9. Cardiovascular system Flashcards
how many chambers in the heart? what are they?
4….left atrium, left ventricle, right atrium, right ventricle
how many valves? what are they?
tricuspid, pulmonic, mitral, aortic
what happen to aortic valve with bacterial endocarditis?
fatal infection of inner lining of heart caused by bacteria entering blood and to the heart
Where is sinoatrial node located? what is it? what does it do?
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
Where is the atrioventricular node located? what is it? what does it do?
medial and posterior to tricuspid valve…an area of sub-specialised cells that spread impulse from atria to ventricles
what is the relationship between cardiac output, stroke volume and heart rate? what do they tell
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
what is the relationship between cardiac output, blood pressure and total peripheral resistance? what drugs can help to lower BP?
CO x TPR = BP; Beta-blockers lower heart rate, diuretics lower stroke volume, calcium channel blocker lower arterial pressure
what is the other name for preload? what does it mean?
LVEDP (Left ventricular end-diastolic pressure); the amount of ventricular stretch at the end of diastole
what is the other name for afterload? what does it mean?
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
what is the calculation of cardiac index?
cardiac output divided by body surface area
in ECG (electrocardiogram), what is P wave, QRS complex and T wave?
P wave = atrial depolarization
QRS complex = ventricular depolarization
T wave = ventricular repolarization
how to work out ejection fraction?
EF (%) = SV / EDV x 100; SV = stroke volume; EDV = end-diastolic volume
how to tell if ejection fraction is normal?
left ventricular walls are coming close together during systole and anterior mitral valve leaflet is almost touching the septum during diastole
what is VO2 max (maximal oxygen uptake)? why is it important?
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
how much lower is a woman’s VO2 max compared to a man? why?
20% lower; due to body size, composition, blood volume and hemoglobin content
how to calculate VO2 max? how does each component tell?
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
which had significantly lower VO2 max? african or european women?
african
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
systolic; diastolic
why diastolic pressure may even fall slightly at higher exercise intensities?
increase in muscle blood flow
systolic, diastolic, mean arterial pressure and heart rate….which will rise in response to resistance training?
all
sudden cardiac death occurs at a much lower rate compared with traditional estimates. T or F
F; higher
increased incidence of atrial fibrillation in athletes. T or F
T
what gender, what race and what sport are recognized to have higher risk for sudden cardiac disease?
male, black, basketball
what might contribute to heart disease/failure in athletes?
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)
for age >= 35 and <35, what heart diseases are more common?
> =35, ischemic heart disease/acute coronary syndrome
<35, hypertrophic cardiomyopathy
what can hypertrophic cardiomyopathy cause?
myocyte disarray and increased fibrosis create area of conduction block and predispose to reentry arrhythmias
what is arrhythmogenic right ventricular cardiomyopathy (ARVC)? what is the characteristic? what is the best way to diagnose? what to do if diagnosed?
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
what are the symptoms of heart failure?
dyspnoea (difficult breathing), orthopnoea (shortness of breath when lying flat), lower limb swelling aka edema
what are the downsides of beta blocker?
prevent increase in heart rate that typically occurs with exercise, impair exercise performance
for patients after myocardial infarction, exercise program should be recommended with heart rate around what levels?
HR<120/min or resting HR+20/min
resistance training is included in cardiac rehabilitation program for post MI patients and patients with chronic heart failure. T or F
T
