Learning to accurately perform a cardiac auscultation is an important skill for medical students, and this procedure can aid in the diagnosis of a number of major heart problems. A cardiac auscultation must be done accurately, otherwise the results will not be accurate. Therefore it is important to take your time and carry out each step with confidence and attention.
Steps
Part 1 of 3: Prepare the Patient
Step 1. Find an adequately lit, quiet room
A quiet room allows for instant amplification of heart sounds. This reduces the chance of an abnormal heartbeat escaping.
- If you are a male medical professional, always find a colleague before performing a physical exam on a female patient. The rationale behind this approach is that a colleague will work alongside the patient, avoiding the risk of sexual embarrassment.
- This guarantees the safety and professionalism of the medical professional and gives peace of mind and protection to the patient.
Step 2. Introduce yourself and get an overview of what will happen during the auscultation
Auscultation of the heart causes anxiety in patients, especially those who perform it for the first time. Consequently, taking the time to explain what you are going to do allows the patient to know what to expect during the exam and helps keep them calm.
- This short chat before the exam also helps build a relationship between the patient and the practitioner and conveys a sense of trust.
- Also consider this an opportunity to inform the patient that the examination will be done with no clothing and / or no undergarments on the upper body to ensure proper auscultation.
Step 3. Please ask the patient to remove clothing covering the upper body
Ask the patient to remove the upper body clothing and ask him to lie down on the examination table once he has done so. Leave the room while undressing to ensure privacy.
- Warm the stethoscope with your hands while you wait. A cold stethoscope causes tension on the skin. Tight skin will hinder the clear transmission of heart sounds to the stethoscope.
- Knock before re-entering the exam room to make sure the patient is ready for the exam.
- Offer the patient a sheet with which he can cover himself as soon as you approach. You should cover the patient with a cloth to ensure that only the areas for immediate examination remain exposed.
- Always remember that a patient lying with a bare chest feels discomfort. Properly covering the patient is an important indication of professionalism.
Part 2 of 3: Perform the Auscultation
Step 1. Stand on the patient's right side
Standing on the right side facilitates auscultation.
Step 2. Feel the patient's heart
This operation, also known as palpation, involves placing the right hand over the patient's left pectoral. The palm of the hand should be against the edge of the breastbone and the fingers should be just below the nipple. The hand must adhere to the chest, with the fingers well extended. Be sure to tell the patient what you intend to do before starting, and explain the purpose. While practicing palpation, keep the following in check:
- Can you feel a point of maximum impulse (PMI), which indicates the location of the left ventricle? Try to pinpoint its exact location, which is usually near the mid-clavicular line. If the ventricle is normal in size and functioning well, it should be about the size of a 2 cent coin. If it is enlarged, it could find near the armpit.
- What is the duration of the pulse? If the patient suffers from hypertension, the pulse lasts longer. However, this is a difficult and largely subjective assessment.
- How strong is the impulse?
- Do you feel a vibration? If a valve is partially blocked, you may be able to detect it. If you notice a murmur during auscultation, check again for a vibration.
Step 3. Start auscultation with the stethoscope diaphragm positioned at the apex of the heart
The apex of the heart is located about two fingers below the nipple. A gentle upward shift of the left breast must be done on women to feel the heartbeat. Once the diaphragm is in place, listen carefully.
- The diaphragm is the listening part of the stethoscope with a large circumference and a flat surface. The diaphragm helps to hear normal high-pitched heart tones.
- There are two normal heart sounds, S1 and S2. S1 corresponds to the closure of the mitral and tricuspid valves of the heart during cardiac contraction. S2 corresponds to the closure of the aortic and pulmonary valves during the relaxation of the heart. S1 is stronger than S2 at the apex, as this is closer to the mitral valve.
Step 4. Auscultate 3 more points
After having auscultated the apical part of the heart, it is important to move on to these other areas of the heart:
- The left side of the patient's sternum, below (in the fifth intercostal space). This is the best place to auscultate the tricuspid valve.
- The left side of the patient's sternum, in the upper part (in the second intercostal space). This is the best place to auscultate the pulmonary valve.
