Life-threatening Ventricular Dysrhythmias Research Articles

Rare case of Torsades de Pointes in severe hypothyroidism: literature review and challenges in management

BackgroundHypothyroidism can manifest as several important cardiac abnormalities. There are few reports of ventricular dysrhythmias (VDs) in hypothyroidism. We described a rare case of VDs in severe hypothyroidism and reviewed the literature behind its management.Case presentationA 67-year-old gentleman, with poor compliance to treatment for Hashimoto’s thyroiditis, presented with palpitations to the Emergency Department. He had runs of non-sustained ventricular tachycardia (NSVT). He was treated with intravenous (IV) amiodarone and admitted to the intensive care unit for observation. He then developed recurrent Torsades de Pointes (Tdp) despite treatment with several anti-arhythmics. He required electrical cardioversion and eventual transvenous overdrive pacing (OP). VT recurred while he was on OP. VT resolved and he was weaned off OP only after adequate thyroid hormone replacement.ConclusionsVDs, including NSVT, Tdp, and VT, are rare and potentially lethal in hypothyroidism. Our case demonstrates important challenges in the management of severe hypothyroidism. Here, VDs are often refractory to treatment with drugs and electrical means. The choice(s) of anti-arrhthymics requires careful consideration and can be difficult before thyroid function tests are known. Amiodarone use should be cautioned as it is associated with thyroid dysfunction and QT interval prolongation.There is no literature to guide thyroid hormone replacement in this disease. Aggressive replacement is associated with adverse cardiovascular effects. Our case showed a fine balance between the risk of rapid thyroid hormone replacement and the urgency to terminate VDs. Its administration should be carefully monitored amidst bridging strategies like electrical cardioversion and OP to manage life-threatening VDs.

Arrhythmias and diabetes: heart block, ventricular arrhythmias, and death

Arrhythmias and diabetes: heart block, ventricular arrhythmias, and death

Nurses' Performance Regarding Life Threatening Ventricular Dysrhythmias among Critically Ill Patients

Background: Ventricular dysrhythmias (VD) are the important cause of cardiovascular morbidity and mortality, particularly in those with structural heart disease. It is fundamental importance for nurses to recognize normal and pathological electrocardiographic tracings and allowing the adoption of appropriate and immediate interventions. Aim of the study: was to assess nurses' performance regarding life threatening ventricular dysrhythmia among critically ill patients in intensive care units at Zagazig University Hospitals. Subjects and Methods: Research design: A descriptive design was utilized to achieve the aim of this study and to answer the research questions. Setting: The study was conducted at all cardiac Intensive Care Units at Zagazig University Hospitals. Subjects: A convenient sample of 50 nurses was included in this study. Tools of data collection: Two tools were used; Questionnaire and observational checklists regarding life threatening VD. Data were collected over a period of six months started from July 2018 to December 2018. Results: The results of the study revealed that the majority of the studied nurses their age ranged from 20-29 years old and was female, near to half of nurse's graduated from bachelor nursing, and two third of nurses had years of experience in ICU more than 2 years. The present study clarified that three quarter of the studied nurses had unsatisfactory knowledge and more than half of them had unsatisfactory practice regarding life threatening ventricular dysrhythmias. Conclusion: Based on the results can be concluded that the studied nurses had unsatisfactory level of knowledge and practice regarding life threatening VD and need to be improved. Also, there was no significant relation between total knowledge score and total practice score. Recommendations: the study is recommended to there is a need to In–service training programs for the purpose of updating the knowledge and skills of nurses working with intensive care units for early identification and management of life threatening dysrhythmias and Periodic evaluation of nurses' knowledge and practice.

Critical care nurses' knowledge and practice regarding life-threatening ventricular dysrhythmias

Working memory is widely discussed in competitive sports. Researchers have systematically investigated the working memory system in the field of sports which was mainly based on papers publishing in English. Therefore, it is essential, in our opinion, to provide an overview of papers focusing on working memory and its relevance in sport psychology which were published in other languages, like Chinese. The China National Knowledge Infrastructure (CNKI) database was searched in November 2017, with no date restrictions, chose the theme as index item and index words were athlete and working memory (index mode was specific match). Studies were included if they were empirical research which used quantification index to demonstrate their results (investigated the relation of working memory and athlete), contained a population of athlete, involved in working memory task, published on normal domestic journals or the thesis of master or doctor. In total, 41 citations were identified, 13 of which were retrieved for full-text indexed and then conducted a quantitative analysis. There was little amount of studies in this field and most of which used scales and experimental research design methods. The studies contained the effect of working memory on athlete cognition and performance, the detriment of working memory because of combat sports as well as the impact factors on athlete working memory. Research of working memory and athlete in China gets some achievements. Inter-disciplinary research and working memory training will be trends of this field in the future.

