#1) What represents atrial depolarization and atrial contraction? #2) What represents ventricular depolarization, systole and S1? #3) What represents mid-systole and ventricular repolarization #4) What represents diastole and S2? #5) What represents the rapid-filling phase of diastole? #6) What represents the variable cardiac period?
#1) depolarization = ECG p-wave. contraction = pressure a-wave. #2) V. depolarization = end of QRS. V. systole = isovolumic contraction. S1 = AV valve closure (c-wave) #3) Mid-systole = opening of the semilunar valves. V. repolarization = t-wave #4) Diastole = closing of the semilunar valves. S2 = dicrotic notch. #5) Rapid-filling phase of diastole = y descent #6) Variable period = diastasis
Where is the best place to hear the aortic valve? Pulmonic? Tricuspid? Apex?
Aortic = 2RICS. Pulmonic = 2LICS. Tricuspid = 4LICS (lower left parasternal border). Mitral = 5LICS at midclavicular line.
What is the second S2 split sound you hear with inspiration?
P2. With inspiration the pulmonary bed takes in more blood, forcing the RV to eject more blood. Since it is weaker it takes a longer period of time to eject all the blood, delaying closure of the pulmonic valve.
A patient comes in complaining of difficulty breathing. She just got off a plane from China and noted a pain in her calf while flying. What abnormal heart sound would you expect to hear in this patient? In what other conditions would you hear this?
An abnormally loud P2 that you can hear all the way down at the apex. This is because the clot lodged in the pulmonary artery increases the pressure in the artery, causing P2 to be very loud. You would also hear this in left ventricular failure or mitral disease because this decreases ejection fraction, thus also increasing pressure in the pulmonary artery.
A patient comes in complaining of fatigue when walking. You listen to his heart and hear a widely split S2. What factors go into your differential diagnosis?
Right bundle branch block = late P2 (slower contraction of right ventricle than normal), RV overload (pulmonic stenosis, increased volume or pressure) = late P2 (ventricle takes longer to finish contracting) or mitral regurgitation = early A2 (LV finishes emptying earlier than normal)
A patient comes to see you with persistent, fixed splitting of their S2 sound. What direction is blood flowing in their heart?
This patient has atrial septal defect. This is caused by a hole in the atrial septum, allowing blood to flow from the left atrium to the right atrium.
You are practicing your physical exam technique on your fellow classmate. While listening to his heart in the supine position, he rapidly raises his legs towards the ceiling. What heart sound might come out when he does this?
S3. It is the sound of blood rushing into the ventricles from the atria during the rapid filling phase. This is exaggerated by him raising his legs because the act increases venous return. You must be listening with the bell to hear this sound.
A patient comes to your clinic and you are listening to his heart. You hear a low frequency sound just before the first heart sound. He has a history of long-standing hypertension. When would you never hear this sound?
This is S4. This is caused by blood hitting a stiff, noncompliant ventricle during atrial contraction. During atrial fibrillation, the atria are not contracting, so you would never hear it during atrial fibrillation.
In what position do you listen for third heart sounds?
Later decubitis position
How can you tell the difference between a split S1 heart sound and an S4? A split S2 and S3?
If you can hear it with the diaphragm it's not a gallop. Gallop sounds you can only hear with the bell. Additionally, the gallop sounds will be heard at the apex of the heart and split sounds will be heard in the upper chest.
A patient comes in with a high frequency "pop" ejection sound right after S1 around the apex of the heart. What is causing this sound?
This is caused by a less compliant semilunar valve, most commonly when the aortic valve is fused so it only has two leaflets. The pressure builds up behind the valve and causes the pop sound when it opens.
Where do you typically hear a split S1?
A patient comes in with rheumatic fever and you listen to his heart. If his inflammatory process has become fairly advanced, what sound do you expect to hear? How can you use this to assess left atrial pressure?
A mitral opening snap. The inflammatory process makes the valve stiff and it snaps when it opens during diastole. You can use this to assess left atrial pressure because the shorter the time between A2 and the opening snap of the mitral valve, the greater the pressure in the left atrium and the stiffer the valve.
How do you differentiate a mitral opening snap from a split S2?
The split S2 is only heard in the pulmonic region where the mitral opening snap is heart everywhere. It also does not vary with respiration.
A patient comes in to see you and while auscultating around the apex of her heart you hear a mid systolic click. You have the patient do the Valsalva maneuver and the sound moves closer to S1. What is your diagnosis?
This is mitral valve prolapse, caused by valve leaflets that are too big for the heart. During late systole one of the leaflets pops into the atrium and causes a clicking sound. Anything that increases blood volume in the ventricle will make the click occur later. Anything that decreases blood to the ventricle (valsalva maneuver) will make the heart smaller and the prolapse gets worse and happens earlier.
Whats the difference between a heart sound and a murmur?
A murmur occurs when blood accelerates from stenosis and creates vibrations due to turbulence. A heart sound is a single solitary sound that comes and goes.
What questions need to be answered when diagnosing a murmur?
Is it systolic, diastolic or both? What is the pattern? Where is it loudest? Does it radiate?
How does assessment of radiation of a heart murmur help you differentiate between pulmonic and aortic stenosis?
Aortic murmurs will radiate to the carotid arteries. Pulmonic stenosis will be heart in the midclavicular region where the pulmonary artery goes through the lungs.
Where could a systolic murmur be occurring?
Aoritc valve, mitral regurgitation or ventricular septal shunt.
Where could a diastolic murmur be occurring?
Mitral valve (stenosis) or aortic vavle (regurgitation)
How do you grade murmurs?
1/6 = less than S1/S2. 2/6 = equal to S1/S2. 3/6 = greater than S1/S2. 4/6 = palpable thrill. 5/6 = heard with stethoscope partially on chest. 6/6 audible to naked ear.
What is the most common heart murmur?
Systolic crescendo-decrescendo murmur
A patient comes to see you for a routine heart exam. You hear a crescendo-decrescendo murmur in his axillary region with the bell of the stethoscope. What is the likely diagnosis?
Where do you auscultate to hear aortic regurgitation?
LLSB (lower left sternal border)
Why do most women have mid-systolic ejection murmur by the end of pregnancy?
Many women become anemic, which thins the blood and causes turbulent flow which can be heart.
What are the pathologic mid-systolic ejection murmurs?
Semilunar valve narrowing and intraventricular obstruction
What makes a mid-systolic murmur crescendo and decrescendo?
It starts when the semilunar valve opens and increases in intensity as velocity of blood exiting the valve increases. The sound decreases in intensity as the pressure in the ventricle decreases and stops when semilunar valves shut.
What are the different types of aortic stenosis?
Valvular, subvalvular and supravalvular
How do pressure gradients compare in the aorta and in the ventricles in someone with aortic stenosis?
The aorta is much less than the ventricles because the ventricles need to pump harder to get blood out of the aortic valve.
What must you assume if a patient presents with an S4 and dyspnea?
Aortic stenosis. It may not be, but this is the first thing to rule out because if someone has symptomatic aortic stenosis their one year survival rate is about 50%.