Clinical Evaluation of Therapy Cool Path Duo Cardiac Ablation System for the Treatment of Ischemic Ventricular Tachycardia (VT) (Ablate-VT)

• Primary Safety is defined as the incidence of intra-procedural, acute or sub-chronic, serious cardiac adverse events, up to 7 days post-procedure. [ Time Frame: 7 days ] [ Designated as safety issue: Yes ]
• Acute Success is achieved when all clinically relevant VT substrates (spontaneous and induced VT episodes) are terminated and no longer inducible upon hospital discharge (i.e., last study ablation procedure prior to hospital discharge). [ Time Frame: Hospital Discharge ] [ Designated as safety issue: No ]

To demonstrate that ablation with the Therapy Cool Path Duo cardiac ablation system can eliminate ischemic VT and that its use does not result in an unacceptable risk of serious adverse events.

Ventricular Tachycardia (VT) is a common complication of ischemic heart disease that is often life threatening. Ventricular tachycardia is defined as three or more beats of ventricular origin in succession at a rate greater than 100 beats per minute. There are no normal QRS complexes associated with VT, and the rhythm is usually regular. Patients with VT experience unpleasant heart palpitations, dyspnea, and syncope, all of which decrease their overall quality of life. They also suffer the consequences of impaired hemodynamics, loss of cardiac efficiency, and are at an increased risk of sudden cardiac death (SCD), which accounts for approximately half of all deaths from patients with cardiovascular disease.

Historically, antiarrhythmic medications served as the first line therapy for the treatment of VT, in spite of low efficacy and high recurrence rates. But in recent years, internal cardioverter defibrillators (ICDs) have become the treatment of choice. Although, ICDs are effective in terminating most arrhythmias, rarely does so without some episodes requiring poorly tolerated shock therapy. Ablative therapy offers an important option for frequent control with the potential for long-term VT elimination. Radiofrequency catheter ablation offers the ability to provide immediate control of recurrent VT. Since the early 2000's, strategies, tools, and techniques have been improving to identify key ablation sites and to deliver effective lesions.

Radiofrequency ablation is successful in treating some but not all arrhythmias. With non irrigated technology it has been difficult to ablate ischemic VT. This may be due to an inadequate lesion size. Irrigated electrodes were developed to create larger lesions. Open irrigation at the catheter tip not only produces larger lesions, but also helps reduce the risk of coagulum (clots) and charring due to high temperatures.

Inclusion Criteria:

• Patient is 18 years of age or older
• Patient has an ICD or will be implanted with one prior to discharge of ablation procedure
• Patient has had at least 2 documented spontaneous episode of sustained ischemic VT within the previous 6 months
• Patient is resistant, intolerant or refractory to at least one Class I or III AAD
• Patient has been informed of the nature of the study and has agreed to its provisions and provided written informed consent approved by the Institutional Review Board

Exclusion Criteria:

• Non-ischemic VT
• History of stroke or transient ischemic attack within 6 months prior to enrollment
• MI or previous cardiac surgery within 2 months prior to enrollment
• Patient is pregnant or nursing
• Patient has chronic NYHA class IV heart failure
• Limited life expectancy of 6 months or less
• Patient is currently participating in another investigational drug or device study
• Patient is unable or unwilling to cooperate with the study procedures
• Known presence of intracardiac thrombi
• Severe aortic stenosis or flailed mitral valve
• Major contraindication to anticoagulation therapy or coagulation disorder
• Left Ventricular Ejection Fraction <10%