Abstract | BACKGROUND: The goal of this study was to obtain physiologically significant increases in peak left ventricular (LV) systolic pressure and stroke volume with latissimus dorsi muscle (LDM) stimulation in cardiomyoplasty ( CMP). We hypothesized that preserving LDM integrity by vascular delay and intermittent stimulation would significantly increase LDM cardiac assistance. METHODS: In 4 control dogs and 12 dogs that had undergone a vascular delay (VD) procedure, LV dysfunction was induced by intracoronary microsphere injections. Cardiomyoplasty surgery was performed 14 days later, followed by progressive LDM conditioning. In the control dogs and in 6 of the VD dogs, the LDM was stimulated 24 hours per day (VD plus constant stimulation [CS]). In the other 6 VD dogs, LDMs were stimulated on a daily schedule of 10 hours on and 14 hours off (VD plus interrupted stimulation [IS]). Latissimus dorsi muscle stimulated beats were compared with nonstimulated beats 9 weeks later. RESULTS: In the control dogs, LDM stimulation had minimal effects. In VD + CS and VD + IS, LDM stimulation increased peak LV pressure, stroke volume, stroke work, and stroke power (p < 0.05). However, these changes were greater in the VD + IS group, in which LDM stimulation increased peak aortic pressure by 17.6 +/- 1.7 mm Hg, peak LV pressure by 19.7 +/- 1.1 mm Hg, peak positive LV dp/dt by 398 +/- 144 mm Hg per second, stroke volume by 5.1 +/- 0.7 mL, stroke work by 10.9 +/- 0.9 gm.m, and stroke power by 122.7 +/- 11.6 gm.m per second (p < 0.05 compared with VD + CS). Quantitative morphometric analysis showed minimal LDM degeneration in the VD + IS group (7.5% +/- 1.1%), and VD + CS group (10.5% +/- 4.5%) compared with the control group (29.5% +/- 4.5%, p < 0.05). CONCLUSIONS: VD and IS considerably increased the LV assistance with LDM stimulation. Further studies of this combined approach to CMP should be planned.
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Authors | A Kashem, W P Santamore, B Chiang, L Unger, A T Ali, A D Slater |
Journal | The Annals of thoracic surgery
(Ann Thorac Surg)
Vol. 71
Issue 6
Pg. 1866-73
(Jun 2001)
ISSN: 0003-4975 [Print] Netherlands |
PMID | 11426760
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)
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Topics |
- Animals
- Cardiomyoplasty
(methods)
- Diastole
(physiology)
- Dogs
- Electric Stimulation
(methods)
- Ischemic Preconditioning, Myocardial
- Myocardial Contraction
(physiology)
- Stroke Volume
(physiology)
- Systole
(physiology)
- Ventricular Dysfunction, Left
(physiopathology, surgery)
- Ventricular Function, Left
(physiology)
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