Heart murmurs for beginners š„ š„ š„ Part 1:Aortic & Mitral stenosis, Aortic & mitral regurgitation.
Summary
TLDRIn this episode of the Learn Medicine Show, Dr. Coleman explores four common heart murmurs, explaining their causes and characteristics. He begins with the basics of heart sounds, then delves into systolic murmurs like aortic stenosis and mitral regurgitation, and diastolic murmurs including aortic regurgitation and mitral stenosis. Using the LUB-WOOSH-DUB schema and sound wave visuals, he helps listeners identify and understand these murmurs, providing insights into their clinical presentations and significance in cardiology.
Takeaways
- š The script is an educational video by Dr. Coleman on the Learn Medicine Show, focusing on heart murmurs and their identification in medical exams.
- š Basic heart sounds are represented as S1 and S2, with S1 sounding like 'LUB' and S2 like 'DUB', and the gaps between them are systole and diastole, respectively.
- š Heart murmurs are caused by disruptions in blood flow, resulting in turbulence that produces audible vibrations, which are documented in heart sound diagrams.
- š The first murmur discussed is aortic stenosis, characterized by an ejection systolic murmur with a crescendo-decrescendo sound wave, remembered by 'LUB-WOOSH-DUB'.
- š Aortic stenosis is due to the narrowing of the aortic valve, leading to turbulent blood flow and symptoms like angina, syncope, and dyspnea.
- š Mitral regurgitation is another systolic murmur, described as pan-systolic with a plateau waveform, so loud it can drown out S1 and S2, and is associated with conditions like mitral valve prolapse.
- š The murmur of mitral regurgitation is loudest at the heart's apex and can radiate to the left axilla, with clinical signs including a displaced apex beat and peripheral edema in severe cases.
- š Aortic regurgitation is a diastolic murmur heard during early diastole with a decrescendo waveform, often described as 'lub-tar', and can be caused by rheumatic fever or connective tissue diseases.
- š Aortic regurgitation's murmur is loudest at the left sternal edge, with clinical signs such as a collapsing pulse and a wide pulse pressure.
- š Mitral stenosis causes a mid-diastolic murmur with an opening snap and a decrescendo waveform, described as 'lub-di-der', and is commonly due to rheumatic fever.
- šµ The murmur of mitral stenosis is heard loudest at the apex, with clinical signs including malar flush and a tapping apex beat, and is associated with symptoms like dyspnea and palpitations.
Q & A
What is the basic unit of heart sounds in medical notes?
-The basic unit of heart sounds in medical notes is represented as S1, S2, and S1 again, which signifies one movement through the cardiac cycle.
What are the phases of the cardiac cycle referred to as systole and diastole?
-Systole refers to the gap between S1 and S2, which is the contraction phase of the heart. Diastole is the gap between S2 and the next S1, which is the relaxation phase of the heart.
How are the normal heart sounds S1 and S2 typically described?
-The normal S1 heart sound is often described as sounding like 'LUB,' while the S2 sound is described as 'DUB.'
What causes a heart murmur?
-Heart murmurs occur when there is a disruption of normal laminar blood flow, which can be caused by physiological or pathophysiological conditions, leading to turbulent flow and audible vibrations.
What type of murmur is associated with aortic stenosis?
-Aortic stenosis is associated with an ejection systolic murmur, characterized by a crescendo-decrescendo sound wave.
How is the murmur of aortic stenosis typically recognized and remembered?
-The murmur of aortic stenosis can be recognized and remembered using the schema LUB-WOOSH-DUB.
What are the common causes of aortic stenosis?
-The common causes of aortic stenosis include age-related calcification, congenital bicuspid valve, and rheumatic fever.
What is the characteristic murmur of mitral regurgitation?
-Mitral regurgitation is characterized by a pan-systolic murmur, which occurs throughout the entire duration of systole and has a plateau waveform.
How does mitral regurgitation affect the heart sounds?
-Mitral regurgitation causes a loud murmur that drowns out both S1 and S2, resulting in a burbling sound being heard instead.
What are the typical clinical presentations of aortic regurgitation?
-Aortic regurgitation may present with a smear in the clinical history and symptoms such as angina.
How is the murmur of mitral stenosis described and what does it indicate?
-The murmur of mitral stenosis is described as a mid-diastolic murmur with an opening snap and a decrescendo sound wave, indicating turbulent flow due to the narrowed mitral valve.
What are the common causes of mitral stenosis?
-The most common cause of mitral stenosis is rheumatic fever, with less common causes including congenital heart disease and systemic diseases such as lupus.
