Lecture 11: Cardiac Cycle and Heart Sounds Flashcards
Does a murmur always indicate that there is a problem or an underlying dz?
No, not always.
If a patient is diagnosed with a heart murmur, what should you do next?
Conduct an electrocardiogram
Systole corresponds with:
Contraction/relaxation
Depolarization/ repolarization
Contraction
Depolarization
Diastole corresponds with:
Contraction/relaxation
Depolarization/ repolarization
Relaxation
Repolarization
What is the difference between systolic BP and diastolic BP?
Systolic BP–> the pressure exerted on the artery when the heart contracts
Diastolic BP–> the pressure on the artery when the heart is at rest
In the cardiac cycle, do the electrical and mechanical activity occur at the same time?
Yes
Atrial systole occurs during?
P wave
Atrial diastole occurs during?
PR interval
—-slow conduction through the AV node—
Ventricular Systole occurs during?
QRS complex
(which is also atrial diastole and repolarization)
Late ventricular systole occurs during?
ST segment
Ventricular diastole (repolarization) occurs during?
T wave
The lub sound or S1 comes from?
AV valves closing
The dub sound or S2 comes from?
Semilunar valves closing
S3 sounds, which can sounds like Ken-tuckee occurs from?
blood filling the relaxed and empty ventricle (ventricular filling)
S4 sounds, which present as Tenness-ee occur from?
atrial filling from high pressure in SVC (occurs before S1)
Which side of the heart is a low pressure system; L or R?
Right.
Left side of the heart is a high pressure ssystem
What is the order of heart sounds?
S4–> S1–> S2–> S3–> S4–> S1
What are the 2 abnormal valve heart sounds?
1. Regurgitation–> turbulent flow sound when blood is moving in the opposite direction than what it should be
2. Stenosis–> Noise when blood moves through a stiff, damaged valve.
How do we idenfy abnormal heart sounds?
We identify them by when they occur in the cardiac cycle:
- sytolic murmur will occur in ventricular systole
- diastolic murmur will occur in ventricular diastole
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for what and what intercostal spaces ?
*Aortic : Right 2nd ICS along sternum
*Pulmonic: Left 2nd ICS along sternum
Erbs Point: (S1S2) Left 3rd ICS
*Tricuspid: Lower left sternal border/4th ICS
*Mitral: Left 5th ICS, medial to mid clavicular line
How are heart murmurs graded?
On a scale of 1-6
1. Soft murmur in quiet room
2. Soft murmur in loud room
3. Prominent heard murmur
4. Loud murmur with a thrill
5. Loud heard with edge of steth tilted against chest
6. Loud murmur heard from 5-10mm from chest + thrill
What is considered a pathologic murmur?
Any murmur that is great or equal to 3/6
What valves are open and closed during ventricular systole?
Ventricular systole (ventricular contraction)
- Semilunar valves= open
- AV valves= closed
What is aortic stenosis?
What is pulmonic stenosis?
Aortic stenosis–> restricted flow through the aortic valve
Pulmonic stenosis–> restricted through through the pulmonic valve.
What valves are open and closed during atrial systole?
Semilunar valves are closed
AV valves are open.
What are the general rules for what makes murmurs loud or soft?
RINSPIRATION- Inspiration makes RIGHT murmurs in the tricuspid and pulmonic valve louder
LEXPIRATION- expiration makes LEFT murmurs in the mitral and aortic valves louderder
Preload is the volume of blood sent to the heart.
What happens to the murmur when preload is increased or decreased?
Preload is increased--> louder
When preload is decreased--> softer
Why is HOCM (hypertrophic obstructive cardiomyopathy)
one of the two exceptions for the rules of preload?
An increase in preload improves an aortic murmur by pushing the septum away from the aortic outflow tract, letting blood eject moreesily.
A decrease in preload worsens the aortic murmur because less blood is pushing the outflow track open, thus, fucking up blood flow.
Why is MVP (mitral valve prolapse) the second exception for the rules of preload?
IN MVP: mitral valve cusps prolapse into left atria under normal pressure and blood flow.
Increase in preload improves murmur by returning the prolaspsed leaflets to their normal position.
Afterload is the pressure the ventricles have to generate to move blood forward into the arterial system (PVR).
What happens to the murmur when afterload is increased or decreased?
Increased afterload–> makes the murmur louder
Decreased afterload–> makes the murmur softer
Except with HOCM and MVP, where the opposite occurs.
Aortic stenosis
Aortic stenosis –> increasing, then decreasing murmur between S1 and S2
1. Old- SAD: Syncopy, Angina, Dyspnea
2. Calcified aortic valve
3. Radiates UP to carotids (cresendo-descendo presentation)
Mitral regurgitation
A constant, steady murmur heard between S1 and S1
Best heard at apex of heart and radiates to the axilla.
Tricuspid regurgitation
Want to TRI some drugs?
-Usually due to IV drug abuse
-Constant murmur between S1 and S2.
Aortic regurgitation
Seen in:
- CT disorder
- Marfan’s syndrome
- Femoral bruits
- Head bobbing
- Water hammer pulse
AR, there she BLOWS
-early blowing diastolic murmur that occurs during S2 and S1
Mitral stenosis
D/t Rheumatic fever
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Heard between S2 and S1, when the mitral valve opens, it causes an OS (opening snap
HOCM
is associated with sudden cardiac death at a young age.
What is different during preload and after load as discussed earlier?
Decreased pre/afterload= louder murmur
Increased pre/afterload = softer murmur
Mitral valve prolapse
Characterized by?
- Click in the middle of systole
- IF YOU SEE MYCOMATOUS VALVULAR DZ–> THINK OF MITRAL VALVE PROLAPSE
