Fig. 2. Effects of methylmethacrylate monomer (MMA) on the rapid cooling contractures in guinea pig papillary muscles (n = 7). Steady-state contractile force evoked by 2-Hz stimulation followed by immediate cooling from 37°C to less than 5°C achieved within 1.5 s, as shown by the temperature measurement in bottom record. Note the prolongation of the time to peak contracture with 1.5 mm MMA.