hi this is tom from zero define is calm in this video I'm going to be going through heart murmurs you can find written notes on this topic at zero define is calm or in the cardiology section of the zero to finals Medicine book let's jump straight in first of all we need to talk about the normal heart sounds and we refer to these as s1 and s2 the first heart sound or s1 is caused by the closing of the atrioventricular valves now this is the tricuspid and the mitral valve and this happens at the start of systolic contraction of the ventricles so as the ventricles try to push blood out of the heart the valves between the atria and the ventricles need to closed to prevent blood from flowing back into the atria the second heart sound or s2 is caused by the closing of the semilunar valves and this is the pulmonary and the aortic valves once the systolic contraction is complete then this is to prevent blood flowing back from the pulmonary arteries or the aorta into the ventricles now this s1 and s2 can be heard during auscultation of the heart sounds as a lub dub sound so let's have a listen to that now [Music] next let's move on to a third heart sound and we call this s3 and this is heard roughly 0.1 seconds after the second heart sound it's quite subtle so you can only just about hear an extra sound after the second heart sound let's listen to an example what causes this sound is I think of it as rapid ventricular filling causing the chordae tendineae or the tendons inside the heart to pull to their full length and twang like a guitar string this can be normal in young patients you know 15 to 40 years old because the heart functions so well that the ventricles easily and rapidly fill with blood but in older patients it can indicate heart failure as the ventricles and the cord is stiff and weak so they reached their limit much quicker than normal so the way I picture this is you know an older patient bending over and their tight hamstrings very quickly and sharply tightening as they reach the limit of their flexibility this often sounds a bit like lub d dub lub d dub so let's have a listen again to what that sounds like and see whether you can distinguish a third heart sound after the second heart sound [Music] next let's talk about the fourth heart sound and we call this s4 and this is heard directly before s 1 and s 4 is always abnormal and it's relatively rare to hear what this indicates is a really stiff or hypertrophic ventricle and the sound is caused by turbulent flow from an atria that's contracting against a ventricle that is non-compliant or doesn't want to fill with blood so the ventricles really stiff the atria is trying to force blood in and this is causing a turbulent flow and what it sounds like is little of dub so let's have a listen and see if you can distinguish that fourth heart sound just before the first one now let's talk about heart murmurs so when you're listening to murmurs you want to auscultate with the bell of your stethoscope to hear low pitched sounds and the diaphragm of your stethoscope to hear high pitched sounds and you can think of this as a a child's high pitched scream from their diaphragm or a church bell giving a deep bong you want to listen over the four different valve areas in term four murmurs so the pulmonary area is at the second intercostal space on the left sternal border the aortic area is on the second intercostal space on the right sternal border the tricuspid area is in the fifth intercostal space on the left sternal border and the mitral area is on the fifth intercostal space in the midclavicular line and this is the apex area you can also listen at what's called herbs point and this is the third intercostal space on the left sternal border and this is the best place for listening to the heart sound so s 1 s 2 s 3 and s 4 there's a couple of special maneuvers you can use to look extra clever in your skis this would be to put the page on the left hand side or roll them over onto their left hand side to listen to mitral stenosis or you can sit the patient up lean them forward and ask them to take a deep breath out and hold and this helps you to hear a or tick regurgitation there's a few features of a moment that you can assess and we use a mnemonic called script so s is for site meaning where is the murmur loudest c is for character so is it soft blowing crescendo meaning getting louder decrescendo meaning getting quieter or crescendo decrescendo meaning getting louder and then quieter R is for radiation so can you hear this murmur going to the carotid as you would in a text enosis or going to the left axilla as you would in mitral regurgitation I is for intensity so what grade is the murmur P is for pitch is it high-pitched or is it low and grumbling and pitch basically indicates the velocity of the murmur and then finally T is for timing so is it systolic or diastolic so I go through that mnemonic again script meaning sight character radiation intensity pitch and timing let's talk about the grade of murmurs so grading a murmur is quite subjective but it can be helpful in assessing the severity of the defect and it will also make you sound clever when you grade a murmur in your Aki's if in doubt it's probably grade 2 or 3 so grade 1 is difficult to hear grade 2 is quiet grade 3 is easy to hear grade 4 is easy to hear and with a palpable thrill so when you put your hand on the chest you can feel the murmur grade 5 is when you can hear the murmur with your stethoscope barely touching their chest and grade 6 is when you can hear the murmur with your stethoscope actually off to the chest just holding it nearby let's talk about hypertrophy and dilatation of the heart fabula heart disease can cause hypertrophy which is where the heart muscle thickens outwards and into the chamber of the heart or it can lead to dilatation which is where the heart muscle gets thinner and expands think of it blowing up like a balloon and this happens in different heart areas depending on where the pathology is when the heart muscle is pushing against a stenotic valve it has to work a lot harder to try to get the blood to go through that valve so this what results in hypertrophy so if you have mitral stenosis the left atrium is pushing really hard against that mitral valve so you get left atrial hypertrophy when you have a or ticks to notice that left ventricle is pushing really hard against that IATA Crowl so you end up with left ventricular hypertrophy when you have a leaky valve that allows blood to flow back into the chamber it stretches the muscle and results in dilatation so when you have mitral regurgitation there's blood flowing back through the mitral valve into the left atrium so you end up with left atrial dilatation when you have a or tick regurgitation there's blood flowing back from the aorta into the left ventricle so you end up with left ventricular dilatation let's talk about our first murmur so we'll start with mitral stenosis and this is where the mitral valve becomes narrowed and makes it difficult for the left atrium to push blood through to the ventricle it's caused by two things rheumatic heart disease and