Severe Arrhythmias Research Articles

Preoperative Transthoracic Echocardiography Predicts Cardiac Complications in Elderly Patients with Coronary Artery Disease Undergoing Noncardiac Surgery.

PurposeGuidelines have not recommended routine transthoracic echocardiography (TTE) for elderly patients prior to noncardiac surgery. We aimed to evaluate the significance of preoperative TTE to predict perioperative cardiac complications (PCCs) for elderly patients with coronary artery disease (CAD) undergoing noncardiac surgery.Patients and methodsWe retrospectively reviewed 2204 patients over 65 years of age with CAD who underwent TTE before intermediate- or high-risk noncardiac surgery in a teaching hospital in China between September 2013 and August 2019. The revised cardiac risk index (RCRI) was assessed. PCCs comprised acute coronary syndrome, heart failure, new-onset severe arrhythmia, nonfatal cardiac arrest, and cardiac death. Logistic regression was used to build the prediction model for PCCs. Discrimination was evaluated using receiver operating characteristic curves, and a nomogram of the predictive model was constructed.ResultsPCCs occurred in 189 (8.6%) patients. Multivariable analysis showed that eight clinical risk factors (age, history of myocardial infarction, insulin therapy for diabetes, New York Heart Association classification, preoperative serum creatinine, preoperative electrocardiogram ST-T abnormality and pathological Q wave, and American Society of Anesthesiologists classification) and five TTE parameters (left atrial anteroposterior dimension, left ventricular ejection fraction, left ventricular diastolic dysfunction, pulmonary hypertension, and regional ventricular wall motion abnormality) were associated with PCCs. The receiver operating characteristic curve for the clinical plus TTE model provided better discrimination for PCCs compared with the RCRI model (area under the curve: 0.731 vs 0.564; P < 0.001) and the clinical model (area under the curve: 0.731 vs 0.697, P = 0.001), respectively. The clinical plus TTE model was presented as a prognostic nomogram.ConclusionPreoperative TTE may help predict PCCs in elderly patients with CAD undergoing noncardiac surgery, and the prognostic nomogram from this study appeared to be useful for the assessment of perioperative cardiac risk.

Blunt traumatic right coronary artery dissection presenting with second-degree atrioventricular block and late-onset severe cardiogenic shock

BackgroundBlunt chest injury may induce several cardiovascular traumata, requiring immediate care. Right coronary artery dissection (RCA) is an extremely rare sequela in this setting and is associated with high mortality, if it remains undiagnosed.Case presentationWe present the case of an RCA dissection after blunt chest trauma in a 16-year-old patient, who initially presented with a second-degree atrioventricular block as solitary manifestation on admission. Typical electrocardiographic findings, such as ST segmental changes or pathological Q waves were absent. Serial echocardiograms excluded segmental motion abnormalities, pericardial effusion or right ventricular strain. Nevertheless, a complementary computed tomography coronary angiography revealed this potentially lethal condition several hours later. The patient underwent an emergency surgical myocardial revascularization under the circulatory support of veno-arterial extracorporeal membrane oxygenation and suffered a prolonged right ventricular insufficiency with severe late-onset cardiogenic shock, due to an extensive myocardial infarction of the inferoseptal ventricular wall.ConclusionRight coronary artery dissection after high-speed blunt chest injury constitutes a diagnostic challenge, especially in the absence of typical electrocardiographic and echocardiographic findings in young patients. This condition may dramatically deteriorate in time, leading to severe cardiogenic shock and life-threatening arrhythmias.

Severe Arrhythmia Caused by Abscess Endocarditis on a Bicuspid Aortic Valve: Case Report and Literature Review

The incidence of infective endocarditis (IE) on the bicuspid valve is high with serious complications. Perivalvular extension is one of the most serious complications because it can be complicated by conduction disorders such as AV block or bundle branch block or rhythm disorders, often with a poor prognosis. We report a rare case of infective endocarditis in a bicuspid aortic valve complicated by perivalvular abscess and trifasicular block.

