Conventional Antiarrhythmic Therapy Research Articles

АНАЛИЗ МАРКЕРОВ СИСТЕМЫ ГЕМОСТАЗА У ПАЦИЕНТОВ С ФИБРИЛЛЯЦИЕЙ ПРЕДСЕРДИЙ НЕКЛАПАННОГО ГЕНЕЗА С ТРОМБОЭМБОЛИЧЕСКИМИ ОСЛОЖНЕНИЯМИ

Introduction. Atrial fibrillation (AF) is one of the most common heart rhythm disorders. The risk of developing thromboembolic complications, including ischemic stroke, in patients with AF is 5 times higher than that in patients with sinus rhythm; therefore, one of the main directions in the treatment of patients with this rhythm disorder is the prevention of thromboembolic complications. Objective: to study the markers of monitoring the blood coagulation system in the blood serum of patients with non-valvular AF receiving anticoagulant therapy and having a history of thrombotic and thromboembolic complications. Materials and methods. The study included 31 healthy volunteers (without a history of AF, thrombosis) and 31 patients over 18 years of age with a diagnosis of AF (mean age 66.2±8.1), receiving anticoagulant therapy and having a history of thrombotic and thromboembolic events. complications. Therapy taken by patients at the time of inclusion in the study was in line with current recommendations and included standard conventional antiarrhythmic and anticoagulant therapy, as well as therapy for the underlying cardiovascular disease. Biomarkers of thrombus formation and pro-inflammatory activation (L-selectin, thrombomodulin) were determined by enzyme immunoassay using diagnostic kits from BiomedicaGmbH, Austria. Results. During the screening of 2820 patients treated in the Department of CHLSRS&EX for the nosology of AF in the period 01.2020-01.2023, 31 patients were included in the study, who were diagnosed with thrombotic and thromboembolic complications (0.01% of the total number of screened patients) against the background of regular anticoagulant therapy . Among all patients included in the study, thrombotic complications in AF were as follows: thrombosis of the left atrial appendage was noted in 17 patients (54%), spontaneous echo contrast of grade II or more in 5 patients (16%), cardioembolic stroke - in 3 patients (10%) , thrombosis of peripheral arteries (2 (6%)), thrombosis on EKS electrodes (2 (6%)). The concentration of soluble thrombomodulin in the blood serum of patients with thrombotic and thromboembolic complications was reduced compared with the group of healthy volunteers (2073.0±548.6 vs. 2845.3±726.4 pg/ml; p=0.004). Serum levels of L-selectin in patients with thrombotic and thromboembolic complications were reduced compared to healthy volunteers (1.5±0.6 vs. 2.4±1.3 µg/mL; p=0.04). Conclusion. In patients with thrombotic and thromboembolic complications that occurred against the background of adequate anticoagulant therapy, there was a decrease in serum soluble thrombomodulin and L-selectin, which may indicate damage to the endothelium, activation of thrombus formation and inflammation.

Triple Antiarrhythmic Therapy in Newborns with Refractory Atrioventricular Reentrant Tachycardia.

Atrioventricular reentrant tachycardia (AVRT) is the most common form of supraventricular tachycardia in newborns. AVRT is sometimes refractory to conventional antiarrhythmic therapy. We describe our experience about the use of the triple combination of flecainide + propranolol + amiodarone as third-line regimen for refractory and recurrent AVRT in newborns. We considered a series of 14 patients who had failed both first-line and second-line therapy and were treated using the combination of flecainide + propranolol + amiodarone. Transoesophageal electrophysiologic study (TES) was performed to test the effectiveness of medical therapy during hospitalization and to try to reduce the amount of therapy, after amiodarone wash-out, before 1 year of age. TES was repeated at 1 year of age to test the spontaneous resolution of the arrhythmia after treatment discontinuation. Rhythm control was achieved in all 14 patients. At a mean age of 9.3 ± 2months, AVRT was not inducible by TES in 11/12 amiodarone-free patients. At a mean age of 14.1 ± 3months, AVRT was still inducible in 7/12 patients after interrupting the entire antiarrhythmic therapy (58.3%). Triple combination was effective as third-line option to suppress AVRT refractory to single and double antiarrhythmic therapy, with no significant adverse events. Our experience suggests that triple therapy could be maintained for a short-term treatment, discontinuing amiodarone before 1 year of age to avoid long-term side effects. Newborns who needed triple therapy appear to have a lower chance of accessory pathway disappearance at 1 year of age. TES could be useful for risk stratification of recurrences at the time of drug discontinuation in infants considered to be at higher risk of recurrent AVRT.

