Etiology of inappropriate therapy		Clues typical for the etiology	Possible solutions by the electrophysiologist
Supraventricular source of tachycardia meeting the implantable cardioverter-defibrillator rate cutoff:
	Sinus tachycardia	Arrhythmia occurs with physical exertion	Reprogram the implantable cardioverter-defibrillator
			Start beta-blocker therapy
	Paroxysmal supraventricular tachycardia	History of paroxysmal supraventricular tachycardia	Start antiarrhythmic drug therapy or radiofrequency ablation therapy
	Atrial fibrillation/flutter with rapid ventricular response	History of atrial rhythm disturbance	Reprogram the implantable cardioverter-defibrillator
			Start antiarrhythmic drug therapy or radiofrequency ablation therapy
Environmental interference from equipment in the home, workplace or hospital		Patient is near the suspected electromagnetic field source at the time of implantable cardioverter-defibrillator discharge	Avoid exposure to electromagnetic source or provide improved shielding
Interaction of pacemaker and implantable cardioverter-defibrillator		Patient has both implanted devices	Evaluate interaction
			Consider reprogramming either the implantable cardioverter-defibrillator or the pacemaker
Malfunction of the implantable cardioverter-defibrillator		No symptoms before discharge	Evaluate the lead and generator with a chest radiograph
		Discharge reproduced with arm movement	Test the device with movement
			Commonly must replace the sensing lead of the device
“Phantom shock” (hypnagogic muscle contraction interpreted by the patient as implantable cardioverter-defibrillator discharge)		Occurs at night, usually while drifting off to sleep	No event recorded by the implantable cardioverter-defibrillator
			Reassure patient