Multifocal Atrial Tachycardia Secondary to Infusion of Dimenhydrinate

Dimenhydrinate (NN-dimethyl-2-diphenylmetoxyethylamine; 8-Chloro theophyllinate) is a salt of two drugs: diphenhydramine and 8-chlorotheophylline, a chlorinated derivative of the theophylline [1]. It is used therapeutically as an antiemetic, antinauseant and to prevent motion sickness [2]. Diphenhydramine overdose causing hyperpyrexia, status epilepticus, coma, and cardiac arrhytmias has been reported [3,4]. Additionally, life-threatening ventricular dysrhythmias were reported in a 4 month-old infant intentionally administered an overdose of dimenhydrinate [5].

Paroxysmal atrial fibrillation precipitated by amiodarone-induced thyrotoxicosis five months after cessation of therapy

Amiodarone is currently indicated for the treatment of life-threatening ventricular dysrhythmias. It is also used for the treatment of supraventricular dysrhythmias and as maintenance therapy after successful cardioversion of atrial flutter or atrial fibrillation. Adverse effects related to its expanded use are increasingly common. We describe a case of amiodarone-induced thyrotoxicosis occurring 5 months after cessation of therapy and discuss the pathophysiology and treatment of this disorder.

Electrocardiographic changes with segmental akinesia after chloral hydrate overdose

We report a case of deliberate ingestion of 12.5 g chloral hydrate in a 25-year-old psychiatric patient. Coma and life-threatening ventricular dysrhythmias were observed soon after ingestion. Repeated electrocardiographic examination was consistent with ischemic changes appearing on day 3. They were associated with segmental abnormal left ventricular wall motion by echocardiography. A coronary angiogram was performed and was normal. Toxic metabolites of chloral hydrate, trichloroethanol and trichloroacetic acid were found in the urine until day 7. This case illustrates that with halogenated aliphatic hydrocarbons, sustained changes in cardiac contractility may occur in addition to early life-threatening ventricular dysrhythmias.

Lack of utility of telemetry monitoring for identification of cardiac death and life-threatening ventricular dysrhythmias in low-risk patients with chest pain

Study objective Low-risk patients with chest pain are often admitted to monitored beds; however, the use of telemetry beds in this cohort is not evidence based. We tested the hypothesis that monitoring admitted low-risk patients with chest pain for dysrhythmia is low yield (<1% detection of life-threatening dysrhythmias requiring treatment). Methods We conducted a prospective cohort study of emergency department (ED) patients with chest pain with a Goldman risk score of less than 8%, a normal initial creatine kinase–MB level, and a negative initial troponin I level admitted to non-ICU monitored beds. Investigators followed the hospital course daily. The main outcome was cardiovascular death and life-threatening ventricular dysrhythmia during telemetry. Results Of 3,681 patients with chest pain who presented to the ED, 1,750 patients were admitted to non-ICU monitored beds. Of these, 1,029 patients had a Goldman risk score of less than 8%, a troponin I level of less than 0.3 ng/mL, and a creatine kinase–MB level of less than 5 ng/mL (accounting for 59% of all chest pain telemetry admissions). During hospitalization, there were no patients with sustained ventricular tachycardia/ventricular fibrillation requiring treatment on the telemetry service (0%; 95% confidence interval [CI] 0% to 0.3%). There were 2 deaths: neither was cardiovascular in nature or preventable by monitoring (cardiovascular preventable death rate=0%; 95% CI 0.0% to 0.3%). Conclusion The routine use of telemetry monitoring for low-risk patients with chest pain is of limited utility. Admission to nonmonitored beds might help alleviate ED crowding without increasing risk of adverse events caused by dysrhythmia in patients with a Goldman risk of less than 8%, an initial troponin I level of less than 0.3 ng/mL, and a creatine kinase–MB level of less than 5 ng/mL.