Mexiletine for ventricular arrhythmias in patients with chronic coronary syndrome: a cohort study

Background The pharmacological therapy of ventricular arrhythmias in patients with unsuccessful or not feasible catheter ablation and contraindication or inefficacy to amiodarone and beta-blockers, is controversial. The present study investigated the effectiveness and tolerability of mexiletine in patients with recurrent ventricular arrhythmias and ischaemic heart disease, when the conventional antiarrhythmic therapy failed. Methods We enrolled all consecutive patients with unsuccessful/not feasible catheter ablation and ineffective/contraindicated amiodarone or beta-blockers, which started the mexiletine treatment for refractory ventricular tachycardia (VT) or ventricular fibrillation (VF) between January 2010 and January 2020. The primary endpoint was the total number of VT/VF episodes after the beginning of mexiletine therapy. The 2 secondary endpoints were the overall number of therapies released by implantable cardioverter-defibrillators (ICDs) and the discontinuation of the pharmacological therapy. The events occurring during the mexiletine treatment period were compared with those observed in a matched duration interval before the initiation of therapy. Results Thirty-four consecutive patients (27 males, 79.4%; mean age 74.0 ± 9.5 years) with ischaemic heart disease were finally analysed. The median of mexiletine treatment was 26.5 months (interquartile range: 18.75–38.25 months). After the mexiletine start, VT/VF episodes and ICD interventions significantly decreased (respectively: 74 vs 33 episodes, p = 0.002; 116 vs 52 interventions, p = 0.02) in comparison with a matched period without mexiletine. Six patients (13.9%) discontinued the treatment because of severe side effects. Conclusions The treatment period following the mexiletine start was associated with a significant reduction of ventricular arrhythmias. The rate of side effects requiring dosage reduction or interruption was not neglectable.

Quinidine-responsive out-of-hospital polymorphic ventricular tachycardia in patients with coronary heart disease.

We recently reported that patients with coronary artery disease (CAD) who develop polymorphic ventricular tachycardia (VT) during the healing phase of an acute coronary event, generally fail to respond to revascularization or standard antiarrhythmic therapy but respond immediately to quinidine therapy. Here, we describe that CAD patients presenting with out-of-hospital polymorphic VT without a recent coronary event or an obvious precipitating factor, also respond uniquely to quinidine therapy. Retrospective study of patients with unheralded, mainly out-of-hospital, polymorphic VT related to CAD but without evidence of acute myocardial ischaemia. We identified 20 patients who developed polymorphic VT without precipitating factors. The polymorphic VT events were triggered by extrasystoles with short (376 ± 49 ms) coupling interval. Arrhythmic storms occurred in 70% patients. These arrhythmic storms were generally refractory to conventional antiarrhythmic therapy but invariably responded to quinidine therapy. Revascularization was antiarrhythmic in 3 patients despite the absent clinical or ECG signs of ischaemia. During long-term follow-up (range 2 months to 11 years), 3 (15%) of patients not receiving quinidine developed recurrent polymorphic VT. There were no recurrent arrhythmias during long-term quinidine therapy. Patients with CAD may develop polymorphic VT in the absence of obvious acute ischaemia or apparent precipitating factors, presenting as out-of-hospital polymorphic VT with high risk of arrhythmic storms that respond uniquely to quinidine therapy.

Quinidine-Responsive Polymorphic Ventricular Tachycardia in Patients With Coronary Heart Disease.

