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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 -
PloS One 2022The mouse is a useful preclinical species for evaluating disease etiology due to the availability of a wide variety of genetically modified strains and the ability to...
The mouse is a useful preclinical species for evaluating disease etiology due to the availability of a wide variety of genetically modified strains and the ability to perform disease-modifying manipulations. In order to establish an atrial filtration (AF) model in our laboratory, we profiled several commonly used murine AF models. We initially evaluated a pharmacological model of acute carbachol (CCh) treatment plus atrial burst pacing in C57BL/6 mice. In an effort to observe micro-reentrant circuits indicative of authentic AF, we employed optical mapping imaging in isolated mouse hearts. While CCh reduced atrial refractoriness and increased atrial tachyarrhythmia vulnerability, the left atrial (LA) excitation patterns were rather regular without reentrant circuits or wavelets. Therefore, the atrial tachyarrhythmia resembled high frequency atrial flutter, not typical AF per se. We next examined both a chronic angiotensin II (Ang II) infusion model and the surgical model of transverse aortic constriction (TAC), which have both been reported to induce atrial and ventricular structural changes that serve as a substrates for micro-reentrant AF. Although we observed some extent of atrial remodeling such as fibrosis or enlarged LA diameter, burst pacing-induced atrial tachyarrhythmia vulnerability did not differ from control mice in either model. This again suggested that an AF-like pathophysiology is difficult to demonstrate in the mouse. To continue searching for a valid murine AF model, we studied mice with a cardiac-specific deficiency (KO) in liver kinase B1 (Cardiac-LKB1), which has been reported to exhibit spontaneous AF. Indeed, the electrocardiograms (ECG) of conscious Cardiac-LKB1 KO mice exhibited no P waves and had irregular RR intervals, which are characteristics of AF. Histological evaluation of Cardiac-LKB1 KO mice revealed dilated and fibrotic atria, again consistent with AF. However, atrial electrograms and optical mapping revealed that electrical activity was limited to the sino-atrial node area with no electrical conduction into the atrial myocardium beyond. Thus, Cardiac-LKB1 KO mice have severe atrial myopathy or atrial standstill, but not AF. In summary, the atrial tachyarrhythmias we observed in the four murine models were distinct from typical human AF, which often exhibits micro- or macro-reentrant atrial circuits. Our results suggest that the four murine AF models we examined may not reflect human AF well, and raise a cautionary note for use of those murine models to study AF.
Topics: AMP-Activated Protein Kinases; Animals; Atrial Fibrillation; Atrial Flutter; Atrial Function, Left; Atrial Remodeling; Carbachol; Cardiac Pacing, Artificial; Disease Models, Animal; Electrocardiography; Mice; Mice, Inbred C57BL; Myocardium; Myocytes, Cardiac; Tachycardia, Ventricular
PubMed: 34995278
DOI: 10.1371/journal.pone.0256512 -
Journal of Cardiology Cases Sep 2021The use of leadless trans-catheter pacemakers is increasing particularly in the elderly population. However, its indication for those with anatomical anomaly remains...
The use of leadless trans-catheter pacemakers is increasing particularly in the elderly population. However, its indication for those with anatomical anomaly remains unknown. We had a 75-year-old woman with atrial standstill and ventricular escape. Micra leadless pacemaker (Medtronic, Inc, Minneapolis, MN, USA) failed to be deployed due to too enlarged right atrium accompanied by atrial septal deficiency, followed by successful implantation of transvenous pacemaker lead by using SelectSecure lead (Medtronic) with a C315 delivery catheter that enhanced back-up force toward the ventricular septum against significant tricuspid regurgitation. The Micra is a promising system, but we should understand its limitations as well as alternative systems particularly for such an anatomical anatomy. < A Micra leadless trans-catheter pacemaker is a promising system with less invasiveness, particularly for elderly patients, but we should understand its technical limitation and consider alternative systems if necessary, particularly for those with enlarged right heart.>.
PubMed: 34466178
DOI: 10.1016/j.jccase.2021.02.015 -
ESC Heart Failure Oct 2021Giant cell myocarditis (GCM) is a rare condition. Its association with SARS-CoV-2 has not been described before. The 46-year-old female patient was admitted to the...
Giant cell myocarditis (GCM) is a rare condition. Its association with SARS-CoV-2 has not been described before. The 46-year-old female patient was admitted to the clinic on September 2020. She had 7 year adrenal insufficiency history and infarct-like debut of myocardial disease in November 2019. After COVID-19 in April 2020, cardiac disease progressed. The examination showed low QRS voltage, QS complexes in V -V leads, atrial standstill, left ventricular systolic and restrictive dysfunction, elevated anti-heart antibodies, and subepicardial late gadolinium enhancement by magnetic resonance imaging. Endomyocardial biopsy and pacemaker implantation were performed, but the patient died suddenly due to ventricular tachycardia or ventricular fibrillation (the resuscitation was ineffective). The autopsy revealed GCM, SARS-CoV-2, and Parvovirus B19 were detected in the myocardium. The role of SARS-CoV-2 in the pathogenesis of autoimmune myocarditis is discussed.
Topics: COVID-19; Cardiomyopathies; Contrast Media; Death, Sudden, Cardiac; Female; Gadolinium; Genetic Diseases, Inborn; Giant Cells; Heart Atria; Heart Block; Humans; Middle Aged; SARS-CoV-2
PubMed: 34327860
DOI: 10.1002/ehf2.13520