Heart murmurs for beginners 🔥 🔥 🔥 Part 1:Aortic & Mitral stenosis, Aortic & mitral regurgitation.

Summary

In 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

• 📚 The script is an educational video by Dr. Coleman on the Learn Medicine Show, focusing on heart murmurs and their identification in medical exams.
• 💓 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.
• 🔍 Heart murmurs are caused by disruptions in blood flow, resulting in turbulence that produces audible vibrations, which are documented in heart sound diagrams.
• 🚀 The first murmur discussed is aortic stenosis, characterized by an ejection systolic murmur with a crescendo-decrescendo sound wave, remembered by 'LUB-WOOSH-DUB'.
• 🌊 Aortic stenosis is due to the narrowing of the aortic valve, leading to turbulent blood flow and symptoms like angina, syncope, and dyspnea.
• 📉 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.
• 🌐 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.
• 🔁 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.
• 📍 Aortic regurgitation's murmur is loudest at the left sternal edge, with clinical signs such as a collapsing pulse and a wide pulse pressure.
• 📉 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.
• 🎵 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

00:00

📚 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.

05:05

🔍 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.

10:05

🎵 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.

👋 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.

Keywords

💡Heart Murmurs

Heart murmurs are abnormal sounds heard during the heartbeat cycle, caused by turbulent blood flow through the heart's chambers or valves. In the video, heart murmurs are the central theme, with four specific types being discussed: aortic stenosis, mitral regurgitation, aortic regurgitation, and mitral stenosis. These murmurs are characterized by their timing, quality, and location, and are significant in diagnosing heart conditions.

💡Systole

Systole refers to the phase of the cardiac cycle when the heart muscle contracts, pumping blood out of the ventricles. In the script, it is mentioned that the gap between the first (S1) and second (S2) heart sounds represents systole. Systolic murmurs, such as those in aortic stenosis and mitral regurgitation, occur during this phase, indicating issues with the heart's pumping action.

💡Diastole

Diastole is the phase of the cardiac cycle when the heart is relaxed and filling with blood. The gap between S2 and the next S1 is known as diastole. Diastolic murmurs, such as those in aortic regurgitation and mitral stenosis, are heard during this phase, suggesting problems with the heart's filling or the closure of its valves.

💡Aortic Stenosis

Aortic stenosis is a condition characterized by the narrowing of the aortic valve, which restricts blood flow from the left ventricle to the aorta. The video describes its associated murmur as an ejection systolic murmur, which is heard best in the aortic region and apex of the heart, and radiates towards the carotid arteries.

💡Mitral Regurgitation

Mitral regurgitation occurs when the mitral valve does not close properly, allowing blood to flow backward from the left ventricle into the left atrium. The script mentions this condition produces a pan-systolic murmur, which is loud enough to obscure the normal heart sounds and is associated with symptoms like dyspnea and fatigue.

💡Aortic Regurgitation

Aortic regurgitation is a condition where the aortic valve does not close completely, leading to blood leaking back into the left ventricle during diastole. The video script describes the murmur as an early diastolic murmur with a decrescendo pattern, heard best at the left sternal edge.

💡Mitral Stenosis

Mitral stenosis is caused by the narrowing of the mitral valve opening, which obstructs blood flow from the left atrium to the left ventricle. The video explains that this condition results in a mid-diastolic murmur with an opening snap, which is heard loudest at the apex and radiates to the axilla.

💡Ejection Systolic Murmur

An ejection systolic murmur is a type of heart murmur that occurs during systole and is characterized by a crescendo-decrescendo sound wave pattern. The script uses the term to describe the murmur of aortic stenosis, which starts softly, increases in intensity, and then decreases, correlating with the force of blood being ejected through the narrowed aortic valve.

💡Pan-Systolic Murmur

A pan-systolic murmur is heard throughout the entire systolic phase of the cardiac cycle and is typically represented by a plateau waveform. The script mentions that mitral regurgitation produces such a murmur, indicating turbulent blood flow due to the mitral valve not closing properly.

