Treatment Of Life-threatening Ventricular Arrhythmias Research Articles

PO-02-106 GENERAL ANESTHESIA VERSUS CONSCIOUS SEDATION WITH LOCOREGIONAL ANESTHESIA IN S-ICD IMPLANTATION: A MONOCENTRIC RETROSPECTIVE ANALYSIS

In patients not requiring pacing, the subcutaneous implantable cardioverter-defibrillator (S-ICD) has emerged as a safe and effective alternative to the transvenous implantable cardioverter-defibrillator (TV-ICD) for the treatment of life-threatening ventricular arrhythmias. The S-ICD’s larger size requires a larger pocket for insertion and peri-procedural lead tunnelling carries high nociceptive potential, resulting historically in 65% of S-ICD implantations being performed under general anesthesia (GA). This study seeks to demonstrate that conscious sedation with locoregional anesthesia (CS-LA) is a safe and effective alternative to general anesthesia (GA) in S-ICD implantation. A total of 138 S-ICD implantations (90 under CS-LA) at our institution between 2013 and 2020 were studied The CS-LA technique was performed with conscious sedation, local anesthesia of the pocket and xyphoid incision sites, and post-procedural intercostal nerve blocade of the 4th to 7th intercostal spaces with a mixture of 10mL of 0.5% bupivacaine and 20mL of 2% lidocaine without epinephrine. Analgesic efficacy in the 24 post-operative hours was evaluated by Numerical Pain Rating Scale (NPRS) score and by total analgesic medication dosage received. Safety was evaluated by comparing the incidence of significant adverse events (AE): hypotension <80 mmHg or requiring vasopressors, bradycardia <40 bpm, or desaturation <90% for more than two minutes or requiring non-invasive ventilation maneuvers. Post-procedural pain at 15 minutes and at 24 hours was significantly less in the CS-LA group, with a difference of -0.90 (p=0.04) and -1.21 (p=0.004) respectively. Post-procedural opioid consumption was 10.64mg of per os morphine equivalents (p=0.046) lower than in the CS-LA group. No significant difference in the likelihood of at least one adverse event occurring was noted, with CS-LA demonstrating OR 1.95 (95% CI [0.86, 4.40], p=0.11) for at least one AE. Only one patient in the CS-LA arm required conversion to GA, due to excessive agitation during the procedure. S-ICD implantation under CS-LA was superior at 15 minutes and 24 hours to GA in terms of analgesic efficacy and post-procedural patient comfort. CS-LA’s safety profile was similar to GA, with no significantly increased risk of suffering at least one adverse event.

GENERAL ANESTHESIA VERSUS CONSCIOUS SEDATION WITH LOCOREGIONAL ANESTHESIA IN S-ICD IMPLANTATION: A MONOCENTRIC RETROSPECTIVE ANALYSIS

GENERAL ANESTHESIA VERSUS CONSCIOUS SEDATION WITH LOCOREGIONAL ANESTHESIA IN S-ICD IMPLANTATION: A MONOCENTRIC RETROSPECTIVE ANALYSIS

Bretylium, a Class III Antiarrhythmic, Returns to the Market

Bretylium, with an extensive pharmacologic and medicinal history, was approved by the United States Food and Drug Administration in 1986 for "short-term prevention and treatment of ventricular fibrillation (VF) and treatment of life-threatening ventricular arrhythmias and ventricular tachycardia (VT) unresponsive to adequate doses of a first-line antiarrhythmic agent, such as lidocaine." The NDA sponsor withdrew bretylium from the market in 2011, largely due to unavailability of raw materials required for its production; prior to this, bretylium was removed from the 2000 ACLS Guidelines algorithm for VF/pulseless VT given the challenges obtaining raw materials for drug manufacture. Recently, bretylium has been reintroduced into the US market by a generic pharmaceutical company with the same indications as before. This article provides a history of the salient trials evaluating the efficacy and safety of bretylium and looks to the future as bretylium finds its place in the modern day management of ventricular arrhythmia.

