pulse pressure lab

What is the cardiac cycle?

The cycle of contraction and relaxation of atria and ventricles

Is blood filled or pumped out a chamber during systole?

Pumped out

Is blood filled or pumped out a chamber during diastole?

Filled

What happens in atrial diastole?

• blood delivered into atria via veins

• 80% of blood passively into the ventricles, which. is also in diastole

What happens in atrial systole

• Last 20% of blood left in atria is delivered into the ventricles by atrial systole

What happens in ventricular systole?

• Begins shortly after atrial systole

• Ventricular contraction begins, pressure rises, AV valves are closed

• Ejection phase: as pressure begins to rise in the ventricles, blood is pumped into the great arteries

What happens in ventricular diastole?

• Cycle begins to repeat

What is the 1st heart sound?

• Lub - AV valves close

What is the 2nd heart sound?

• dub - SL valves close

What is a heart murmur?

• abnormal heart sound

• indicates a defect in one of the valves

What is pulse?

• surges of pressure in arteries (as heart pushes blood out during the cardiac cycle)

• equivalent to heart rate

What is heart rate?

• Number of beats per minute

• Normal: 60-100 bpm

• Average resting heart rate: 70-76 bpm

• Average heart beat lasts 0.8 seconds

How is heart rate calculated?

(60 seconds) / (HR duration) = HR

What is blood pressure?

• Pressure exerted against the walls of arteries

What is systolic blood pressure?

• Pressure exerted against walls of arteries during ventricular systole

What is diastolic blood pressure?

• Pressure exerted by blood onto arterial walls during ventricular diastole

How is blood pressure measured?

• By using a sphygmomanometer

• mmHg

• SBP over DBP

What is normal blood pressure?

Systolic: Less than 120

AND

Diastolic: Less than 80

What is elevated blood pressure?

• systolic: 120-129

  AND

• diastolic: less than 80

What is high blood pressure (stage 1 hypertension?)

• systolic: 130-139

  OR

• diastolic: 80-89

What is high blood pressure (stage 2 hypertension?)

• systolic: 140 or higher

  OR

• diastolic: 90 or higher

What is hypertensive crisis?

• systolic: 180 or higher

  AND/OR

• diastolic: 120 or higher

How do you measure systolic and diastolic blood pressure?

1. Place blood pressure cuff on upper left
   arm

2. Place stethoscope on the brachial artery
   3. Inflate pressure in cuff un<l circula<on is
   cut off
   • Do not inflate higher than 160mmHg

3. Use valve to slowly release pressure
   by ̴ 2mmHg/second

4. The first sound heard in the stethoscope
   (crackling or knocking sound) = pressure
   reading at this <me is the systolic
   pressure
   • This is called the sounds of Korotkoff

5. When that sound disappears = pressure
   reading at this <me is the diastolic
   pressure

What are the sounds of Korotkoff?

• the sounds heard in a stethoscope when measuring blood pressure

What is TPR?

Total Peripheral Resistance

• the amount of force exerted on circulating blood by the vasculature

What is stroke volume?

• The amount of blood pumped by the left ventricle during one contraction

• Average SV is 70mL

What is cardiac output?

• The amount of blood pumped by the heart in one minute

• CO = SV x HR

How can BP be calculated?

BP = CO x TPR

What is pulse pressure?

• difference between the SBP and DBP

• Pulse pressure = SBP - DBP

What is mean arterial pressure (MAP)?

• average pressure in a patient’s arteries during one cardiac cycle

• represents the force generated by the heart during contraction

• considered a better indicator of perfusion to vital organs SBP

• MAP = DBP + (pulse pressure/3)