Effects of cisapride on ventricular repolarization in children

Life-threatening ventricular dysrhythmias mainly attributed to QTc prolongation have been reported in adults and children who were using cisapride, a prokinetic agent that facilitates gastrointestinal motility. Recent adult and paediatric case reports have suggested an association of malignant ventricular dysrhythmias with administration of cisapride in conjunction with drugs that inhibit its cytochrome P-450 metabolism. Therefore, to analyse the time- and dose-related effects of cisapride on ventricular repolarization, we prospectively studied infants and children receiving cisapride with no concomitant medications. Standard 12-lead resting ECGs were obtained from 38 patients (mean age: 6.6 +/- 4.4 y) before the first dose of cisapride (0.8-1.2 mg/kg/d) therapy, and 3 d, 7 d and 1 mo after the first dose of continuing cisapride therapy. The corrected QT interval (QTc), dispersion of QT and QTc (QTD, QTcD) were calculated. Patients were divided into two groups according to dose of cisapride: Group 1 (n = 22) (0.8 mg/kg/d), Group 2 (n = 16) (1.2 mg/ kg/d). Data obtained from these patients were compared with a control group consisting of 372 normal children. No clinical adverse effects such as palpitations, presyncope or syncope were noted during the study. Baseline QTc, QTD and QTcD measurements of the study group were not different from those of the control group. Mean QTc values of the study group on days 7 and 30 of cisapride therapy were found to be significantly higher than those of the control group (p < 0.001 and <0.0001, respectively). Mean QTc values of the study group on days 7 and 30 of therapy were also significantly higher than those of baseline value (p < 0.01 and <0.001, respectively). Mean QTD and mean QTcD values that were recorded throughout the cisapride treatment in the study group were not found to be different from the baseline values and the values of the controls. Mean QTD and QTcD were also not found to be different between Groups 1 and 2. However, mean QTc was found to be more significantly increased from baseline at the first month of therapy in Group 2 (p < 0.05). The results of this study suggest that cisapride treatment cause prolongation of ventricular repolarization without causing increased heterogeneity of repolarization (QT dispersion). However, the clinical significance of this effect is unclear, because all the patients in this study group remained asymptomatic, without signs of dysrhythmia.

Sotalol: What the emergency nurse needs to know

<h2>Summary</h2> Sotalol represents a new and beneficial theapeutic alternative for the treatment of life-threatening ventricular dysrhythmias. With the rapid emergence of these new pharmaceutical agents, it is important that emergency nurses become familiar with both the beneficial and adverse effects of these drugs.

904-50 Pacemaker Cardioverter Defibrillators in Young Patients

Although life-threatening ventricular dysrhythmias are uncommon in young patients, there are underlying heart diseases that may predispose these patients to ventricular tachycardia or ventricular fibrillation (VT\VF). To test the hypothesis that tiered therapy with a pacemaker-cardioverter defibrillator (PCD) is a therapeutic option for young patients at risk for sudden death, we reviewed our experience with these devices. Nine patients, aged 9–33 years (17.7 ± 7, mean ± SD) at the time of implantation, received PCD's between March, 1993, and the present. Post-operative diagnoses included complete repair of tetralogy of Fallot (2), Senning for D-transposition of the great arteries (1), double outlet right ventricle, status post ventricular septal defect closure baffling the left ventricle to the aorta (1), and Fontan for single ventricle with pulmonary stenosis (1). Other diagnoses included Wolff-Parkinson-White (WPW) (1), WPW and dilated cardiomyopathy (1), arrhythmogenic right ventricular dysplasia (1), and long QT syndrome (1). All patients had inducible or clinical unstable VT\VF before implantation except one patient with WPW who had a family history of sudden death. Seven of the patients had failed antiarrhythmics before implantation. Defibrillator electrode configurations consisted of epicardial patches (4), transvenous alone (3), and transvenous with subcutaneous patch(es) (2). In 10.4 ± 5 (range 2–17) months of follow-up, overdrive pacing was successful in one patient, and there have been appropriate defibrillator discharges in five patients (56%). Seven of the nine patients remain on antiarrhythmics. There was only one complication, a moderate pericardial effusion two months following transvenous lead implantation in a 24.9 kg nine-year old. No system has required revision to date. In relatively short-term follow-up over 50% of our patients successfully have used tiered therapy from pacemaker-cardioverter defibrillators. This implies that these therapies protect selected young patients from sudden cardiac death, potentially greatly increasing their life span.

Heart Transplantation After Cardioverter-Defibrillator Implantation: A Case Control Study

A case control study was performed to determine whether previous implantable cardioverter-defibrillator (ICD) insertion adversely affects outcome after heart transplantation. Six male heart transplant recipients who had undergone ICD insertion 12 +/- 5 months before heart transplantation were compared to a cohort of six heart transplant recipients who were matched according to age, preoperative status and hemodynamics, date of transplantation, graft ischemic time, history of a previous cardiac operation, and duration of follow-up. There were no significant differences in operating room time, chest tube drainage, time to extubation, and the duration of intensive care unit or hospital stay between the two groups. Furthermore, there were no significant differences in the number of units of packed cells, fresh frozen plasma, platelets and cryoprecipitate transfused. The number of treated rejection episodes and the number of patients requiring intravenous antibiotics for infection in the first 90 days was identical between groups. It was concluded that heart transplantation after ICD implantation did not appear to carry more risk than heart transplantation after a previous cardiac operation. Our limited experience supports the potential use of the ICD in patients with life-threatening ventricular dysrhythmias who are awaiting transplantation.

