STATIC LEFT LATISSIMUS-DORSI CARDIOMYOPLASTY - EFFECT ON LEFT-VENTRICULAR FUNCTION

When the latissimus dorsi is used for ventricular augmentation in card iomyoplasty, a delay of several weeks occurs before the muscle revascu larizes, adheres to the heart, and is transformed to fatigue-resistant status. This study analyzes the effect of static (unstimulated) cardi omyoplasty on left ventricular function. Four mongrel dogs underwent s taged left latissimus dorsi cardiomyoplasty. Left ventricular pressure was measured with a micromanometer catheter. Left ventricular volume was measured by sonomicrometry. Cardiac output, heart rate, preload re cruitable stroke work, maximum elastance, left ventricular end-diastol ic volume, left ventricular end-diastolic pressure, stroke work, and t he diastolic relaxation constant were measured before and immediately after cardiomyoplasty with the myoplasty static. Results, expressed as mean +/- standard error of the mean, showed no significant difference s in indexes of systolic function (stroke work, 1017 +/- 223 gm . cm t o 984 +/- 403 gm . cm; preload recruitable stroke work, 110 +/- 13 gm . cm/cm3 to 115 +/- 19.8 gm . cm/cm3; maximum elastance, 10.38 +/- 5.6 mm Hg/ml to 13.59 +/- 6.5 mm Hg/ml; cardiac output 4.51 +/- 0.43 L/mi n to 4.21 +/- 0.34 L/min) or diastolic function (left ventricular end- diastolic volume, 21 +/- 5.2 ml to 20 +/- 5.3 ml; left ventricular end -diastolic pressure, 13 +/- 3.5 mm Hg to 15 +/- 3 mm Hg; diastolic rel axation constant 42.8 +/- 5.2 msec to 42.5 +/- 4.5 msec). Heart rate a lso remained unchanged (131 +/- 8.9 beats/min to 140 +/- 9.8 beats/min ). The static (unstimulated) left latissimus dorsi cardioplasty can be done with little effect on left ventricular systolic or diastolic fun ction in the normal canine heart.