NUR 339 Final
- Coronary circulation
Answer two main coronary arteries, lefts and right arteries arise from aortic arch just past aortic valve
- left coronary artery splits to-
Answer -become left anterior descending- supplies LV, anterior portion of septum, papillary muscle; circumflex- supplies lt. lateral wall of LV
- right coronary artery
Answer supplies SA node (pace maker) and RV; extends to back of heart' posterior descending artery supplies posterior septum, ventricle, and posterior papillary muscle
- control of coronary circulation
Answer coronary arteries are mostly perfuse during diastole (rest of the body is perfused by systole)
- Preload
Answer stretch (length) of LV myocardial fibers at end of diastole; mainly deter- mined by venous return; filling volume of heart
- frank-starling law
Answer greater the stretch, the greater the force of contraction
- Increased preload
Answer as preload increases, stroke volume and cardiac output increases; increased blood volume (fluid overload), heart valve regurgitation, septal defects 1 / 3
- Decreased preload
Answer decreased blood volume (dehydration)
- Medication that decreases preload
Answer diuretics (furosemide)
- Afterload
Answer resistance to ventricular ejection, pressure ventricle must overcome to pump out blood; largely determined by BP (hypertension- increased afterload)
- Afterload increased
Answer as afterload increases, stroke volume and cardiac output decreases
- Medication that decreases afterload
Answer antihypertensive meds, vasodilators, beta blockers, alpha blockers
- atherosclerosis
Answer major causes of CHD, narrowing of coronary arteries due to buildup of plaque (buildup of lipids)
- Plaque formation
Answer plaque partially occludes vessel and causes ischemia; lipid core may grow, rupture, hemorrhage
- Coronary heart disease (CHD)
Answer heart disease caused by impaired coronary blood flow; main cause is atherosclerosis 2 / 3
- Chronic ischemic heart disease
Answer stable angina, variant angina, silent MI (with- out symptoms)
- Acute coronary syndrome
Answer unstable angina, myocardial infarction (Non-ST segment elevation MI; ST-segment elevation MI)
- Angina
Answer chest pain or pressure associated with transient myocardial ischemia; pain typically lasts 2-10 minutes and relieved with rest or vasodilators
- stable angina
Answer short lived; occurs after exertion, exposure to cold or stress; relieved by rest or use of NTG; caused by fixed obstruction due to atherosclerosis
- Unstable angina
Answer unpredictable; may occur at rest and is usually prolonged; new onset or exertional angina with increase in severity; caused by plaque disruption
- variant angina
Answer caused by vasospasm rather than atherosclerotic plaque; pain usually occurs at rest, during sleep, with minimal exercise or stress; pain often follows cyclic pattern (happens at same time every day); treated with calcium channel antagonist, short and long term nitrates
- myocardial infarction (MI)
- / 3
Answer loss of coronary blood flow and subsequent death of myocardial cells and tissue; usually due to