Radiology, Vol 199, 59-64, Copyright © 1996 by Radiological Society of North America
Latissimus dorsi muscle: assessment of stimulation after cardiomyoplasty with Doppler US tissue imaging
NR Grubb, GR Sutherland, C Campanella, A Fleming, CJ Sinclair and KA Fox
Department of Cardiology, Royal Infirmary of Edinburgh, Scotland.
PURPOSE: To evaluate Doppler ultrasound (US) tissue imaging for assessment
of stimulated skeletal muscle contraction. MATERIALS AND METHODS: Seven
patients were studied after left latissimus dorsi cardiomyoplasty. Myograft
contraction programmed on alternate cardiac cycles was assessed with
Doppler US tissue imaging. Beat-to-beat variation in inferior wall motion
was assessed by examining peak myograft velocities during 10
muscle-assisted and 10 nonassisted cardiac cycles. The temporal
relationship between electrostimulation and myograft contraction, changes
in cardiac geometry, and the effect of alterations in stimulation voltage
and muscle synchronization were assessed. RESULTS: Significant beat-to-beat
variation in velocity profile could be detected in the proximal myograft in
six patients (P < .05). Potentiation of infero-posterior wall motion was
measurable in five patients (mean peak systolic wall velocity: nonassisted,
2.5 cm.sec-1 +/- 0.5 [standard deviation]; assisted, 7.8 cm.sec-1 +/- 6.3).
The response between stimulation voltage and inferoposterior wall velocity
was sigmoid. CONCLUSION: Doppler US tissue imaging depicted the effects of
myostimulator programming on muscle contraction and ventricular wall
motion.
