How to Assess the Heart with a Stethoscope

Hi, I’m Maris from Level Up RN, and in this guide, I’ll walk you through the essential steps of heart auscultation using a stethoscope.

By the end of this article, you’ll understand:

✅ How to properly use your stethoscope
✅ The five auscultation sites and what they reveal about heart function
✅ Normal heart sounds (S1 & S2) and abnormal findings (S3, S4, murmurs, friction rubs)


I'll also include mnemonics and memory hacks to help you recall key concepts easily!

If you’re using our Health Assessment Flashcards, follow along—or grab a set at LevelUpRN.com.

Understanding Your Stethoscope

A stethoscope has two primary components for listening:

1. The Diaphragm (for High-Pitched Sounds)

  • Larger side of the chest piece
  • Used for high-pitched sounds such as:
    ✔️ Normal heart sounds (S1, S2)
    ✔️ Lung sounds (breath sounds)
    ✔️ Bowel sounds
  • Requires firm pressure against the patient’s skin

2. The Bell (for Low-Pitched Sounds)

  • Smaller side of the chest piece
  • Used for low-pitched sounds, including:
    ✔️ Murmurs (caused by turbulent blood flow)
    ✔️ Bruits (vascular turbulence, often in carotid arteries)
    ✔️ Gallops (S3, S4)
  • Requires light pressure to avoid flattening the bell, which could diminish low-frequency sounds

🔹 Memory Hack:

  • Diaphragm = High-pitched sounds → Use Heavy pressure ("H" in both words!)
  • Bell = Low-pitched sounds → Use Light pressure (Two "L’s" in "bell" = Low & Light!)

Heart Auscultation: The 5 Key Sites

To accurately auscultate the heart, listen in five specific locations following the A P T M mnemonic:

🩺 A P T M – All People Enjoy Time Magazine

Valve Location Key Function
Aortic Valve 2nd intercostal space, right sternal border Regulates blood flow from the left ventricle to the aorta
Pulmonic Valve 2nd intercostal space, left sternal border Controls blood flow from the right ventricle to the pulmonary artery
Erb’s Point 3rd intercostal space, left sternal border Optimal site to hear all heart sounds equally (E for Equal!)
Tricuspid Valve 4th intercostal space, left sternal border Separates right atrium from right ventricle
Mitral Valve (Apex/PMI) 5th intercostal space, left midclavicular line Separates left atrium from left ventricle; point of maximal impulse (PMI)

🔹 Why is Erb’s Point Important?

  • It is not a valve, but it is a central location where all heart sounds are heard at equal volume.
  • Often used to detect murmurs that might not be easily heard elsewhere.

🔹 Pro Tip for Precise Auscultation:

  • Start at the Aortic Valve and move downward in order to ensure a systematic approach.
  • If you hear an abnormal sound, go back and listen again carefully using both the diaphragm and bell.

Heart Sounds: Normal vs. Abnormal

✅ Normal Heart Sounds: S1 & S2

🔹 S1 ("Lub")

  • Caused by the closure of the mitral and tricuspid valves (AV valves)
  • Marks the beginning of systole (ventricular contraction)
  • Loudest at the apex (Mitral area, 5th intercostal space, midclavicular line)

🔹 S2 ("Dub")

  • Caused by the closure of the aortic and pulmonic valves (semilunar valves)
  • Marks the end of systole (beginning of diastole)
  • Loudest at the base of the heart (Aortic & Pulmonic areas, 2nd intercostal spaces)

Abnormal Heart Sounds & Their Clinical Significance

❗ Extra Heart Sounds: S3 & S4

🔹 S3 ("Ventricular Gallop")

  • Occurs right after S2
  • Caused by rapid filling of the ventricles due to fluid overload
  • Common in heart failure or volume overload conditions
  • Mnemonic: SLOSH-ing in (mimics the rhythm of an S3 sound)

🔹 S4 ("Atrial Gallop")

  • Occurs just before S1
  • Caused by stiff, non-compliant ventricles (often due to scar tissue from an old heart attack)
  • Common in hypertension, left ventricular hypertrophy, or myocardial infarction
  • Mnemonic: A STIFF wall (mimics the rhythm of an S4 sound)

❗ Murmurs: What Do They Mean?

A murmur is an extra heart sound caused by turbulent blood flow.

