Angina Flashcards
Define ischemic heart disease
Ischemic heart disease is a condition where there is inadequate blood supply and oxygen to a portion of the myocardium
What are the 3 determinants of O2 demand?
Heart rate, Contractility and wall tension in the myocardium during systole
List the 4 factors affecting coronary blood flow (supply)
Narrowing of the vessels caused by atherosclerosis
Endothelial cell dysfunction - impairs vasoconstriction
Anatomic factors - diameter of the lesion impeding blood flow and length of the lesion
Metabolic factors - adenosine, nitric oxide and prostaglandins
What are some risk factors for IHD?
Tobacco smkoing, hypertension, diabetes mellitus, low HDL cholesterol, aging, gender, ethnic background
What is a thromboembolism?
A large plaque that breaks through endothelial lining and expose collagen-rich connective tissue to the blood. Plaque ruptures and clotting is started. (Thrombus)
List some symptoms of IHD
Extreme fatigue, chest pain, heart palpitations and swelling in the legs and feet
List the different types of angina
Stable angina - predictable chest pain. Increased demand on the heart caused by a fixed narrowing of the coronary vessels
Unstable angina - pain occuring with reduced levels of excertion or pain at rest. Risk of MI
Variant/Prinzmetal angina. Uncommon, occurs at rest due to coronary spams
Exaplain the coronary steal phenomenon
See answer in notes
What is the rationale of treatment in IHD?
Use drugs that will improve perfusion of the myocardium or reduce its metabolic demand. Myocardial oxygen demand is based on the heart rate, contractility, preload and afterload
What is the action of nitrates in ischemic heart disease management?
Produce venous dilation, decrease preload and decrease O2 demand
What is the action of CCBs in ischemic heart disease management?
Decrease vascular resistance, increase coronary and myocardial blood flow and decrease myocardial contractility
What is the action of beta-blockers in ischemic heart disease management?
Decrease heart rate and contractility
What is the MOA of nitrates?
Not entirely known, but believe to convert nitrates to nitric oxides. This activates guanylate cyclase, increases GMP and activates protein kinase. Relaxes smooth muscles and reduces cardiac oxygen consumption
What is significant of the pharmacokinetics?
SL route is preferred: 15-30 min duration of action. Very rapid onset of action through this mechanism.
Give 3 adverse effects of nitroglycerin?
Postural hypotension, flushing, dizziness and reflex tachycardia.
