[Therapeutic strategies in inappropriate ICD therapy].
20-30% of ICD patients suffer from inappropriate ICD therapy due to misclassification of supraventricular tachycardia (SVT) as ventricular tachycardia. Inappropriate ICD therapies are not only painful for patients, but also proarrhythmogenic and can reduce device longevity due to battery depletion. Therapy of inappropriate ICD episodes is a puzzle of optimized ICD programming, antiarrhythmic therapy and radiofrequency (RF) ablation. Single-chamber ICD detection algorithms are effective in reducing inappropriate ICD therapy particularly due to sinus tachycardia or atrial fibrillation. Dual-chamber ICD detection algorithms were developed to improve specificity of SVT discrimination. However, large prospective, controlled trials showing superiority of dualchamber over single-chamber devices are lacking. It appears that patients with slow ventricular tachycardias, being at high risk for inappropriate ICD therapy, might benefit from dual-chamber ICD therapy. Concerning pharmacological therapy of inappropriate ICD episodes, the OPTIC study recently showed superiority of class III antiarrhythmics (sotalol and amiodarone) over beta-blockers. RF ablation of cavotricuspid isthmus is of proven benefit in ICD patients with inappropriate episodes due to typical flutter and should also be considered in atrial tachycardia. If patients with paroxysmal atrial fibrillation despite optimized antiarrhythmic medication will benefit from trigger elimination or substrate modification by RF ablation has still to be proven. In patients with inappropriate ICD episodes and drug-refractory chronic permanent atrial fibrillation, AV node ablation can effectively eliminate inappropriate ICD therapy, however, at the price of potential ventricular asynchrony and progression of heart failure due to right ventricular pacing. Thus, upgrading to biventricular ICD therapy should be considered in these patients.
Klein
Gunnar
G
Abteilung Kardiologie und Angiologie, Medizinische Hochschule Hannover. gunnarklein@yahoo.de
Korte
Thomas
T
D000465:Algorithms; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use*; D001145:Arrhythmias, Cardiac / Q000175:diagnosis* / Q000209:etiology / Q000517:prevention & control*; D017115:Catheter Ablation; D017147:Defibrillators, Implantable / Q000009:adverse effects*; D004554:Electric Countershock / Q000009:adverse effects / Q000379:methods; D004562:Electrocardiography / Q000379:methods; D006801:Humans; D019300:Medical Errors / Q000517:prevention & control*; D013813:Therapy, Computer-Assisted / Q000379:methods*
D000889:Anti-Arrhythmia Agents