Shannon entropy Morlet wavelet Transform (SEMWT) and Kernel Weight Convolutional Neural Network (KWCNN) classifier for arrhythmia in electrocardiogram recordings

The automatic detection and classification of life-threatening arrhythmia is life-threatening in treatment of a variety of cardiac diseases. Cardiac arrhythmias are irregular heartbeats that are either too fast (tachycardia) or too slow (bradycardia). Minor alteration in the morphology or dynamics of the Electrocardiogram (ECG) can induce severe arrhythmia events, that can decrease the heart's ability to pump blood and cause breathing difficulties, chest pain, tiredness, and loss of consciousness. A unique deep learning technique for classification of distinct types of arrhythmia utilizing feature extraction is provided in this research. To acquire morphological features, the Shannon Entropy Morlet Wavelet Transform (SEMWT) is done to every heart beat. This work uses Empirical Mode Decompositions (EMDs) with Fuzzy Weight Beetle Swarm Optimization (FWBSO) is introduced for signal noise removal. Then, utilising Kullback-Leibler Divergence Kernel Principal Component Analysis (KLDKPCA) and Dynamic Time Wrapping ECG segments are selected, whereas morphological features from P-QRS-T waves are extracted using SEMWT. SEMWT improves the time and frequency resolution of an ECG signal, making it easier to decode critical information. ECG signal was divided into low-frequency approximation and high-frequency detail components after applying SEMWT. Then, with high accuracy, a Kernel Weight Convolutional Neural Network (KWCNN)-based automated arrhythmia classification is constructed. This work’s resulted are evaluated with performance metrics of Sensitivity (SEN), F-measure, Positive Predictivity (PP) and Accuracy (ACC). Over the whole MIT-BIH Arrhythmias Database, the suggested approach was tested. The suggested classification approach was first tested in MATLAB, with the results compared to those of other methods.

Peak Oxygen Uptake on Cardiopulmonary Exercise Test Is a Predictor for Severe Arrhythmic Events during Three-Year Follow-Up in Patients with Complex Congenital Heart Disease.

Patients with congenital heart disease (CHD) are at increased risk for severe arrhythmia and sudden cardiac death (SCD). Although implantable cardioverter defibrillators (ICD) effectively prevent SCD, risk stratification for primary prophylaxis in patients with CHD remains challenging. Patients with complex CHD undergoing CPET were included in this single-center study. Univariable and backwards stepwise multivariable logistic regression models were used to identify variables associated with the endpoint of severe arrhythmic event during three years of follow-up. Cut-off values were established with receiver operating characteristic (ROC) curve analysis. Survival analysis was conducted via Kaplan–Meier plots. Severe Arrhythmia was documented in 97 of 1194 patients (8.1%/3 years). Independent risk factors for severe arrhythmia during follow-up were old age and a low peak oxygen uptake (O2peak) on multivariable analysis. Patients with more advanced age and with O2peak values of less than 24.9 mL/min/kg were at significantly increased risk for the occurrence of severe arrhythmias during follow-up. The combined analysis of both risk factors yielded an additional benefit for risk assessment. Age at CPET and O2peak predict the risk for severe arrhythmic events and should be considered for risk stratification of SCD in patients with complex CHD.

The Prognostic Value of Cardiac Troponin I in Patients with or without Three-Vessel Disease Undergoing Complete Percutaneous Coronary Intervention.

Postprocedural cardiac troponin I (cTnI) elevation commonly occurs in patients undergoing percutaneous coronary intervention (PCI); however, its prognostic value remains controversial. This study aimed to investigate the prognostic value of peak postprocedural cTnI in cardiac patients with or without three-vessel disease (TVD) undergoing complete PCI. A total of 1237 consecutive patients (77% males, mean age 58 ± 10 years) with normal baseline cTnI levels were enrolled, 439 patients (77% males, 59 ± 10 years) with TVD, and 798 patients (77% males, 57 ± 10 years) with single- or double-vessel disease (non-TVD). The primary outcome was the occurrence of major adverse cardiovascular events (MACE), defined as a composite of non-fatal MI, non-fatal stroke, unplanned revascularization, re-hospitalization due to heart failure or severe arrhythmias, and all-cause death. During the median follow-up of 5.3 years, a total of 169 patients (13.7%) developed MACE, including 73 (16.6%) in the TVD group and 96 (12.0%) in the non-TVD group (p = 0.024). After adjustment, the multivariate Cox analysis showed that hypertension (HR 1.50; 95% CI: 1.01–2.20; p = 0.042), TVD (HR 1.44; 95% CI: 1.03–2.02; p = 0.033), and cTnI ≥ 70× URL (HR 2.47; 95% CI: 1.28–4.78, p = 0.007) were independently associated with increased MACE during long-term follow-up. Further subgroup analyses showed that cTnI ≥ 70× URL was an independent predictor of MACE in TVD patients (HR 3.32, 95% CI: 1.51–7.34, p = 0.003), but not in non-TVD patients (HR 1.01, 95%CI: 0.24–4.32, p = 0.991). In conclusion, elevation of post-PCI cTnI ≥ 70× URL is independently associated with a high risk of MACE during long-term follow-up in patients with TVD, but not in those with non-TVD.