infective endocarditis and it causes a mid diastolic low-pitched rumbling murmur due to the low velocity of the blood flow because the blood is flowing through such a narrow area it flows only very slowly and rumbles its way through you also get a loud s1 due to the thick valves that require a large systolic force to shut once the systolic force reaches a certain threshold the valve shuts very suddenly so what you end up with is this loud love and then a dub door so let's have a listen to it so did you catch that firt that loud first heart sound and then that second heart sound followed by that durer rumbling murmur let's have one more listen a few other features of mitral stenosis is that you'll be able to palpate a tapping apex beat due to the mild s1 and it's also associated with a mallow flush this is a flushing of the patient's cheeks due to back pressure of blood into the pulmonary system causing a rise in co2 and phaser dilation it's also quite commonly associated with atrial fibrillation and this is due to the left left atrium struggling to push blood through a stenotic valve and causing disruption to the electrical signals and resulting fibrillation of the atria the next moment to talk about is mitral regurgitation mitral regurgitation is when an incompetent mitral valve allows blood to flow back through during systolic contraction in the left ventricle because during systole there's blood flowing backwards through this valve you end up with something called a pansystolic murmur meaning the murmur is present throughout the systolic period and it causes a high-pitched whistling murmur due to the high velocity of blood flow through the leaky valve this murmur sounds a bit like burrr burrr because it happens the entire way through systole let's have a listen [Music] you can hear that the murmur is present throughout the whole of systole between s1 and s2 and this is what we call a pansystolic murmur let's have a listen one more time when you hear this murmur listen at the exilic as it tends to radiate to the left axilla it's also associated with congestive cardiac failure because the leaking valve causes a reduced ejection fraction and causes a backlog of blood that is waiting to pass through the left side of the heart therefore you might also hear a third heart sound when listening to this murmur if there's heart failure present so what causes mitral regurgitation well the most common cause is idiopathic weakening of the valve with age so as the patient ages their valve just naturally gets a bit weaker it can also be associated with ischemic heart disease infective endocarditis rheumatic heart disease or connective tissue disorders such as our last Danlos syndrome or Marfan syndrome next let's talk about a otic stenosis so a otic stenosis is probably the most common valve disease that you'll encounter it essentially means a narrow a otic valve and so as blood flows through this narrow Altec valve during systolic contraction there will be turbulence of blood flow so this causes an ejection systolic murmur and this is a murmur that occurs while blood is being ejected from the left ventricle and it's a high-pitched murmur because of the high velocity of systolic contraction it's also what we call a crescendo decrescendo murmur as it gets louder and then quieter due to the speed of blood flow during the different times of systolic contraction so you'll hear the first heart sound in the second heart sound and then between those hearts you'll hear a systolic murmur that gets louder and then quieter it causes a murmur that sounds a bit like burrow dub so if you can hear it there's a few other signs that you'll find in a patient when they or texture notice the murmur will radiate up to the carotid as the turbulence continues up into the neck so you can put your stethoscope over the carotid arteries and listen for a murmur there it's also associated with a slow rising pulse and a narrow pulse pressure so when you palpate the pulse it'll be slow to rise and when you do the blood pressure the systolic and diastolic pressure will be quite close to each other patients with aortic stenosis also have symptoms of exertion or syncope but this is lightheadedness and fainting when exercising and this is due to difficulty maintaining good flow of blood to the brain through that narrow valve the most common cause of aortic stenosis is just idiopathic age-related calcification of that valve it's just the valve becoming older with age and calcifying becoming hardened and narrowed it can also be caused by rheumatic heart disease the final murmur that we're going to talk about is a otic regurgitation chaotic regurgitation is basically where the aortic valve becomes incompetent and blood is able to flow back from aorta into the left ventricle because blood flow back through this valve will happen during diastole chaotic regurgitation causes an early diastolic and quite a soft murmur so it sounds a bit like lub tah see if you can hear it on this example don't worry if you can't hear it it's a really subtle murmur that even cardiologists can miss so have another listen just see if you can hear it after the second heart sound a gentle soft early diastolic murmur a otic regurgitation is associated with something called Corrigan's pulse and a Corrigan's pulse which is also called a collapsing pulse is when it rapidly appears and then disappears as the blood is pumped out of the ventricles and then immediately starts flowing back through the aortic valve into the ventricles they ought to agree Gurjit ation often results in heart failure and this is due to the back pressure of blood waiting to get through the left-hand side of the heart it can also cause something called an Austin Flint murmur and this is worth knowing about just for your exams it's heard at the apex and is an early diastolic rumbling murmur and this is caused by blood flowing back through the aortic valve and over the mitral valve causing the mitral valve leaflets to vibrate this is very difficult to hear in real life a otic regurgitation is caused again by idiopathic age-related weakness but it's also worth remembering that it can be caused by connective tissue disorders such as Earl lost Danlos syndrome or Marfan syndrome where patients with these conditions have difficulty in creating strong connective tissues leading to weakness of the valve leaflets so thanks for watching I hope you found this video helpful if you did don't forget there's plenty of other resources on the zero to finals website including loads and loads of notes on various different topics that you might cover in medical school with specially made illustrations there's also a whole test section where you can find loads of questions to test your knowledge and see where you're up to in preparation for your exams there's also a blog where I share a lot of my ideas about a career in medicine and tips on how to have success as a doctor and if you want to help me out on YouTube you can always leave me a thumbs up give me a comment or even subscribe to the channel so that you can find out when the next videos are coming out so I'll see you again soon