title: In vitro atrial septal ablation using high-intensity focused ultrasound.
abstract: BACKGROUND
  High-intensity focused ultrasound (HIFU) has been applied clinically as a noninvasive therapeutic tool. Atrial septostomy is a palliative treatment for pulmonary artery hypertension. The purpose of this study was to assess the feasibility of atrial septal ablation in vitro using HIFU.
  
  
  METHODS
  Fourteen sections of atrial septum from pig hearts were treated. Focused ultrasound energy was applied with an operating frequency of 5.25 MHz at the nominal focal point intensity of 4.0 kW/cm(2) for 0.4 sec in 1-sec intervals.
  
  
  RESULTS
  Lesions were created with ultrasonic exposures ranging from 40 to 120 pulses. There were significant relationships between HIFU exposure time and lesion area on the exposed site (R(2) = 0.3389, P < .0001) and lesion volume (R(2) = 0.6161, P < .0001).
  
  
  CONCLUSIONS
  HIFU has the potential to create focal perforations without direct tissue contact. This method may prove useful for noninvasive atrial septostomy.
authors.affiliation: Division of Cardiology, Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA. ytakei@aol.com
authors.forename: Yasuyoshi
authors.initials: Y
authors.lastname: Takei
authors.forename: Robert
authors.initials: R
authors.lastname: Muratore
authors.forename: Andrew
authors.initials: A
authors.lastname: Kalisz
authors.forename: Kazue
authors.initials: K
authors.lastname: Okajima
authors.forename: Kohei
authors.initials: K
authors.lastname: Fujimoto
authors.forename: Takuya
authors.initials: T
authors.lastname: Hasegawa
authors.forename: Kotaro
authors.initials: K
authors.lastname: Arai
authors.forename: Yelena
authors.initials: Y
authors.lastname: Rekhtman
authors.forename: Grace
authors.initials: G
authors.lastname: Berry
authors.forename: Marco R
authors.initials: MR
authors.lastname: Di Tullio
authors.forename: Shunichi
authors.initials: S
authors.lastname: Homma
mesh_terms: D000818:Animals; D017548:Echocardiography, Transesophageal; D065627:Familial Primary Pulmonary Hypertension; D005240:Feasibility Studies; D006346:Heart Septum / Q000000981:diagnostic imaging / Q000601:surgery*; D057086:High-Intensity Focused Ultrasound Ablation / Q000379:methods; D006976:Hypertension, Pulmonary / Q000601:surgery; D066298:In Vitro Techniques; D013552:Swine; D018084:Ultrasonography, Interventional