (TMT) and acute myocardial injury (MI). In both cases, aetiological diagnosis was based on the antibody screening test (all cats had IgM titres ⩾1:64) and MI was demonstrated by a concomitant severe increase of the serum concentration of cardiac troponin I (5.1-23.6 ng/ml; upper hospital limit <0.2 ng/ml). In both cats, TMT and MI were aggravated by left atrial dilation and dysfunction, as well as congestive heart failure. In one cat, atrial standstill was also documented, while the other cat showed an intracardiac thrombus. Both cats underwent an extensive diagnostic work-up aimed at excluding additional comorbidities that could contribute to able to contribute to TMT and MI, and received appropriate antiprotozoal (ie, clindamycin) and cardiovascular therapy (eg, furosemide, pimobendan and clopidogrel). This was followed by a simultaneous decline in serology titres, normalisation of troponin level and the resolution of clinical, electrocardiographic, radiographic and echocardiographic abnormalities. In the light of these results, therapies were interrupted and subsequent controls ruled out any disease relapse.
RELEVANCE AND NOVEL INFORMATION
Although represents an often-cited cause of myocarditis in feline medicine, the existing literature on the demonstration of -associated cardiac compromise in cats is extremely limited. Accordingly, this report provides a useful contribution to pertinent scientific literature since it describes TMT and acute MI in two -positive cats.
PubMed: 36339325
DOI: 10.1177/20551169221131266 -
HeartRhythm Case Reports Sep 2022
PubMed: 36147716
DOI: 10.1016/j.hrcr.2022.06.010 -
Korean Circulation Journal Sep 2022
PubMed: 35927039
DOI: 10.4070/kcj.2022.0094 -
Cureus May 2022Atrial standstill is a rare condition in which the atrium loses its mechanical contraction with or without losing the electrical conduction. In this report, we discuss...
Atrial standstill is a rare condition in which the atrium loses its mechanical contraction with or without losing the electrical conduction. In this report, we discuss a case of a 64-year-old male patient with a history of hypertrophic cardiomyopathy (HCM) and persistent refractory atrial fibrillation (AF). He underwent ablation therapy with a successful return to sinus rhythm. However, post-procedure echocardiography imaging showed the absence of left atrium mechanical activity. We aim to highlight the importance of assessing atrial mechanical activity by imaging after sinus cardioversion in order to treat any preventable complications promptly.
PubMed: 35755564
DOI: 10.7759/cureus.25293 -
Orphanet Journal of Rare Diseases May 2022Arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) is associated with ventricular arrhythmia, heart failure (HF), and sudden death. Thromboembolism is...
Rare and potential pathogenic mutations of LMNA and LAMA4 associated with familial arrhythmogenic right ventricular cardiomyopathy/dysplasia with right ventricular heart failure, cerebral thromboembolism and hereditary electrocardiogram abnormality.
BACKGROUND
Arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) is associated with ventricular arrhythmia, heart failure (HF), and sudden death. Thromboembolism is also an important and serious complication of ARVC/D. However, the etiology of ARVC/D and thromboembolism and their association with genetic mutations are unclear.
METHODS
Genomic DNA samples of peripheral blood were conducted for whole-exome sequencing (WES) and Sanger sequencing in the ARVC/D family. Then, we performed bioinformatics analysis for genes susceptible to cardiomyopathies and arrhythmias. Further, we analyzed how the potential pathogenic mutations were affecting the hydrophobicity and phosphorylation of amino acids and their joint pathogenicity by ProtScale, NetPhos and ORVAL algorisms.
RESULTS
We discovered a Chinese Han family of ARVC/D with right ventricular HF (RVHF), cerebral thromboembolism, arrhythmias (atrial fibrillation, atrial standstill, multifocal ventricular premature, complete right bundle block and third-degree atrioventricular block) and sudden death. Based on the WES data, the variants of LMNA p.A242V, LAMA4 p.A225P and RYR2 p.T858M are highly conserved and predicated as "deleterious" by SIFT and MetaSVM algorithms. Their CADD predicting scores are 33, 27.4 and 25.8, respectively. These variants increase the hydrophobicity of their corresponding amino acid residues and their nearby sequences by 0.378, 0.266 and 0.289, respectively. The LAMA4 and RYR2 variants lead to changes in protein phosphorylation at or near their corresponding amino acid sites. There were high risks of joint pathogenicity for cardiomyopathy among these three variants. Cosegregation analysis indicated that LMNA p.A242V might be an important risk factor for ARVC/D, electrocardiogram abnormality and cerebral thromboembolism, while LAMA4 p.A225P may be a pathogenic etiology of ARVC/D and hereditary electrocardiogram abnormality.
CONCLUSIONS
The LMNA p.A242V may participate in the pathogenesis of familial ARVC/D with RVHF and cerebral thromboembolism, while LAMA4 p.A225P may be associated with ARVC/D and hereditary electrocardiogram abnormality.
