Second Heart Sound

The second heart sound category of this website will help you to learn about the second heart sound including physiologically split, second heart sound with persistent splitting, second heart sound with fixed splitting, increases the aortic intensity, and more.

Before you take this session, you should have finished the normal heart sounds session and first heart sound sessions. You should feel gratified with your ability to listen and be familiar with normal heart sounds.
Please use good quality headphones or earphones. Computer or phones speakers often fail to reproduce some heart sounds.

The second heart sound is a short burst of auditory vibrations of varying intensity, frequency, quality, and duration. The second heart sound is produced by the closure of the aortic and the pulmonary valve.
A split second heart sound (S2 heart sound) is best heard at the pulmonic valve listening post, as P2 is much softer than A2. The A2 sound is normally much booming than the P2 due to higher pressures in the left side of the heart.

Heart rate, sex, age, height, and weight had little or no backlash on the splitting pattern of the second heart sound; 15% of the subjects exhibited fixed splitting of the second sound in either, but not both, in a supine or upright position.
In severe HTN (hypertension), a loud second heart sound may be prolonged and slurred-falsely mimicking a split S2.


  1. Nature: High pitched shorter duration (0.12s)
  2. Sounds: D-U-B (loud and sharp)
  3. Frequency: 50 Hz
  4. Area: it is better heard over the left 2nd intercostals space. 1.5 inch away from the midline.
  5. It occurs after the ‘Apex beat” and carotid pulse, the end of the T-wave of ECG.


  • It indicates the end of ventricular systole and the beginning of ventricular diastole.
  • A clear 2nd HS indicates that semilunar valves are closing properly. i.e there is no regurgitation.

In the medical practices, correct diagnosis and understanding of the case are important. So, while doing auscultation hearing the sounds correctly and identifying the abnormalities in it is important. Having prior practice to the sound will be a plus point for you, as we can do better in things we are familiar with. So, this site will be a friend in gaining practice in auscultation and learning different cases regarding it. So, practice as much you want and gain your self- confidence and help for your future practices. This site will always be a friend in need in case of learning about heart sounds.

Second Heart Sound – Physiologically Split 2

Second Heart Sound with Persistent Splitting

Second Heart Sound with Fixed Splitting

Second Heart Sound: Fixed Splitting, Increased Aortic Intensity

Second Heart Sound: Fixed Splitting, Decreased Aortic Intensity

Second Heart Sound and Late Systolic Click

Second Heart Sound and a Tumor Plop

Opening Snap and Second Heart Sound

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