Life-threatening Rhythm Disturbances Research Articles

Retrospective analysis of outcomes in patients with myocardial infarction in late admission to PCI center

Aim. This study aims to determine the impact of invasive treatment strategy on long-term outcomes in patients with ST-segment elevation myocardial infarction (STEMI) in late admission to PCI center (12-48 hours from the symptom onset) in comparison with conservative management.Material and methods. The study population included 154 people with STEMI, admitted to V. P. Polyakov Samara Regional Clinical Cardiology Dispensary during 12-48 hours after onset of myocardial ischemia symptoms, for the period of inclusion (2013-2017). The mean age of the patients was 57,2±9,2 years old. The study evaluated two time periods: intrahospital and long-term (during 4 years from the index hospitalization). The primary end-point: cardiovascular death. The secondary combined end-point included: myocardial infarction recurrence, life-threatening rhythm disturbances, acute bleeding, heart failure NYHA III-IV functional class. The patients were divided into two groups depending on initially chosen management strategy: invasive (I) (n=113; 73,4%) or conservative (II) treatment (n=41; 26,6%).Results. Comparing frequency of occurrence of cardiovascular death depending on chosen treatment tactics, we found that the probability of lethal outcome from cardiovascular causes in conservatively treated patients increased by 20,64 times (95% confidence interval (CI): 1,04-408,61), p=0,018 during intrahospital period of the study. The analysis performed using the Kaplan-Meier method showed the medians of the time of lethal outcome occurrence: in conservative group — 76,5 months (95% CI: 67,6-85 months), in invasive group — 92,1 months (95% CI: 88,9-95,3 months), p=0,014.Conclusion. This study presented the results of our own retrospective study which confirms that revascularization in late-presenting patients with STEMI (12-48 hours from the symptom onset) results in improving the outcomes in both intrahospital and long-term periods.

Reperfusion arrhythmias – Underestimated cause of sudden cardiac death?

Life-threatening rhythm disturbances in the course of the acute coronary syndrome are assumed to be caused by myocardial ischemia. However, in animal studies, it is reperfusion that brings greater electrical instability, and more often leads to serious arrhythmias, especially when the preceding ischemic period lasts up to 30 min. Studies show that in most individuals who have been successfully resuscitated from ventricular fibrillation associated with coronary artery disease, it is transient and not permanent coronary occlusion that was involved. Additionally, reperfusion-induced lethal arrhythmia often concerns people without atherosclerosis and then it is usually caused by coronary artery spasm. Our hypothesis states, that reperfusion arrhythmias are a significant cause of sudden cardiac death, especially those occurring during sleep, and the problem is underestimated. Little research is published on this issue, and so far, only remnant-like lipoproteins appear to be a promising specific risk factor. We believe that considerable efforts should be made to explore the mechanisms behind reperfusion-induced arrhythmias to apply finally appropriate and effective prevention.

Formation of antianginal pharmacotherapy in the historical aspect. From theoretical background to practical effect

Angina pectoris is the most common form of chronic coronary insufficiency, treatment of which consists in reducing the number, duration and severity of anginal pains, as well as improving the prognosis: preventing the development of cardiovascular complications such as acute myocardial infarction, life-threatening rhythm disturbances and congestive heart failure. The treatment of coronary artery disease (CAD) has recently undergone significant changes. This is primarily due to the wide introduction into clinical practice of surgical and endovascular methods of myocardial blood flow restoration, which have moved the use of pharmacological of antianginal agents to the background. Despite this, the clinic continues to feel the need for drugs with anti-ischemic properties. This is due to the fact that there is a group of patients who, for various reasons, cannot undergo revascularization of the heart. This is due to the fact that there is a group of patients who, for various reasons, cannot undergo cardiac revascularization. These include individuals with morphological features of the coronary bed, technical obstacles to surgery, increasing number of cases of diabetic microangiopathy as a cause of myocardial ischemia, frequent recurrence of angina after coronary angioplasty. Finally, today we are not yet able to meet all the needs for myocardial revascularization. Thus, the clinical interest in antianginal therapy remains. The present review shows analysis of usage medications with various pharmacological properties in patients with angina in the historical aspect since the second half of the IX century, evolution of the researchers’ ideas about the mechanism of antianginal action, the amount of drugs used. A brief characteristic of modern antianginal drugs presented in the recommendations of the European Society of Cardiologists last revision (2019) is given.

