Antiarrhythmic Drug Therapy to Avoid Implantable Cardioverter Defibrillator Shocks

Abstract

Implantable cardioverter defibrillators (ICDs) have been used for over 30 years to prevent sudden cardiac death (SCD). The first indications for ICD placement were secondary prevention; later trials demonstrated a primary prevention benefit of ICD therapy in patients at risk of SCD. ICD therapy prolongs life in both patient populations. 1 However, the efficacy of an ICD depends on its ability to correctly detect ventricular arrhythmia and deliver antitachycardia pacing or shocks. In cases of inadequate arrhythmia classification by the device, atrial fibrillation (AF) with rapid conduction to the ventricles can lead to inappropriate shocks. The ability of an ICD to correctly detect this arrhythmia is essential to avoid shock delivery. Furthermore, technical problems such as lead fractures, oversensing of myopotentials or external noise can lead to shock application. ICD shocks can be painful if experienced in the awake state and may reduce quality of life in affected patients.2 Shocks, whether appropriate or not, tend to occur frequently after the implantation of an ICD and avoiding shocks is a reasonable therapeutic target. 3 Current evidence suggests that ICD shocks increase the risk of mortality.4 It remains a matter of debate if this finding depends on the context of a specific cardiac substrate or the shock per se.5 Of less controversy is the fact that patients who receive ICD shocks experience reduced quality of life. This has been a consistent finding in published studies that was already evident from data in the first available trials, such as the Antiarrhythmics Versus ICDs (AVID) trial. The occurrence of ICD shocks was associated with reduced physical functioning and decreased mental wellbeing. Another study reported that patients who experienced an ICD shock did not adapt well to living with an ICD and were generally more anxious than ICD recipients who received no shock.6 Accordingly, shock reduction by medical, interventional or technical means is a desirable goal. General MeasuresMost patients receiving ICDs for primary prevention of SCD are affected by heart failure with reduced left ventricular ejection fraction (LVEF <35 %). Should these patients meet the criteria for cardiac resynchronisation therapy (CRT), implantation is indicated to achieve mortality and morbidity benefits. 7 In addition, CRT responders exhibit fewer ventricular tachycardia/ventricular fibrillation (VT/VF) episodes after implantation than patients not receiving CRT.8 In general, care should be taken to keep these patients on optimal medical therapy including high-dose b-blockers, as these drugs lead to a reduction in rates of SCD and overall mortality in patients with ischaemic and non-ischaemic cardiomyopathy. If such treated patients develop arrhythmias despite b-blocker treatment, an additional anti-arrhythmic treatment will be necessary. In clinical practice, an adjunctive antiarrhythmic is administered to more than half of patients who have an ICD. Serum Potassium LevelsBesides pharmacological interventions, simple meth...

Analysis of mortality risk following receipt of implantable cardioverter defibrillators in patients with and without heart failure

“…Therapeutic agents such as b-blockers, class I or class III antiarrhythmic drugs effectively suppress arrhythmias, but may have side effects. Some drugs could even influence the function of ICDs by altering defibrillation or pacing threshold [22]. In our ICD cohort, anti-arrhythmic drugs provided a strong protective role with around 40% reduction in the hazard of mortality.…”

A new approach in cardioverter-defibrillator implantation in patients with coronary artery disease

“…Из всех антиаритмических препаратов, препараты IС класса вызывают наибольшее увеличение ПС [18]. Изучение влияния антиаритмических препаратов II и III классов (бета-адреноблокаторы и амиодарон) на ПС не выявило его изменений, прием соталола также не влиял на хронический ПС [19]. В частности, у пациентов с перенесенным инфарктом миокарда наличие рубца или ишемизированного миокарда в зоне имплантации электрода может в отдаленном периоде отразиться на его параметрах (повышение ПС, снижение АЖС).…”

Evaluation of the feasibility of cardiac gating for SBRT of ventricular tachycardia based on real‐time ECG signal acquisition

“…Ventricular tachycardia (VT) is a cardiac arrhythmia that can lead to sudden death. 1 Conventional treatment techniques, including the use of anti‐arrhythmic drugs, 2 implantable cardioverter defibrillator, 3 and catheter ablation with radiofrequency, 4 are associated with a high rate of recurrence of VT episodes. 5 , 6 , 7 Stereotactic body radiation therapy (SBRT) with one single fraction of 25 Gy prescribed to the arrhythmogenic scar region of the heart has become an attractive noninvasive approach for treating VT. 8 , 9 , 10 , 11 , 12 , 13 Recent results published in the literature have shown promising outcomes demonstrating that patients have complete or near complete resolution of VT after treatment with radiation.…”