Introduction
Dr Pitt O Lim
The heart receives 5% or 250 ml/min of cardiac output and extracts 75% of oxygen delivered, even under basal conditions, compared with less than 5% for the skeletal muscle, therefore, when oxygen requirement rises, the only way to match this is for coronary flow to increase.1 This review concerns new techniques for estimating coronary flow, against a brief historical backdrop and a concise overview of coronary haemodynamics relevant to coronary microvascular dysfunction (CMD), an exhaustive rendition of which is published elsewhere.2
Angina and coronary artery disease
Angina pectoris, which in Latin literally means