Which of the following is true about fouh hea sound `S4' :

Answer is C (Heard during ventricular filling) The fouh hea sound (S4) is a low pitched presystolic sound produced in ventricles during ventricular filling. Fouh Hea Sound (S4) Fouh Hea sound occurs in association with an effective atrial contraction() (It is presumably caused by inrush of blood into the ventricles when the atria contracts and hence it is also called the Atrial Hea Sound) It is heard during the ventricular filling phase of the cardiac cycle (PresystolicQ hea sound) It is low pitched (frequency usually 20 cycle/sec or less-(Guyton) It is not audible to the unaided ear Normally the fouh hea sound can almost never be heard even with a stethascope because of its weakness and low frequency (Guyton) S4 becomes audible when diminished ventricular compliance increases the resistance to normal filling When audible the S4 is best heard with the bell of the stethescopeQ Pathologically may be seen in patients with Systemic Hypeension Ischaemic Hea Disease Pulmonic stenosis (Right S4) Aoic Stenosis Mitral Regurgitation Pulmonary H.T (Right S4) HOCM Physiologically may be seen in patients with Increasing age Loudest (Best heard) at the Left ventricular Apex when the patient is in left Lateral position It is accentuated by mild isotonic or isometric exercises in the supine position