4.1 Summary of IHD

The_______ supplies the right atrium, right ventricle, and conduction system (including the AV node artery).

right coronary artery (RCA)

The ______ divides into the circumflex and left anterior descending (LAD) arteries.

left main coronary artery

Coronary circulation begins at the aorta via the________

left and right coronary arteries

Most perfusion occurs during ______, not ________

diastole, not systole.

Autoregulation maintains oxygen delivery via ________

reactive hyperemia.

_________ are produced locally or systemically, while _______ are produced locally

vasoconstrictors, vasodilators

Vasoconstrictors?

1. Angiotensin II

2. Endothelin

3. thromboxane A2

4. NTs

Vasodilators?

1. Nitric oxide,

2. CO₂

3. adenosine

Which factors impair vascular tone?

• Atherosclerosis

• Diabetes mellitus

• Tobacco use

• Inflammation

Atherosclerosis typically affects_______, may affect ______ in women or patients with metabolic syndrome

epicardial coronary vessel

endocardial vessels

Which factors decrease supply?

• Atherosclerosis

• Vasospasm

• High heart rate

• Low cardiac output

• Cardiac fibrosis

Which factors increase demand?

• Increased MVO2

• Increased heart rate or stroke volume

• Diseases that increase wall tension

_______ allows increased flow during exercise but is lost in disease states, leading to ischemia.

Coronary reserve

____ occlusion adequate coronary reserve, asymptomatic

_____ occlusion impaired coronary reserve, symptoms with exercise

70-90%

_____ occlusion symptoms at rest, "critical occlusion"

>90%

________ is the primary symptom of ischemic heart disease

Chest pain (angina pectoris)

Pain only with exertion, no symptoms at rest

Stable angina

Pain at rest or worsening exertional pain

Unstable angina

Vasospasm-related, not exertion-induced

Variant (Prinzmetal) angina

Ischemia occurs when _________

myocardial oxygen supply < demand

May occur without adequate angiogenesis, increasing risk of ischemia

Myocyte Hypertrophy

Heart muscle thickens in response to wall stress

Myocyte Hypertrophy

Adaptive compensation for high pressure or volume

Myocyte hypertrophy

Limit contractility and cardiac output

Collagen deposition

Reduces wall stress, and new tissue is noncontractile and does not aid in pumping

Collagen deposition

Low O2 causes switch from FA oxidation to glycolysis (less efficient)

Altered metabolism

Limits energy production and has an increased risk of arrythmias

Altered metabolism

In atherosclerosis, endothelial damage ___________

impairs NO generation

In atherosclerosis, _______ and ______ lead to vasoconstriction

inflammatory cytokines and platelet activation

Drugs that ENHANCE SUPPLY & DECREASE DEMAND

1. ARBs

2. ACEi

3. Statins

4. CCBs

5. Beta-blockers

Drugs that ENHANCE SUPPLY

1. Aspirin

2. Nitrates

Drug that DECREASES DEMAND

Ranolazine

Pharmacological approaches to IHD via VASODILATION?

1. nitrates

2. β-blockers

3. DHP CCBs

Pharmacological approaches to IHD by ACTING ON PLAQUES?

1. ACEIs

2. aspirin

3. statins

Pharmacological approaches to IHD by REDUCING MYOCARDIAL WORK?

1. Ranolazine

2. non-DHP CCBs

3. ACEI

4. ARBs

5. β-blockers