Arrhythmias and Heart Failure in Pregnancy: A Dialogue on Multidisciplinary Collaboration.

The prevalence of CVD in pregnant people is estimated to be around 1 to 4%, and it is imperative that clinicians that care for obstetric patients can promptly and accurately diagnose and manage common cardiovascular conditions as well as understand when to promptly refer to a high-risk obstetrics team for a multidisciplinary approach for managing more complex patients. In pregnant patients with CVD, arrhythmias and heart failure (HF) are the most common complications that arise. The difficulty in the management of these patients arises from variable degrees of severity of both arrhythmia and heart failure presentation. For example, arrhythmia-based complications in pregnancy can range from isolated premature ventricular contractions to life-threatening arrhythmias such as sustained ventricular tachycardia. HF also has variable manifestations in pregnant patients ranging from mild left ventricular impairment to patients with advanced heart failure with acute decompensated HF. In high-risk patients, a collaboration between the general obstetrics, maternal-fetal medicine, and cardiovascular teams (which may include cardio-obstetrics, electrophysiology, adult congenital, or advanced HF)—physicians, nurses and allied professionals—can provide the multidisciplinary approach necessary to properly risk-stratify these women and provide appropriate management to improve outcomes.

Acute Heart Failure, 90-Day Mortality, and Gravitational Ischemia in the Brain.

During the 90 days following hospitalization for acute heart failure, the ejection fraction and type of discharge medications have been shown in clinical trials to have little effect on mortality. We examined the recent literature addressing brain-related etiologies of sudden death following heart failure. Two mechanisms of sudden unexpected death have been suggested to possibly result from four significant influences on pathophysiology in the brain. The two causes of sudden death are (1) severe cardiac arrhythmia and (2) neurogenic pulmonary edema. They are both mediated through the brainstem autonomic nuclei generally and executed specifically through the dorsal motor nucleus of the vagus nerve. The four significant influences on pathophysiology, all contributing to ischemia in the brainstem autonomic nuclei, are: (1) Hyper-stimulation of neurons in the solitary tract nucleus, increasing their metabolic requirements; (2) Inadequate blood flow at a vascular watershed terminus, perfusing the autonomic nuclei; (3) Additionally decreased blood flow, globally throughout the brain, following vasoconstriction related to relative hyperventilation and decreased pCO2 levels; (4) Gravitational ischemia in the brainstem caused by the weight of the cerebral hemispheres sitting above the brainstem. Changes in head tilt release gravitational ischemia in the brain. There is no specific head position relative to gravity that is considered favorable or unfavorable for an extended period of time, longer than 24 h. Even a small degree of head elevation, used in managing pulmonary congestion, may increase gravitational ischemia in the posterior fossa and brainstem. In this paper, we suggest a new and important research avenue for intervening in cardiac arrhythmias and preventing their occurrence through the non-invasive use of head-tilting and other head repositioning maneuvers. This could potentially help many geriatric patients with heart failure, who have decreased mobility in bed, and who tend to stay in one position longer, thereby increasing gravitational ischemia in the brain.

Capabilities of long-term ECG monitoring in patients with myocardial infarction: the longer, the better?

Background. In modern cardiology, 24-hour electrocardiogram (ECG) monitoring has a high diagnostic value, but this method has a number of disadvantages in detecting episodes of unstable life-threatening arrhythmias. An increase in ECG monitoring duration allows expanding the possibilities of diagnosing life-threatening arrhythmias.Objective. To study the possibilities of long-term ECG monitoring (48–120 hours) in the detection of life-threatening arrhythmic events and parameters of myocardial electrical instability in patients with ST-segment elevation myocardial infarction (STEMI).Design and methods. The study included 71 STEMI patients. All patients from the 4th day of STEMI underwent multi-day ECG monitoring in 3 leads using a telemetric ECG recording complex with an average recording duration of 90.4 ± 30.2 hours. The analysis of episodes of myocardial ischemia, rhythm and conduction disturbances, turbulence and heart rate variability, late ventricular potentials and dispersion of the QT interval within 5 days was carried out.Results. Long-term monitoring allowed detecting high-grade ventricular extrasystoles. Analysis of episodes of myocardial ischemia in the postinfarction period revealed significant differences in the data of 120h-ECG monitoring in comparison with 24h-ECG. Multiday ECG monitoring made it possible to detect dysfunction of the autonomic regulation of cardiac activity in patients 2 times more often.Conclusion. A comprehensive assessment of the possibilities of multi-day ECG monitoring is a promising direction in predicting severe arrhythmias in patients in the postinfarction period.