Handling of Ventricular Fibrillation in the Emergency Setting.

Ventricular fibrillation (VF) and sudden cardiac death (SCD) are predominantly caused by channelopathies and cardiomyopathies in youngsters and coronary heart disease in the elderly. Temporary factors, e.g., electrolyte imbalance, drug interactions, and substance abuses may play an additive role in arrhythmogenesis. Ectopic automaticity, triggered activity, and reentry mechanisms are known as important electrophysiological substrates for VF determining the antiarrhythmic therapies at the same time. Emergency need for electrical cardioversion is supported by the fact that every minute without defibrillation decreases survival rates by approximately 7%–10%. Thus, early defibrillation is an essential part of antiarrhythmic emergency management. Drug therapy has its relevance rather in the prevention of sudden cardiac death, where early recognition and treatment of the underlying disease has significant importance. Cardioprotective and antiarrhythmic effects of beta blockers in patients predisposed to sudden cardiac death were highlighted in numerous studies, hence nowadays these drugs are considered to be the cornerstones of the prevention and treatment of life-threatening ventricular arrhythmias. Nevertheless, other medical therapies have not been proven to be useful in the prevention of VF. Although amiodarone has shown positive results occasionally, this was not demonstrated to be consistent. Furthermore, the potential proarrhythmic effects of drugs may also limit their applicability. Based on these unfavorable observations we highlight the importance of arrhythmia prevention, where echocardiography, electrocardiography and laboratory testing play a significant role even in the emergency setting. In the following we provide a summary on the latest developments on cardiopulmonary resuscitation, and the evaluation and preventive treatment possibilities of patients with increased susceptibility to VF and SCD.

Subcutaneous implantable cardioverter defibrillator implantation: An analysis of Italian clinical practice and its evolution

BackgroundThe subcutaneous implantable cardioverter defibrillator (S-ICD) is a relatively novel alternative to the transvenous ICD for the treatment of life-threatening ventricular arrhythmias, and is currently used in the clinical practice of several centers. The aim of this analysis was to describe current Italian practice regarding S-ICD implantation and its evolution over the years. MethodsWe analyzed 607 consecutive patients (78% male, 48 ± 16 years) who underwent S-ICD implantation in 39 Italian centers from 2013 to 2017. ResultsStructural cardiomyopathy was present in 78% of patients and 30% of patients received their device for secondary prevention. The proportion of patients with dilated cardiomyopathy and with left ventricular ejection fraction ≤35% increased from ≤2014 to 2017 (from 38% to 58%, from 33% to 53%, respectively; both p < 0.05). Almost all procedures (97%) were performed in electrophysiology laboratories. Over the last 4 years, the 2-incision implantation technique has been widely adopted, with sub- or inter-muscular positioning of the generator, under local anesthesia or deep sedation (≤2014 versus 2017: all p < 0.001). Defibrillation testing was performed in 81% of patients. Shock energy of ≤65 J was successful in 93.9% of patients and the overall cardioversion success rate at ≤80 J was 99.8%. ConclusionsOur analysis confirmed that the S-ICD continues to be preferentially used in specific patients (younger, less frequently with dilated cardiomyopathy and low ejection fraction.). Nonetheless, we noted a trend toward the wider use of S-ICD in patients with dilated cardiomyopathy and systolic dysfunction over the years. Novel approaches have been adopted while the acute efficacy of the system has remained stably high.

