Ventricular tachycardia in structurally normal hearts: recognition and management.

Idiopathic ventricular tachycardia is a defined set of tachycardias when structural or pathological cause has been ruled out for the same. This paper tries to define and classify these arrhythmias to organize a logical therapeutic approach to deal with them. 60-80% of the idiopathic tachycardias originate from the right ventricular outflow tract (RVOT) and in 10% from the left ventricular outflow tract (LVOT). Outflow tract tachycardias have either LBBB or RBBB morphology with early R wave transition in chest leads. Adenosine, beta blockers and calcium channel blockers is the common medical treatment. Radiofrequency ablation is however the treatment of choice. Verapamil sensitive left ventricular tachycardia (ILVT) and propranolol sensitive left ventricular tachycardia (IPVT) are the other two forms recognized. RF ablation seems ideal for long-term management of ILVT and implantable cardioverter defibrillator (ICD) for IPVT. Inherited channelopathies include catecholaminergic polymorphic ventricular tachycardia (CPVT), Brugada syndrome and long QT syndrome where there is an inherited disorder in the ion-exchange channels of the cell-membrane leading to tachycardia. Prognosis in these is variable; CPVT, in particular, has a malignant course when untreated. RF ablation and placement of an ICD are important in the overall management of specific arrhythmia.

Heart failure: a unique presentation of typical atrioventricular nodal reentrant tachycardia.

Cardiomyopathy due to various ventricular and supraventricular arrhythmias, including isolated cases of atypical atrioventricular nodal reentrant tachycardia, have been described. In this case report typical slowfast atrioventricular nodal reentrant tachycardia resulting in cardiomyopathy is being documented for the first time. In the setting of depressed left ventricular function, an episode of tachycardia pushed this patient into heart failure. Radiofrequency ablation of the slow pathway was successful in eliminating her tachycardia with the return of left ventricular function to normal. A follow-up of two years post-ablation revealed the patient to be symptom-free.