title: Effects of wrapping tightness on acute cardiac function in dynamic cardiomyoplasty.
abstract: BACKGROUND
  It has not been clarified how tightly the heart should be wrapped for maximal augmentation of cardiac function in cardiomyoplasty.
  
  
  METHODS
  Hearts in acute failure induced by propranolol were wrapped with the left latissimus dorsi muscle, loosely (loose CMP), moderately (moderate CMP), and tightly (tight CMP) in each of 5 pigs. To measure the pressure between the latissimus dorsi muscle and the left ventricle (LV), a Millar pressure catheter with a latex balloon was placed on the anterior wall of the LV. Left ventricular wall tension was calculated according to Laplace's law, using the difference between the LV pressure and the balloon pressure.
  
  
  RESULTS
  In the loose CMP, moderate CMP, and tight CMP groups, the mean balloon pressures during unassisted beats were 8.2, 10.4, and 13.2 mm Hg, respectively. During unassisted beats, the mean LV wall tension values were 38,683, 29,938 (p < 0.05 versus loose CMP), and 26,652 (p < 0.05 versus loose CMP) dynes/cm, respectively, the peak LV pressures were 76.8, 73.8, and 65 (p < 0.05 versus loose CMP) mm Hg, respectively, and the stroke volumes were 12.8, 9.2, and 8.5 (p < 0.05 versus loose CMP) mL, respectively. During assisted beats, the mean LV wall tension values were 20,059, 11,290, and 7,893 (p < 0.05 versus loose CMP) dynes/cm, respectively, the peak LV pressures were 94.1, 98.1, and 92.0 mm Hg, respectively, and the stroke volumes were 13.8, 11.6, and 9.4 (p < 0.05 versus loose CMP) mL, respectively.
  
  
  CONCLUSIONS
  During unassisted beats, tight CMP (13 mm Hg) had the advantage of diminishing LV wall tension, but the disadvantage of diminishing LV pressure and stroke volume, compared with loose CMP (8 mm Hg). Moderate CMP (10 mm Hg), however, had the advantage of diminishing LV wall tension without a decrease in LV pressure and stroke volume.
authors.affiliation: First Department of Surgery, Gifu University School of Medicine, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Takagi
authors.forename: H
authors.initials: H
authors.lastname: Hirose
authors.forename: E
authors.initials: E
authors.lastname: Sasaki
authors.forename: M
authors.initials: M
authors.lastname: Bando
authors.forename: Y
authors.initials: Y
authors.lastname: Furuzawa
authors.forename: S
authors.initials: S
authors.lastname: Murakawa
authors.forename: Y
authors.initials: Y
authors.lastname: Mori
mesh_terms: D000818:Animals; D001243:Assisted Circulation; D018421:Cardiomyoplasty / Q000379:methods*; D006439:Hemodynamics / Q000502:physiology; D011312:Pressure; D013318:Stroke Volume / Q000502:physiology; D013552:Swine