The US Experience of the Wearable Cardioverter-Defibrillator in Pediatric Patients

Certain pediatric patients are at risk for sudden cardiac death. The wearable cardioverter-defibrillator (WCD) can be used in clinical situations in which implantable cardioverter-defibrillator placement is not ideal. The objectives of the study are to examine the effectiveness, safety, and compliance of the WCD in the identification and treatment of life-threatening ventricular arrhythmias in pediatric patients. All United States pediatric patients <18 years who wore a WCD, from 2009 to 2016 were retrospectively reviewed. In total, 455 patients were identified. The median age was 15 (3-17) years, median duration of WCD use was 33 (1-999) days and median patient wear time was 20.6 (0.3-23.8) hours per day. The population was divided into 2 groups: (1) patients with implantable cardioverter-defibrillator problem, n=63 and (2) patients with nonimplantable cardioverter-defibrillator problem, n=392. Wear time per day was >20 hours in both groups. Wear duration was shorter in the implantable cardioverter-defibrillator problem group, 26 days versus 35 days, P<0.05. There were 7 deaths (1.5%); all not wearing WCD at time of death. Eight patients (1.8%) received at least 1 WCD shock treatment. Of the 6 patients (1.3%) who had appropriate therapy, there were 7 episodes of either polymorphic ventricular tachycardia or ventricular fibrillation with a total of 13 treatments delivered. All episodes were successfully converted and the patients survived. The WCD has overall adequate compliance with appropriate wear times and wear durations in pediatric patients. The WCD is safe and effective in treating ventricular arrhythmias that can lead to sudden cardiac death in pediatric patients.

Have the Findings from Clinical Risk Prediction and Trials Any Key Messages for Safety Pharmacology?

Anti-arrhythmic drugs are a mainstay in the management of symptoms related to arrhythmias, and are adjuncts in prevention and treatment of life-threatening ventricular arrhythmias. However, they also have the potential for pro-arrhythmia and thus the prediction of arrhythmia predisposition and drug response are critical issues. Clinical trials are the latter stages in the safety testing and efficacy process prior to market release, and as such serve as a critical safeguard. In this review, we look at some of the lessons to be learned from approaches to arrhythmia prediction in patients, clinical trials of drugs used in the treatment of arrhythmias, and the implications for the design of pre-clinical safety pharmacology testing.

Select Articles Published on the Topic of Arrhythmia and Electrophysiogy in 2013

Select Articles Published on the Topic of Arrhythmia and Electrophysiogy in 2013

Safety and Efficacy of a Totally Subcutaneous Implantable-Cardioverter Defibrillator

The most frequent complications associated with implantable cardioverter-defibrillators (ICDs) involve the transvenous leads. A subcutaneous implantable cardioverter-defibrillator (S-ICD) has been developed as an alternative system. This study evaluated the safety and effectiveness of the S-ICD System (Cameron Health/Boston Scientific) for the treatment of life-threatening ventricular arrhythmias (ventricular tachycardia/ventricular fibrillation). This prospective, nonrandomized, multicenter trial included adult patients with a standard indication for an ICD, who neither required pacing nor had documented pace-terminable ventricular tachycardia. The primary safety end point was the 180-day S-ICD System complication-free rate compared with a prespecified performance goal of 79%. The primary effectiveness end point was the induced ventricular fibrillation conversion rate compared with a prespecified performance goal of 88%, with success defined as 2 consecutive ventricular fibrillation conversions of 4 attempts. Detection and conversion of spontaneous episodes were also evaluated. Device implantation was attempted in 321 of 330 enrolled patients, and 314 patients underwent successful implantation. The cohort was followed for a mean duration of 11 months. The study population was 74% male with a mean age of 52±16 years and mean left ventricular ejection fraction of 36±16%. A previous transvenous ICD had been implanted in 13%. Both primary end points were met: The 180-day system complication-free rate was 99%, and sensitivity analysis of the acute ventricular fibrillation conversion rate was >90% in the entire cohort. There were 38 discrete spontaneous episodes of ventricular tachycardia/ventricular fibrillation recorded in 21 patients (6.7%), all of which successfully converted. Forty-one patients (13.1%) received an inappropriate shock. The findings support the efficacy and safety of the S-ICD System for the treatment of life-threatening ventricular arrhythmias.