Cost-Effectiveness of Cardioverter-Defibrillator Implantation in Kazakhstan.

Cardiovascular disease is the leading cause of morbidity and mortality worldwide. The implementation of effective technologies such as Implantable cardioverter-defibrillator (ICD) for patients at risk of sudden cardiac death requires additional health system resources.ObjectiveTo assess the economic effectiveness of ICD in comparison with conservative tactics for preventing life-threatening rhythm disturbances in Kazakhstan.MethodsA Markov model was built with a time horizon of 35 years. Mortality and utility data were obtained from the available literature. The economic parameters of the model are based on the approved tariffs for medical services in Kazakhstan and clinical protocols. Following WHO recommendations, a willingness to pay threshold of three times gross domestic product per capita was used to assess cost-effectiveness. A discount rate of 3.5% was applied to both costs and benefits. To deal with parameter uncertainties and to provide robust analysis, a probabilistic sensitivity analysis was performed, randomly varying all inputs subject to uncertainty assuming a statistical distribution.ResultsThe total costs in the primary prevention (PP) group by ICD implantation and in the control group were 8,903,786 tenges and 3,194,414 tenges, respectively. The discounted total quality-adjusted life-years saved (QALYs) in the ICD and control groups were 6.48 and 4.98, respectively. The indicator of incremental cost-effectiveness ratio amounted to3791604 tenge, which is below the willingness to pay threshold and indicates the cost-effectiveness of using ICD as a PP strategy in patients with sudden cardiac death risk factors in the health care of Kazakhstan.ConclusionThe ICD for the primary prevention of the development of life-threatening rhythm disturbances and sudden cardiac death is a cost-effective health technology from the position of a payer in the health care system of Kazakhstan.

Clinical features and outcome of MIS-C patients: an experience from Central Anatolia.

BackgroundMultisystem inflammatory syndrome in children (MIS-C) is a new clinical condition characterized by signs of inflammation and multiorgan dysfunction due to cytokine storm associated with SARS-CoV-2. The clinical spectrum of MIS-C ranges from mild to severe, and even to mortal multisystem involvement. To guide clinicians, we evaluated detailed demographic characteristics, clinical features, laboratory findings, and outcomes of MIS-C cases.MethodsWe performed a retrospective study of patients with MIS-C who were managed in the Department of Pediatric Infectious Disease in the Selcuk University Faculty of Medicine, Konya, Turkey. MIS-C patients were divided into three clinical severity groups (mild, moderate, and severe) and separated into three age groups (< 5 years, 5–10 years, > 10 years). We compared the characteristics of MIS-C cases according to the severity of the disease and by age groups.ResultThirty-six children with MIS-C were evaluated (52.8% male, median age of 7.8 years). A clinical spectrum overlapping with Kawasaki disease (KD) was the most common presentation (69.4%) in all age groups. The most common clinical symptoms were fever (100%), mucocutaneous rash (69.4%), and gastrointestinal symptoms (66.6%). There was no statistically significant difference in echocardiographic abnormality between KD-like and the other clinical spectra (p > 0.05). All life-threatening rhythm disturbances were observed in severe cases. No patients died.ConclusionIt is important to increase the awareness of physicians about the MIS-C disease, which can present with different combinations of different systemic findings, so that patients can be diagnosed and treated in a timely manner. Key Points• A single tertiary centre study shows that children with MIS-C can present with different clinic spectra other than Kawasaki diseases.• Electrocardiographic and echocardiographic evaluation is important in early diagnosis of children with MIS-C.• Pro-BNP can be used as a screening test in the emergency room for children with prolonged and unexplained fever for determine early cardiac involvement of MIS-C.• The lack of require biological agents and favourable outcomes in children with MIS-C may be related with administration of steroid therapy with IVIG in early stage of disease.