Polymorphic ventricular tachycardia (VT) without QT prolongation is well described in patients without structural heart disease (mainly idiopathic ventricular fibrillation and Brugada syndrome) and in patients with acute ST-elevation myocardial infarction. Retrospective study of patients with polymorphic VT related to coronary artery disease, but without evidence of acute myocardial ischemia. The authors identified 43 patients in whom polymorphic VT developed within days of an otherwise uncomplicated myocardial infarction or coronary revascularization procedure. The polymorphic VT events were invariably triggered by extrasystoles with short (364±36 ms) coupling interval. Arrhythmic storms (4-16 events of polymorphic VT deteriorating to ventricular fibrillation) occurred in 23 (53%) patients. These arrhythmic storms were always refractory to conventional antiarrhythmic therapy, including intravenous amiodarone, but invariably responded to quinidine therapy. In-hospital mortality was 17% for patients with arrhythmic storm. Patients treated with quinidine invariably survived to hospital discharge. During long-term follow-up (of 5.6±6 years; range, 1 month to 18 years), 3 (16%) of patients discharged without quinidine developed recurrent polymorphic VT. There were no recurrent arrhythmias during quinidine therapy Conclusions: Arrhythmic storm with recurrent polymorphic VT in patients with coronary disease responds to quinidine therapy when other antiarrhythmic drugs (including intravenous amiodarone) fail.

Fosphenytoin for control of electrical storm in acute myocardial infarction and Purkinje fiber‐mediated arrhythmias

Purkinje fiber-mediated arrhythmias in the setting of acute myocardial infarction are poorly responsive to conventional antiarrhythmic therapy, increases overall mortality and often requires radiofrequency ablation (RFA) for control. In this study, we report the use of intravenous Fosphenytoin for the control of arrhythmic storm in patients with acute myocardial infarction. Six patients with acute myocardial infarction (5 AW/1 LW) and Purkinje-triggered ventricular arrhythmias refractory to conventional antiarrhythmics were treated with intravenous Fosphenytoin before considering RFA. Arrhythmia control was obtained in all patients after the initial bolus dose. Breakthrough episodes were seen in 5/6 within 24-36hours of the initial bolus, necessitating a second bolus. Complete arrhythmia control was obtained in all patients within 72hours and 5/6 patients were successfully discharged from the hospital. One patient succumbed to sepsis in hospital while another patient succumbed to Sub Dural Hematoma after 3 months. Intravenous Fosphenytoin should be considered before RFA for control of Purkinje fiber-mediated refractory arrhythmias in acute myocardial infarction patients.

Fish Oil for the Reduction of Atrial Fibrillation Recurrence, Inflammation, and Oxidative Stress

BackgroundRecent trials of fish oil for the prevention of atrial fibrillation (AF) recurrence have provided mixed results. Notable uncertainties in the existing evidence base include the roles of high-dose fish oil, inflammation, and oxidative stress in patients with paroxysmal or persistent AF not receiving conventional antiarrhythmic (AA) therapy. ObjectivesThe aim of this study was to evaluate the influence of high-dose fish oil on AF recurrence, inflammation, and oxidative stress parameters. MethodsWe performed a double-blind, randomized, placebo-controlled, parallel-arm study in 337 patients with symptomatic paroxysmal or persistent AF within 6 months of enrollment. Patients were randomized to fish oil (4 g/day) or placebo and followed, on average, for 271 ± 129 days. ResultsThe primary endpoint was time to first symptomatic or asymptomatic AF recurrence lasting >30 s. Secondary endpoints were high-sensitivity C-reactive protein (hs-CRP) and myeloperoxidase (MPO). The primary endpoint occurred in 64.1% of patients in the fish oil arm and 63.2% of patients in the placebo arm (hazard ratio: 1.10; 95% confidence interval: 0.84 to 1.45; p = 0.48). hs-CRP and MPO were within normal limits at baseline and decreased to a similar degree at 6 months (Δhs-CRP, 11% vs. −11%; ΔMPO, −5% vs. −9% for fish oil vs. placebo, respectively; p value for interaction = NS). ConclusionsHigh-dose fish oil does not reduce AF recurrence in patients with a history of AF not receiving conventional AA therapy. Furthermore, fish oil does not reduce inflammation or oxidative stress markers in this population, which may explain its lack of efficacy. (Multi-center Study to Evaluate the Effect of N-3 Fatty Acids [OMEGA-3] on Arrhythmia Recurrence in Atrial Fibrillation [AFFORD]; NCT01235130).

