Ischemic Heart Disease (Coronary Artery Disease) - Module 1

Narrowing of obstruction of the coronary artery(ies) sufficient to prevent adequate blood and oxygen supply to the myocardium (may progress to myocardium damage)

Define Ischemic heart disease

Ischemic heard disease

What does IHD stand for

Inadequate blood and oxygen supply to the myocardium (no permanent damage)

Define ischemia

Inadequate blood and oxygen supply to the point of myocardium damage

Define infarction

Atherosclerotic and non-atherosclerotic

What are the two types of ischemic heart disease causes

Atherosclerosis

What is the most common causes of IHD

False, less common

T/F: non-atherosclerotic causes of IHD is very common

Embolus into coronary artery, trauma, coronary artery dissection/aortic dissection

What are some non-atherosclerotic causes of IHD

Aortic dissection flap can cover coronary artery entrance and stop blood from flowing into coronary artery

Explain how an aortic dissection can lead to IHD

Fatty streak on intima

How does atherosclerotic plaque begging

Starts as fatty steak and progresses into a superficial erosion of endocardial layer. Thrombus forms and occludes artery

Describe how atherosclerotic plaque progresses

Distal to an arterial branching

Where does atherosclerotic plaque usually occur

Age, smoking, DM, dyslipidemia, HTN

What are the major risk factors for IHD

Abdominal obesity, family Hx, obesity, physical inactivity

What are some other predisposing risk factors of IHD

Decreased blood supply to myocardium or increased demand of blood

What are the possible causes of ischemia

True

T/F: ischemia is reversible

Death or necrosis of tissue

What is infarction

Prolonged ischemia, total occlusion of blood flow to the tissue

What causes infarction

If wall is being supplied by multiple arteries, may just cause ischemia

In what instance would a total occlusion of blood in a coronary artery not cause infarction

False, irreversible

T/F: infarction is reversible

CAD and increased metabolic demand

What are the 2 most common causes of myocardial ischemia

Coronary artery disease

What does CAD stand for

Plaque in vessel which impedes blood flow

What is CAD

Hypertrophic cardiomyopathy or aortic stenosis

What are some causes of increased metabolic demand

Causes more muscle which increases the demand

Explain how hypertrophic cardiomyopathy can cause myocardial ischemia

Heard is working harder against the high afterload so demands for blood

Explain how aortic stenosis can cause myocardial ischemia

Downstream

Does everything downstream or upstream from the obstruction die in infarction

Collateral circulation from another vessel

When would everything downstream from and obstruction NOT die

1 hour

When does cell death start to occur with infarction

4 house

When is cell death complete in infarction

Myocardial infarction

What does MI stand for

Heart attack

What is the more common name for myocardial infarction

Angina pectoris (chest pain) and SOB

What are the 2 main symptoms of ischemia/MI

Syncope, fatigue, can be asymptomatic, sweating, nausea/vomiting, anxiety

What are some other symptoms of ischemia/MI

Women tend to have more vague/slight symptoms. This may include stomach feeling a little off or left shoulder pain

Explain how the symptoms of MI may differ in women

Pulmonary edema and Cardiomegaly

What findings on a CXR may indicate IHD

Heart starts to dilate b/c working so hard

Explain why patients may have Cardiomegaly or pulmonary edema with IHD

Cardiomegaly on CXR

What does this image show

S4, possible S3, MR murmur

What findings on auscultation may indicate IHD

Systolic murmur at apex

What murmur indicates MR

60%

What % of patients have MR after an acute MI

Reduced O2 delivery

What causes angina

Heaviness, burning or aching pain in the chest +/- left arm

What may be some indications of angina

Coronary spasm

What may also cause angina pectoris

Quick/acute thickening or contract of coronary artery that causes decrease blood flow (kinda like a acute stenosis)

What is a coronary spasm

Predictable, regular chest pain

What is stable angina

Stable plaque (slow forming, smooth)

What causes stable angina

Rest or nitroglycerine

What is the treatment of stable angina

Ease pain

What is the purpose of treating stable angina with nitroglycerine

More intense/painful chest pain, not predictable

What is unstable angina

Immediate intervention (emergency)

What is the treatment for unstable angina

Unstable angina

Is stable or unstable angina more concerning

MI causes loss of blood to the heart muscle which interrupts the electrical signals, causing arrhythmias (VT/VF). This then progressing into asystole

Describe how MI can progress into cardiac arrest

VT and VF

What arrhythmias does MI cause

CPR and defibrillator (AED/manual defibrillation)

What is the treatment with someone with MI, VT/VF, asystole

10%

Survival rate drops by ______% every minute with no pulse

Thrombolytic and PCI or emergency bypass

How is the patient treated once the pulse is back after an MI

Non-STEMI

What does NSTEMI stand for

ST elevation

What does STE stand for

Zone of ischemia with small zone of cell death

What causes NSTEMI

Subendocardial MI only (usually)

What type of MI causes NSTEMI

Depressed

What does the ST segment look like with NSTEMI

Transmural

What is another term for STEMI

Through the whole thickness of the myocardium (endo to epi)

What part of the heart wall is affect with a STEMI

Elevated

What does the ST segment look like with STEMI

STEMI (NSTEMI is still bad tho)

Is NSTEMI or STEMI more serious

P wave

What is 1

R

What is 2

T wave

What is 3

PR segment

What is 4

QRS complex

What is 5

ST segment

What is 6

QRS

What represent electric systole

ST segment

What represents mechanical systole

ST segment is same level as TP segment

Describe the normal ECG

Isoelectric

What is another term for a normal ECG

ST segment is lower than TP segment

Describe the appearance of ST depression

Ischemia

What does ST depression indicate

ST segment above TP segment

Describe the appearance of ST elevation

Infarction

What does ST elevation indicate

Normal ECG

What does this image represent

NSTEMI (ST depression)

What does this image represent

STEMI (ST elevation)

What does this image represent

Ischemia

What condition does this ECG indicate

Infarction

What condition does this ECG indicate

Heart blocks (AV block, LBBB), Qwaves peaked T waves, revered T waves, any arrhythmia originating in ventricle

What are some other ECG changes that may indicate MI

Atria and vertices aren't communication

What is an AV block

New LBBB may indicate a MI starting

Describe the relationship between and LBBB and MI

Wide QRS

Describe the appearance of an LBBB

False not always a MI may just be an LBBB

T/F: an LBBB always indicates a MI

LBBB (may indicate MI)

What arrhythmia does this image represent

Old MI (from necrotic tissue)

What does Q waves indicate

Acute MI

What does peaked T waves indicate

Chronic ischemia

What does reversed T waves indicate

Lifestyle modifications

What is the treatment for IHD

Quite smoking, diet (avoid salt, fat, alcohol), exercise, stress management, weight loss, BP reduction (treat HTN)

What are some examples of lifestyle modifications for IHD

Nitroglycerine

What is the medication for pain relief

Palvix and warfarin/coumadin

What are some medications for anitcoagulation

IHD causes stagnant flow so try to prevent clots

Why may a patient with IHD be treated with anticoagulation

Decrease HR and afterload

What do beta blockers do