WCHS Mr. Alasti PLTW HBS Human Body Systems 3.1.2 Cardiac Calculations

What are two measures of someone’s cardiovascular health?

Blood pressure and heart rate

What is the main responsibility of the heart?

Circulating blood throughout the body

What information does someone’s heart rate provide?

How well the circulatory system is working

What do changes in someone’s heart rate affect?

The amount of blood pumped to the body’s tissues

Pulse

The rhythmic expansion and recoil of arteries resulting from heart contraction

What happens concerning pulses during each heartbeat?

A pressure wave, or pulses, pass along an artery walls as it bulges and relaxes to accommodate the surge of blood

What does ABI diagnose

Peripheral Artery Disease, PAD

Why is PAD a dangerous thing?

It can cause blood clots

What are the two kinds of strokes and what are they?

Ischemic: blockage of an artery or blood vessel due to plaque or a tear in the artery wall

Hemorrhagic: a weak spot in the vessel wall that gives and bursts, causing blood to flow out of the opening

Arteriosclerosis

The general term for the thickening, hardening, and loss of elasticity in artery walls, often due to aging or high blood pressure

Atherosclerosis

A specific, common type of ateriosclerosis cause by plaque buildup (fats, cholesterol) that narrows arteries and restricts blood flow

What action is being pictured?

A pulse

What does each pulse correspond to?

One heart beat

Range of normal resting heart rates for adults

60-100 bpm

What are some factors that can increase heart rate?

Physical activity or exercises, illness, and stress

What are some factors that can decrease heart rate?

Meditation and relaxation techniques

What other measurement does pulse allow the measurement of?

Blood pressure

Blood Pressure

The pressure that blood experts upon the walls of blood vessels, especially arteries, usually measured with sphygmomanometer

What does the pulse of blood through arteries cause the blood pressure to do?

Rise and fall during each beat

Systolic Pressure

Pressure in the arteries when the heart undergoes systole— the heart contracts to push blood throughout the body

Diastolic Pressure

Pressure in the arteries when the heart undergoes diastole— the heart is at rest, allowing the chambers to fill with blood

Systole

The stage in a heartbeat when contraction of the heart pushes blood out of the chambers and into the aorta and the pulmonary artery

Diastole

The stage in a heartbeat when the heart is relaxed and the heart chambers fill with blood

Equation to calculate blood pressure

Systolic pressure/Diastolic pressure= mmHg

What is the artery typically used to measure blood pressure?

Brachial artery

What tool is typically used to measure blood pressure?

Sphygmomanometer

Steps to measuring blood pressure

1. Place the cuff on the upper arm and a stethoscope on the brachial artery

2. Inflate the cuff past the systolic pressure, cutting off blood flow, and listen for the audible sound of the pulse in the stethoscope to stop

3. Slowly release the pressure in the cuff so blood flow returns to the artery and you can hear pulses in the stethoscope (the sound you first hear in the stethoscope is systolic pressure)

4. Continue releasing pressure (when the pulse is no longer heard, that is diastolic pressure)

Normal systolic and diastolic levels

Systolic: Less than 120 mmHg

Diastolic: Less than 80 mmHg

Elevated (prehypertension) systolic and diastolic levels

Systolic: 120-129 mmHg

Diastolic: Less than 80 mmHg

Hypertension stage 1 systolic and diastolic levels

Systolic: 130-139 mmHg

Diastolic: 80-89 mmHg

Hypertension stage 2 systolic and diastolic levels

Systolic: 140 mmHg or higher

Diastolic: 90 mmHg or higher

Hypertensive crisis systolic and diastolic levels

Systolic: Higher than 180 mmHg

Diastolic: Higher than 120 mmHg

What should someone do immediately if their blood pressure is measured at hypertensive crisis?

Seek emergency care immediately

Cardiac Output

A measure of how much blood is pumped by both ventricles in one minute; quantified as mL per minute

What values can you use to calculate cardiac output?

Heart rate and stroke volume

What does cardiac output help you know?

Whether sufficient oxygen and nutrients are being delivered to various parts of the body

Equation to calculate cardiac output

Cardiac output (mL/min)= heart rate (bpm) x stroke volume (mL/b)

Stroke Volume

The amount of blood being pumped out of the heart with each heartbeat; quantified as mL per beat

What is the average stroke volume?

75 mL/beat

If a client’s heart rate jumps to 140 beats per minute, how would that affect their cardiac output?

Increase their cardiac output

True or False: Dehydration decreases cardiac output

True; because stroke volume is decreased, the heart pumps less blood with each beat

What are some consequences of low cardiac output?

Fatigue, low levels of oxygen in the blood, breathlessness, trouble breathing, and hypotension

ABI

Ankle-brachial index

List the pulse points of the body

• Carotid

• Brachial

• Radial

• Ulnar

• Femoral

• Popliteal

• Tibiallis posterior

• Dorsalis pedis

Label the pulse points

1. Carotid

2. Brachial

3. Radial

4. Ulnar

5. Femoral

6. Popliteal

7. Tibialis Posterior

8. Dorsalis Pedis

What two pulses can tell you about blood flow in the feet?

Dorsalis pedis and tibialis posterior

What might differences in pressure of arms versus legs mean?

It may indicate a problem with the heart of blood vessels, or other further issues like peripheral artery disease (PAD)

What can measurements like heart rate, blood pressure, cardiac output, and ABI determine?

The likelihood that someone has a cardiovascular condition

What is a common disease related to the heart and blood vessels?

Peripheral Artery Disease (PAD)

What can someone with PAD present with in the legs?

Skin discoloration due to reduced blood flow

What might a vessel with atherosclerosis contain?

Plaque buildup