Evaluation of Hepatic Dysfunction in Patients Receiving Intravenous Amiodarone at an Academic Veterans Affairs Medical Center

Purpose: Amiodarone is a class III anti-arrhythmic used for the treatment of life-threatening ventricular arrhythmias. The adverse effects of oral amiodarone are well documented and involve most organ systems leading to the cessation of the medication in 10-15% of patients. In contrast, IV amiodarone has been documented in only a few case reports causing transaminitis. Several studies have indicated that hepatic dysfunction may be the diluent rather than the drug itself. Amiodarone is dissolved in polysorbate-80 and animal studies show that it causes hemolysis, cholestasis, and reversible fat accumulation in rat hepatocyte cell lines within three hours of exposure. Other medications with the polysorbate-80 diluent also support the hypothesis that it may be a causative factor of hepatic injury. The purpose of this study is to evaluate the degree of hepatic dysfunction and mortality in patients receiving intravenous amiodarone at the Michael E. DeBakey VA Medical Center between July 2005 and July 2011. The primary objective is to determine the incidence of transaminitis (ALT or AST > twice the normal value) in patients receiving IV amiodarone. Secondary objectives include determining the incidence of in-hospital and all-cause mortality. Methods: The study is a single-center, retrospective chart review of patients who have received IV amiodarone between July 2005 and July 2011. Patients less than 18 years of age or pregnant were excluded in addition to those who received only oral amiodarone, or received IV amiodarone one week prior to hospital admission. Descriptive statistics will be used to analyze baseline characteristics and study outcomes. Data will be presented in percentages, mean and median values. Results: A total of 1510 patients received intravenous amiodarone from July 2005 to July 2011. Seventy-eight patients, approximately 5.16% had elevated liver enzymes [median:range; AST 253:82-12005; ALT 189:37-10006] after the administration of IV amiodarone. Of the 78 patients with transaminitis, 10 developed fulminate hepatic failure (AST or ALT >1000) with 90% all-cause mortality. Most patients developed a transient transaminitis that lasted three days on average that resolved with cessation of the medication. Conclusion: Although transaminitis is common with oral amiodarone, only 5.16% developed transaminitis while receiving intravenous amiodarone. Since the transaminitis resolved after cessation of the medication, it is more of a transient hepatic injury. The incidence of fulminate hepatic failure was rare but with an all cause mortality of 90%.

Safety and Efficacy of a Subcutaneous Implantable-Defibrillator

Introduction: A subcutaneous implantable cardioverter-defibrillator (S-ICD) that does not require a transvenous lead has been developed. The purpose of this study was to evaluate the safety and efficacy of the S-ICD for the treatment of life-threatening ventricular arrhythmias.

Cardioverter-defibrillators: a cost or an investment?

Implantable cardioverter-defibrillator (ICD) therapy has emerged as the most effective treatment for life-threatening ventricular arrhythmias. Most studies indicate that ICD therapy in appropriately selected patients at high risk of sudden cardiac death (SCD) is associated with cost-effectiveness ratios similar to, or better than, other accepted treatments, including renal dialysis. The up-front costs of ICD therapy are admittedly high and as such, ICD implantation is more akin to an operation than a drug. As would be the case for a life-saving operation, the adoption of short time horizons is apt to lead to underestimations of cost effectiveness. As well as the time horizon, the underlying aetiology of the arrhythmic substrate, implantation technique, ICD battery life, and the presence of co-morbidities are important issues in maximizing cost effectiveness. Above all, we should consider that ICD therapy is the only available option for prolonging survival in patients who are at risk of SCD.