Topics: Amino Acids; Arrhythmogenic Right Ventricular Dysplasia; Death, Sudden; Electrocardiography; Heart Failure; Humans; Lamin Type A; Laminin; Mutation; Ryanodine Receptor Calcium Release Channel; Thromboembolism
PubMed: 35526016
DOI: 10.1186/s13023-022-02348-z -
Biology Mar 2022Cardiolaminopathies are a heterogeneous group of disorders which are due to mutations in the genes encoding for nuclear lamins or their binding proteins. The whole... (Review)
Review
Cardiolaminopathies are a heterogeneous group of disorders which are due to mutations in the genes encoding for nuclear lamins or their binding proteins. The whole spectrum of cardiac manifestations encompasses atrial arrhythmias, conduction disturbances, progressive systolic dysfunction, and malignant ventricular arrhythmias. Despite the prognostic significance of cardiac involvement in this setting, the current recommendations lack strong evidence. The aim of our work was to systematically review the current data on the main cardiovascular outcomes in cardiolaminopathies. We searched PubMed/Embase for studies focusing on cardiovascular outcomes in mutation carriers (atrial arrhythmias, ventricular arrhythmias, sudden cardiac death, conduction disturbances, thromboembolic events, systolic dysfunction, heart transplantation, and all-cause and cardiovascular mortality). In total, 11 studies were included (1070 patients, mean age between 26-45 years, with follow-up periods ranging from 2.5 years up to 45 ± 12). When available, data on the -mutated population were separately reported (40 patients). The incidence rates (IR) were individually assessed for the outcomes of interest. The IR for atrial fibrillation/atrial flutter/atrial tachycardia ranged between 6.1 and 13.9 events/100 pts-year. The IR of atrial standstill ranged between 0 and 2 events/100 pts-year. The IR for malignant ventricular arrhythmias reached 10.2 events/100 pts-year and 15.6 events/100 pts-year for appropriate implantable cardioverter-defibrillator (ICD) interventions. The IR for advanced conduction disturbances ranged between 3.2 and 7.7 events/100 pts-year. The IR of thromboembolic events reached up to 8.9 events/100 pts-year. Our results strengthen the need for periodic cardiological evaluation focusing on the early recognition of atrial arrhythmias, and possibly for the choice of preventive strategies for thromboembolic events. The frequent need for cardiac pacing due to advanced conduction disturbances should be counterbalanced with the high risk of malignant ventricular arrhythmias that would justify ICD over pacemaker implantation.
PubMed: 35453731
DOI: 10.3390/biology11040530 -
Frontiers in Cardiovascular Medicine 2022Atrial standstill (AS) is a rare condition defined by the lack of atrial electrical and mechanical activities. It is usually clinically manifested as symptomatic...
Atrial standstill (AS) is a rare condition defined by the lack of atrial electrical and mechanical activities. It is usually clinically manifested as symptomatic bradycardia, which requires permanent pacemaker (PPM) implantation. Traditional right ventricular apical pacing causes electrical and mechanical dyssynchrony resulting in left ventricular dysfunction, heart failure, and arrhythmias. As a novel physiological pacing strategy, left bundle branch area pacing (LBBaP) has demonstrated effectiveness and safety in recent years, but its application in exceptional conditions is rarely reported. We report the case of a 47-year-old female, who was diagnosed with AS complicated with a giant atrium, and successfully received a single-chamber PPM with LBBaP.
PubMed: 35425822
DOI: 10.3389/fcvm.2022.836964 -
European Heart Journal. Case Reports Jun 2023Anti-mitochondrial antibody (AMA)-associated myopathy is known to be concomitant with primary biliary cirrhosis and to cause both skeletal muscle disorders and...
BACKGROUND
Anti-mitochondrial antibody (AMA)-associated myopathy is known to be concomitant with primary biliary cirrhosis and to cause both skeletal muscle disorders and arrhythmias, myocardium disorders, and respiratory muscle disorders. We report a case of AMA-associated myopathy in which the bradycardia-related symptoms preceded the skeletal muscle symptoms.
CASE SUMMARY
A 59-year-old woman visited the emergency room in our hospital following a syncopal event. The patient was bradycardiac (45 b.p.m.) with a junctional rhythm resulting from sick sinus syndrome (SSS) and was suffering from heart failure. Blood tests revealed elevated creatine kinase (CK) and hepatic enzymes. She underwent permanent pacemaker implantation. However, it proved difficult to detect the electrical potential in the right atrium. Although successful atrial pacing was achieved at the lower right atrial septum, the atrial threshold was markedly high and she depended on ventricular pacing. One year later, neurological examination and muscle biopsy confirmed the diagnosis of AMA-associated myopathy. Following this diagnosis, steroid pulse therapy was initiated. Steroid administration relieved her symptoms and lowered the CK levels but the atrial standstill persisted. The patient takes low-dose prednisolone and has had an uneventful course for 3 years.
DISCUSSION
To the best of our knowledge, this is the first case of AMA-associated myopathy diagnosed by the first symptom related to bradycardia due to SSS. Patients with AMA-associated myopathy can experience a variety of cardiac symptoms, including arrhythmias, and initially complain of cardiac symptoms without symptoms of skeletal myopathy. This disease should be considered when diagnosing patients with arrhythmia and elevated CK.
PubMed: 37323533
DOI: 10.1093/ehjcr/ytac158