The Use of CT to Identify Damaged Heart Muscle in Patients Undergoing Ventricular Tachycardia Ablation.
The Use of CT to Identify Damaged Heart Muscle in Patients Undergoing Ventricular Tachycardia Ablation.
Patients with ventricular tachycardia (VT) undergo catheter ablation. During the ablation
 procedure, the heart is mapped to determine areas of heart muscle damage. The heart scarring
 areas are often the source of the VT. Delayed enhancement CT has recently been used to
 determine areas of scarring . This study is to determine if the areas of damaged heart muscle
 mapped with the delayed enhancement CT correlate with the same areas that are determined
 during the catheter ablation.
Catheter ablation of ventricular tachycardia (VT) is performed in patients who have recurrent
 VT despite the use of other therapies. Electroanatomic mapping of the left ventricular
 myocardium is performed as part of these procedures to define the arrhythmogenic substrate
 for subsequent ablation. We hypothesize that delayed enhancement multi-detector computed
 tomography (MDCT) will identify areas of myocardial scarring or fibrosis that correlate with
 findings of voltage mapping in patients with a prior myocardial infarction who are undergoing
 VT ablation. We will perform a pilot study involving 10 patients with coronary artery disease
 scheduled for VT ablation to determine the ability of delayed enhancement MDCT to identify
 arrhythmogenic substrates in these patients, when compared with electroanatomic mapping. All
 patients will undergo a standard of care 64-slice MDCT study, followed 5 minutes later by the
 research delayed enhancement acquisition. We will evaluate the relationship between
 hyperenhanced myocardium, as detected by delayed enhancement MDCT, and abnormal myocardium
 detected on voltage mapping, defined as areas of myocardium with < 0.5 mV signal amplitude.
 Studies will be performed on the new Siemens 64-slice dual source CT scanner, which reduces
 radiation exposure from the scan by 33-50%. This study will generate preliminary data which
 will be used for subsequent NIH/AHA grant applications or industry sponsored trials.
Inclusion Criteria:

 -  Age > 21 years

 -  Prior myocardial infarction

 -  Scheduled for CT scan < 1 week prior to VT ablation for ventricular arrythmia

 Exclusion Criteria:

 -  Serum creatinine > 1.8 mg/dL

 -  Contrast dye allergy

 -  Atrial fibrillation

 -  Unable to lie flat for the duration of image acquistion (15-20 minutes)

 -  Clinical instability at time of CT study acquisition

 -  Women of childbearing potential

 -  Personal or social problems that might prevent compliance with the study