Knowledge Assessment and Preparation for the Certified Emergency Nurses Examination

Knowledge Assessment and Preparation for the Certified Emergency Nurses Examination

Defibrillation Effects of Intravenous Nifekalant in Patients with Out‐of‐Hospital Ventricular Fibrillation

Nifekalant (NF), a pure K(+) channel blocker developed in Japan, has been reported to be effective in the treatment of life-threatening ventricular arrhythmias. We studied its efficacy in 18 men and 4 women with out-of-hospital ventricular fibrillation (VF) admitted to our emergency department between August 2001 and March 2004. The number of DC shocks delivered for out-of-hospital VF, serum Na(+) and K(+), arterial blood pH, and base excess were compared in 8 patients treated with NF, 0.3 mg/kg i.v. followed by a continuous intravenous (group N) versus 14 patients treated with lidocaine, 2 mg/kg, i.v. (group C). The two groups were similar with respect to their baseline characteristics. Sinus rhythm returned in 5 of 8 patients in group N versus 2 of 14 patients in group C (P < 0.05). These seven patients were admitted to the intensive care unit, though all died within 1 month. The results of this study suggest that NF may be effective in defibrillation of out-of-hospital VF, though controlled studies are needed to confirm our observations.

Single-finger subcutaneous defibrillation lead and “active can”: a novel minimally invasive defibrillation configuration for implantable cardioverter-defibrillator implantation in a young child

Implantable cardioverter defibrillators (ICDs) provide a safe and effective treatment for life-threatening ventricular arrhythmias. Several investigators have demonstrated that ICD use in pediatric patients is feasible, effective, and associated with a low risk of sudden death in follow-up. However, ICD placement in young children can usually be accomplished only by a thoracotomy approach involving multiple incisions and placement of epicardial defibrillation electrodes. We describe a less invasive yet efficacious lead configuration likely to be associated with a lower complication rate.

Interactions of antiarrhythmic drugs and implantable devices in controlling ventricular tachycardia and fibrillation.

Implantable cardioverter defibrillators (ICDs) have proven highly successful in the treatment of life-threatening ventricular arrhythmias. Despite the efficacy of the ICD in terminating ventricular arrhythmias, antiarrhythmic drugs remain an important adjunct to ICD therapy. The use of antiarrhythmic drug therapy in combination with the ICD is synergistic in terms of beneficial effects, but also has the potential for some adverse interactions. Knowledge and recognition of these potential interactions is important for any physician managing patients with an ICD. This review summarizes the benefits and adverse effects of ICD in combination with antiarrhythmic drug therapy, and provides guidelines to ensure safe application of this hybrid therapy.

Intravenous amiodarone and off-pump coronary artery bypass graft procedures: A new role for intraoperative antiarrhythmic therapy?

Intravenous amiodarone and off-pump coronary artery bypass graft procedures: A new role for intraoperative antiarrhythmic therapy?

Evolution of diagnostic and interventional cardiac electrophysiology: a brief historical review

The field of clinical cardiac electrophysiology has evolved dramatically over the last 30 years, beginning with description of the first His bundle recording in 1969. Subsequently, in the early 1970s, more sophisticated diagnostic electrophysiologic techniques were developed to diagnose and guide drug treatment of arrhythmias. These diagnostic techniques were further advanced during the late 1970s and 1980s to electrically map arrhythmias and guide their surgical ablation. Surgical treatments of both supraventricular and ventricular arrhythmias proliferated in the 1970s and 1980s, with overall excellent results. However, because of the morbidity and mortality associated with arrhythmia surgery, it was ultimately replaced in the 1990s by radiofrequency catheter ablation (RFCA) for treatment of most forms of supraventricular tachycardia and idiopathic ventricular tachycardia, and by the automatic implantable cardioverter defibrillator (ICD) for treatment of life-threatening ventricular arrhythmias associated with coronary artery disease and dilated cardiomyopathy. At present, the only arrhythmias that cannot be reliably and safely cured by RFCA are chronic atrial fibrillation and life-threatening ventricular arrhythmias. For chronic atrial fibrillation, new catheter designs are being developed to create linear ablation lines mimicking the curative MAZE operation. For life-threatening ventricular arrhythmias, the ICD has been increasingly utilized as transvenous lead systems and smaller devices have been developed. In the next millennium, new developments that may be expected for treatment of atrial fibrillation and life-threatening ventricular arrhythmias include catheter systems for linear RFCA of atrial fibrillation, ICDs for both atrial and ventricular defibrillation, and biventricular pacing ICDs for patients with congestive heart failure.

