The primary objective is to provide additional corroborative safety and efficacy data for the Navistar ThermoCool catheter for the treatment of subjects with ischemic Ventricular Tachycardia.

This study is a prospective, non-randomized, single-arm, multi-center condition of approval evaluation. The device is currently FDA approved for commercial distribution. Subjects with ischemic ventricular tachycardia will be considered for the condition of approval study. This study will be conducted at up to 30 centers in a minimum of 249 evaluable subjects.

Inclusion Criteria:

1. Documented spontaneous episodes of sustained ventricular tachycardia (must satisfy one)

   1. For patients with ICDs: Documented episodes must be four (4) or greater for entry into the study.
   2. For patients without ICDs: Documented episodes must be two (2) or greater within two (2) months and the assessment will be performed by a review of ECGs and hospitalization records.
   3. Incessant VT due to prior myocardial infarction (defined as present for more than one (1) hour and refractory to or immediately recurrent after administration of antiarrhythmic medication and cardioversion).

2. Spontaneous occurrence of symptomatic ventricular tachycardia despite antiarrhythmic drug therapy or ICD intervention.

3. Left ventricular ejection fraction > 10% as estimated by echocardiography, contrast ventriculography or radionuclide imaging within the previous ninety (90) days.

4. Age eighteen (18) years or older.

5. Signed Patient Informed consent form.

6. Able and willing to comply with all pre-, post-, and follow-up testing requirements.

Exclusion Criteria:

1. Definite protruding left ventricular thrombus on pre-ablation echocardiogram.
2. Myocardial infarction within the preceding two (2) months. Patients with incessant VT (defined as present for more than one (1) hour and refractory to or immediately recurrent after administration of antiarrhythmic medication and cardioversion) may be enrolled if their MI is at least three (3) weeks old.
3. Patients with idiopathic VT.
4. Other disease process likely to limit survival to less than twelve (12) months.
5. Class IV heart failure.
6. Serum creatinine of > 2.5 mg/dl.
7. Thrombocytopenia (defined as platelet count <80,000) or coagulopathy.
8. Contraindication to heparin.
9. Women who are pregnant.
10. Cardiac surgery (i.e. ventriculotomy, atriotomy) within the past two (2) months. Patients with incessant VT (present 50% of the time with intervention for a period >12 h) may be enrolled if their surgery is at least three (3) weeks old.
11. Acute illness or active systemic infection.
12. Unstable angina.
13. Severe aortic stenosis or flail mitral valve.
14. Uncontrolled heart failure.
15. Significant congenital anomaly or medical problem that, in the opinion of the Principal Investigator, would preclude enrollment in the study.
16. Enrolled in an investigational study evaluating another device or drug.

All enrolled subjects who signed the informed consent form and were eligible for inclusion in the clinical study

3-year follow up

Serious adverse events (SAE) were those that meet the protocol definition of SAE, excluding the Cardiovascular Specific Adverse Events occurring within 7 days of the ablation procedure, but including deaths that occurred within the time frame. Deaths occurring after 7 days post-ablation were considered non-serious per the protocol definition.