Rationale of therapy in the patient with acute myocardial infarction and life-threatening arrhythmias: A focus on bretylium

Experimental evidence suggests a number of pathologic and electrophysiologic mechanisms that may help initiate ventricular arrhythmias accompanying myocardial ischemia and infarction. Early and late phase events are associated with reentry or an enhancement of focal mechanisms, or both. These can initiate ventricular tachycardia (VT) or ventricular fibrillation (VF), or both. The presence of distinct mechanisms that may initiate and maintain life-threatening dysrhythmias early in myocardial ischemia suggest different pharmacologic approaches for their prevention or suppression. Another consideration concerns patients subjected to coronary artery angioplasty or thrombolytic therapy and the development of arrhythmias associated with reperfusion of the once ischemic myocardium. The electrophysiologic mechanisms associated with reperfusion arrhythmias are unknown, and little is known about appropriate therapy for each episode of cardiac dysrhythmia. Ventricular extrasystoles or VT usually precedes VF. These premonitory arrhythmias are poor criteria for the institution of antiarrhythmic drug therapy, because VF develops within 1 to 10 minutes after the appearance of the rhythmic disturbances. Some authorities suggest that all patients with acute myocardial infarction should receive prophylactic antiarrhythmic therapy, because warning arrhythmias either do not occur at all or provide insufficient time to intervene pharmacologically. Many of the new class 1 antiarrhythmic agents effectively reduce the frequency of premature ventricular depolarizations, but lack specific antiflbrillatory activity. However, the recent introduction of bretylium into clinical cardiology opens a new approach to preventing life-threatening ventricular dysrhythmias. Along with other members of class III, bretylium exerts different cardiac electrophysiologic effects than do the other 3 classes of drugs. Bretylium has been designated as class III because it increases the action potential duration and prolongs the effective refractory period. The other class III drugs, including amiodarone, sotalol, clofilium and pranolium, experimentally prevent the establishment of a reentry pathway that can initiate VF. Bretylium along with these other class III agents is primarily antifibrillatory rather than antiarrhythmic. Thus, antiarrhythmic agents that reduce the frequency and complexity of premature ventricular depolarizations are not necessarily antifibrillatory. It is necessary to reorient our thinking about how pharmacologic interventions may influence the course of events in patients at risk of developing life-threatening ventricular arrhythmias. Because the lethal event is most often associated with VF, it may be sufficient to have an agent that protects against this electrophysiologic disorder even though it does not completely prevent or suppress other ventricular arrhythmias.

Advances in the Treatment of Life-Threatening Ventricular Rhythm Disturbances

Rodolphe Ruffy, MD, Assistant Professor of Medicine and director of the Cardiac Electrophysiology Laboratories and Heart Station, Washington University School of Medicine, the Jewish Hospital of St Louis: The history and clinical course of the patient described herein afford excellent examples of some sorely needed recent advances in the treatment of heart disease. The dissemination of efficient mobile resuscitation facilities that are outside the hospital, the growing success of intensive care units in sustaining lives of victims of large myocardial infarctions (MIs), and the progress of intraoperative myocardial preservation techniques that permit surgical interventions, despite the presence of advanced organic heart disease, have notably increased the number of patients at high risk of chronic, recurrent, life-threatening ventricular dysrhythmias. Patients who survive their first episode, in or out of the hospital, have an inordinately high risk of experiencing a recurrence within the first year unless vigorous efforts are made to protect

Quantitative indices of intra-aortic balloon pump (IABP) dependence during post-infarction cardiogenic shock.

This study attempts to quantitate post-infarction cardiogenic shock IABP dependence in instances of massive myocardial infarction with the use of hemodynamic indices plotted over time-course trajectories. Mortality is predicted when age and hemodynamic performance are also considered. It appears that post-infarction IABP dependence can be quantitated and that such information can be useful in considering diagnostic and therapeutic alternatives during the course of IABP support and cardiogenic shock. The analysis suggests that such IABP-dependent patients could be considered for therapeutic alternatives. They do not expire during the first 50 hours of IABP support and neither improve nor deteriorate during the second 50 hours of support. They remain in Class B without the occurrence of life-threatening ventricular dysrhythmias for a sufficient time for cardiac catheterization to determine the appropriateness of corrective procedures.