Percutaneous Hemodynamic Support With Impella 2.5 During Scar-related Ventricular Tachycardia Ablation

Inclusion Criteria: * male or female * age 18 to 90 years * catheter ablation of ventricular tachycardia * Left Ventricular ejection fraction less than or equal to 40% or hypertrophic cardiomyopathy Exclusion Criteria: * Any reversible cause of VT \[electrolyte derangements, medication related itc\] * Evidence of active, ongoing cardiac ischemia as the cause of VT * Patients who have experienced any cerebral ischemic event including any TIA in the preceding one month * Mural thrombus in left Ventricle * Presence of mechanical aortic valve * Severe Aortic Stenosis \[orifice area of 2.0 cm2 or less\] or moderate to severe aortic insufficiency * Severe abnormalities of the aorta that would preclude Impella insertion, including aneurysms and extreme tortuosity or calcifications * Liver dysfunction or markedly abnormal coagulation parameters \[as defined by platelet count less than or equal to 50,000/ul\] * Any condition resulting in contraindication to anticoagulation \[eg GI bleeding\] * Women who are known to be pregnant or have had a positive B-HCG test 7 days prior to procedure * Patients whose life expectancy is less than one year * Mental Impairment precluding patient or family from providing informed consent or completing the appropriate follow up