Cardiovascular Physiology —
Coronary Circulation & Ischemic Heart Disease
Review of coronary circulation
R coronary a [RCA]
acute marginal br
posterior interventricular br (posterior descending a [PDA])
L coronary a
L main
anterior interventricular br (left anterior descending a [LAD])
diagonal branches [D1, D2, D3]
septal branches
circumflex br [LCx]
obtuse marginal branches [OM1, OM2, OM3]
Normal coronary blood flow
phasic changes in blood flow
epicardial blood flow
endocardial blood flow
Control of coronary blood flow
local muscle metabolism
oxygen demand as major factor
nervous control
parasympathetic stimulation
sympathetic effects
alpha vasoconstriction — epicardial
beta vasodilation — intramuscular
muscle metabolism
70% of energy from fatty acid metabolism
loss of adenosine in severe ischemia
Ischemic heart disease
atherosclerosis & acute coronary occulusion
thrombus formation & embolus
vessel spasm & secondary thrombosis
collateral (anastomotic) circulation
myocardial infarction
causes of death
systolic stretch → ↓ CO
blood damming → pulmonary congestion
ventricular fibrillation (VF)
K depletion
injury current
sympathetic reflex stimulation
development of circus rhythms
rupture
cardiac tamponade
pericardiocentesis
coronary steal
pain in CHD
angina pectoris
referred pain
anginal equivalents
drug therapy
nitrates
beta-blockers (e.g., propranolol)
surgical treatment
CABG (coronary-artery bypass grafting)
(saphenous-) vein grafts
LIMA, RIMA, & radial-artery grafts
coronary angioplasty
balloon angioplasty
stents
laser ablation & rotablator techniques