Ripple Mapping Guided Ablation of Ischaemic Ventricular Tachycardia.
Ripple Mapping Guided Ablation of Ischaemic Ventricular Tachycardia.
The Ripple VT-1 Study is a prospective clinical trial that aims to investigate if catheter
 ablation of ventricular tachycardia in patients with ischaemic heart disease can be
 effectively performed using Ripple Mapping.
Patients who have ischaemic heart disease and are at sufficient risk of, or have suffered,
 ventricular tachycardia may receive implantable cardioverter defibrillator (ICD) devices. ICD
 devices provide life-saving shocks to terminate ventricular tachycardia. There is however
 substantial evidence that correlates each life-saving shock with worsening prognosis.

 Catheter ablation is a procedure that can treat the cause of ischaemic ventricular
 tachycardia (VT). Most catheter ablation procedures for ischaemic VT are performed in normal
 rhythm, with an end-point of arrhythmic substrate modification. Arrhythmic substrate
 modification refers to the process by which abnormal electrical activity in cardiac scar
 tissue (from ischaemic heart disease) is identified and treated by ablation.

 Substrate modification catheter ablation procedures for ischaemic VT have been demonstrated
 to reduce ICD shocks and VT episodes in randomised trials compared to medications. However,
 ablation procedure outcomes are still imperfect with a recurrence rate of 50-60%.

 Ripple Mapping is a method of mapping the hearts electrical signals, that may allow better
 identification of the abnormal activity within scar and so improve recurrence rates following
 ablation.

 Patients referred for ablation of ischaemic VT, who have an ICD, will undergo their procedure
 with Ripple Mapping and subsequently followed up over a year, at 3 monthly intervals. The
 main assessed outcome will be ICD or VT events over a year. This will be compared to the
 number of ICD or VT events the year prior to ablation.
Inclusion Criteria:

 1. Patients with coronary artery disease and ischaemic cardiomyopathy requiring ICD
 implantation for primary or secondary prevention.

 2. Any episode of VT detected or treated appropriately (within monitor zone or therapy
 (ATP/shock) delivered) or by 12 lead ECG if the rate below the detection level of the
 device. An episode of VT will be defined as lasting more than 30 secs or a regular
 high rate episode meeting VT criterion for >50% of the time before the first therapy
 is delivered (i.e. VT degenerating into VF is acceptable under these circumstances).

 3. Ablation or medical therapy would be considered reasonable option for ongoing
 management.

 4. Males or females 18 - 80 years of age.

 5. Suitable candidate for catheter ablation.

 6. Signed informed consent.

 Exclusion Criteria:

 1. Contraindication to catheter ablation.

 2. VT due to reversible causes.

 3. Severe valvular disease or ventricular thrombus.

 4. Active gastrointestinal bleeding.

 5. Serum Creatinine >200μmol/L or on dialysis.

 6. Active fever or infection.

 7. Life expectancy shorter than the duration of the trial.

 8. Allergy to contrast.

 9. Intractable heart failure (NYHA Class IV).

 10. Bleeding or clotting disorders or inability to receive heparin.

 11. Malignancy needing surgery, chemotherapy or radiotherapy.

 12. Pregnancy or women of child-bearing potential not using a highly effective method of
 contraception.

 13. Unable to attend follow-up visits or ICD clinics.