tokens: During hypotension produced by SNP similar decreases were observed in mean pulmonary arterial pressure ( p less than 0 . 01 ) , central venous pressure ( p less than 0 . 001 ) , left ventricular end - diastolic pressure ( p less than 0 . 01 ) , total peripheral resistance ( p less than 0 . 001 ) , rate pressure product ( p less than 0 . 001 ) , and oxygen content difference between arterial and mixed venous blood ( p less than 0 . 05 ) , while heart rate ( p less than 0 . 001 ) and cardiac output ( p less than 0 . 05 ) were increased .