Выявление риска жизнеугрожающих нарушений сердечного ритма у детей первого года жизни

To identify the risk of life-threatening heart rhythm disturbances in children in the age group of one year of life, 50 conditionally healthy children at the time of the study were examined. They were divided into 2 groups: 1 group (31 children): children born through the natural birth canal and 2 group – 19 children born using abdominal delivery. The risk of developing various life-threatening cardiac arrhythmias were determined by measuring the index of «electric quality of the heart» according to ECG analysis. As a result of the study, in children of the 1st group, sinus arrhythmia (74 % of children) was most frequently registered, sinus tachycardia (32 %) and sinus bradycardia (26 %) were less common. In the second group ofthe examined patients, sinus arrhythmia was registered in 100 % of cases, sinus bradycardia in 57,9 %, out of which 10 % had pronounced (&lt;5 ‰), sinus tachycardia in 42,1 % of children. We found out that there were no significant differences in the risk of developing life-threatening cardiac arrhythmias according to ECG data in children, depending on the circumstances of the birth. In all the examined children, by determining the index of «electric quality of the heart», the risk of developing heart rhythm disturbance was established, and it was higher in children born from surgical labor: every third child was found to have an average or high risk of developing life-threatening rhythm disturbances.

Sudden Arrhythmic Death at the Higher End of the Heart Failure Spectrum.

The risk of sudden cardiac death (SCD) is high in heart failure (HF) patients. Sudden arrhythmic death (SAD) is a frequent cause of exit in HF patients at the lower end of the HF spectrum, and implantable cardioverter-defibrillators have been recommended to prevent these life-threatening rhythm disturbances in select patients. However, less is known regarding the cause of SCD in patients at the upper end of the HF spectrum, despite the fact that the majority of out-of-hospital SCD victims have unknown or near-normal/normal left ventricular ejection fraction (LVEF). In this review, we report the epidemiology, summarize the mechanisms, discuss the diagnostic challenges, and propose a stepwise approach for the prevention of SAD in HF with near-normal/normal LVEF.

Role of standard resting ECG in the assessment of sudden cardiac death risk

Today the ECG is still, over 100 years after its invention (Willem Einthoven 1903), the most commonly used diagnostic procedure in clinical cardiology. In recent years, we have accumulated knowledge that has significantly expanded the diagnostic possibilities of ECG, through the recognition of patterns associated with a number of primary electrical diseases of the myocardium, the so-called inherited arrhythmogenic diseases. These clinical entities are caused by gene mutations that determine a substrate leading to the onset of life-threatening rhythm disturbances. The study of ECG abnormalities in these diseases showed characteristic phenotypic traits, which in combination with information derived from molecular genetics, have allowed using the ECG as a prognostic tool as well as a diagnostic test. The assessment of genotype-phenotype correlations in inherited arrhythmogenic diseases has allowed to advance the idea of the ECG as an inheritable trait. Such heritable quantitative traits are potentially related to the risk of sudden death in the general population, which is known to have a familial predisposition. This article summarizes the pathophysiology and phenotypic manifestation of the main arrhythmogenic diseases. Also shown are current possibilities and limitations of the use of a simple and low-cost technology, not only as a tool for diagnosis but also as a tool to identify prognostic markers. We will show how, rather surprisingly, the ECG often allows extracting the most important information for appropriate risk classification and clinical management.

Efficacy and Safety of Ibutilide for Chemical Cardioversion of Atrial Fibrillation and Atrial Flutter in Cancer Patients

BackgroundAtrial fibrillation and atrial flutter (AF/AFL) are the most common arrhythmias encountered in clinical practice. Rate versus rhythm control remains a difficult decision, especially in the acute setting. ibutilide is a class iii antiarrhythmic indicated for pharmacological cardioversion of recent-onset AF/AFL. At the University of Texas MD Anderson Cancer Center, restoration of sinus rhythm is desirable because many patients have contraindications to anticoagulation. In addition, most are on multiple medications that prolong the QT interval; therefore, the objective of this study was to establish the safety and efficacy of ibutilide. MethodsThis was a retrospective chart review of 81 patients who were identified via the pharmacy database as receiving ibutilide for AF/AFL from January 2002 to May 2006. Outcomes including cardioversion rates and effects on the QT interval were recorded. ResultsIbutilide use was associated with successful cardioversion in 75% of patients. Out of 81 patients, 68 patients (84%) were on at least 1 medication that prolonged the QT interval at the time of ibutilide administration. However, no significant changes in the corrected QT interval pre and post ibutilide cardioversion were noted in any group of patients. ConclusionsOverall, ibutilide is safe and effective in cancer patients when used for acute cardioversion of AF/AFL. Despite the use of multiple medications that can potentially prolong the QT interval, no patient experienced serious life-threatening rhythm disturbances or significant QT prolongation during ibutilide administration.

