Ventricular tachycardia is considered as a dangerous electrical rhythm abnormality .It can immediately degenrate into ventricular fibrillation and result in SCD in many.Ironically, it is also a fact , a patient with VT can present silently without any symptom .Some VTs are slow and recurrent without much affecting The hemodyanmics.
In chronic recurrent, beningn VT (Some may consider it , ” height of absurdity ” to call a VT beningn ! but it is a reality , the term beningn denotes – very remote chance of converting into VF) ” Is there any other therapeutic option other than convertng into sinus rhythm. “( Read related topics)
The following paper was presented in the Annual scientific sessions of Cardiological society of India, Kochi , seven years ago in 2002
VENTRICULAR RATE CONTROL IN VENTRICULAR TACHYCARDIA
S.Venkatesan,,. Madras Medical College. Chennai
Mangement of hemodynamically stable recurrent ventricular tachycardia remains a delicate clinical problem. Reverting to sinus rhythm is considered as the only aim of treating VT.While rate control is accepted as a therapeutic option in atrial fibrillation, it is not so, for ventricular tachycardia.In this context we attempted to analyse the effect of Amiodarone on ventricular rate in stable ventricular tachycardia which fail to convert to sinus rhythm.
The study cohort consisted of 49 patients with stable VT who were admitted in the coronary care unit of Govt. General Hospital between 1998 to 2002.The criteria for inclusion were systolic BP>100mmHg and absence of hypoperfusion of vital organs The mean age was 52 years (range 26-68) with a male female ratio of 4:1. Of the study group 36 patients were either reverted with IV lignocaine , Amiodarone ( 150-300mg bolus ) or DC cardioversion . 13 patients who did not respond to either of these were followed up with Amiodaroneinfusion(1000mg) for 24 hours. The baseline diagnosis were old MI (6)) DCM (3) Arrhythmogenic RV displasia(2). Idiopathic VT was diagnosed in 2 patients.All these patients had VT during most part of the 24 hour follow up.
The pre Amiodarone mean ventricular rate was 152 (124 –196). Post amiadaorne (at 24hrs) mean ventricular rate was 128(88-142). The time taken for 50% heart rate reduction was 6.6h (4-24h). The average systolic blood pressure improved from 100 to 112mmhg . These patients were discharged in stable clinical status with oral Amiodarone and were referred for EP study.
It is concluded that Amiodarone, apart from it’s cardioverting ability , has a distinct ventricular rate controlling effect which can be of therapeutic value in at least certain subset of chronic recurrent VT.
Final message
Some of the patients with VT carry a very low risk of VF and SCD .In these patients , the only other major aim is to prevent tachycardiac cardiomyopathy that can be done with drugs which controls the ventricular rate whenever VT occurs !
Corrrecting the primary cause like cardiac failire , revascularisation ,detailed EP study ,tachycardia mapping , followed by RF ablation and ICD implantation is the state of the art approch in the management of VTs.But this small clinical observation was made to impress rate control could also be an option in patients in whom these procedures are contraindicated or not available .
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Dr.S.Venkatesan MD 