What clinical signs might be observed in a patient with mitral stenosis during examination?
-Clinical signs in a patient with mitral stenosis may include dyspnea, palpitations if atrial fibrillation is present, malar flush, and a tapping apex beat.
Outlines
š Introduction to Heart Murmurs and Sounds
Dr. Coleman introduces the topic of heart murmurs in the context of medical exams, emphasizing the importance of understanding basic heart sounds (S1 and S2) and the cardiac cycle phases (systole and diastole). He explains that murmurs arise from disruptions in blood flow, which can be due to physiological or pathophysiological conditions. The episode aims to familiarize viewers with normal heart sounds and then introduce murmurs, starting with systolic murmurs such as aortic stenosis, characterized by an ejection systolic murmur with a crescendo-decrescendo pattern.
š Aortic Stenosis and Mitral Regurgitation Murmurs
The script delves into the specifics of aortic stenosis, detailing its cause by the abnormal narrowing of the aortic valve and its clinical presentation, which includes angina, syncope, and dyspnea. The murmur is best heard in the aortic region and apex of the heart, with radiation towards the carotid arteries. It is then contrasted with mitral regurgitation, which presents a pan-systolic murmur that overrides S1 and S2, and is caused by the abnormal closure of the mitral valve. Clinical signs include dyspnea and fatigue, with the murmur loudest at the apex and radiating into the left axilla.
šµ Diastolic Murmurs: Aortic Regurgitation and Mitral Stenosis
The script moves on to diastolic murmurs, starting with aortic regurgitation, an early diastolic murmur caused by the incomplete closure of the aortic valve, allowing blood to regurgitate. This results in a decrescendo murmur best heard at the left sternal edge. Causes include rheumatic fever and connective tissue diseases. The second diastolic murmur discussed is from mitral stenosis, characterized by a mid-diastolic murmur with an opening snap due to the narrowed mitral valve. The murmur is heard loudest at the apex and radiates to the axilla, with causes ranging from rheumatic fever to congenital heart disease and systemic diseases like lupus.
š Conclusion and Engagement Invitation
Concluding the tutorial, Dr. Coleman invites viewers to engage with the content by liking, subscribing, sharing, and commenting their thoughts. He thanks the viewers for watching and hints at future episodes, promising more informative content in the Learn Medicine Show series.
Mindmap
Keywords
š”Heart Murmurs
š”Systole
š”Diastole
š”Aortic Stenosis
š”Mitral Regurgitation
š”Aortic Regurgitation
š”Mitral Stenosis
š”Ejection Systolic Murmur
š”Pan-Systolic Murmur
š”Decrescendo
š”Opening Snap
Highlights
Introduction to the Learn Medicine Show covering four heart murmurs in exams.
Explanation of basic heart sounds represented as S1, S2, and S1, detailing cardiac cycle phases.
Description of normal heart sounds 'LUB' for S1 and 'DUB' for S2.
Murmurs result from disruptions in blood flow, causing audible vibrations.
Introduction to systolic murmurs, starting with aortic stenosis.
Aortic stenosis produces an ejection systolic murmur with a crescendo-decrescendo sound wave.
Memory aid 'LUB-WOOSH-DUB' for recognizing aortic stenosis murmur.
Cause of aortic stenosis includes age-related calcification and congenital bicuspid valve.
Clinical signs of aortic stenosis include angina, syncope, and dyspnea.
Mitral regurgitation causes a pan-systolic murmur throughout systole with a plateau waveform.
Mitral regurgitation's murmur is so loud it can drown out S1 and S2.
Causes of mitral regurgitation include mitral valve prolapse and ischemic heart disease.
Clinical presentation of mitral regurgitation with dyspnea and fatigue.
Introduction to diastolic murmurs starting with aortic regurgitation.
Aortic regurgitation produces an early diastolic murmur with a decrescendo sound wave.
Causes of aortic regurgitation include rheumatic fever and connective tissue diseases.
Mitral stenosis creates a mid-diastolic murmur with an opening snap and decrescendo wave.
Mitral stenosis is commonly caused by rheumatic fever and presents with dyspnea.
Conclusion of the tutorial with an invitation for feedback and future episodes.
Transcripts
Hello, and welcome back to the LearnĀ Medicine Show. My name is Dr. Coleman,Ā Ā
and in this episode, we are covering fourĀ heart murmurs that typically come up in exams.Ā Ā
We're going to start by covering theĀ basic heart sounds, and then we'll addĀ Ā
in the murmurs so that you can getĀ to know them. Let's get into this.