Evaluating the Cost-effectiveness of Catheter Ablation of Atrial Fibrillation.

Atrial fibrillation (AF) is one of the most common cardiac conditions treated in primary care and specialty cardiology settings, and is associated with considerable morbidity, mortality and cost. Catheter ablation, typically by electrically isolating the pulmonary veins and surrounding tissue, is more effective at maintaining sinus rhythm than conventional antiarrhythmic drug therapy and is now recommended as first-line therapy. From a value standpoint, the cost-effectiveness of ablation must incorporate the upfront procedural costs and risks with the benefits of longer term improvements in quality of life (QOL) and healthcare utilisation. Here, we present a primer on cost-effectiveness analysis (CEA), review the data on cost-effectiveness of AF ablation and outline key areas for further investigation.

Antiarrhythmic Effect of Ranolazine in Combination with Class III Drugs in an Experimental Whole‐Heart Model of Atrial Fibrillation

Ranolazine is evaluated for antiarrhythmic therapy of atrial fibrillation (AF). The electrophysiologic mechanisms of ranolazine in combination with class III drugs were studied in an isolated whole-heart model of stretch-related AF. Thirty rabbits were fed with amiodarone (50mg/kg/day, n=10), dronedarone (50mg/kg/day, n=10), or placebo (n=10) for 6weeks. Subsequently, in isolated hearts, AF was induced by high-rate atrial pacing and acute atrial dilatation. In placebo-treated hearts, d,l-sotalol (50μM) was acutely administered. Ranolazine (10μM) was additionally infused in all groups. Chronic amiodarone (+26±7ms, P<0.05) or dronedarone (+22±4ms, P<0.05) as well as acute application of d,l-sotalol (+20±3ms, P<0.05) increased atrial action potential duration (aAPD90 ). Additional treatment with ranolazine did not significantly change aAPD90 (P=ns). Class III drugs did not affect interatrial conduction time, while ranolazine significantly increased it (amiodarone group: +15±3ms, dronedarone group: +11±3ms, sotalol group: +15±6ms; P<0.05 each). Ranolazine led to an additional increase in atrial effective refractory period (aERP), thus leading to an enhanced atrial postrepolarization refractoriness (aPRR, +17±6ms, +21±4ms and +16±8ms, P<0.05, respectively). Acute atrial dilatation increased AF incidence compared with baseline. Amiodarone-pretreated hearts showed a lower incidence of AF. Additional infusion of ranolazine further diminished AF. Dronedarone or acute infusion of sotalol did not significantly suppress AF, while additional treatment with ranolazine in these groups also reduced AF incidence. In this study, ranolazine on top of class III antiarrhythmic therapy had a beneficial effect. The increase in interatrial conduction time and marked atrial aPRR suppressed AF. These results shed further light on a potential therapeutic benefit of ranolazine on top of conventional antiarrhythmic therapy for rhythm control in AF.

Atrial Fibrillation Ablation

Atrial fibrillation is the commonest cardiac arrhythmia, with significant morbidity related to symptoms, heart failure, and thromboembolism, which is associated with excess mortality. Over the past 10 years, many centers worldwide have reported high success rates and few complications after a single ablation procedure in patients with paroxysmal atrial fibrillation. Recent studies indicate a short-term and long-term superiority of catheter ablation as compared with conventional antiarrhythmic drug therapy in terms of arrhythmia recurrence, quality of life, and arrhythmia progression. As a result, catheter ablation is evolving to a front-line therapy in many patients with atrial fibrillation. However, in patients with persistent long-standing atrial fibrillation catheter ablation strategy is more complex and time-consuming, frequently requiring repeat procedures to achieve success rates as high as in paroxysmal atrial fibrillation. In the near future, however, with growing experience and evolving technology, catheter ablation of atrial fibrillation may be extended also to patients with long-standing atrial fibrillation.

