Cardiovascular (Heart)

Question 1

Cardiovascular Diseases

Answer 1

Coronary Artery disease:

•Myocardial Ischemia: O2 content cannot meet metabolic demands of myocardium

•Acute coronary syndromes: plaque blockage, coronary spasm causing sudden reduced blood flow to heart

Angina

Myocardial infarct

Heart failure: left and right HF

Shock: hypovolemia, cardiogenic, neurogenic, septic, anaphylactic

Congenital heart defects

Question 2

4 Main Coronary Arteries

Answer 2

•Right coronary artery

•Left main coronary artery (widow maker)

•Left anterior descending (widow maker)

•Left circumflex artery

Blockage of these arteries is common cause of angina, heart disease, heart attacks and heart failure

Question 3

Cardiac Output Formula

Answer 3

HR (beats/min) x Stroke Volume (ml/beat) = CO

Question 4

Stroke Volume

Answer 4

volume of blood pumped out by left ventricle during systole

60-100 mL/beat

Question 5

Normal Cardiac Output

Answer 5

Normal stroke = 60-100 ml/min

Normal HR = 70 BPM

Cardiac output = HR x Stroke
70 x 60 ml = 4200
70 x 100 ml = 7000

Normal cardiac output = 4.2 - 7 L/min

Question 6

Ejection Fraction

Answer 6

Volume pumped out of left ventricle divided by volume in the left ventricle at end of diastole

Stroke volume / End diastolic volume

Normal: 75 ml/120ml = 62%

Question 7

Frank-Starling Law

Answer 7

States that the stroke volume of the left ventricle will increase as the left ventricular volume increases due to myocyte stretch causing a more forceful systolic contraction

Question 8

Heart Failure

Answer 8

Decreased contractility. Decreased ability for muscle to snap back

Question 9

Preload

Answer 9

Stretching of cardiac muscle at end of diastole, right before contraction

Decreased preload = decreased stretch = decreased contractility = decreased cardiac output

Question 10

Afterload

Answer 10

The pressure the heart works against to eject blood during systole (ventricular contraction)

High afterload = decreased CO

High afterload is caused by a high pressure in arteries

Question 11

Stable angina

Answer 11

Chronic coronary obstruction
Gradual narrowing

Activated by physical exertion or stress

Symptoms: Pressure, heaviness, radiate to left neck or jaw, arm, shoulder. Pallor, diaphoresis, dyspnea.

Causes:
Stable plaques
Uncontrolled diabetes
Hypertension
Increased LDLs
Decreased HDLs
Sedentary lifestyle
High BMI
Genes

Question 12

Prinzmetal angina

Answer 12

Not from blockage, but rather from spasms.

Unstable, unpredictable, can occur at rest.

With or without atherosclerosis .

Occurs at night.

Hyperactivity of SNS

Can cause dysrhythmias

Treated with longterm meds

Question 13

Silent Ischemia

Answer 13

Mental stress induced ischemia

Asymptomatic. Doesn’t present as typical ischemia.

If symptomatic: fatigue, dyspnea, feeling of unease

Can occur on their own or when individuals have angina

Increased risk for cardiac event

Causes: Diabetes mellitus, cardiac transplant, previous MI (nerve injury), Mental stress

Question 14

Angina causes

Answer 14

Vessel spasm

Atherosclerosis: Stable plaques

Atherosclerosis: Unstable complicated plaques

Hypotension
Anemia
Hypoxemia
Increased O2 demand

Question 15

Unstable Plaques

Answer 15

Unstable plaques can rupture and lift off the artery wall, leading to an acute event such as heart attack, stroke or death. Unstable plaques are potentially more dangerous than stable plaques because of their propensity to rupture and cause complete obstruction to blood flow.

Question 16

considerations for female patients

Answer 16

Atypical symptoms of MI and angina: palpitations, anxiety, weakness, fatigue

42% of women do not have chest pain. Women present with more fatigue and right sided chest pain.

Heart disease and stroke leading cause of death in women

Microvascular changes

Question 17

Acute Coronary Syndrome

Answer 17

refers to a group of conditions that include ST-elevation myocardial infarction (STEMI), non-ST elevation myocardial infarction (NSTEMI), and unstable angina.

Question 18

Stable vs Unstable Angina

Answer 18

Stable: Increased O2 demand in setting of a stable atherosclerotic plaque. Vessel unable to dilate enough to allow proper blood flow

Unstable: Plaque ruptures and thrombus forms around the ruptured plaque, causing partial occlusion of the vessel. Angina pain at rest or progresses rapidly over short period

Question 19

NSTEMI

Answer 19

Plaque ruptures and thrombus causes partial occlusion. Damage limited to myocardium below endocardium.

ST wave depression, T wave inversion

Question 20

STEMI

Answer 20

Complete occlusion of blood vessel. Damage extends frim endocardium to epicardium

ST elevation

Question 21

How long can cardiac cells withstand ischemic conditions

Answer 21

20 minutes

Question 22

Myocardial stunning

Answer 22

Temporary loss of contractile function persists hours to days after perfusion is restored

Question 23

Hibernating myocardium

Answer 23

Tissue persistently ischemic and undergoes metabolic adaptation to prolong myocyte survival until perfusion can be restored

Question 24

Valve dysfunction: Stenosis

Answer 24

Valve opening becomes narrow, doesn’t open all the way. blood has hard time getting through

“Doorway isn’t all the way open so it is hard to get blood past”

Aortic stenosis most common (valve between left ventricle and aorta)

Mitral stenosis also common (valve between left atria and left ventricle)

Question 25

Valve dysfunction: Regurgitation

Answer 25

Valve doesn’t close good enough, blood leaks backwards

“Doorway” doesn’t close properly so blood leaks back into chamber