Week 3, Coronary heart disease

Question 1

What is the most frequent cause of death in developed countries?

Answer 1

Coronary heart disease

Question 2

What is the approximate distribution of Resistance between large coronary vessels and their small vessel branches? How does this affect their ability to respond to a stenosis in the large vessel?

Answer 2

5% in large vessels 95% in small vessels

Question 3

At what % of occlusion of a large coronary does its resting and maximal flow begin to decrease?

Answer 3

At 50% occlusion maximal flow begins to drop At 80% occlusion resting flow rate begins to drop.

Question 4

What other factors are involved besides a stenosis to evoke CHD?

Answer 4

Dysfunction of the endothelial cells near the stenosis. -Inappropriate vasoconstriction or impaired vasodilation. Impaired NO or Adenosine release. -Loss of antithrombotic properties. Impaired NO or prostacyclin release.

Question 5

What is Angina Pectoralis? What are the types?

Answer 5

Severe, dull/pressing pain in the chest, of limited duration. Often radiates, typically to left arm. Usually provoked by physical activity, cold, or a large meal. Classic and Prinzmetal angina, Stable and Unstable angina.

Question 6

Describe classic angina

Answer 6

Stress induced, ST depression Alleviated by nitrates Caused by coronary occlusion Common type

Question 7

Describe Prinzmetal angina

Answer 7

Occurs at rest or sleep

ST elevation

Not very responsive to nitrates

Caused by Coronary Spasm

Question 8

Describe Stable angina

Answer 8

Has a good prognosis

Caused by a quiescent plaque

Has stable characteristics

Occurs at a predictable level of physical activity

Usual frequency and usual pain amount

Question 9

Describe unstable angina

Answer 9

Bad prognosis

Caused by a Ruptured Plaque

Unstable characteristics

occurs more frequently,

more painful

caused by lower levels of physical activity

Question 10

Describe Acute Coronary Syndrome

Answer 10

May be from either AMI or Unstable Angina

Sypmtoms indicate ACS if:

1) it is the first angina-pain occurence
2) in a CHD patient, the angina is not relieved by nitrates or is unusually severe.

May occur with ST elevation: ST-elevation Mycardial Infarct (STEMI) or Q-Wave Myocardial Infarct QMI

or without ST elevation: unstable angina, Non-ST-Elevated MI (NSTEMI), or Non-Q MI (NQMI)

Question 11

What are the effects of hypoxia in AMI?

Answer 11

ATP depletion

Decreased pump activity

Increased intracellular Na+

Increased intracellular Ca++

Edema

Altered membrane potential

Arrhythmia

Anaerobic glycolysis, lowered pH

Cell death

Question 12

Complications that can result from AMI

Answer 12

decreased contractility

• stasis and thrombus generation
• Cardiogenic shock

Arrhythmia

-vent fibrillation, death

Necrosis

• Papillary muscle or valve defect –> regurgitation and congestive heart failure
• subsequent decreased contractility –> congestive heart failure,
• pericarditis –>pericardial effusion, cardiac tamponade
• Ventricle rupture –> cardiac tamponade

Question 13

How is ACS managed?

Answer 13

Acute Coronary Syndrome:

ECG is performed –> Is there ST elevation?

Yes, ST elevation: STEMI, immediate percutaneous coronary intervention (PCI), also called coronary angioplasty, using a ballon catheter or stent.

No, Unstable Angina or Non-STEMI: Check if Troponin levels are elevated

Yes, troponin is elevated:

Question 14

What are ways to prevent CHD?

Answer 14

Do not smoke

Physical exercise, avoiding sedentary lifestyle

Manage hypertension

Manage Diabetes

Manage hyperlipidemias

Question 15

In CHD patients, what precautions are taken to prevent AMI?

Answer 15

Prophylactic anticoagulants, Aspirin

Monitor the CHD

Hospitalize if angina occurs, especially unstable angina

Surgery or angioplasty, stents if needed