21. Atherosclerosis

Question 1

What causes atherosclerosis?

Answer 1

BIG 5:

• smoking
• hypertension
• diabetes
• high cholesterol
• lack of physical activity

Question 2

What are 90% of MIs attributable to?

Answer 2

Modifiable risk factors like the big 5

Question 3

What causes myocardial necrosis? What are the consequences?

Answer 3

Sustained ischemia results in myocardial necrosis:

• immediate impairment of contractility
• susceptibility to arrhythmias
• long term scarring and remodeling
• systolic dysfunction

Question 4

How are serum biomarkers used as indicators of MI?

Answer 4

Draw blood –> look for large myocardial proteins that only leak into the blood when cardiac myocyte membranes break down

Question 5

How is time critical in the treatment of acute MI?

Answer 5

Patients who receive thrombolytic drugs w/in 2 hrs have HALF the mortality of those who receive it after 6 hrs

Question 6

What are the main goals in treating acute MI? How is each achieved?

Answer 6

Restore O2 supply:
-stop/reverse thrombosis (asprin, clot-busting drugs)
-invasive revascularization (catheterization)
Reduce O2 demand:
-lower HR, SBP, volume (beta blockers, nitrates, ACE inhibitors)

Question 7

What is the mortality rate of MIs reaching the hospital w/ a pulse?

Answer 7

10%

Question 8

What is congestive heart failure? Causes?

Answer 8

• Heart fails to create sufficient Q to meet metabolic needs of tissues (hypotension; forward failure) OR
• fails to pump away the blood returned it to it (congestion; backward failure)

Question 9

What is the final, common end-point of nearly every form of cardiac disease?

Answer 9

Congestive heart failure

Question 10

What factors contribute to systolic dysfunction?

Answer 10

• Impaired contractility

- Abnormal LV emptying due to high afterload

Question 11

What is the most effective heart failure therapy?

Answer 11

Combined therapies of inotropes (afterload reduction) and diuretics (venous vasodilators)