💡Decrescendo

Decrescendo refers to a gradual decrease in sound intensity. In the context of the video, it describes the pattern of certain heart murmurs, such as in aortic regurgitation, where the sound gets quieter over time, reflecting the decrease in the force of blood flow during diastole.

💡Opening Snap

An opening snap is an additional heart sound that occurs shortly after S2 and before a diastolic murmur in conditions like mitral stenosis. The video script explains that it is produced when the high pressure in the left atrium forces open the stenosed mitral valve, creating a distinct sound that is part of the mid-diastolic murmur.

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 Learn  Medicine Show. My name is Dr. Coleman,  

and in this episode, we are covering four  heart murmurs that typically come up in exams.  

We're going to start by covering the  basic heart sounds, and then we'll add  

in the murmurs so that you can get  to know them. Let's get into this.

Heart sounds can be graphically represented  in medical notes as S1, S2, and S1 again,  

and this represents one movement  through the cardiac cycle.  

The gap between S1 and S2 is known as systole, and  the gap between S2 and S1 is known as diastole.

Before we start adding in murmurs, I want you to  be familiar with the normal heart sound. So let's  

briefly cover these. The S1 heart sound usually  sounds like the word "LUB," and the S2 "DUB."

Let's add in the heart sounds briefly so  you can familiarise yourself with this.

Now let's turn our attention towards  heart murmurs. Murmurs occur when there  

is a disruption of normal laminar  blood flow. The disruption can be  

caused by physiological or pathophysiological  conditions, and this leads to turbulent flow,  

which produces audible vibrations. These  audible vibrations vary in their volume  

based on the turbulent flow produced. These  pictorial representations of sound waves  

are what we use to document murmurs in our heart  sounds diagram. So let's get down to business  

now and start by looking at systolic murmurs.  Our first systolic murmur is aortic stenosis.  

Aortic stenosis typically produces what's  known as an ejection systolic murmur. This  

is a murmur that occurs during systole and is  represented by a crescendo-decrescendo sound wave.  

One strategy for recognising and remembering  this murmur is using the schema LUB-WOOSH-DUB.  

We'll now add in the murmur and heart  sounds so you can fully appreciate this.

This murmur is produced by the  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,  

and the first heart sound is produced by the  closure of the tricuspid and mitral valves.  

Systole then occurs. The ventricles  contract, forcing blood through the  

pulmonary and aortic valves. Narrowing of  the aortic valve creates turbulent blood flow  

through the aortic valve. It is this turbulent  blood flow that produces our crescendo-decrescendo  

murmur. Finally, the S2 heart sound is  produced by the closure of the pulmonary  

and aortic valves. Let's now add in the murmur  so that you can appreciate this in real-time.

"Now that we've heard the murmur, let's take a  closer look at aortic stenosis. Aortic stenosis  

is caused by abnormal narrowing of the aortic  valve, and the aetiology includes age-related  

calcification, congenital bicuspid valve, and  rheumatic fever. The clinical history will  

typically include angina, syncope, and dyspnea.  The murmur of aortic stenosis is characterised as  

an ejection systolic murmur. The murmur is louder  in expiration and heard best in the aortic region  

and in the apex of the heart. The murmur radiates  in the direction of blood flow towards the carotid  

arteries. On clinical examination, you may also  find a slow-rising pulse and low blood pressure.

Let's turn our attention to mitral regurgitation.  Here we have another systolic murmur, but this  

time it's described as a pan-systolic murmur. As  you may have already gathered from its name, this  

occurs throughout the entire duration of systole.  This murmur is represented visually with a plateau  

waveform, meaning that the volume of the murmur  remains consistent throughout its duration.  

The murmur is so loud that  it drowns out S1 and S2,  

and instead, a burbling sound is heard. Let's  pause and take a quick listen to this now.

This pan-systolic murmur is caused by abnormal  closure of the mitral valve. Let's take a closer  

look to get a better understanding of this. So,  blood flows from the atria through the mitral  

and tricuspid valves into the ventricles, and at  this point, the mitral and tricuspid valves would  

normally close to produce our S1 heart sound. But  instead of this, the mitral valve prolapses into  

the left atrium, and this causes turbulent blood  flow, which generates a murmur that drowns out the  

S1 and the S2 heart sound. Let's add in the murmur  so that you can appreciate this in real-time.