Heart sounds can be graphically representedĀ in medical notes as S1, S2, and S1 again,Ā Ā
and this represents one movementĀ through the cardiac cycle.Ā Ā
The gap between S1 and S2 is known as systole, andĀ the gap between S2 and S1 is known as diastole.
Before we start adding in murmurs, I want you toĀ be familiar with the normal heart sound. So let'sĀ Ā
briefly cover these. The S1 heart sound usuallyĀ sounds like the word "LUB," and the S2 "DUB."
Let's add in the heart sounds briefly soĀ you can familiarise yourself with this.
Now let's turn our attention towardsĀ heart murmurs. Murmurs occur when thereĀ Ā
is a disruption of normal laminarĀ blood flow. The disruption can beĀ Ā
caused by physiological or pathophysiologicalĀ conditions, and this leads to turbulent flow,Ā Ā
which produces audible vibrations. TheseĀ audible vibrations vary in their volumeĀ Ā
based on the turbulent flow produced. TheseĀ pictorial representations of sound wavesĀ Ā
are what we use to document murmurs in our heartĀ sounds diagram. So let's get down to businessĀ Ā
now and start by looking at systolic murmurs.Ā Our first systolic murmur is aortic stenosis.Ā Ā
Aortic stenosis typically produces what'sĀ known as an ejection systolic murmur. ThisĀ Ā
is a murmur that occurs during systole and isĀ represented by a crescendo-decrescendo sound wave.Ā Ā
One strategy for recognising and rememberingĀ this murmur is using the schema LUB-WOOSH-DUB.Ā Ā
We'll now add in the murmur and heartĀ sounds so you can fully appreciate this.
This murmur is produced by theĀ abnormal narrowing of the aortic valve.
Let's take a closer look now at how this occurs.
Blood flows from the atria into the ventricles,Ā Ā
and the first heart sound is produced by theĀ closure of the tricuspid and mitral valves.Ā Ā
Systole then occurs. The ventriclesĀ contract, forcing blood through theĀ Ā
pulmonary and aortic valves. Narrowing ofĀ the aortic valve creates turbulent blood flowĀ Ā
through the aortic valve. It is this turbulentĀ blood flow that produces our crescendo-decrescendoĀ Ā
murmur. Finally, the S2 heart sound isĀ produced by the closure of the pulmonaryĀ Ā
and aortic valves. Let's now add in the murmurĀ so that you can appreciate this in real-time.
"Now that we've heard the murmur, let's take aĀ closer look at aortic stenosis. Aortic stenosisĀ Ā
is caused by abnormal narrowing of the aorticĀ valve, and the aetiology includes age-relatedĀ Ā
calcification, congenital bicuspid valve, andĀ rheumatic fever. The clinical history willĀ Ā
typically include angina, syncope, and dyspnea.Ā The murmur of aortic stenosis is characterised asĀ Ā
an ejection systolic murmur. The murmur is louderĀ in expiration and heard best in the aortic regionĀ Ā
and in the apex of the heart. The murmur radiatesĀ in the direction of blood flow towards the carotidĀ Ā
arteries. On clinical examination, you may alsoĀ find a slow-rising pulse and low blood pressure.
Let's turn our attention to mitral regurgitation.Ā Here we have another systolic murmur, but thisĀ Ā
time it's described as a pan-systolic murmur. AsĀ you may have already gathered from its name, thisĀ Ā
occurs throughout the entire duration of systole.Ā This murmur is represented visually with a plateauĀ Ā
waveform, meaning that the volume of the murmurĀ remains consistent throughout its duration.Ā Ā
The murmur is so loud thatĀ it drowns out S1 and S2,Ā Ā
and instead, a burbling sound is heard. Let'sĀ pause and take a quick listen to this now.
This pan-systolic murmur is caused by abnormalĀ closure of the mitral valve. Let's take a closerĀ Ā
look to get a better understanding of this. So,Ā blood flows from the atria through the mitralĀ Ā
and tricuspid valves into the ventricles, and atĀ this point, the mitral and tricuspid valves wouldĀ Ā
normally close to produce our S1 heart sound. ButĀ instead of this, the mitral valve prolapses intoĀ Ā
the left atrium, and this causes turbulent bloodĀ flow, which generates a murmur that drowns out theĀ Ā
S1 and the S2 heart sound. Let's add in the murmurĀ so that you can appreciate this in real-time.
Mitral regurgitation is caused by abnormalĀ closure of the mitral valve, and this canĀ Ā
be due to a number of reasons, including mitralĀ prolapse, ischemic heart disease, rheumatic fever,Ā Ā
and infective endocarditis. The clinical historyĀ will usually include dyspnea and fatigue."
