Effect of sudden reductions of the arterial blood pressure on the mean diastolic coronary resistance

Summary At the beginning of a 10 sec arterial haemorrhage, vascular elasticity induces an increase of mean diastolic coronary resistance. Then, the increase is counteracted by the relaxation of the vascular musculature, which causes a coronary hyperaemia when, after the haemorrhage is arrested, the vascular wall is stretched by a sudden though slight increase of blood pressure.Acknowledgment. The authors wish to thank Mr Rodolfo Dalla Valle for his technical assistance.