Mitral regurgitation is caused by abnormal  closure of the mitral valve, and this can  

be due to a number of reasons, including mitral  prolapse, ischemic heart disease, rheumatic fever,  

and infective endocarditis. The clinical history  will usually include dyspnea and fatigue."

Mitral regurgitation produces a pan-systolic  murmur that is loudest at the apex of the heart  

and radiates into the left axilla. Other  signs you may see on examination include  

a displaced apex beat and a parasternal heave.  In severe cases, you may see peripheral oedema.  

Let's now turn our attention towards diastolic  murmurs, and we're going to cover two.  

The first one is aortic regurgitation.  This murmur is heard during diastole  

and is considered an early diastolic murmur. It  is represented pictorially with a decrescendo  

sound wave. The words "lub-tar" can be  used to describe how this murmur sounds.  

Let's listen to this in real time  so you can appreciate this better.

Aortic regurgitation is caused by  abnormal closure of the aortic valve.  

Let's take a closer look at this using animation.  The first heart sound is produced by the closure  

of the tricuspid and mitral valves. Systole  occurs when the ventricles contract,  

forcing blood through the pulmonary and  aortic valves. Incomplete closure of the  

aortic valve allows blood to regurgitate back  into the ventricle. This turbulent blood flow  

causes our diastolic murmur. Let's now add in the  heart sounds and watch this occur in real time.

Aortic regurgitation is caused by  abnormal closure of the aortic valve.  

This may occur due to rheumatic fever but  is also seen in connective tissue diseases  

such as Marfan's syndrome and rheumatological  conditions like rheumatoid arthritis and lupus.  

Another possible cause is infective  endocarditis. The clinical history  

will usually present with the smear, and the  patient may present with symptoms of angina.  

Aortic regurgitation produces an early diastolic  murmur that is her loudest at the left sternal  

edge and radiates towards the apex of the heart.  Other signs you might see on clinical examination  

include a collapsing pulse, a wide pulse  pressure, and a displaced apex beat.  

Now let's turn our attention to our final  murmur, the murmur of mitral stenosis.

Mitral stenosis produces a diastolic murmur that  is described as a mid-diastolic murmur. It has  

an opening snap and a decrescendo sound wave,  meaning it starts loud and then becomes quieter.  

To help recognise this mid-diastolic murmur,  the terms "lub-di-der" are often used. Let's  

pause for a moment to listen to this in real-time  so that you can appreciate this better. [Music]

Mitral stenosis, as its name suggests, is caused  by abnormal narrowing of the mitral valve.  

Let's now take a look at an animation to  see how this narrowing causes the murmur.

The S1 heart sound is produced by the closure  of the tricuspid and mitral valves. Systole  

then occurs, where ventricular contraction pushes  blood through the pulmonary and aortic valves.  

Closure of the pulmonary and aortic  valves produces the S2 heart sound.  

But milliseconds after this, accumulated blood in  the left atrium increases the left atrial pressure  

to a point where the stiffened mitral valve is  forced open, and this produces an opening snap.  

Almost immediately after S2, blood rushes through  the narrowed mitral valve, producing turbulent  

flow, and this is audible vibrations from these  that produce our mid-diastolic decrescendo murmur.  

Let's take a moment now to add in the murmur  so you can appreciate it in real-time. [Music]

Mitral stenosis is an abnormal  narrowing of the mitral valve.  

The most common cause of this is rheumatic fever,  and less common causes include congenital heart  

disease and systemic diseases such as lupus. The  clinical history typically presents with dyspnea  

and palpitations if atrial fibrillation is  present. Mitral stenosis produces a mid-diastolic  

murmur with an opening snap that is heard loudest  at the apex and radiates to the axilla. Other  

signs that you may see on clinical examination  include malar flush and a tapping apex beat.  

And that brings us to the end of the  tutorial. So, if you enjoyed this, please  

like and subscribe, share with your friends, and  let me know what you think in the comments below.  

Thanks for dropping by. I'll see you again soon.