All of the following statements about third Hea sound (S3) are true, except -

The third hea sound (S 3 ) occurs during the rapid filling phaseof ventricular diastole. It can be a normal finding in children,adolescents, and young adults; however, in older patients it signifieshea failure. A left-sided S 3 is a low-pitched sound best heard overthe left ventricular (LV) apex. A right-sided S 3 is usually betterheard over the lower left sternal border and becomes louder withinspiration. Harrison's principle of internal medicine,20th edition,pg no.1545