Mitral regurgitation produces a pan-systolicĀ murmur that is loudest at the apex of the heartĀ Ā
and radiates into the left axilla. OtherĀ signs you may see on examination includeĀ Ā
a displaced apex beat and a parasternal heave.Ā In severe cases, you may see peripheral oedema.Ā Ā
Let's now turn our attention towards diastolicĀ murmurs, and we're going to cover two.Ā Ā
The first one is aortic regurgitation.Ā This murmur is heard during diastoleĀ Ā
and is considered an early diastolic murmur. ItĀ is represented pictorially with a decrescendoĀ Ā
sound wave. The words "lub-tar" can beĀ used to describe how this murmur sounds.Ā Ā
Let's listen to this in real timeĀ so you can appreciate this better.
Aortic regurgitation is caused byĀ abnormal closure of the aortic valve.Ā Ā
Let's take a closer look at this using animation.Ā The first heart sound is produced by the closureĀ Ā
of the tricuspid and mitral valves. SystoleĀ occurs when the ventricles contract,Ā Ā
forcing blood through the pulmonary andĀ aortic valves. Incomplete closure of theĀ Ā
aortic valve allows blood to regurgitate backĀ into the ventricle. This turbulent blood flowĀ Ā
causes our diastolic murmur. Let's now add in theĀ heart sounds and watch this occur in real time.
Aortic regurgitation is caused byĀ abnormal closure of the aortic valve.Ā Ā
This may occur due to rheumatic fever butĀ is also seen in connective tissue diseasesĀ Ā
such as Marfan's syndrome and rheumatologicalĀ conditions like rheumatoid arthritis and lupus.Ā Ā
Another possible cause is infectiveĀ endocarditis. The clinical historyĀ Ā
will usually present with the smear, and theĀ patient may present with symptoms of angina.Ā Ā
Aortic regurgitation produces an early diastolicĀ murmur that is her loudest at the left sternalĀ Ā
edge and radiates towards the apex of the heart.Ā Other signs you might see on clinical examinationĀ Ā
include a collapsing pulse, a wide pulseĀ pressure, and a displaced apex beat.Ā Ā
Now let's turn our attention to our finalĀ murmur, the murmur of mitral stenosis.
Mitral stenosis produces a diastolic murmur thatĀ is described as a mid-diastolic murmur. It hasĀ Ā
an opening snap and a decrescendo sound wave,Ā meaning it starts loud and then becomes quieter.Ā Ā
To help recognise this mid-diastolic murmur,Ā the terms "lub-di-der" are often used. Let'sĀ Ā
pause for a moment to listen to this in real-timeĀ so that you can appreciate this better. [Music]
Mitral stenosis, as its name suggests, is causedĀ by abnormal narrowing of the mitral valve.Ā Ā
Let's now take a look at an animation toĀ see how this narrowing causes the murmur.
The S1 heart sound is produced by the closureĀ of the tricuspid and mitral valves. SystoleĀ Ā
then occurs, where ventricular contraction pushesĀ blood through the pulmonary and aortic valves.Ā Ā
Closure of the pulmonary and aorticĀ valves produces the S2 heart sound.Ā Ā
But milliseconds after this, accumulated blood inĀ the left atrium increases the left atrial pressureĀ Ā
to a point where the stiffened mitral valve isĀ forced open, and this produces an opening snap.Ā Ā
Almost immediately after S2, blood rushes throughĀ the narrowed mitral valve, producing turbulentĀ Ā
flow, and this is audible vibrations from theseĀ that produce our mid-diastolic decrescendo murmur.Ā Ā
Let's take a moment now to add in the murmurĀ so you can appreciate it in real-time. [Music]
Mitral stenosis is an abnormalĀ narrowing of the mitral valve.Ā Ā
The most common cause of this is rheumatic fever,Ā and less common causes include congenital heartĀ Ā
disease and systemic diseases such as lupus. TheĀ clinical history typically presents with dyspneaĀ Ā
and palpitations if atrial fibrillation isĀ present. Mitral stenosis produces a mid-diastolicĀ Ā
murmur with an opening snap that is heard loudestĀ at the apex and radiates to the axilla. OtherĀ Ā
signs that you may see on clinical examinationĀ include malar flush and a tapping apex beat.Ā Ā
And that brings us to the end of theĀ tutorial. So, if you enjoyed this, pleaseĀ Ā
like and subscribe, share with your friends, andĀ let me know what you think in the comments below.Ā Ā
Thanks for dropping by. I'll see you again soon.
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