The purpose of this research study is to evaluate the safety and feasibility of the Impella 2.5 Circulatory Support System for use during mapping and ablation of ventricular tachycardia in the setting of Ventricular dysfunction.

The Impella 2.5 is a percutaneous heart pump that will be used to provide partial circulatory support -. The Impella 2.5 is approved by the US Food and Drug Administration and is being tested to see if it helps keep the patient's blood pressure stable during the cardiac ablation procedure. The Impella 2.5 Circulatory Support System works by placing a small pump into the left pumping chamber of the heart which will then help the heart circulate blood throughout the body. The Impella 2.5 Circulatory Support system will be removed once the heart no longer needs help with the pumping action which can be at any time from just after the completion of the heart procedure up to several days post procedure as determined by physician.

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

The lack of a control group precludes drawing definitive conclusions between the lack of either statistically or clinically significant changes in perioperative markers of end-organ perfusion/function and the use of a pLVAD.