Cardiac Physiology

Question 1

With activity what happens to HR, SV, CO, SBP, DBP?

Answer 1

HR - increase

SV - increase

CO - increase

SBP - increase

DBP - same

Question 2

What is the equation for MABP and what is the significance of MABP (MAP) ?

Answer 2

MAP= DBP + 1/3(PP)
PP= SBP-DBP

-average arterial pressure during a single arterial cycle

-represents organ perfusion pressure

-generally, MAP > 70 mmHg is enough to sustain organ perfusion

NORMAL: 65-110 mmHg

** if MAP falls significantly below 60 mmHg for prolonged period –> tissues won’t get enough blood flow, and organ ischemia may occur

Question 3

What happens to heart rate with increasing ex. intensity?

Answer 3

heart rate increases with exercise until it plateaus and reaches HR max

Question 4

What can happen with heart rate with training?

Answer 4

at a given workload, someone’s heart rate with training will be less

Question 5

What happens to CO as ex. workload increases?

Answer 5

cardiac output increases and then plateaus

CO= SV x HR

-stroke volume increases then plateaus

-heart rate increases more linearly with increases in exercise workload

Question 6

What kind of relationship do heart rate and vo2 share?

Answer 6

a linear relationshihp

Question 7

What are some pathologies that affect the heart?

Answer 7

CAD:
-stable angina: can be provoked by exercise; can happen regularly after meal, during times of stress
-unstable angina: can happen at rest; more serious

-angina causes myocardial ischemia and can cause dysrhythmia

-long lasting anginal attack may prelude MI

-Women present with atypical chest
discomfort more frequently than men that may include neck/shoulder pain, nausea, vomiting, fatigue, dyspnea with or without chest discomfort

-ALWAYS DOCUMENT THIS

Question 8

DOUBLE PRODUCT- relation to anginal threshold

Answer 8

RPP= HR x SBP = MVO2 X 10^3

-less than 5% of patients can change their anginal threshold

-what can you do to increase anginal threshold/performance?
–> lower HR and SBP by slowly increasing the work and intensity of exercise,
–> can shift the curve so they hit anginal threshold later on

Question 9

Angina Scale

Answer 9

1+ light, barely noticeable
2+ moderate, bothersome
3+ severe, very uncomfortable–> STOP EX
4+ most severe pain ever experienced

Question 10

RISKS OF EXERCISE WITH A-FIB

Answer 10

-greater risk for throwing clots (often on Coumadin)

> 50% of adults >65 years have dysrhythmias

-pulse rate does not work with pt with dysrhythima (ex: pulse ox)

uncontrolled a-fib (> 100 bpm)

-controlled a-fib: less than or equal to 100 bpm

Question 11

What type of cardiomyopathy can lead to CHF?

Answer 11

dilated CM

enlarged+ stretched heart muscle–> weakness of heart–> CHF

CHF: Congestive heart failure (CHF) is a serious condition that occurs when the heart can’t pump enough blood to meet the body’s needs.

Question 12

Signs of congestive HF

Answer 12

SIGNS: edema, difference in breath, weight gain, fatigue, dysrhythmias

PLAN: rest, diet, activity modification

Question 13

What is the significance of the RPP?

Answer 13

Both heart rate and blood pressure are incorporated in the rate pressure product (RPP), an indirect index of myocardial oxygen consumption that predicts cardiac function, morbidity, and mortality in patients with cardiovascular disease.

-rate pressure product is equal to VO2

Question 14

What is a specific differential assessment of cardiac problems?

Answer 14

EKG rate/EKG rhythm and ST-level

Question 15

What is the target Borg Dyspnea scale rating for pulmonary rehab?

Answer 15

4-6/10 or 12-14/20

Question 16

How to rate an individual’s dyspnea level based on their ability to count to 15:

Answer 16

Level 0 - on a single breath

Level 1 - requires two breaths

Level 2 - requires three breaths

Level 3 - requires four breaths

Level 4 - unable to count

** objective way to quantify dyspnea