Tratamiento ablativo de la fibrilación auricular

Atrial fibrillation is the commonest cardiac arrhythmia, with significant morbidity related to symptoms, heart failure, and thromboembolism, which is associated with excess mortality. Over the past 10 years, many centers worldwide have reported high success rates and few complications after a single ablation procedure in patients with paroxysmal atrial fibrillation. Recent studies indicate a short-term and long-term superiority of catheter ablation as compared with conventional antiarrhythmic drug therapy in terms of arrhythmia recurrence, quality of life, and arrhythmia progression. As a result, catheter ablation is evolving to a front-line therapy in many patients with atrial fibrillation. However, in patients with persistent long-standing atrial fibrillation catheter ablation strategy is more complex and time-consuming, frequently requiring repeat procedures to achieve success rates as high as in paroxysmal atrial fibrillation. In the near future, however, with growing experience and evolving technology, catheter ablation of atrial fibrillation may be extended also to patients with long-standing atrial fibrillation.Full English text available from:www.revespcardiol.org

Upstream therapy in atrial fibrillation

atrial fibrillation (aF) is the most common rhythm disorder and a frequent cause for hospitalization and increased mortality and morbidity. the conventional antiarrhythmic therapy has limited options for prevention of aF, so other ways of prevention are being researched. the so-called upstream therapy is being studied for possible beneficial effects and was included in some guidelines of conduct in Europe and worldwide. In this review we indicate the evidence for the effects of different drug classes for primary and secondary prevention of aF. We discuss the action of the inhibitors of the renin-angiotensin system, aldosterone receptors blockers, antilipemic and antioxidant agents and other impact options.

Sahaja yoga: A unique adjunctive approach for the management of cardiac arrhythmias?

Sahaja yoga (SY) is a unique meditative technique that has both spiritual and mundane aspects. Although SY has generally been regarded as a practice of spiritual and mental well-being, it is also closely associated with a variety of subtle influences on some organ systems. SY has been suggested to have some beneficial effects in a variety of psycho-somatic diseases [1]. Besides subtle effects throughout the whole body, sympatho-vagal regulation associated with SY technique has been proposed as the direct evidence of its beneficial effects on some organ systems including cardiovascular system etc. As describedbelow,SYpracticemaybe regarded as anadjunctiveoption for the management of a variety of cardiac arrhythmias primarily on the basis of its potential effects on the autonomic nervous system largely through unknown mechanisms. Autonomic imbalance including hyperactivation of sympathetic system has been known to be associated with the occurrence of life threatening conditions including acute coronary syndromes (ACS) and may directly trigger malign arrhythmic events in arrhythmia-prone subjects [2]. Hyperactivation of sympathetic system is also well known to prolong QT interval, and impair some indices of autonomic nervous system including heart rate variability (HRV) and heart rate turbulence (HRT) etc. thatmay serve asmarkers of arrhythmogenesis in susceptible subjects. Therefore, therapeutic strategies aiming at management of autonomic imbalance on topof conventional anti-arrhythmic therapy in arrhythmia-prone subjects have gained particular importance in the recent years. However, therapeutic options including beta blockers, sympathetic ganglion blockage etc. have limited value for the management of autonomic imbalance as these approaches generally

Novel Pharmacological Interventions to Maintain Sinus Rhythm after DC Cardioversion

Despite the availability of potentially curative interventions for atrial fibrillation, there remains an important role for conventional anti-arrhythmic therapy and anti-coagulation combined with direct current cardioversion. Unfortunately, the latter approach is disturbed by high recurrence rates of atrial fibrillation. In recent years, several adjunctive therapies have emerged which may facilitate the maintenance of sinus rhythm. These novel therapies and their potential mechanisms of action are reviewed in this article.