A Multicenter, Long-Term Study on Arrhythmias in Children with Ebstein Anomaly

To assess the prevalence, history, and treatment of arrhythmias, in particular preexcitation and Wolff–Parkinson–White (WPW) syndrome, in patients with Ebstein anomaly (EA) during childhood and adolescence, we performed a multicenter retrospective study of all consecutive live-born patients with EA, diagnosed, and followed by pediatric cardiologists between 1980 and 2005 in The Netherlands. During a follow-up after EA diagnosis of 13 years 3 months (range: 6 days to 28 years 2 months), 16 (17%) of the 93 pediatric EA patients exhibited rhythm disturbances. Nine patients showed arrhythmic events starting as of the neonatal period. Supraventricular tachycardia was noted in 11 patients. One patient died in the neonatal period due to intractable supraventricular tachycardia resulting in heart failure and one patient died at 5 weeks of age most probably due to an arrhythmic event. The 14 surviving patients all show preexcitation, albeit 4 of them intermittently, and all have a right-sided accessory pathway location. Nine patients underwent catheter ablation of an accessory pathway. Only four patients are currently on antiarrhythmic drugs. The 17% prevalence of rhythm disturbances in pediatric EA patients, most commonly supraventricular arrhythmias, is significantly lower than in adult EA patients. Life-threatening rhythm disturbances are not frequent early in life. Symptomatic patients are well treated with radiofrequency catheter ablation.

Cardiology patient page. Familial dilated cardiomyopathy.

Cardiology patient page. Familial dilated cardiomyopathy.

K+ channel structure-activity relationships and mechanisms of drug-induced QT prolongation.

Pharmacological intervention, often for the purpose of treating syndromes unrelated to cardiac disease, can increase the vulnerability of some patients to life-threatening rhythm disturbances. This may be due to an underlying propensity stemming from genetic defects or polymorphisms, or structural abnormalities that provide a substrate allowing for the initiation of arrhythmic triggers. A number of pharmacological agents that have proven useful in the treatment of allergic reactions, gastrointestinal disorders, and psychotic disorders, among others, have been shown to reduce repolarizing K(+) currents and prolong the QT interval on the electrocardiogram. Understanding the structural determinants of K(+) channel blockade may provide new insights into the mechanism and rate-dependent effects of drugs on cellular physiology. Drug-induced disruption of cellular repolarization underlies electrocardiographic abnormalities that are diagnostic indicators of arrhythmia susceptibility.

Proarrhythmia: A Paradoxic Response to Antiarrhythmic Agents

Antiarrhythmic drugs may effectively terminate and prevent symptomatic tachycardias, but they may also provoke life-threatening rhythm disturbances. The electrophysiologic mechanisms responsible for proarrhythmia can be extrapolated from the existing models of reentry and abnormal automaticity. Although all antiarrhythmic drugs may cause proarrhythmia with seemingly similar frequency, the profile of the disturbance with each class of agents appears somewhat distinct. All agents may cause an increased frequency of premature beats or new or worsened ventricular tachycardia, but the classic form of proarrhythmia due to type la agents is torsades de pointes. Recent information has provided clues to the underlying mechanism of drug-induced torsades de pointes and has provided a clinical picture of patients with this adverse effect. Types lb and lc agents only rarely precipitate torsades de pointes. The latter, however, may cause a rapid, sustained, monomorphic ventricular tachycardia in certain high-risk patients that can be resistant to resuscitation efforts. Amiodarone may cause a broad variety of arrhythmias that are complicated by their extended duration and difficulty in distinguishing proarrhythmia from simple inefficacy. Proarrhythmia is a relatively common, paradoxic side effect that necessitates the clinician to make careful risk-benefit decisions in choosing antiarrhythmic drug therapy.