9. Cardiovascular system

Question 1

how many chambers in the heart? what are they?

Answer 1

4….left atrium, left ventricle, right atrium, right ventricle

Question 2

how many valves? what are they?

Answer 2

tricuspid, pulmonic, mitral, aortic

Question 3

what happen to aortic valve with bacterial endocarditis?

Answer 3

fatal infection of inner lining of heart caused by bacteria entering blood and to the heart

Question 4

Where is sinoatrial node located? what is it? what does it do?

Answer 4

near the opening of superior vena cava on superior lateral wall of right atrium; it is an area of sub-specialized cells, also known as pacemaker, that spread impulse to the rest of the right and left atria through preferential conductive pathways

Question 5

Where is the atrioventricular node located? what is it? what does it do?

Answer 5

medial and posterior to tricuspid valve…an area of sub-specialised cells that spread impulse from atria to ventricles

Question 6

what is the relationship between cardiac output, stroke volume and heart rate? what do they tell

Answer 6

CO = SV x HR; CO = total volume pumped out of heart per minute; SV = volume out of heart per beat; HR = heart beats per minute

Question 7

what is the relationship between cardiac output, blood pressure and total peripheral resistance? what drugs can help to lower BP?

Answer 7

CO x TPR = BP; Beta-blockers lower heart rate, diuretics lower stroke volume, calcium channel blocker lower arterial pressure

Question 8

what is the other name for preload? what does it mean?

Answer 8

LVEDP (Left ventricular end-diastolic pressure); the amount of ventricular stretch at the end of diastole

Question 9

what is the other name for afterload? what does it mean?

Answer 9

SVP (systemic vascular resistance); the amount of resistance the heart must overcome to open the aortic valve and push the blood volume out into the systemic circulation

Question 10

what is the calculation of cardiac index?

Answer 10

cardiac output divided by body surface area

Question 11

in ECG (electrocardiogram), what is P wave, QRS complex and T wave?

Answer 11

P wave = atrial depolarization
QRS complex = ventricular depolarization
T wave = ventricular repolarization

Question 12

how to work out ejection fraction?

Answer 12

EF (%) = SV / EDV x 100; SV = stroke volume; EDV = end-diastolic volume

Question 13

how to tell if ejection fraction is normal?

Answer 13

left ventricular walls are coming close together during systole and anterior mitral valve leaflet is almost touching the septum during diastole

Question 14

what is VO2 max (maximal oxygen uptake)? why is it important?

Answer 14

the maximum rate of oxygen your body is able to use during exercise; the higher it is, the more efficiently your body can use that oxygen to generate max amount of ATP energy

Question 15

how much lower is a woman’s VO2 max compared to a man? why?

Answer 15

20% lower; due to body size, composition, blood volume and hemoglobin content

Question 16

how to calculate VO2 max? how does each component tell?

Answer 16

cardiac output x systemic arteriovenous oxygen difference at peak exercise; CO = amount of blood pumped out of the heart per minute; SAOD = the amount of oxygen taken up from the blood by the tissues

Question 17

which had significantly lower VO2 max? african or european women?

Answer 17

african

Question 18

systolic/diastolic blood pressure tends to increase during incremental exercise. systolic/diastolic is largely determined by overall peripheral resistance and tends to stay relatively constant during incremental exercise

Answer 18

systolic; diastolic

Question 19

why diastolic pressure may even fall slightly at higher exercise intensities?

Answer 19

increase in muscle blood flow

Question 20

systolic, diastolic, mean arterial pressure and heart rate….which will rise in response to resistance training?

Answer 20

all

Question 21

sudden cardiac death occurs at a much lower rate compared with traditional estimates. T or F

Answer 21

F; higher

Question 22

increased incidence of atrial fibrillation in athletes. T or F

Answer 22

T

Question 23

what gender, what race and what sport are recognized to have higher risk for sudden cardiac disease?

Answer 23

male, black, basketball

Question 24

what might contribute to heart disease/failure in athletes?

Answer 24

supply/demand mismatch, pro-arrhythmogenesis, micro-scarring of heart, doping (lead to cardiac cell damage), massive release of catecholamines (eg dopamine and adrenaline) into circulation (hormones produced by adrenal glands in response to emotional or physical stress which exacerbate myocardial dysfunction and cause heart failure), coronary artery calcification (associated by high level of activity)

Question 25

for age >= 35 and <35, what heart diseases are more common?

Answer 25

> =35, ischemic heart disease/acute coronary syndrome

<35, hypertrophic cardiomyopathy

Question 26

what can hypertrophic cardiomyopathy cause?

Answer 26

myocyte disarray and increased fibrosis create area of conduction block and predispose to reentry arrhythmias

Question 27

what is arrhythmogenic right ventricular cardiomyopathy (ARVC)? what is the characteristic? what is the best way to diagnose? what to do if diagnosed?

Answer 27

inherited cardiomyopathy characterized by ventricular arrhythmias; characteristic = myocyte loss with fibrofatty replacement; cardiac MRI is the most sensitive diagnostic imaging modality; placement of implantable cardioverter defibrillator based on estimate risk of SCD

Question 28

what are the symptoms of heart failure?

Answer 28

dyspnoea (difficult breathing), orthopnoea (shortness of breath when lying flat), lower limb swelling aka edema

Question 29

what are the downsides of beta blocker?

Answer 29

prevent increase in heart rate that typically occurs with exercise, impair exercise performance

Question 30

for patients after myocardial infarction, exercise program should be recommended with heart rate around what levels?

Answer 30

HR<120/min or resting HR+20/min

Question 31

resistance training is included in cardiac rehabilitation program for post MI patients and patients with chronic heart failure. T or F

Answer 31

T