Causes of death in the antiarrhythmics versus implantable defibrillators (AVID) trial

OBJECTIVESThis study analyzed the causes of death in the Antiarrhythmics Versus Implantable Defibrillators (AVID) Trial.BACKGROUNDBoth implantable cardioverter-defibrillators (ICDs) and antiarrhythmic drugs (AADs) are used as mainstays of treatment for life-threatening ventricular arrhythmias in patients who have survived either ventricular fibrillation or sustained ventricular tachycardia with hemodynamic compromise and serious symptoms. The AVID Trial compared the effectiveness of these two therapies. Survival was better with the ICD. Assessment of the cause of death should help to determine the mechanism of improvement in survival with the ICD.METHODSOf 1,016 patients enrolled in the AVID Trial, 202 patients died. The mode of death was determined by the unblinded Principal Investigator and independently by an Events Committee, which reviewed materials meticulously blinded with respect to treatment. Deaths were classified as cardiac or noncardiac. Cardiac deaths were further classified as arrhythmic or nonarrhythmic, and causes of noncardiac death were identified.RESULTSDeaths were more frequent in patients treated with an AAD (n = 122), compared with patients treated with the ICD (n = 80), unadjusted p < 0.001, p = 0.012 adjusted for sequential monitoring. In AVID, 157 deaths were cardiac, and 79 were arrhythmic. The major effect of the ICD was to prevent arrhythmic death (AAD = 55, ICD = 24, nominal unadjusted p < 0.001). Nonarrhythmic cardiac deaths were equal (AAD = 39, ICD = 39). Patients treated with an AAD had a slightly greater incidence of noncardiac deaths (28 vs. 17, p = 0.053), primarily due to pulmonary and renal causes.CONCLUSIONSThe ICD is more effective than an AAD in reducing arrhythmic cardiac death, while nonarrhythmic cardiac death is unchanged. Of note, apparent arrhythmic death still seems to constitute 38% of all cardiac deaths despite treatment with an ICD. However, the ICD remains superior to an AAD in prolonging survival after life-threatening arrhythmias.

Health-related quality-of-life assessment of patients with life-threatening ventricular arrhythmias.

The purpose of this study was to determine whether treatments for life-threatening ventricular arrhythmias are associated with quality-of-life (QOL) and psychological distress. Multidimensional measures of QOL and psychological distress were used to cross-sectionally compare patients with ICDs to patients treated with antiarrhythmic drugs and patients without serious cardiac conditions. The sample consisted of 157 patients: 35 patients treated with antiarrhythmic medication only, 24 patients treated with ICD only, 25 patients treated with ICD and antiarrhythmic medication, and 73 controls. Patients completed the Medical Outcomes Study SF-36 health survey, the Brief Symptom Inventory, and background questionnaires. There were no significant differences in self-reported QOL and psychological distress between patients with or without ICD, and the occurrence of defibrillator shocks was unrelated to QOL and psychological distress. However, patients treated with antiarrhythmic drugs reported greater QOL impairment in physical functioning, vitality, emotional role limitations, and sleep, as well as greater psychological distress than patients not treated with antiarrhythmics. These limitations may be attributed to adverse effects arising from antiarrhythmic pharmacotherapy. Results of the present investigation suggest that QOL and psychological distress are maintained among ICD patients, whereas treatment with antiarrhythmic drugs are associated with a diminished QOL and greater psychological distress. These findings may assist cardiologists to select the optimal treatment for life-threatening ventricular arrhythmias that minimizes disturbances in health-related QOL and psychological distress and increases patient compliance.