[Influence of the relations between atrial systole and ventricular systole on the intensity of the 1st tone and on the Q-1degree tone interval].
1959
E VITOLO, and
R RUMOLO, and
M BALLARINO, and
G FOLLI
UI
MeSH Term
Description
Entries
D006347
Heart Sounds
The sounds heard over the cardiac region produced by the functioning of the heart. There are four distinct sounds: the first occurs at the beginning of SYSTOLE and is heard as a "lubb" sound; the second is produced by the closing of the AORTIC VALVE and PULMONARY VALVE and is heard as a "dupp" sound; the third is produced by vibrations of the ventricular walls when suddenly distended by the rush of blood from the HEART ATRIA; and the fourth is produced by atrial contraction and ventricular filling.