Maturation of hiPSC-derived cardiomyocytes in cardiac microtissues promotes adult alternative splicing of sodium channel revealing mutation effects associated with cardiac arrhythmia

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – EU funding. Main funding source(s): Marie Skłodowska-Curie Actions - Individual Fellowship Background The cardiac sodium channel encoded by SCN5A gene undergoes fetal-to-adult isoform switch postnatally, regulated by alternative splicing. Various mutations in SCN5A associated with severe cardiac arrhythmia have been previously studied using cardiomyocytes derived from human induced pluripotent stem-cells (hiPSC-CMs), demonstrating the importance of a human cardiac cellular context for such analysis. Mutations in the adult isoform of SCN5A are however of difficult evaluation in hiPSC-CMs, because of their typical immature/fetal-like characteristics. Combining hiPSC-CMs in 3-dimensional microtissues together with hiPSC-derived cardiac fibroblasts and endothelial cells induced maturation in gene expression and functional properties, including electrophysiology. Purpose We investigated whether the maturation promoted by the microtissue system could reveal the functional phenotype of a mutation in the adult isoform of SCN5A. Methods We derived hiPSC-CMs from a cardiac arrhythmia patient carrying two compound mutations in SCN5A: p.W156X in exon 4 and p.R225W in the adult splicing variant of exon 6 (exon 6B). Using CRISPR/Cas9, we corrected exon 4 mutation to investigate specific effects of exon 6B mutation on sodium current by single-cell patch clamp. HiPSC-CMs were matured in tricell-type cardiac microtissues and analysed after dissociation. The mechanism underlying exon 6B expression was investigated by overexpressing or knocking-out the alternative splicing regulator MBNL1 in hiPSC-CMs. Results ddPCR analysis showed low expression of exon 6B-containing transcripts in hiPSC-CMs, accompanied by no effect of exon 6B mutation on the sodium current. Instead, maturing hiPSC-CMs in cardiac microtissues promoted SCN5A exon 6B expression and revealed the contribution of both SCN5A mutations to the diseased cellular electrophysiology. MBNL1 was upregulated in microtissues and indeed its overexpression was sufficient to increase exon 6B levels in hiPSC-CMs, while lack of MBNL1 prevented the switch of SCN5A splicing isoforms. Conclusions Our data demonstrate that a maturation of hiPSC-CMs is required to express the adult SCN5A isoform. This was achieved in the microtissue system via upregulation of MBNL1, and allowed to reveal SCN5A mutation contributions, by dissecting changes in ionic current that cause adult arrhythmic disease phenotypes in humans.

Are human induced pluripotent stem cell derived cardiomyocytes a good cellular model for studying incomplete penetrance in arrhythmogenic cardiomyopathy?

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – EU funding. Main funding source(s): European Regional Development Fund and Interreg V-A Italy-Austria 2014-2020 and Department of Innovation, Research and University of the Autonomous Province of Bolzano-South Tyrol (Italy). Background Human induced pluripotent stem cell derived cardiomyocytes (hiPSC-CMs) were previously used to model several inherited heart diseases (1). Among these, arrhythmogenic cardiomyopathy (ACM) is characterized by a fibrofatty myocardial replacement and severe ventricular arrhythmias (2). ACM is mainly caused by mutations affecting proteins of intercalated discs (3) and shows incomplete penetrance and variable expressivity (4). Purpose To evaluate whether hiPSC-CMs provide a good in vitro model to study incomplete penetrance in ACM. Material and methods hiPSCs were generated from buffy coats of 6 close relatives. Three of them were ACM patients carrying a deletion of exon 4 in the PKP2 gene causing a premature stop codon, 2 were asymptomatic (ASY) PKP2 mutation carriers and 1 was a healthy control (CTR). Whole exome sequencing of the 6 individuals was performed. The purified hiPSC-CMs were cultured in basal and adipogenic medium and examined by ddPCR, western blot, Wes™ immunoassay system, patch clamp and immunofluorescence. Results All family members tested negative for additional mutations in ACM genes. As expected, half the amount of wild type (wt) PKP2 mRNA was found in ACM and ASY than in CTR hiPSC-CMs (2.25±0.27vs4.29±0.70 wtPKP2/HPRT1; p=0.028) (2.08±0.38vs4.29±0.70 wtPKP2/HPRT1; p=0.052). Of note, the mutated (mut) PKP2 mRNA was detected and significantly more expressed in ACM than in ASY hiPSC-CMs (0.33±0.04vs0.11±0.06 mutPKP2/HPRT1; p=0.029). While we confirmed a reduced amount of wt plakophillin-2 protein in ACM and ASY compared to CTR hiPSC-CMs (0.19±0.07vs0.81±0.28 wtPKP2/GAPDH; p=0.016), (0.25±0.07vs0.81±0.28 wtPKP2/GAPDH; p=0.11), the truncated protein was not detected. Moreover, a significantly lower expression of the active form of β-catenin (ABC) has been shown in ACM and ASY than in CTR hiPSC-CMs (0.93±0.18vs1.30±0.09 ABC/GAPDH; p=0.057), (0.76±0.10vs1.30±0.09 ABC/GAPDH; p=0.0057). In basal medium, ACM hiPSC-CMs had a significant lower overall sodium current density compared to CTR (-49.82±2.8 vs -69.38±4.8 pA/pF; p&amp;lt;0.0001) and to ASY (-49.82±2.8 vs -68.92±4.3 pA/pF; p&amp;lt;0.0001) hiPSC-CMs. In adipogenic medium, ACM hiPSC-CMs showed a higher lipid accumulation and a higher sarcomere disorganization than CTR (1580±219vs615±199 intensity/nuclei; p=0.0351) (0.019±0.001vs0.028±0.003 myofibril alignment index; p=0.039) and ASY (1580±219vs689±146 intensity/nuclei; p=0.0059) (0.019±0.001vs0.027±0.001 myofibril alignment index; p=0.010) hiPSC-CMs. Conclusions Here we report that ACM express a significantly higher amount of mutated PKP2 mRNA than ASY iPSC-CMs. Even though no differences were detected for plakophilin-2 and active β-catenin proteins between ACM and ASY iPSCM-CMs, the ACM showed a fatty phenotype and altered electrical activity that differed significantly from the CTR as well as from the ASY hiPSC-CMs, demonstrating that these cells provide a valid model to study incomplete penetrance in ACM.

A case report of the first hereditary transthyretin cardiac amyloidosis diagnosed in Vietnam

Amyloid cardiomyopathy is a cardiovascular disease characterized by infiltration of amyloid into the heart muscle and other organs in the body, triggering impaired function of the heart and other organs. There are three main subtypes of amyloidosis including primary or AL amyloidosis, secondary or AA amyloidosis and hereditary or familial amyloidosis. Hereditary amyloidosis is less common, caused by an autosomal-dominant mutation most frequently in the transthyretin gene and has a more favorable prognosis.1,3 In this paper, we will be looking into a rare case of hereditary transthyretin amyloid disease with a genetic mutation (mutant TransThyRetin Amyloidosis - ATTRm), the first to be reported in Vietnam. That is a 47-year-old Vietnamese man with various clinical manifestations, including gastrointestinal disturbances (diarrhea, watery stool), periorbital purpura, macroglossia, autonomic neuropathy (dizziness, orthostatic hypotension, limb numbness, faint), and cardiovascular symptoms (dyspnea, leg edema, severe heart arrhythmias). The patient has a notable family history of many members appeared to have shown signs of the same disease and passed on without a diagnosis. A multimodality team in hematology, nuclear medicine, genetics, dermatology, and cardiology was assigned to the patient. We concluded that the patient was suffering from a form of ATTRm with a different genetic mutation from the common gene mutation in the world. Our patient is currently enrolled in a research program with a pharmaceutical manufacturer providing specific treatment and free medication. He is responding well to treatment and has shown signs of improvement.

Impact of Covıd-19 Pandemıc on Severe Ventrıcular Arrhythmıa and Icd Therapy

BACKGROUND AND OBJECTIVES: The regular clinical follow-up of the patient with the implantable cardioverter-defibrillator (ICD) device was seriously affected by the COVID-19 outbreak. Due to the high risk of contamination, patients didn’t admit to the clinics for the ICD device control. It has been observed that arrhythmic events increased during the COVID-19 outbreak. In this study, we aimed to investigate the frequency of severe ventricular arrhythmias and ICD device therapy in COVID-19 patients with ICD. METHODS: In this single center-observational study, we assessed severe ventricular arrhythmias and ICD therapies by analyzing recorded data of 33 patients (24 males, 72.7%) 3 months before and after getting COVID-19 during the COVID-19 pandemic in Van, Turkey, between 15 August 2020 and 15 January 2021. RESULTS: Before the diagnosis of COVID-19, 6 ventricular tachycardias and 1 ventricular fibrillation episode were observed. When we analyzed the records after the diagnosis COVID-19, 17 ventricular tachycardia, and 3 ventricular fibrillation episodes were observed. Considering the ICD device therapies, 5 of these severe tachyarrhythmias were terminated by anti-tachycardia pacing (ATP) and 2 with shock therapy before the diagnosis of COVID-19. After the COVID-19, 14 of them were terminated by ATP, and 6 of them were terminated by shock therapy. CONCLUSION: The effects of the COVID-19 pandemic, especially on ventricular arrhythmia, have not been reported sufficiently. In our study, it was observed that life-threatening ventricular arrhythmias and the ICD therapies were increased in patients with COVID-19, especially in the first month after the diagnosis of COVID-19.

Modeling neuro-cardiac disorders using patient-specific iPSC and CRISPR/Cas9 technologies

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a severe genetic arrhythmia associated with dysfunction in more than 80% of the type 2 cardiac ryanodine receptor (RyR2). It is characterized by ventricular tachycardia induced by catecholamines, by SNA stimulation (i.e. sympathetic tone), which manifests as syncope or even sudden death in childhood. CPVT patients can also frequently develop neuro-psycho behavioral disorders, including autism. Autism is a neurodevelopmental disorder characterized by difficulties with social interaction and communication, and by restricted and repetitive behavior. Autism appears from an early age. Research suggests that autism develops from a combination of genetic and nongenetic, or environmental, influences. The behavioral and cognitive features of autism are associated with pervasive abnormalities in the central nervous system (CNS). As RyR2 is expressed in heart and brain, and based on our previous work, we hypothesize that leaky RyR2 in CPVT patients affects both the cardiomyocytes and neurons. Using patient-specific induced pluripotent stem cell (hiPSC), we differentiate them into cardiomyocytes and neurons. We performed structural and functional characterizations of the control and CPVT cardiomyocytes and neurons by immunofluorescence, fluorescent confocal microscopy, IonOptix and video-edge capture was done. From the different differentiation protocols, we are able to obtain ventricular cardiomyocytes and neurons from the CNS. CPVT cardiomyocytes exhibit calcium and contractile defects, leaky RyR2 which are typical of CPVT. Surprisingly, CPVT neurons exhibit impaired size, altered intracellular calcium handling, leaky RyR2 and neurotransmitter secretion. From the same CPVT patient, we are able to obtain ventricular cardiomyocytes and CNS neurons. Our preliminary data demonstrate that CPVT cardiomyocytes and neurons exhibit defects including RyR2 leak and neuronal impairment reminiscent of autism. This demonstrates for the first time a potential role of RyR2 mediated calcium leak in autism.

Potassium Level Variation Following Packed Cell Transfusion in Critically Ill Adult Patients-How Alert Should We Be?

One of the most clinically important effects following the administration of packed cell transfusion (PCT) is hyperkalemia, which can cause severe life-threatening cardiac arrhythmias. This retrospective population-based cohort study included adults hospitalized between January 2007 and December 2019 in a general intensive care unit for 24 h or more, with normal levels of serum potassium on admission. We assessed changes in serum potassium levels after administration of one unit of packed cells and sought to identify clinical parameters that may affect these changes. We applied adjusted linear mixed models to assess changes in serum potassium. The mean increase in serum potassium was 0.09 mEq/L (C.U 0.04–0.14, p-value < 0.001) among the 366 patients who were treated with a single PCT compared to those not treated with PCT. Increased serum potassium levels were also found in patients who required mechanical ventilation, and to a lesser degree in those treated with vasopressors. Hypertension, the occurrence of a cerebrovascular accident, and increased creatinine levels were all associated with reduced serum potassium levels. Due to the small rise in serum potassium levels following PCT, we do not suggest any particular follow-up measures for critically ill patients who receive PCT.

A method to measure data complexity of a complicated medical data set

AbstractIn this article, we consider data complexity in the context of calcium transient signal data collected from induced pluripotent stem cell‐derived cardiomyocytes. We present a novel way to measure data complexity based on the nearest neighbour searching method. Data complexity here is seen as overlapping and mixed data classes in addition to a relatively great number of data cases. Complexity affects classification results, which were run with nearest neighbour searching, feedforward artificial neural networks and random forests for seven genetic cardiological disease classes and healthy controls. The data are obtained from individuals carrying mutations for genetic cardiac diseases with induced pluripotent stem cell (iPSC) technology and the diseases include hypertrophic cardiomyopathy with two different founder gene mutations, dilated cardiomyopathy, long QT syndrome type 1 and 2, Brugada syndrome, a severe genetic ventricular arrhythmia (CPVT) and healthy controls. The data are from calcium transients from spontaneously beating iPSC‐derived cardiomyocytes cultured in a biotechnology laboratory. When the genotype of the iPSC‐derived cardiomyocytes is the same as the donor of the tissue sample and based on the characteristics of the calcium transients, it was possible to classify the seven diseases and healthy controls with machine learning. Peak data first detected before actual pre‐processing from calcium transient signals corresponded to beats (repeating excitation–contraction coupling) of induced stem cell‐derived cardiomyocytes and formed the basis of classification. During pre‐processing of the calcium transient signals, we found that such techniques among others as even strong outlier cleaning or class size balancing by generating artificial cases improved only slightly or not at all classification accuracies. Therefore, the current data set was sufficiently complicated for our data complexity study. Random forests produced the best classification accuracies, 68% for all eight classes.

