Flashcards in Heart sounds and murmurs Deck (11):
what causes an S1, S2, S3, S4 heart sounds?
S1 corresponds to AV valves closing (mitral, tricuspid)
S2 corresponds to pulmonic and aortic valve closing
S3 corresponds to rapid ventricular filling in early diastole - associated with high filling pressures (e.g. mitral regurgitation), common in dilated ventricals,
S4 occurs in late diastole - due to atrial kick, associated with high atrial pressure and often due to ventricular hypertrophy
what does the a wave correspond to on the jugular venus pulse curve
atrial contraction - seen in late ventricular diastole
what does the c wave correspond to on the jugular venus pulse curve
right ventricular contraction - tricupid valve is buldging into the atrium -- increases pressure on venous system
what does the v wave correspond to on the jugular venus pulse curve
increased atrial pressure due to filling against closed tricupid valve -- leading up to the opening of the AV valves (mitral and tricupid)
what venus pulse wave occurs at a similar time as the S4 heart sound?
a wave - during atrial contraction
what abnormaltiy of the jugular venous pulse is expected in a patient with atrial fibrillation?
absent a wave
which EKG segment is associated with the AV valve closure?
QRS - ventricular contraction
immediately precedes S1
when does normal splitting occur? What causes this?
aortic valve closes slightly before pulmonic valve
on inspiration the increase in venous return to the right atrium causes an increase in preload to the right ventrical, which then takes slightly longer to pump out larger volume of blood. As a consequence the pulmonic valve takes slightly longer to close.
on expiration the slitting (time between aortic and pulmonic valve closure) is shorter
when would wide splitting occur? how would this be affected by inspiration vs expiration
conditions in which there is delayed right ventricular emptying (e.g. pulmonic stenosis or right bundle branch block)
wide splitting is exaggerated on inspiration due to even larger right ventricular preload more blood to pump out before pulmonic valve can close
when does fixed splitting occur?
atrial septal defects
left to right shunt leads to increased right atrial and right ventricular volumes which increases flow through the pulmonic valve - so much additional flow is taking place due to the shunt that regardless of breath, pulmonic closure is greatly delayed