- The right side of the patient's sternum, at the top (in the second intercostal space). This is the best place to auscultate the aortic valve.
- Remember that the apex of the heart is the best place to auscultate the mitral valve.
Step 5. Repeat steps 2 and 3, this time using the diaphragm bell
The bell is the auscultatory part of the diaphragm with the smallest circumference and concave surface. It is sensitive to abnormal heart sounds called murmurs.
- The bell should be applied lightly over the skin to increase sensitivity to puffs. Grab the sides of the bell with your thumb and forefinger. Place the palm of your hand against the patient's chest to make sure the bell is positioned without pressing.
- The bell should create a hermetic seal with the skin to facilitate listening to abnormal heart sounds. Compare the timing of the heart tones with the pulse of the carotid artery.
Step 6. Ask the patient to lie down on their left side and ensure proper coverage with the sheet
This position amplifies the heart tones of the apex. Place the bell lightly on the apex and listen for any puffs.
- Ask the patient to sit down, lean forward, exhale fully, and stop breathing. This maneuver accentuates the murmurs.
- Place the diaphragm of the stethoscope over the apex two-finger distance to the left of the tip of the sternum. This is the last step of cardiac auscultation.
Step 7. Leave the examination room and allow the patient to get dressed
Do not discuss the results of the examination with the patient who is still undressed.
Part 3 of 3: Interpreting the Results
Step 1. Identify if your heart rhythm is regular or irregular
The first step in interpreting the results of the exam is to take 5 seconds to listen to the sounds you are listening to. Next, when palpating your pulse, determine which tone is first (S1). The S1 tone is the one synchronized with the pulse. So it is necessary to establish if the rhythm is regular or irregular, following the S1 tone.
If the rhythm is irregular, an electrocardiogram should be done immediately
Step 2. Try to evaluate your heart rate
By counting how many S1 tones you hear in 10 seconds and then multiplying by 6, you find out what the patient's heart rate is. If the resting heart rate is below 60 bpm (beats per minute) or above 100 bpm, an EKG should also be done and additional medications may be needed.
- It is necessary to keep in mind that sometimes a patient's pulse may not always be in tune with the heartbeat, as in atrial fibrillation. For this reason, it is preferable to auscultate the patient's heart without taking the pulse when evaluating his heart rhythm and rate.
- By counting how many sounds you hear between the S1 tones, you can determine if there is a "gallop" rhythm (when you hear two or even three additional sounds between the S1 tones). A galloping rhythm usually means heart failure, but it is normal in children and athletes.
Step 3. Listen for murmurs
Valve stenosis and valve insufficiency both produce murmurs. Murmurs are long-lasting pathological heart sounds, usually heard from S1 to S2 or S2 to S1. Systolic murmurs are what can be heard from S1 to S2, while diastolic murmurs are what can be heard from S2 and S1.
- Mitral insufficiency is characterized by a perceptible systolic murmur in the mitral area.
- Mitral stenosis is characterized by a perceptible diastolic murmur in the mitral area.
- Aortic insufficiency is characterized by a perceptible diastolic murmur in the aortic area.
- Aortic stenosis is characterized by a perceptible systolic murmur in the aortic area.
- Atrial and ventricular septal defects are characterized by systolic and diastolic murmurs.
Step 4. Watch out for a runaway pace
A gallop-like rhythm is an additional heart sound that occurs following S2 (S3) or just before S1 (S4). Heart sounds S3 and S4 are more easily heard with the stethoscope bell.
- An S3 is normal in patients under 40, but in older ones it may indicate left ventricular failure. It occurs during ventricular filling and is usually due to an enlargement of the ventricular chamber.
- The presence of an S3 indicates decreased contractility, myocardial insufficiency or a volume overload of the ventricle.
- An S4 is due to reduced ventricular compliance, increased ventricular stiffness, and increased tissue strength. This can be heard in trained athletes or in older adults.
- Causes of S4 include hypertensive heart disease, coronary artery disease, aortic stenosis, and cardiomyopathy.