Occurrence and predictors of severe arrhythmia in patients with myocarditis

Abstract Funding Acknowledgements Type of funding sources: None. Background/Introduction Patients with myocarditis are at risk for severe, life-threatening arrhythmia. However, predictors to identify high-risk patients are lacking. Purpose We investigated the occurrence and potential risk factors of severe arrhythmia in myocarditis patients. Methods 212 myocarditis patients that were hospitalized for arrhythmia monitoring at a tertiary university hospital were retrospectively enrolled. Non-sustained ventricular tachycardia (VT), sustained VT, ventricular fibrillation or cardiac arrest were considered as severe arrhythmia. We used a stepwise logistic regression model to investigate potential predictors. These included age, sex, clinical presentation (chest pain, palpitations, dyspnea, syncope, cardiac murmur, edema, pericardial friction, arrhythmia at presentation, Killip-class), comorbidities (hypertension, diabetes, coronary heart disease), imaging parameters (left ventricular ejection fraction [LVEF], pericardial effusion, edema and LGE on MRI), ECG variables (PQ depression, ST elevation, ST depression) and maximum levels of blood biomarkers (CRP, leukocytes, Troponin T, CK-MB). Results Mean age was 40.8 years, 73.1% were male and mean LVEF was 52.9%. During the hospital stay, 40 (18.9%) patients experienced severe arrhythmia: 33 (15.6%) non-sustained VT, 9 (4.2%) sustained VT, 1 (0.5%) ventricular fibrillation and 3 (1.4%) cardiac arrests (arrhythmia not mutually exclusive). Most arrhythmia occurred in the first 72h of monitoring (Figure). Significant predictors selected by the stepwise model (OR [95% CI]) for severe arrhythmia were LVEF (per 1% increase 0.95 [0.92; 0.99], p=0.005), syncope at presentation (7.9 [1.5; 40.4], p=0.01), any arrhythmia at first presentation (6.5 [1.3; 32.7], p=0.02) and CK-MB (per 10-unit increase 1.2 [1.1; 1.3], p=0.001). Conclusion(s) Myocarditis patients with low LVEF, presenting with arrhythmia and syncope and with increased CK-MB are at increased risk for severe arrhythmia and should be closely monitored. Further studies are needed to define, if patients without these risk factors might be safely discharged early.

Mitral valvuloplasty with left atrial appendage closure and pacemaker implantation in a dog with severe myxomatous mitral valve degeneration: a case report

BackgroundMitral valvuloplasty (MVP) has been widely recognized as a treatment option for myxomatous mitral valve disease (MMVD). However, postoperative complications such as thromboembolism, arrhythmia, and pancreatitis in some cases have resulted in death. We treated a dog with severe MMVD complicated by impaired sinus function with MVP and pacemaker implantation. Also, due to an intrinsic procoagulant state and severe arrhythmia after the MVP, left atrial appendage (LAA) closure was performed to reduce the postoperative risk of thrombosis.Case presentationAn 11-year-old castrated 7.5-kg male Miniature Schnauzer with a history of congestive heart failure was brought to Shiraishi Animal Hospital for MMVD surgical treatment. Echocardiography revealed an enlarged left atrium and ventricle secondary to MMVD. Sinus arrest with 2 to 3-second periods of asystole was identified by electrocardiogram. Mitral valvuloplasty was performed with cardiopulmonary bypass to treat the MMVD. After coronary reperfusion, there was no spontaneous electrical activity. Cardiac arrest continued. Based on this surgical outcome, a permanent pacemaker was implanted. In addition, LAA closure with an AtriClip was performed to prevent intra-atrial thrombus formation. Cardiac remodeling and congestion were ameliorated after surgery. Sinus rhythm was restored 5 days postoperatively; however, the patient continued pacemaker dependent. All cardiac drugs were discontinued 3 months after surgery. The owner reported no postoperative complications (i.e., thrombosis), and the patient was brought for a check-up 4 months after the operation in good health.ConclusionsFor surgical MMVD cases complicated with impaired sinus function, the chances of spontaneous sinus rhythm are low, requiring pacemaker implantation. LAA closure may be considered to protect against decreased atrial function after mitral valvuloplasty and prevent intra-atrial thrombus formation.

