CVS Flashcards
Where is apex of the heart found?
5th intercostal space on the left
What is the transverse pericardial sinus?
Behind the artery and pulmonary trunk, you can insert a scalpel or finger. This is often used in surgery to clamp the aorta shut
What are the names of the valances on the right of the heart?
Tricuspid and pulmonary
What are the names of the valves on the left of the heart?
Mitral and aortic
Why do valves open and close?
Pressure differences on either side of the valve
What prevents inversion of valves during systole?
During systole there is high pressure which would cause inversion of the mitral and tricuspid valves if they were not attached to papillary muscles via chordate tendonae
What are the three layers of the pericardium?
Outer fibrous layer
Parietal serous membrane
Visceral serous membrane
What is cardiac tamponade and how is it treated?
Cardiac tamponade= the pericardial sac filling with fluid meaning that the heart is compressed as the fibrous layer means that the heart cannot expand.
This is treated by pericardiocentesis which is inserting a needle to remove this fluid
What do regurgitations mean?
That valves are incompetent and don’t close properly so blood moves back giving turbulent blood flow, which is heard as a murmur.
What is mitral regurgitation
A murmur which occurs in systole after the mitral valve closes and when the atria contracts blood moves back to the atria causing turbulent flow
What is aortic regurgitation?
This occurs during diastole, when the valve shuts the blood from the aorta fall back into the ventricle causing turbulent flow
What is mitral stenosis?
It is heard in diastole when the valance is meant to be opened but does not open fully the blood flows through at a higher pressure
What is aortic stenosis?
It is heard in systole as the valves are meant to open then but as it doesn’t fully open blood flows through at high pressure
What is S3?
A third heart sound, which is heard in early diastole, which is normal in children and athletes but a sign of heart failure in adults, this is not valvular origin
When do you hear right sided heart sounds?
Inspiration
Because there is lower pressure in thoracic cavityso more blood goes to lungs, so increased blood flow in RHS of the heart.
What are best heard during expiration?
Right sided heart murmurs as the diaphragm contracts forcing blood out the lungs which then travels to the left hand side
Why would you ask a patient to hold their breathe when listening to chest sounds?
So you can definitely hear heart sounds but not lung sounds- a wheeze may sound like a heart sound
Where do you listen for heart sounds?
All- aortic valve(2nd-3rd intercostal space on RHS)
Prostitutes- pulmonary valve (2nd-3rd LHS intercostal space)
Take- tricuspid valve ( left sternal border)
Money- mitral valve- apex of heart
What are the pressures of the different areas in the heart?
RA= 0-4 RV= 25/4 PA= 25/10 LA= 5 LV= 120/4 A= 120/80
What is perfusion rate?
The rate of blood flow
What is cardiac output for the average 70 kg male?
5l per minute
But can increase to 25l per minute
What are capacitance vessels?
They can increase the volume of blood that they hold without increasing pressure
What are resistance vessels?
Arterioles can contract to the restrict blood flow
Stroke volume equation
Stroke volume= volume of blood pumped at each beat (70ml) at heart rate of 70bpm, this gives 5 litres of blood per minute
Cardiac output equation
Cardiac output= stroke volume x heart rate
What is afterload?
The pressure of the wall of the left ventricle during ejection
What is preload?
The amount of the ventricles are stretched in diastole
Why do MIs occur?
Cardiac arteries are end arteries, so when they are blocked there will be a lack of oxygen to the left ventricle. Diffusion distance is too great so cannot supply.
What is a coronary sinus?
The venous drainage of the heart to the RA, through the coronary osteomyelitis
What give the greatest resistance?
Arterioles amd precapillary sphincters can restrict flow. Total peripheral resistance increases arteriole pressure but decreases venous pressure
What is the Frank starling law of the heart?
The more that the heart fills the harder it will contract the bigger the stroke volume. An increase in venous pressure will fill the heart morebut how much the ventricles fill depends on their compliance. A normal heart will fill to a volume of 120 ml and a pressure 10mmHg.
What are causes of aortic stenosis?
Degenerative ( fibrosis, calcification)
Congenital (bicuspid form)
Chronic rheumatic fever
Old age
What does aortic stenosis sound like?
Crescendo decrescendo murmur
Causes of mitral valve stenosis
Rheumatic fever
Fusion of valvular leaflets
Causes of aortic regurgitation
Aortic root dilation
Valvular damage