Skeletal Muscle Powered Ventricle: Comparison of Double‐Layered Small Ventricle and Single‐Layered Large Ventricle

Canine left latissimus dorsi (LD) muscles were used to construct two kinds of skeletal muscle powered ventricles (SMPV): a double layered small size (10‐17 mL) SMPV (A), and a single‐layered large size (40–70 mL) SMPV (B). The same muscle was used sequentially for the construction of both SMPV. A mock circulation system was used for testing. This allowed for change of the preload (10–60 mmHg) and afterload (40–160 mmHg) independently. The peak developed pressure (PDP) and stroke volume (SV) were measured, and the stroke work (SW) was analyzed on line by a computer. The isovolumic PDP was 93.3 ± 11.8 mmHg at 10 mmHg preload, and 157.7 ± 20.2 mmHg at 60 mmHg for A, and 37.8 ± 5.5 mHg and 107.8 ± 8.5 mmHg for B. The SV and SW at 50 mmHg preload and 80 mmHg afterload were 18.30 ± 1.25 mL and 1.06 ± 0.10 × 10 6 erg for A, and 34.18 ± 2.36 mL and 2.51 ± 0.28 × 10 6 erg for B. The SV and SW at 20 mmHg preload and 160 mmHg afterload were 2.65 ± 0.31 mL and 0.27 ± 0.05 × 10 6 erg for A, and 1.03 ± 0.23 mL and 0.04 ± 0.01 × 10 6 erg for (B). The SW generated by the large single‐layered SMPV is similar to that reported for the canine left ventricle but requires a high preload. The large single‐layered SMPV showed a higher dependence on pre‐ and afterload changes than the double layered small SMPV, which generates a higher pressure even at low preloads.