title: Right latissimus dorsi cardiomyoplasty augments left ventricular systolic performance.
abstract: We hypothesized that the right latissimus dorsi cardiomyoplasty augments left ventricular performance. Five dogs underwent staged right latissimus dorsi cardiomyoplasty. Ventricular function was studied 1 to 3 weeks later. Left ventricular pressure was measured with a micromanometer and left ventricular dimensions with piezoelectric crystals. Inferior vena caval occlusion was used to vary preload. Pressure-volume data were collected with the muscle unstimulated and stimulated at 1:2 and 1:1 muscle/heart ratios. The end-systolic pressure-volume relation (mm Hg/mL), stroke work, preload recruitable stroke work, left ventricular end-diastolic volume, and the diastolic relaxation constant were calculated and expressed as mean +/- standard deviation. Stimulated beats at a 1:2 ratio showed an increase in stroke work of 42.1% (978 +/- 381 to 1,390 +/- 449 g.cm; p < 0.01) and preload recruitable stroke work of 28.8% (59.4 +/- 20.7 to 76.6 +/- 11.0 g.cm/cm3; p = 0.05) compared with the unstimulated beats. With the stimulator on at 1:1, smaller changes occurred: stroke work increased 9% (1,167 +/- 390 to 1,273 +/- 363 g.cm; not significant) and preload recruitable stroke work increased 27% (63.9 +/- 22.7 to 80.9 +/- 23.1 g.cm/cm3; p = 0.05). There were no significant changes in the end-systolic pressure-volume relation. The diastolic relaxation constant did not change at 1:1 (36 +/- 9.7 to 37 +/- 6.4 ms; not significant) or 1:2 (36 +/- 9.3 to 39 +/- 8.2 ms; not significant). Left ventricular end-diastolic volume was unchanged at 1:1 (34 +/- 10.7 to 32 +/- 10.3 mL) and at 1:2 (31 +/- 9.0 to 32 +/- 8.7 mL).(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Surgery, Allegheny General Hospital, Pittsburgh, Pennsylvania 15212.
authors.forename: S E
authors.initials: SE
authors.lastname: Park
authors.forename: B L
authors.initials: BL
authors.lastname: Cmolik
authors.forename: R R
authors.initials: RR
authors.lastname: Lazzara
authors.forename: D R
authors.initials: DR
authors.lastname: Trumble
authors.forename: J A
authors.initials: JA
authors.lastname: Magovern
mesh_terms: D000818:Animals; D002311:Cardiomyopathy, Dilated / Q000601:surgery; D004285:Dogs; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D008297:Male; D009132:Muscles / Q000601:surgery*; D012016:Reference Values; D013908:Thoracotomy; D016277:Ventricular Function, Left / Q000502:physiology*