Overview
This lecture introduces the basics of cardiac auscultation, including key heart sounds, valve locations, and how to use a stethoscope to assess heart health.
Basics of Cardiac Auscultation
- Cardiac auscultation is used to assess heart health by listening to heart sounds with a stethoscope.
- The main normal heart sounds are S1 ("lub") and S2 ("dub").
- Abnormal findings can include murmurs, clicks, S3, and S4 sounds.
Heart Valve Locations and Auscultation Mnemonic
- The mnemonic "A PTM" helps remember the order: Aortic, Pulmonary, Tricuspid, Mitral.
- Valve sounds are auscultated where sound travels, not at anatomical locations.
Aortic Valve
- Located at the 2nd intercostal space, right sternal border.
- S2 ("dub") is louder here.
Pulmonary Valve
- Located at the 2nd intercostal space, left sternal border.
- S2 is also louder at this location.
Tricuspid Valve
- Found at the 4th or 5th intercostal space, left sternal border.
- S1 ("lub") is louder here.
Mitral Valve
- Auscultated at the 5th intercostal space, midclavicular line (below the nipple in males).
- S1 is louder at the mitral area.
Point of Maximum Impulse (PMI)
- Located near the mitral valve auscultation site.
- PMI indicates where the heartbeat is strongest against the chest.
- Strong PMI at rest can be clinically significant.
Key Terms & Definitions
- Auscultation — Listening to internal body sounds (e.g., heart) with a stethoscope.
- S1 & S2 — First and second heart sounds; S1 is "lub," S2 is "dub".
- Murmur — Abnormal heart sound, often due to turbulent blood flow.
- Intercostal space — The space between two ribs.
- Point of Maximum Impulse (PMI) — The area where the heart's impact is most strongly felt on the chest wall.
Action Items / Next Steps
- Practice locating and auscultating the four heart valves using the "A PTM" mnemonic.
- Observe and palpate the PMI on yourself or a partner.
- Review S1 and S2 heart sounds for identification during auscultation.