Unit 2 Day 1 (Tuesday 4/7)

Question 1

Coronary Atherosclerosis Risk Factors

Answer 1

-risk factors: smoking, hypertension, dyslipidemia, diabetes, obesity, inflammation, stress, sedentary lifestyle, male gender, age, high LDL, low HDL

Question 2

Autoregulation

Answer 2

• an adaptive mechanism to maintain perfusion in face of altered perfusion pressure
• an epicardial coronary stenosis may cause autoregulation to be exhausted and lead to ischemia

Question 3

Treatment for Stable Coronary Heart Disease: Inc O2 Supply

Answer 3

• perfusion pressure: prevent hypotension
• diastolic time: rate-slowing drugs (e.g. beta blockers)
• coronary resistance: vasodilator drugs (e.g., nitrates, calcium channel blockers); coronary angioplasty or bypass surgery
• oxygen content: treat anemia and hypoxemia

Question 4

Treatment of Unstable Coronary Disease: Reducing O2 Demand

Answer 4

• systolic pressure: Antihypertensive drugs
• heart rate: Rate-slowing drugs (beta blockers, calcium channel blockers)
• wall tension: Limit LV cavity size by limiting excessive preload (diuretics, nitrates)
• inotropic state: negative inotropes (beta blockers and Ca channel blockers)
• revascularization: coronary angioplasty, coronary artery bypass surgery

Question 5

Pathophys of Unstable Coronary Artery Disease

Answer 5

• Inflammation in arterial wall
• Weakening of fibromuscular cap
• Abrupt plaque fissure or rupture
• Thrombogenic components (lipids, tissue factor) exposed to blood
• Thrombosis with partial or complete vessel occlusion
• Myocardial injury and/or necrosis (serum markers)
• Cardiac dysfunction, risk of arrhythmias, death

Question 6

Dx of CAD with ECG

Answer 6

• Resting ECG:
– ST segment changes (usually depression) – T wave inversion
– Q-waves (indicate prior infarction)
• Exercise ECG (stress testing): – dynamic ST segment changes

Question 7

Angiography

Answer 7

• diagnostic tool
• underestimates pathologic extent of CAD
• underestimates severity of CAD

Question 8

Angioplasty

Answer 8

• reduces risk of recurrent ischemic events in unstable angina
• balloon dilation to expand vessel wall
• sometimes vessel restenoses

Question 9

Tx for MI with ST Elevation

Answer 9

• Immediate aspirin, nitroglycerin, ± beta blocker

* Reperfusion therapy ASAP: Usually coronary angioplasty, if unavailable thrombolytic therapy

Question 10

Coronary Bypass Grafting

Answer 10

-using other arteries to reperfuse heart
– Internal mammary artery
– Saphenous vein
– Prosthetic materials have not proven successful as coronary grafts