Understanding Heart Sounds for Student Nurses
Build confidence with the basics of cardiac auscultation, understand normal first and second heart sounds and recognise when unexpected findings should be connected with the patient's wider clinical picture.
What are heart sounds?
Heart sounds are produced mainly by the closing of cardiac valves and changes in blood flow during the cardiac cycle. Listening with a stethoscope can contribute useful information when combined with pulse, blood pressure, symptoms and the wider cardiovascular assessment.
The first heart sound
S1 is associated primarily with closure of the mitral and tricuspid valves at the beginning of ventricular systole.
The second heart sound
S2 is associated primarily with closure of the aortic and pulmonary valves near the end of ventricular systole.
Listen to the whole patient
Heart sounds should never be interpreted without considering symptoms, observations, pulse and wider cardiovascular findings.
A systematic approach to cardiac auscultation
Explain and prepare
Explain what you are doing, obtain consent, maintain privacy and position the patient appropriately according to local practice.
Create a quiet environment
Reduce unnecessary noise where possible so subtle cardiac sounds can be heard more clearly.
Listen systematically
Follow the auscultation sequence taught within your programme and local clinical practice.
Connect with the pulse
Consider heart sounds alongside pulse rate, rhythm and the wider cardiovascular assessment.
Start by learning what normal sounds like
Developing confidence in auscultation begins with repeated exposure to normal heart sounds before attempting to recognise more complex abnormalities.
| Feature | What you are considering | Why it matters |
|---|---|---|
| Rate | How frequently the cardiac cycle is occurring. | Connect with the patient's pulse and observations. |
| Rhythm | Whether the timing appears regular or irregular. | Unexpected irregularity may require further assessment. |
| S1 and S2 | Whether the main heart sounds can be distinguished. | Provides the foundation for recognising additional sounds. |
| Additional sound | Whether you hear something beyond the expected pattern. | An unexpected finding should be reported in context rather than independently diagnosed. |
What should make you look more closely?
Unexpected irregularity
An irregular cardiac rhythm should be connected with pulse findings, symptoms and appropriate ECG assessment.
Something you did not expect
If you hear an additional or unusual sound, describe it and seek appropriate reassessment rather than attempting to diagnose its cause.
The patient is unwell
Chest pain, breathlessness, dizziness, syncope or deteriorating observations make any cardiovascular finding more clinically significant.
Heart sounds are only one part of cardiovascular assessment
- Assess pulse rate and rhythm.
- Review blood pressure and relevant trends.
- Consider peripheral perfusion.
- Ask about chest pain, palpitations, dizziness and breathlessness.
- Review relevant respiratory findings.
- Compare with the patient's baseline where known.
- Use ABCDE if the patient appears acutely unwell.
You hear something unexpected
Example
You are completing observations for a patient who reports increasing breathlessness. Their pulse feels irregular and they say they have experienced intermittent palpitations.
During supervised cardiac auscultation, the heart sounds do not seem to follow the regular pattern you have heard previously.
You do not attempt to diagnose the rhythm or label the sounds. Instead, you connect the findings: breathlessness + palpitations + irregular pulse + unexpected auscultation finding.
You complete an appropriate assessment and report the change so that further clinical and ECG assessment can take place.
Describe what you found clearly
Example escalation
βI'm concerned about Mrs Patel. She is more breathless than earlier and reports palpitations. Her pulse feels irregular. During supervised auscultation the rhythm also sounded irregular to me.β
This communicates the finding without claiming a diagnosis and makes it clear why further assessment is required.
Errors to avoid
- Trying to diagnose a valve disorder from one auscultation.
- Listening to the heart without checking the patientβs symptoms.
- Ignoring an irregular pulse because the patient looks comfortable.
- Focusing on terminology instead of recognising meaningful change.
- Failing to compare findings with baseline where known.
- Delaying escalation while repeatedly trying to identify a sound.
- Documenting a diagnosis you are not qualified to make.
Listen β connect β assess β escalate
Use a systematic approach
Learn the expected S1 and S2 pattern and recognise when something appears different.
Look beyond the stethoscope
Consider pulse, symptoms, blood pressure, perfusion and the wider cardiovascular picture.
Respond to deterioration
Use ABCDE when appropriate and report unexpected findings or deterioration promptly.
Build confidence by connecting what you hear with what you see
Heart sounds are most useful when interpreted alongside pulse, observations, symptoms, baseline and the patient's overall clinical condition.
Explore Clinical Confidence β