Impact of myocardial fiber orientation on lesions created by a novel heated saline-enhanced radiofrequency needle-tip catheter: An MRI lesion validation study

Atsushi Suzuki, H. Immo Lehmann, Songyun Wang, Kristi H. Monahan, Kay D. Parker, Maryam E. Rettmann, Michael G. Curley, Douglas L. Packer

Research output: Contribution to journalArticlepeer-review

1 Scopus citations

Abstract

Background: Irrigated needle catheter ablation is efficacious for creation of transmural lesions in the left ventricle (LV). However, interdependence of needle orientation and myocardial fiber orientation and the resulting influence on lesion creation remain unclear. Objective: The purpose of this study was to investigate the impact of myocardial fiber orientation on reproducibility and controllability of lesion creation in LV myocardium using a heated saline-enhanced radiofrequency (SERF) needle-tip catheter system. Methods: Eleven dogs underwent catheter ablation using this novel catheter. Ablative lesions were created using different power and ablation times (15–50 W; application 25–120 seconds; 60°C irrigation saline at 10 mL/min). Hearts were explanted, and lesions were evaluated using 3-T cardiac magnetic resonance (CMR), gross pathologic, and histologic investigations. Results: Forty-three of 57 lesions (75.4%) were transmural, and lesion depth reached approximately 90% of LV wall thickness. Lesion volume in both gross pathology and ex vivo CMR showed a positive linear correlation with power × radiofrequency (RF) time index (r = 0.637, P <.001; and r = 0.786, P <.001, respectively). Maximum width (circumferential direction of LV) and maximum length (long-axis direction) of all lesions were distributed in the middle layer of LV where myocardium runs circumferentially. Paired-sample t-test showed maximum lesion width was significantly greater than maximum lesion length by both CMR and gross pathologic evaluation (26.1 ± 9.6 mm vs 17.2 ± 6.7 mm, P <.001; and 22.5 ± 7.7 mm vs 18.6 ± 5.9 mm, P <.001, respectively). Conclusion: This catheter showed feasibility in creating transmural LV lesions. Power × RF time index was strongly correlated with lesion volume and predicted lesion size. More importantly, SERF lesions extended along the myocardial fiber orientation.

Original languageEnglish (US)
Pages (from-to)443-452
Number of pages10
JournalHeart rhythm
Volume18
Issue number3
DOIs
StatePublished - Mar 2021

Keywords

  • Catheter ablation
  • Intramural ventricular substrate
  • Irrigation needle catheter
  • Transmural lesion
  • Ventricular tachycardia

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine
  • Physiology (medical)

Fingerprint Dive into the research topics of 'Impact of myocardial fiber orientation on lesions created by a novel heated saline-enhanced radiofrequency needle-tip catheter: An MRI lesion validation study'. Together they form a unique fingerprint.

Cite this