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Cryoablation of refractory sustained ventricular tachycardia due to coronary artery disease
J Caceres1, M Akhtar, P Werner
1Electrophysiology Laboratory, Sinai Samaritan Medical Center, Milwaukee, Wisconsin 53233.
Insights
Map-guided cryosurgery effectively treated ventricular tachycardia (VT) in patients with coronary artery disease. This surgical approach, combined with antiarrhythmic drugs, proved successful in 92% of survivors, improving heart function.
Area of Science:
- Cardiology
- Cardiac Surgery
- Electrophysiology
Background:
- Medically refractory sustained monomorphic ventricular tachycardia (VT) poses a significant challenge in patients with coronary artery disease.
- Prior antiarrhythmic drug trials often fail to control VT, necessitating advanced therapeutic strategies.
Purpose of the Study:
- To evaluate the efficacy and safety of map-guided cryosurgery for treating ventricular tachycardia in patients with coronary artery disease.
- To assess the impact of cryosurgery on left ventricular ejection fraction and long-term clinical outcomes.
Main Methods:
- Thirty-nine patients with refractory VT underwent intraoperative endocardial mapping to guide cryothermic applications.
- Cryosurgery involved targeted applications at earliest activation sites during VT; some patients also had subendocardial resection.
- Postoperative programmed ventricular stimulation assessed VT inducibility before hospital discharge.
Main Results:
- 76% of patients were free from inducible or spontaneous VT post-surgery.
- An additional 16% with residual VT achieved control with previously failed antiarrhythmic drugs, resulting in 92% overall efficacy.
- Left ventricular ejection fraction improved significantly from 33% to 39% (p<0.01).
Conclusions:
- Map-guided cryosurgery is an effective treatment for medically refractory ventricular tachycardia in coronary artery disease patients.
- The procedure offers significant improvement in cardiac function and long-term VT control.
- Cryosurgery, alone or combined with drug therapy, provides a high success rate for this challenging patient population.
Abstract:
Thirty-nine patients with medically refractory sustained monomorphic ventricular tachycardia (VT) due to coronary artery disease underwent map-guided cryosurgery. Locations of prior myocardial infarctions had been inferior in 22, anterior in 16 and combined in 1. Mean age was 61 +/- 9 years and the mean number of drug trials per patient before surgery was 3.8 +/- 1.4. Intraoperative endocardial mapping induced 67 tachycardias in 35 patients. Each patient received 6 to 18 (11 +/- 3) endocardial cryothermic applications (15 mm, -60 degrees C, 2 minutes) at areas of earliest activation during VT. Encircling endocardial cryoablation was performed in 4 patients who had unsuccessful mapping. In addition, 11 patients had subendocardial resection of their well-demarcated septal scars as well as cryosurgery. There were 2 in-hospital deaths. At postoperative programmed ventricular stimulation, 28 of the 37 patients (76%) had no inducible or spontaneous VT before hospital discharge. Six patients (16%) with spontaneous or inducible VT had a single morphology and were controlled with antiarrhythmic drugs that had previously failed. Therefore, surgery alone or in combination with drugs was efficacious in 92% of the population surviving surgery. The remaining 3 patients (8%) received automatic implantable cardioverter defibrillators. No significant difference in surgical outcome was seen between patients who had cryosurgery alone and those who had subendocardial resection together with cryoablation. Mean left ventricular ejection fractions before and after surgery were 33 and 39%, respectively (p less than 0.01). Clinical follow-up ranged from 2 to 36 months (18 +/- 12). One patient died of heart failure and another underwent heart transplantation.(ABSTRACT TRUNCATED AT 250 WORDS)