Thoracic auscultation Flashcards
Head of the stethoscope
Diaphragm: drum (larger side)
Bell: low frequency (small)
Cardiac auscultation for a dog
PAM 345 (left)
Tricuspid on right
What is the loudest part of the heart
Point of maximum intensity
Cardiac auscultation on cats
Sternum: right and left parasternal, then sternal
Base then apex
S1 heart sounds
Closure of AV valves (lub)
Mitral and tricuspid sounds
S2 heart sounds
Closure of the semilunar valves (dub)
Aortic/ pulmonic valves
Split S1
Normal in some large/ giant breed dogs
Delayed closure of tricuspid or mitral valve (rare)
Lub, lub, dub
What causes split S1 sounds?
Abnormal ventricular conduction
Ectopic beats, BBB’s, cardiac pacing
Split S2 sounds
Physiologic: due to respiration
Delayed closure of the pulmonic valve
Lub-da-dub
What causes split S2 sounds?
Pulmonic stenosis
Abnormal ventricular condition (VPC’s, left BBB)
Pulmonary hypertension
S3 heart sounds
Early diastole (rapid filling)
S3 gallop or ventricular gallop
Lub-dub-dub
What causes S3 heart sounds?
Volume overload or decreased viscosity
Ventricular dilation with myocardial failure in dogs
DCM, anemia in cats
S4 heart sounds
Late diastole (atrial contraction)
S4 gallop, atrial gallop
Normal in giant breeds
Dub-lub-dub
What causes S4 heart sounds
HCM, SAS, third degree AV block
Grading murmurs
1: very soft, heard in quiet room
2: soft, easily heard
3: moderate- intensity
4: loud without palpable thrill
5: loud murmur with palpable thrill
6: very loud with palpable thrill, and heard with steth off chest wall
Description of murmurs
Grade (1-6)
Localized PMI (left or right / sternal)
Phase (diastole, systolic or both)
Direction (facial, radiate to base, or apex)
Types of murmurs
Early, late or mid
Holosytolic: lub-shhhhh- dub
Pansytolic: shhhh-dub
Diastolic: shhh-lub-dub
Systolic regurgitation
Holosystolic/ regurgitant or pansystolic
Mitral insufficiency, tricuspid insufficiency
Systolic ejection
Holosystolic/ ejection
Between S1 and S2
Pulmonic stenosis, aortic stenosis
VSD loudest on right
Diastolic regurgitation
Decrescendo/ insufficiency
Low pitch with decrease in intensity towards ejection
Aortic insufficiency
Continuous murmur
Systolic and diastolic
Washing machine / schwee-schwoo
Associated with PDA
