Regular tachycardia terminated by ventricular anti-tachycardia pacing in an ICD recipient. What is the mechanism?

This is the case of a misdiagnosed atrioventricular nodal reentry tachycardia (AVNRT) with occasionally 2:1 atrioventricular block terminated by delivery of an inappropriate ventricular antitachycardia pacing scheme, in an ICD recipient. The detailed analysis of stored electrograms facilitated the revelation of the arrhythmic mechanism.

Pseudo-polymorphic Ventricular Tachycardia in a 12-lead Holter Recording.

We present an image of pseudo-polymorphic ventricular tachycardia recording on a 12-lead surface ECG Holter. Although at first glance the appearance of the recording resembled polymorphic ventricular tachycardia, careful investigation revealed normal electrocardiographic findings.

Likelihood of Brugada ECG pattern confirmed after propafenone administration for atrial fibrillation cardioversion.

It has been reported that Brugada syndrome is responsible for about half of the sudden cardiac death events with no evidence of structural heart disease. We report a case of hidden ECG Brugada pattern, revealed after oral propafenone administration in the setting of pharmaceutical atrial fibrillation cardioversion.

Partial inhibition of ongoing antitachycardia pacing sequence due to T-wave oversensing.

We describe a case of partial inhibition of ongoing antitachycardia pacing scheme in an implantable cardioverter defibrillator (ICD) recipient with heart failure of ischemic etiology. The cause of inhibition was related to intermittent oversensing of paced T wave and sensing of intrinsic ventricular activation. In our effort to solve this problem, we reprogrammed the paced ventricular blanking period to a higher level.

Electrical storms in an ICD-recipient with 429 delivered appropriate shocks: therapeutic management with antiarrhythmic drug combination.

The case of a 65 year old man with ischemic cardiomyopathy, an ICD device and recurrent electrical storms is presented. The patient had been implanted with an ICD device due to aborted sudden death. The first electrical storm occurred 12 months later. It was terminated by the administration of intravenous amiodarone and the patient was discharged on maintenance dose amiodarone and b-blocker. After a period of 3 months during which the patient remained asymptomatic, a second arrhythmic clustering occurred and it was controlled by the addition of mexiletine. A total number of 429 appropriate shocks had been delivered by the device. Thereafter and for a seven month follow-up period, the patient remains asymptomatic under this combination of antiarrhythmic drugs.

Ventricular bigeminy after subcutaneous administration of apomorphine in a patient with refractory Parkinson's disease: a case report.

Apomorphine is a well established treatment for the management of sudden, unexpected and refractory levodopa-induced "off" states in fluctuating Parkinson's disease either as bolus injections or as continuous infusions. Incidents of atrial fibrillation associated with the administration of the drug have been reported in the past but no incidents of ventricular arrhythmias. We report a case of ventricular bigeminy recorded in a female patient after the administration of apomorphine.

Complex arrhythmias in Prinzmetal's angina reproduced by cold pressor test.

We describe the case of a young female patient with syncope due to complex arrhythmias associated with Prinzmetal's angina. The clinical situation was reproduced by the cold pressor test.

Irregular ventricular tachycardia underdetected by implantable cardioverter defibrillator device.

A case of sustained monomorphic ventricular tachycardia underdetected by a single chamber implantable cardioverter defibrillator because of RR interval irregularity is presented. The programmed stability criterion is responsible for the underdetection. Special attention must be paid when it comes to programming this detection parameter.

Atrial fibrillation induced by carotid sinus massage.

A case of atrial fibrillation paroxysm induced by carotid sinus massage is reported in a patient with recurrent episodes of syncope. Despite extensive investigations, no cause for the syncopal episodes was determined.

Electroanatomical mapping and ablation of upper loop reentry atrial flutter.

Upper loop reentry is a rare type of non isthmus-dependent atrial flutter with a reentry circuit around the superior vena cava. We present a case of atrial flutter of this type in a 75-year-old man with concomitant sick sinus syndrome. The diagnostic approach used three-dimensional electroanatomical mapping with the upgraded ENSITE 3000 system. This is the first case to be described where, apart from non-contact mapping, the circuit was also tracked in detail with three-dimensional contact mapping. The reentry circuit followed a clockwise course around the superior vena cava and passed through a conduction gap in the crista terminalis. Radiofrequency ablation of this region successfully eliminated the tachycardia.