ThirteenA Flashcards
MTAP
Mitral, Tricuspid, Aortic, Pulmonic
What does S1 signify? What can change the intensity?
Onset of systole
Intensity is usually always the same, but is altered by:
Distance between open AV leaflets at the onset of
contraction
Larger distance = Louder S1
Mobility of valve leaflets
Rate of rise of ventricular pressure
What does S2 signify? Describe the things that may alter it and why?
S2 signifies the end of ventricular systole
Aortic component (A2) precedes pulmonic component (P2)
A2 and P2 components can vary in timing based upon
respiratory variations
Inspiration: Decrease in intrathoracic pressure leads to increased venous return to the right heart
Pulmonic valve stays open slightly longer
Increase in pulmonary vascular capacitance
Blood trapped in pulmonary vascular bed
Less blood flow returns to left heart
Aortic valve closes slightly earlier
Expiration brings A2 and P2 back together
Describe widely split S2.
S2 split at both expiration and inspiration
Delayed closure of the
pulmonic valve
Right bundle branch block
Respiratory variation still present
Describe Fixed Split S2. Cause?
Widely split S2 without
respiratory variation
Classic cause is an atrial septal defect
Chronic shunting of blood from the left heart to right
heart
Delayed pulmonic valve closure
What is a paradoxically split S2?
Describes the situation where the aortic valve closes after the pulmonic valve
S2 sounds normal with inspiration, but paradoxically
splits with expiration
Left bundle branch block, right ventricular pacing
How are murmurs graded? How are the systolic murmurs classified?
Graded from 1 to 6, based on the intensity of the sound
Murmurs can be classified as
Holosystolic
Systolic ejection
Late systolic
What are holocystic murmurs? What are 3 examples? Describe them. How are they recognized clinically?
Onset occurs as soon as systole begins
Mitral regurgitation
Incompetent mitral valve that is unable to prevent backflow of blood into the left atrium
Loudest at cardiac apex
Tricuspid regurgitation
Louder with inspiration
Loudest at lower sternal border
Ventricular septal defect
Typically a harsher/louder murmur, associated with a palpable thrill
When do systolic murmurs begin and end? What are they like? Examples?
Onset begins after IVCT
Stenosis of either semilunar valve (aortic stenosis or
pulmonic stenosis)
Flow across the diseased heart valve begins only after the
systolic pressure exceeds the pressure in the great vessel
Typically “diamond-shaped” or crescendo-decrescendo
Murmur ends at S2
Describe aortic stenosis? Where is it best heard? What happens when the stenosis worsens? What happens to carotid pulse?
Systolic ejection murmur, heard best at the right upper sternal border
May radiate to carotid arteries
As the valve becomes more
stenotic, the murmur peaks
later in systole
Obliteration of S2
Carotid pulse demonstrates diminished and delayed
upstroke (pulsus parvus et tardus)
Flow murmurs
Younger patients can often have innocent flow murmurs
Because of robust cardiac output, there can be increased blood flow across the semilunar valves during systole
These murmurs are typically very soft (grade 1 or 2)
Early-mid peaking
Not pathologic
What are late systolic murmurs? Give two examples.
Murmur begins in mid to late
systole
Two classic conditions which
cause this type of murmur
Mitral valve prolapse (MVP)
Hypertrophic obstructive
cardiomyopathy (HOCM)
describe mitral valve prolapse. What is the murmur like?
Myxomatous degeneration of
the mitral valve leaflets
Creates redundant (“floppy”)
mitral tissue
Mitral valve closes normally in
early systole
Redundant mitral tissue
prolapses into the left atrium in
mid systole
Prolapse of excess mitral tissue
creates a mid-systolic click
The mitral valve leaflets are
redundant and too long for the
left ventricle
Decreasing left ventricular
volume exacerbates this
problem
Strain phase of the Valsalva
maneuver and standing from a
squatting position reduces left
ventricular preload
What is HOCM? What is the murmur like?
Genetic condition characterized
by severe asymmetric septal
hypertrophy
During systole, dynamic
obstruction of left ventricular
outflow
Late-peaking systolic ejection
murmur in the aortic region
Crescendo-decrescendo
Maneuvers that reduce left
ventricular volume increases
the left ventricular outflow
obstruction
Louder murmur
Increasing afterload (handgrip
maneuver) reduces murmur
intensity
What are diastolic murmurs like?
More difficult to appreciate than
systolic murmurs
By definition, diastolic murmurs
begin after S2
Unlike systolic murmurs, an
audible diastolic murmur is
never normal
Diastolic murmurs graded from
1 to 4
Describe aortic regurgitation. What is the murmur like? Other physical findings?
Decrescendo diastolic murmur
Incompetent aortic valve allows blood to backflow into the left ventricle
Increased left ventricular blood volume is ejected across the aortic valve in systole
Systolic ejection murmur
Loudest at the right upper sternal border, with the patient sitting forward and after expiration
Reduced diastolic blood pressure
Widened aortic pulse pressure
Austin-Flint murmur
Eponymous physical findings all over the place
Most of the physical findings
in chronic severe aortic
regurgitation are secondary
to the widened aortic pulse
pressure
What is mitral stenosis? Most common cause? What is the murmur like?
Obstruction to left ventricular inflow
Most common cause is rheumatic heart disease
Murmur is a low-pitched diastolic murmur at the apex
Very difficult to hear because of the relatively low pressure gradients
at which it occurs
Mid diastolic murmur preceded
by an opening snap
Opening snap occurs earlier
in diastole as mitral stenosis
becomes more severe
When is S3 heard? What causes it?
Large pressure gradient between the left atrium and left
ventricle in early diastole
Mitral valve opens and “passive” filling occurs
Rapid gush of blood across the mitral valve
S3 can be normal and also pathologic
In young, healthy patients, S3 can be normal and is the result of robust systolic heart function
More frequently, S3 is heard in pathologic conditions where left atrial pressure is elevated (decompensated congestive heart failure)
What causes an S4 murmur? What is it like? When can it never occur?
Atrial contraction occurs in late diastole
Heard in patients with longstanding systemic hypertension
Pathologic left ventricular hypertrophy
Non-compliant left ventricle
Left ventricular pressure increases in response to systemic
hypertension
Atrial contraction occurs at higher left atrial pressure
Forceful atrial contraction against a non-complaint left ventricle
Organized atrial contraction is required to have an S4
Patients in atrial fibrillation (no organized atrial contraction)
cannot have an S4
