Left posterior fascicular tachycardia

A 37 Yr/Female came to JIPMER, Pondicherry, hospital with chief complaints of palpitaion on and off since last two month. Patient had two episode of palpitation and they were reverted with DC shock at private hospital. Patient was also giving history of similar episode 5 years back. There was no history of giddiness, syncope, diabetes mellitus, hypertension or coronary  artery diseases. During evaluation in cardiology OPD her pulse was 75 beats per minute, BP-110/70 mmhg, ECHO heart was normal. She underwent Cardiac MRI at private hospital which was also normal.

ECG 1(Click on the image to enlarge it)

ECG of the patient is showing regular, broad complex tachycardia,  Left axis deviation, RBBB morphology, RR1 in lead C1, rS complex in lead V6, there is no visible P wave, no capture beat, no fusion beat, QRS duration is 200  msec so the differential diagnosis is Either ventricular tachycardia originating from Left ventricle, most likely from posterior papillary muscle or it could be supraventricular tachycardia with aberrancy ( Although the possibility of later is very less).

Another Tachycardia ECG of the patient

Another Tachycardia ECG of the patient

Sinus ECG of the patient

Sinus ECG of the patient is showing Normal sinus rhythm at rate around 75 beats per minute, normal axis, incomplete RBBB, narrow QRS complex, no st-t wave changes seen, QT interval 400 msec, QTC 447 msec.

So the diagnosis of this patient is most likely left posterior fascicular tachycardia.
Patient  was admitted in JIPMER Cardiology department and she underwent EPS study which conform our diagnosis.


Thank you.