Review note: AI-assisted draft independently checked against the cited sources by a separate AI reviewer. Not clinician-reviewed. Use with your course materials, supervised clinical training and current local policies.
Cardiac auscultation combines where you listen, when a sound occurs, and what else you find in the patient. Listening areas are useful surface landmarks; they are not the exact anatomical positions of the valves.
Anatomy connection: See the five listening sites on the 3D chest wall
The five sites: “APE To Man”
Locate the sternal angle at the second rib, then count intercostal spaces. These are typical adult landmarks:
| Site | Landmark | 3D |
|---|---|---|
| Aortic | 2nd intercostal space, right sternal border | view |
| Pulmonic | 2nd intercostal space, left sternal border | view |
| Erb's point | 3rd intercostal space, left sternal border | view |
| Tricuspid | 4th intercostal space, left sternal border | view |
| Mitral (apical) | 5th intercostal space, left midclavicular line | view |
“Right” and “left” mean the patient's right and left. Open RN, cardiovascular assessment
What the sounds mean
- S1 (“lub”): associated with mitral and tricuspid valve closure at the beginning of ventricular systole.
- S2 (“dub”): associated with aortic and pulmonic valve closure at the end of systole and beginning of diastole. It is usually more prominent at the base of the heart.
- S3: a low-pitched sound shortly after S2, during early ventricular filling. It can accompany heart failure or volume overload, but can also be physiological in children and young adults, and during pregnancy.
- S4: a low-pitched sound just before S1, associated with atrial contraction into a less compliant ventricle.
An extra sound is a finding to interpret with the history, symptoms and examination. S3 alone does not diagnose fluid overload. Open RN, cardiovascular assessment, University of Washington, heart-sound technique, University of Washington, S3 and S4
Use the diaphragm for S1 and S2. Low-frequency left-sided S3 and S4 may be easier to hear with the bell lightly applied at the apex while the patient lies on the left side, if tolerated. University of Washington
Counting the apical pulse
Listen at the adult apical area for 60 seconds, assessing both rate and rhythm. Count each S1–S2 pair as one heartbeat. A commonly taught adult resting range is 60–100 beats/min, interpreted in context. Open RN, cardiovascular assessment
Before administering digoxin, count the apical pulse for a full minute and check the prescribed hold parameters. In standard adult nursing teaching, an apical rate below 60/min means withhold the dose and notify the prescriber. Pediatric thresholds differ, and an individual order may specify other limits. Clarify an unclear order before administration.
Possible toxicity findings include bradycardia, other arrhythmias, nausea, vomiting and visual changes. Assess symptoms as well as the rate and review ordered laboratory results, including renal function and electrolytes. A pulse above 60 does not exclude toxicity. Open RN, cardiac glycosides
NCLEX-style reasoning
- Where is the usual adult apical listening site? The 5th intercostal space at the left midclavicular line.
- A patient with heart failure has a new sound after S2? Consider S3 and assess for worsening congestion; the sound alone is not a complete diagnosis.
- An adult's apical pulse is 56/min before scheduled digoxin, with a hold-below-60 order? Withhold the dose, assess the patient and notify the prescriber. Deterioration requires urgent escalation.
Practice it in 3D
Open Chest-wall listening sites, select each pin and try the heart Practice questions, including the apical-pulse location.
Sources
- Open RN, Nursing Skills 2e, 9.3 Cardiovascular Assessment
- Open RN, Nursing Pharmacology 2e, 6.7 Cardiac Glycosides
- University of Washington School of Medicine, Heart Sounds & Murmurs: technique
- University of Washington School of Medicine, Third and Fourth Heart Sounds
AI-assisted educational content for exam preparation. Clinical assessment and medication administration follow current training, facility policy and patient-specific orders.