A biosensing system using a multiparameter nonlinear dynamic analysis of cardiomyocyte beating for drug-induced arrhythmia recognition

Cardiovascular disease is the number one cause of death in humans. Therefore, cardiotoxicity is one of the most important adverse effects assessed by arrhythmia recognition in drug development. Recently, cell-based techniques developed for arrhythmia recognition primarily employ linear methods such as time-domain analysis that detect and compare individual waveforms and thus fall short in some applications that require automated and efficient arrhythmia recognition from large datasets. We carried out the first report to develop a biosensing system that integrated impedance measurement and multiparameter nonlinear dynamic algorithm (MNDA) analysis for drug-induced arrhythmia recognition and classification. The biosensing system cultured cardiomyocytes as physiologically relevant models, used interdigitated electrodes to detect the mechanical beating of the cardiomyocytes, and employed MNDA analysis to recognize drug-induced arrhythmia from the cardiomyocyte beating recording. The best performing MNDA parameter, approximate entropy, enabled the system to recognize the appearance of sertindole- and norepinephrine-induced arrhythmia in the recording. The MNDA reconstruction in phase space enabled the system to classify the different arrhythmias and quantify the severity of arrhythmia. This new biosensing system utilizing MNDA provides a promising and alternative method for drug-induced arrhythmia recognition and classification in cardiological and pharmaceutical applications.

In-hospital mortality and 6-months prognosis on cardiogenic shock depending on the aetiology in a Mediterranean cohort. The Shock-CAT Study

Abstract Funding Acknowledgements Type of funding sources: None. Background Mortality in cardiogenic shock (CS) remains very high, although the CS aetiology could influence in the acute-phase and long term prognosis. Purpose The aim is to investigate in-hospital mortality and 6 months prognosis (all-cause mortality and cardiovascular readmission) in CS patients depending on the CS aetiology in a Mediterranean cohort. Method Shock CAT study was a multicentre, prospective, observational study conducted between December 2018 and December 2019 in eight public University hospitals in Catalonia (Spain), including CS patients due to acute coronary syndrome (ACS) and other aetiologies. Data on clinical presentation, biomarkers, management, including mechanical assistance support were analyzed comparing ACS and non-ACS patients. In-hospital and 90-days mortality and 6-months prognosis (mortality and cardiovascular readmission) were available and have been compared between groups. Results A total of 382 CS patients were included, mean age was 65.3 (SD 13.9) years and 75.1% were men. Patient were classified in ACS (n=232, 60.7%) and non-ACS (n=150, 39.3%). In ACS group, 77.6% were STEMI, reperfusion in 84.7% of cases, all with primary angioplasty, 9% developed mechanical complications and 19.4% primary ventricular fibrillation. Main non-ACS aetiologies were severe heart failure (36.2%), malignant arrhythmias (22.1%), valve disease (8.0%) and myocarditis (7.4%). ACS group had less prevalence of women (17.7% vs 36%, p=0.001) and previous myocardial infarction (13.9% vs 24.8%, p=0.007). Mechanical assistance device was implanted more frequently in ACS patients (43.1% vs 16.7%, p&amp;lt;0.001, mainly intraaortic balloon pump (35.6% vs 9.8%, p&amp;lt;0.001) and ECMO (10.7% vs 3%, p=0.01). Both shock risk scores were higher in ACS patients, Cardshock (4.5 vs 4.0, p=0.006) and IABP (2.4 vs 1.9, p=0.005). All-patients in-hospital mortality was 33%. This acute-phase mortality was higher in ACS group (37.1% vs 26.7%, p=0.035) although this difference loss the significance at 90-days (40.9% vs 31.8%, p=0.074) and 6-months (45.2 vs 35.8%, p=0.176). Cardiovascular 6-months readmission was 8.7%, without differences between ACS and non-ACS group (9.7% vs 7.3%, p=0.155, respectively). Conclusions One-third of cardiogenic shock patients died during hospital admission. Patients with CS due to ACS had 28% higher in-hospital mortality than non-ACS, although this difference decreased at 90 days and 6 months. Cardiovascular 6-months readmission was 8.7%, without differences between groups.