Cardiac Function: Examining The Heart Flashcards
Used for high frequency sounds such as valve closures, systolic events, and regurgitation murmurs
Diaphragm
Used for low frequency sounds (S3, S4) like a diastolic murmur of mitral stenosis
Bell
Can only hear with patient seated and leaning forward
Aortic regurgitation
MArks the onset of systole with the closure of the AV valves
First heart sound (S1)
Marks the onset of diastole with the closure of the semilunar valves
Second Heart sound (S2)
If the HR is slow, the shorter period is
Systole
To identify S1 vs S2, we want to check the
-Palpable impulse occurs just after S1
Carotid pulse
Found in the right second (or third) intercoastal space
S2
Will be louder, shorter, and sharper
-Higher frequency sound
S2
Heard well across the entire precordium
-coincides with closure of mitral and tricuspid valves
S1
S1 is loudest at the
Apex
S1 should be louder than S2 at the
Apex
S2 should be louder than S1 at the
RICS
The intensity of S1 increases with the strength of
Ventricular contraction
The position of the AV leaflets at the onset of systole affects the intensity of S1, the wider they are apart, the
Louder S1 (indicator of valve disease)
The position of the AV leaflets at the onset of systole depends on the
PR interval
When ventricular systole immediately follows atrial systole, so valve leaflets are wide open and S1 is loud
Short PR interval
Gives more time for leaflets to float together so S is not as loud
Long PR interval
The most important characteristic of S1 is
Intensity
Vigorous ventricular contraction, short PR interval, or delayed closure of valve gives a
Loud S1
If pulse is regular and S1 intensity varies beat-to-beat, consider
AV dissociation (complete heart block)
A loud unexplained S1 can mean
Mitral Stenosis
A faint or absent S1 can mean
Acute aortic regurgitation
The S2 sound has 2 components caused by closure of the
Semilunar valves
We hear a single S2 sound during
Expiration
Normally, for our S2 sound, which closes first
AV closes before PV
Pulmonary circulation is a low pressure system so there is less back pressure in the pulmonary artery and the
P2 is heard later than A2
During inspiration, the interval separating A2 and P2
Increases (A2 first then P2)
In greater than 90% of normal people, A2 and P2 are perceived as a single sound during expiration. In those with splitting, it disappears when they
Sit up
Wide physiologic splitting of S2 can be caused by a
Conduction problem or hemodynamics problem
A Right Bundle Branch Block (RBBB) or left ventricular preexcitation are two types of
Conduction problems leading to physiologic splitting of S2
Prolongation of RV systole, pulmonic stenosis, or pulmonary hypertension w/ RV failure are examples of
Hemodynamics causes of physiologic splitting
A wide and fixed splitting of S2 is caused by an
Atrial Septal Defect
The presence of physiologic splitting of S2 decreases the likelihood of an
Atrial Septal Defect
A low frequency sound that requires the bell to hear
Ventricular or S3 gallop
As a general rule, if there is an S3 gallop than the heart is
Dilated
An atrial or S4 gallop is also a low frequency sound that needs the
Bell
An “opening snap” is indicative of
Mitral stenosis
An “early ejection click” is indicative of
Aortic stenosis
A “midsystolic click” is indicative of
Mitral valve prolapse
Audible vibrations due to increased turbulence
-Defined by timing within the cardiac cycle
Heart Murmurs
Begin with or after S1 and end at or before S2
Systolic Murmurs
Begin with or after S2 and end at or before S1
Diastolic murmurs
Any murmur with a grade of 4/6 or above will also have an accompanying
Thrill