Common causes:
✔️ Valve stenosis (narrowed valve, restricting blood flow)
✔️ Valve regurgitation (leaky valve causing backflow)
✔️ Septal defects (e.g., congenital holes in the heart)

Murmurs are graded on a 1-6 scale:

  • Grade 1 – Very faint
  • Grade 6 – Loud enough to be heard without a stethoscope

❗ Pericardial Friction Rub: A Squeaky Warning Sign

  • A grating, squeaky sound caused by inflamed pericardial layers rubbing against each other.
  • Often heard in pericarditis (inflammation of the pericardium).
  • Sounds like: A squeaky washing machine or creaky leather.

🩺 To differentiate from a pleural friction rub:

  • Ask the patient to hold their breath while you listen.
  • If the sound continues, it's a pericardial friction rub (heart-related).
  • If the sound stops, it's a pleural friction rub (lung-related).

Quick Quiz: Test Your Knowledge!

1️⃣ How should a nurse use a stethoscope to auscultate high-pitched sounds?
✅ Apply firm pressure with the diaphragm

2️⃣ Where is Erb’s Point located?
✅ 3rd intercostal space, left sternal border

3️⃣ What causes the S1 heart sound?
✅ Closure of the mitral and tricuspid valves

4️⃣ An S4 heart sound may be heard in a patient with what condition?
✅ Myocardial infarction (heart attack)

Final Thoughts: Mastering Heart Auscultation

Understanding how and where to listen to heart sounds is essential for accurate cardiac assessment.

💬 How many quiz questions did you get right? Let me know in the comments!
📢 Subscribe to our channel and share this guide with your classmates!

If you found this helpful, hit the like button and tell me which part of auscultation you find most challenging!

Comments

Post a Comment

Popular posts from this blog

Understanding Different Types of Congenital Heart Defects

Image
Let's explore the various types of congenital heart defects, starting with Tetralogy of Fallot . This condition is characterized by four key abnormalities, which can be remembered with the acronym "RAPS" : R ight ventricular hypertrophy (enlargement) A orta displacement P ulmonary stenosis (narrowing) S eptal defect, specifically a ventricular septal defect (VSD) Patients with Tetralogy of Fallot often experience "Tet spells," where they become cyanotic (bluish skin due to lack of oxygen). To alleviate these spells, the knee-to-chest position is recommended. Next is Ventricular Septal Defect (VSD) , where there is a hole in the wall (septum) between the right and left ventricles. You can remember this condition with the word "HOLE." Patients with VSD may develop heart failure and pulmonary hypertension, often leading to frequent lung infections, poor growth, and weight gain. Additionally, extra heart sounds, or murmurs, can often be heard...
Read more

How to Answer Drop-Down Cloze Questions on the NCLEX Exam

Image
Hello everyone, it's Nurse Sarah here! Today, I'm going to guide you through one of the more unique question types you might encounter on the Next Generation NCLEX (NGN) exam—the drop-down close question. This question type can be a bit tricky, so it's crucial to understand how to approach it effectively. Let's get started! What is a Drop-Down Close Question? A drop-down close question differs significantly from the traditional multiple-choice or select-all-that-apply questions. Instead of choosing from a list of predetermined answers, you're required to fill in the blanks within a given statement or scenario by selecting options from drop-down menus. This type of question is designed to test not only your knowledge but also your ability to apply that knowledge in a clinical context. In a drop-down close question, you are presented with a scenario—often drawn from real-world nursing situations. The scenario will include patient information, such as clini...
Read more

Mastering ABG Interpretation: A Step-by-Step Guide to Understanding Compensation in Arterial Blood Gas Analysis

Image
Arterial Blood Gas (ABG) analysis is a fundamental skill in clinical practice, essential for diagnosing and managing patients with acid-base imbalances. While many healthcare professionals can identify whether a problem is respiratory or metabolic, and whether it involves acidosis or alkalosis, the concept of compensation often leads to confusion. This guide aims to demystify compensation in ABG analysis by providing a comprehensive, step-by-step approach. Understanding the Basics: What is Compensation? Before diving into examples, it's crucial to understand what compensation means in the context of ABG analysis. Compensation refers to the body's attempt to restore normal pH levels by counteracting an acid-base disturbance. This process involves the respiratory and metabolic systems working in tandem: Respiratory System : Adjusts pH by regulating the levels of carbon dioxide (PaCO2) through breathing. Metabolic System : Adjusts pH by managing bicarbonate (HCO3-) lev...
Read more