Device-Based Left Atrial Appendage Closure

A 56-year-old man with symptomatic paroxysmal atrial fibrillation refractory to both conventional antiarrhythmic drug therapy and catheter ablation was referred for transcatheter left atrial appendage (LAA) closure. The presence of hypertrophic cardiomyopathy with enlarged left atrial diameter (50 mm), heart failure, recurrent episodes of refractory atrial fibrillation, previous transient ischemic attacks, and hypertension led to a high annual predicted risk of stroke based on CHADS2 (congestive heart failure, hypertension, age ≥ years, diabetes mellitus, prior stroke or transient ischemic attack) criteria (score 4) and HAS-BLED (hypertension, abnormal renal/liver function, stroke, bleeding history or predisposition, labile international normalized ratio, elderly, drugs/alcohol concomitantly) (score 4). The patient also experienced gastrointestinal bleeding. Therefore, a transcutaneous LAA occlusion was attempted with the AMPLATZER Cardiac Plug (ACP) system, and throughout the procedure, the activated clotting time was constantly maintained ≥350 seconds. During implantation, 2 dramatic complications not related to each other developed, which included a massive coronary air embolism and an LAA dissection followed by fast-growing thrombus formation. ### Massive Coronary Artery Embolism Immediately after the deployment …

Should Catheter Ablation be the Preferred Therapy for Reducing ICD Shocks?

In 1980, Mirowski et al1 implanted the first implantable cardioverter-defibrillator (ICD) in a young female with recurrent ventricular fibrillation and provided an innovative approach to aborted sudden cardiac death (SCD). Although the ICD was considered a treatment of last resort during that incipient stage, subsequent years have witnessed prolific expansion of indications for ICD implantation.2 Several large-scale clinical trials have demonstrated its efficacy for both primary and secondary prevention of SCD in patients with ischemic and nonischemic cardiomyopathy.3,4 ICD therapy in such high-risk patients has been shown to improve survival compared with conventional antiarrhythmic drug therapy alone.3,4 The number of ICD implantations has increased significantly in the last decade, with a concurrent decrease in the use of stand-alone antiarrhythmic drugs for ventricular indications.5–7 Current ICDs have sophisticated programming capabilities, atrial and bipolar leads, and are able to deliver antitachycardia pacing algorithms (ATP) in addition to defibrillating shocks. Response by Kuck on p 705 Typically, patients who receive ICDs are at high risk for recurrent arrhythmia; hence, most patients receive 1 or more ICD therapies for spontaneous arrhythmias after implantation.3 Despite the technological evolution of ICD systems, more than 20% of shocks are due to supraventricular arrhythmia and hence are inappropriate.8–10 The ICD uses ATP or defibrillating shocks to terminate episodes of ventricular tachycardia (VT) or ventricular fibrillation (VF). Although the ICD aborts VT/VF, many patients continue to have symptoms such as dizziness, palpitations, nervousness, flushing, or syncope before receiving an ICD shock.11 When the shock is finally delivered, it is physically and emotionally painful and so noxious that 23% of patients dread shocks and 5% of patients prefer to do without an ICD and “take their chances.”12 A significant prevalence of sadness, depression, and even anxiety disorders have been reported after …

Antiarrhythmic Induced Electrical Storm in Brugada Syndrome: A Case Report

Brugada syndrome (BS) may be "unmasked" by several pharmacological and/or physiological agents in an otherwise normal electrocardiogram. Once diagnosed the possibility of persistent ventricular tachycardia/fibrillation exists. Although this is treated with various antiarrhythmic agents, there remains a cohort of patients who fail to respond to conventional antiarrhythmic therapy therefore, amplifying the electrical storm. We report a case of a BS diagnosed via procainamide challenge, the resultant near fatal electrical storm aggravated by amiodarone and the eventual resolution with isoproterenol.

Implantable defibrillators and sudden cardiac death.

