Heart Sounds and Murmurs Flashcards
What physical property is the basis of heart sounds?
Turbulence
What physical action produces S1? What does it sound like?
Closure of the AV valves; “Lub”
What can S1 be split into? What is the basis of this splitting?
The two AV valves do not close at exactly the same time and so there are two sounds: M1 (mitral closure) and T1 (tricuspid closure)
Which ventricle contributes more to the 1st heart sound?
The left
What is typically the loudest heart sound? Why is it the loudest?
S1 is generally louder because there is a bigger pressure change across the AV valves than across the semilunar valves
What is the sound of S2? What produces this sound?
“dub”; produced by closure of semilunar valves
What can S2 be split into? Which occurs first?
A2 and P2; A2 happens first
Which side of the heart contributes more to the 2nd heart sound?
Right
When can S3 be heard? What can it be indicative of if heard in adults?
Early diastole; Can be indicative of ventricular dysfunction (problems w/ ventricular compliance)
When can S4 be heard? What can it be indicative of if heard?
Occurs in late diastole during atrial systole; can reveal problems with ventricular compliance or atrial contraction
What does splitting of S1 generally indicate? What problem might cause this?
Delay in right ventricular contraction; Right bundle branch block
Splitting of which sound is more common?
S2
What does splitting of S2 generally indicate? What problem might cause this?
Indicates delay in the emptying or contracting of the right ventricle; Pulmonary hypertension
What normal physiologic process accentuates splitting?
Inspiration
Why does inspiration accentuate splitting?
Inspiration results in decreased intrathoracic pressure and increased abdominal pressure, increasing venous return and EDV. Increased EDV takes longer time for volume ejection and T1 and P2 will be more likely to split, esp. P2 from A2
What technique allows heart sounds to be visualized?
Phonocardiogram
Between what heart sounds does systole occur?
S1 and S2
Between what heart sounds does diastole occur?
S2 and S1
What are murmurs?
Abnormal heart sounds due to turbulence caused by abnormal pressure gradients
Murmur classification is based on what criteria?
Intensity, quality, duration, and timing of sound
How is intensity of murmurs graded?
On a scale of I-V where V is loudest
What are the major types of valvular dysfunction?
Stenosis and Regurgitation/ insufficiency
How can stenosis result in hypertrophy? What formula explains this response?
Stenosis leads to an increase in the resistance that the first chamber must push against, which leads to hypertrophy; Law of LaPlace- Stress= (P*r)/wall thickness
What is the anatomical basis of valvular regurgitation/ insuffiecincy?
The valve does not form a complete seal when it tries to close meaning some blood leaks backwards
In what phase of the cardiac cycle would an aortic stenosis be heard?
Systole
How would aortic stenosis be manifested on a pressure vs. time graph of the caridac cycle?
The LVP will be much greater than aortic pressure over the course of stroke ejection
When will a murmur due to aortic stenosis end?
A2 portion of S2
What kind of volume profile will a murmur due to aortic stenosis have?
Crescendo follwed by decrescendo
What kind of hypertrophy occurs in response to aortic stenosis?
Concentric hypertrophy
How can aortic stenosis result in heart failure?
Increased stenosis leads to increased resistance and the ventricle can only hypertrophy so much to compensate for that
When will regurgitation across the mitral valve occur the most?
When the pressure gradient btw LV and LA is the greatest, i.e. the ejection phase
When does the murmur begin with mitral insufficiency? How can the duration of the murmur be described?
M1; pansystolic or holosystolic
How would mitral insufficiency be manifested on a pressure vs. time graph of the caridac cycle?
LAP will be much higher during systole than expected
What is the main distinguishing feature of aortic insufficiency?
Increased pulse pressure
What type of hypertrophy is seen with aortic insufficiency?
Eccentric hypertrophy
What is eccentric hypertrophy?
An increase in ventricular length rather than width
When does mitral valve stenosis occur?
Diastole
Where is concentric hypertrophy developed in with mitral valve stenosis?
Left atrium
