Related Experiment Video
Updated: Oct 3, 2026

Optical Mapping of Langendorff-perfused Rat Hearts
Published on: August 11, 2009
Recording of the fourth heart sound by the signal averaging method. Preliminary report
Abstract:
The fourth heart sound was clearly recorded by using the signal averaging method. Furthermore, the simultaneous recording of the Doppler signal with the fourth heart sound was performed. Thus, it was demonstrated that the Doppler signal started after the P wave and followed by the fourth heart sound. In 2 cases, the effect of the double Master's test and taking a bath was studied on the computer averaged phonocardiogram. After the exercise, the amplitude of the fourth heart sound was increased, whereas after taking a bath it was almost unchanged. The above results show that the simultaneous recordings of a computer averaged phonocardiogram and Doppler signal that is associated with cardiac activity can greatly facilitate the interpretation of small vibrations such as the fourth heart sound.
More Related Videos
18:11A Research Method For Detecting Transient Myocardial Ischemia In Patients With Suspected Acute Coronary Syndrome Using Continuous ST-segment Analysis
Published on: December 28, 2012
09:20Microelectrode Array Recording of Sinoatrial Node Firing Rate to Identify Intrinsic Cardiac Pacemaking Defects in Mice
Published on: July 5, 2021
Related Concept Videos
Pulse rhythm
Conversely, an irregular pulse pattern is termed dysrhythmia, stemming from disruptions in cardiac muscle...
Assessment of apical pulse
Assessing the apical pulse is a critical nursing procedure, particularly indicated for:
Assessment of apical radial pulse
The A-R pulse assessment involves simultaneous evaluation of the apical and radial pulses. When the apical and radial pulse rates vary, this assessment helps identify a pulse deficit.
Pre-Procedural Preparation
Heart Sounds
Auscultation is the process of listening to these internal body sounds using a stethoscope. The heart produces four types of sounds, but only two—S1 and S2—can usually be heard with a stethoscope.
S1, also known as the "lub" sound, is caused by the closure of atrioventricular (A-V) valves at the...
Assessment of the Cardiovascular System IV: Auscultation
Normal Heart Sounds
S1 (First Heart Sound)-
S1 is made by the closure of the mitral and tricuspid valves (atrioventricular valves), marking the beginning of systole.
S2 (Second Heart Sound)-
S2 is made by the closure of the aortic and pulmonic valves (semilunar valves), marking the end of the systole.
Cardiovascular System Abnormal Findings II: Auscultation
Abnormal Heart Sounds
Gallops: