PHYS30001 Lecture Notes - Lecture 20: Coronary Artery Disease, Angina Pectoris, Inotrope
Document Summary
Terminology: ischemic heart disease" coronary artery disease coronary heart disease heart disease. Symptoms: none - silent" angina pectoris chest strangling": (pain due to build-up of lactate, and adenosine activation of pain nerve endings) Imbalance between o2 supply and demand: coronary flow is inadequate to maintain steady- state metabolism". Ventricular wall stress consumption bigger, there is more muscle and o2 demand increases overall intra-ventricular pressure: stretch increases contraction strength, o2. Hypertrophy: wall thickness, o2 consumption/g tissue - but because the heart is. Higher systolic pressure: o2 consumption (afterloading) as heart must pump. Inotropic state energy expenditure, increases demand. Heart rate: cardiac cycle energy expenditure (atp splitting: ca homeostasis & x-bridge activity), higher heart rate = higher demand. Diastolic pressure coronary flow is max in diastolic period aortic diastolic pressure determines coronary perfusion (60mm hg normal) Coronary resistance increased by vessel compression (max in systole) vascular tone autoregulation" vessel obstruction.
