RESP 200 - Week 1 - Egan Chapter 10

What is mitral stenosis?

A narrowing of the mitral valve that slows blood flow from the left atrium to the left ventricle.

What is the result of mitral stenosis?

Pressure builds in the left atrium and eventually in the lungs, causing shortness of breath, especially with exercise or when lying down.

What is Coronary Artery Disease?

A group of diseases that cause the coronary arteries to be blocked, usually by plaque build-up (atherosclerosis).

What is the general result of CAD?

A reduction in the flow of oxygen to the heart. Can result in myocardial infarction.

Whare are the 3 types of Acute Coronary Syndrome?

STEMI, NSTEMI, unstable angina

What is a STEMI?

Transmural infarct of the heart wall supplied by the artery.

What is an NSTEMI?

Nontransmural subendocardial infarct.

What is an unstable angina?

Myocardial ischemia but not an infarction.

What is ischemia?

inadequate blood flow to tissues with tissue death.W

What’s an infarction?

An area of tissue dies from lack of oxygen.

What does transmural mean?

Through a wall.

What is a “widowmaker?”

A specific kind of STEMI that affects the left anterior descending coronary artery, which supplie a large portion of the left ventricle septum.

What is the equation for cardiac output and what does it measure?

CO = SV x HR. Measure cardiac output over 1 minute.

What is stroke volume?

The volume of blood ejected by the left ventricle during systole (mL).

What is ejection fraction?

The percent of blood ejected from the left ventricle during systole.

What is the equation for ejection fraction?

stroke volume / end diastolic volume

What is end diastolic volume?

The point at which the left ventricle is most full.

What is the equation for total oxygen content of arterial blood

CaO2 = (Hb x 1.34 x SaO2) + (0.003 x PaO2)

What is PaO2?

The driving pressure of O2 to move from a higher level of pressure to a lower one.

What does 1.34 represent in the CaO2 equation?

The amount of oxygen that can be carried on 1g of hemoglobin.

What happens when the oxyhemoglobin curve shifts to the right?

Hemoglobin releases more oxygen.

What happens when the oxyhemoglobin curve shifts to the left?

Hemoglobin holds onto oxygen more tightly.

What is cooperative binding?

Each O2 that jumps on an Hb molecule change the Hb’s shape to make it easier for the next O2 to jump on. Also works for jumping off.

What happens to O2 as PO2 rises?

More of it binds to hemoglobin.

What happens to O2 as PO2 falls?

Hemoglobin releases more of it.

What causes the oxyhemoglobin curve to shift to the right?

Increase in CO2 or temperature, or decrease in pH (acidosis).

What causes the oxyhemoglobin curve to shift to the left?

Drop in CO2 or temperature, or increase in pH (alkalosis).

What is a normal ejection fraction?

65% (70 mL SV /110 mL EDV)

What is regurgitation?

Back flow of blood through a leaky or malfunctioing valve.

What is stenosis?

Pathological narrowing or constriction of a valve outlet.

What is preload?

The volume of blood in the ventricles at th eend of diastole before th eheart contracts.

What is afterload?

The resistance he ventricles must overcome during systole to eject blood into the arteries.

What do P waves represent?

Atrial depolarization

What does the QRS complex represent?

Ventricular depolarization

What happens during the ST segment?

The ventricles are fully depolarized.

What does the T wave respresent?

Ventricular repolarization