Cardiovascular recording
The cannula implanted into the femoral artery was connected to a pressure transducer, and pulsatile arterial pressure was recorded using an HP-7754A amplifier (Hewlett-Packard, Palo Alto, CA, USA) and an acquisition board (Biopac M-100, Goleta, CA, USA) connected to a personal computer. Mean arterial pressure (MAP) and HR values were derived from the pulsatile arterial pressure recordings.