![Figure 1. The negative inotropic effect of halothane ([square bullet, filled], 1.3 minimum alveolar concentration [MAC]= 1 vol%, 2.7 MAC = 2 vol%, 4 MAC = 3 vol%) and of isoflurane ([round bullet, filled], 1.3 MAC = 1.7 vol%, 2.7 MAC = 3.3 vol%, 4 MAC = 5 vol%) in the absence of inotropes. The forces of contraction without anesthetic were 5.7 mN/mm (2)(4.5–6.9 mN/mm2) in the halothane group (n = 8) and 5.4 mN/mm (2)(4.7–6.1 mN/mm2) in the isoflurane group (n = 8, NS). All values are given as means with 95% confidence intervals. Ordinate = The isometric force of contraction of rat papillary muscles in mN//mm2; abscissa = the MAC fraction of anesthetic.](https://asa2.silverchair-cdn.com/asa2/content_public/journal/anesthesiology/88/5/10.1097_00000542-199805000-00025/2/25ff1.png?Expires=1716650623&Signature=mm68NjE8t1mS-C84E4R1BaRm759yvnUvZ0xg1FWkaWtgkiEZajmnCwUrDfM~f9OhtL0z~1p~TfrlCDyCbyLLfe3PsLTKy2xXdUNpuGO01yC7PPl5MYCyvE4HOsXq0CPiKRlu1HLqENb3NDc3qXF4zWCZZ31R56VU0BxWFQqxQDBqnw~5ZmCHLnwR57ku8bnpwxkVpVGjSWlhBA3~Dl8DNB6kOazmkcJGjTIzc7Ft9BqBGvJVm7CIFFG4-jEAH99CyuFQFIF5Zn9UIfDFU1QZa~LCGzDPtjHgVpodNH-Gmfu-R~mSjb1hnR4AG~5svraRdxV~-ltL4EAIYdCzAzm8Ww__&Key-Pair-Id=APKAIE5G5CRDK6RD3PGA)
Figure 1. The negative inotropic effect of halothane ([square bullet, filled], 1.3 minimum alveolar concentration [MAC]= 1 vol%, 2.7 MAC = 2 vol%, 4 MAC = 3 vol%) and of isoflurane ([round bullet, filled], 1.3 MAC = 1.7 vol%, 2.7 MAC = 3.3 vol%, 4 MAC = 5 vol%) in the absence of inotropes. The forces of contraction without anesthetic were 5.7 mN/mm (2)(4.5–6.9 mN/mm2) in the halothane group (n = 8) and 5.4 mN/mm (2)(4.7–6.1 mN/mm2) in the isoflurane group (n = 8, NS). All values are given as means with 95% confidence intervals. Ordinate = The isometric force of contraction of rat papillary muscles in mN//mm2; abscissa = the MAC fraction of anesthetic.
