Electrical homogenization of ventricular scar by application of collagenase: A novel strategy for arrhythmia therapy

Daigo Yagishita, Olujimi A. Ajijola, Marmar Vaseghi, Ali Nsair, Wei Zhou, Kentaro Yamakawa, Roderick Tung, Aman Mahajan, Kalyanam Shivkumar

Research output: Contribution to journalArticlepeer-review

10 Scopus citations


Background-Radiofrequency ablation for ventricular tachycardia is an established therapy. Use of chemical agents for scar homogenization represents an alternative approach. The purpose of this study was to characterize the efficacy of collagenase (CLG) application on epicardial ventricular scar homogenization. Methods and Results-Myocardial infarcts were created in Yorkshire pigs (n=6) by intracoronary microsphere injection. After 46.6±4.3 days, CLG type 2, type 4, and purified CLG were applied in vitro (n=1) to myocardial tissue blocks containing normal myocardium, border zone, and dense scar. Histopathologic studies were performed to identify the optimal CLG subtype. In vivo high-density electroanatomic mapping of the epicardium was also performed, and border zone and dense scar surface area and late potentials were quantified before and after CLG-4 application (n=5). Of the CLG subtypes tested in vitro, CLG-4 provided the best scar modification and least damage to normal myocardium. During in vivo testing, CLG-4 application decreased border zone area (21.3±14.3 to 17.1±11.1 mm2, P=0.043) and increased dense scar area (9.1±10.3 to 22.0±20.6 mm2, P=0.043). The total scar area before and after CLG application was 30.4±23.4 and 39.2±29.5 mm2, respectively (P=0.08). Late potentials were reduced by CLG-4 application (28.8±21.8 to 13.8±13.1, P=0.043). During CLG-4 application (50.0±15.5 minutes), systolic blood pressure and heart rate were not significantly changed (68.0±7.7 versus 61.8±5.3 mmHg, P=0.08; 77.4±7.3 versus 78.8±6.0 beats per minute, P=0.50, respectively). Conclusions-Ventricular epicardial scar homogenization by CLG-4 application is feasible and effective. This represents the first report on bioenzymatic ablation of arrhythmogenic tissue as an alternative strategy for lesion formation.

Original languageEnglish (US)
Pages (from-to)776-783
Number of pages8
JournalCirculation: Arrhythmia and Electrophysiology
Issue number4
StatePublished - Aug 2013
Externally publishedYes


  • Bioenzymatic ablation
  • Collagenase
  • Radiofrequency
  • Scar homogenization
  • Ventricular tachycardia

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine
  • Physiology (medical)


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