Q. Can you explain Ventricular Tachycardia?
The term is usually reserved for at least four or more beats and modified by the term non sustained. Short runs of non-sustained VT may not have serious implications, especially in a patient with a normal heart. Sustained VT on the treadmill is relatively rare in most exercise laboratories, but when testing a group of patients with VT or ventricular fibrillation as their primary complaint, between 30 per cent and 60 per cent were found to develop VT. It portrays severe underlying disease. As it may deteriorate into sudden VF, it is obviously a cause for immediate termination of exercise. If the patient converts to sinus rhythm spontaneously very quickly, there is less cause for alarm. However, this rhythm must be taken very seriously and either LAD with ischaemia or some type of cardiomyopathy should be suspected when VF occurs.
VT caused by ischaemia almost never has a left bundle branch block (LBBB) pattern. Patients with arrhythmogenic right ventricular dysplasia often have VT, at times originated by exercise. The VT always manifests a LBBB pattern and prolongation of the QRS in the right precordial lead is common. Some patients with this syndrome have ST elevation in V2 and V3 during exercise and they often have a family history of sudden death.