Student's Corner-5

CC BY-NC-ND 4.0 · Indian J Cardiovasc Dis Women WINCARS 2021; 06(03): 216-220
DOI: 10.1055/s-0041-1736524

Jayaraman Balachander

1  Department of Cardiology, Jawaharlal Institute of Post-Graduate Medical Education and Research, Puducherry, India

› Author Affiliations SFX Search Permissions and ReprintsQ1) Both Left Ventricle (LV) S3 and Pericardial Knock are Filling Sounds but Why Pericardial Knock Does Not Change With Respiration?

Answer

A. The LV S3

Expiration can make the S3 louder by the following:

Increasing blood flow out of the lungs into the left atrium (LA) and LV.

The stethoscope coming closer to the chest wall.

The apex beat coming out of the ribs in expiration and thus even S3 can be palpated by this phase.

The S3 is very sensitive to the proximity of the stethoscope to the apex beat, since it is a low-pitched sound.

When the bell of the stethoscope is applied very lightly to the apical region and the patient is turned to the left lateral decubitus position, the LV S3 is heard particularly during expiration.

B. The pericardial knock

The ventricle is restricted to the extent in which it can expand.

This is compensated by very early diastolic filling.

There is also an excessive catecholamine surge in the LV.

Further increase in venous return to the right atrium (RA) on inspiration can only cause the filling pressure to increase, as the right ventricle (RV) is unable to accommodate this increase.

This increase of the RA pressure and the inability of the RV to accommodate this rise results in rise of jugular venous pressure (JVP) or failure of the JVP to fall on inspiration, producing the Kussmaul's sign.

During expiration, the filling pressure of the RA is still high; hence, the filling occurs in the same way to the RV, causing no change in the pericardial knock.

However, the pericardial knock is sensitive to changes in blood volume. Diuretics which decrease the RA filling pressure can eliminate the pericardial knock.

Publication History

Publication Date:
31 October 2021 (online)

© 2021. Women in Cardiology and Related Sciences. This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by-nc-nd/4.0/)

Thieme Medical and Scientific Publishers Pvt. Ltd.
A-12, 2nd Floor, Sector 2, Noida-201301 UP, India

 

 

留言 (0)

沒有登入
gif