Sudden cardiac death (SCD) is among the most common causes of death in developed countries throughout the world. It is estimated that more than 3 million people die yearly from SCD, with a survival rate of less than 1%. In the United States, the Center for Disease Control recently estimated an annual incidence of 450 000 sudden deaths,1 with a survival rate of approximately 5%, although this probably is an overestimation. Although there has been a reduction in total cardiac mortality from 728 115 in 1989 to 719 456 in 1999, the percentage of deaths that are sudden has actually increased from 38% to 47%. The increase was greatest in women older than 65 years of age, from 56.3% to 63.9%. This has resulted primarily from an increase in out-of-hospital sudden deaths. There is a comparable incidence of SCD and survival rate in Western Europe.2 The magnitude of this problem can be understood by noting that SCD accounts for more deaths each year than the total number of deaths from AIDS, breast cancer, lung cancer, and stroke (Figure 1). Unfortunately, it is the first presentation of cardiac disease in 33% to 50% of patients and is 3 times as common in men than in women. Figure 1. Magnitude of the problem of sudden cardiac arrest. Coronary artery disease, with or without myocardial infarction, is by far the most common underlying disease for SCD in the western world, being responsible for approximately 75% of all SCDs.3,4 Cardiomyopathies (dilated and hypertrophic) and primary electrical heart disease account for most of the remainder. The two most important risk factors for SCD (ie, those with highest predictive value) are left ventricular ejection fraction (LVEF) less than 40% and clinical congestive heart failure.3,4 These are followed by significant ventricular arrhythmias (particularly …

The implantable cardioverter defibrillator: technology, indications, and impact on cardiovascular survival*1

Since the introduction of the implantable cardioverter defibrillator (ICD) for the management of patients with high risk of arrhythmic SCD , there has been increasing use of this device. Its basic promise to effectively terminate ventricular tachycardia (VT)–ventricular fibrillation (VF) has been repeatedly met. In several randomized trials, the ICD has been shown to be superior to conventional anti-arrhythmic therapy, both in patients with documented VT-VF (secondary prevention) and those with high risk such as left ventricular ejection fraction and no prior sustained VT-VF (primary prevention). In both groups, the ICD showed overall and cardiac mortality reduction. The device now can more accurately detect VT-VF and differentiate these from other arrhythmias through a series of algorithms and direct-chamber sensing. Therapy options include painless antitachycardia pacing , low-energy cardioversion , and high-energy defibrillation . The technique implant is now simple as a pacemaker with one lead attached to an active (hot) can functioning as the other electrode. Among other improvements is its weight, volume, multiprogrammability, and storage of information,dual-chamber pacing and sensing, dual-chamber defibrillation, and addition of biventricular pacing for cardiac synchronization. It is anticipated that further improvement in ICD technology will take place and the list of indications will grow.

The implantable cardioverter defibrillator: technology, indications, and impact on cardiovascular survival

Since the introduction of the implantable cardioverter defibrillator (ICD) for the management of patients with high risk of arrhythmic SCD, there has been increasing use of this device. Its basic promise to effectively terminate ventricular tachycardia (VT)–ventricular fibrillation (VF) has been repeatedly met. In several randomized trials, the ICD has been shown to be superior to conventional anti-arrhythmic therapy, both in patients with documented VT-VF (secondary prevention) and those with high risk such as left ventricular ejection fraction and no prior sustained VT-VF (primary prevention). In both groups, the ICD showed overall and cardiac mortality reduction. The device now can more accurately detect VT-VF and differentiate these from other arrhythmias through a series of algorithms and direct-chamber sensing. Therapy options include painless antitachycardia pacing, low-energy cardioversion, and high-energy defibrillation. The technique implant is now simple as a pacemaker with one lead attached to an active (hot) can functioning as the other electrode. Among other improvements is its weight, volume, multiprogrammability, and storage of information,dual-chamber pacing and sensing, dual-chamber defibrillation, and addition of biventricular pacing for cardiac synchronization. It is anticipated that further improvement in ICD technology will take place and the list of indications will grow.