<prompt> All of the following heart sounds are heard in chronic mitral stenosis except?Mid diastolic murmurThird heart soundOpening snapLoud S1  <response>: Ans. b. Third heart sound Ref: Harrison 19e p1539, 18e p1930Mid diastolic murmur, opening snap and loud S1 are heard in chronic mitral stenosis but not the third heart sound.Auscultatory Findings in MS: The first heart sound S1 is usually accentuated and slightly delayed. The pulmonic component of the second heart sound P2 also is often accentuated, and the two components of the second heart sound S2 are closely split. The opening snap OS of the mitral valve is most readily audible in expiration at, or just medial to, the cardiac apex. This sound generally follows the sound of aortic valve closure A2 by 0.05-0.12 s. The time interval between A2 and OS varies inversely with the severity of the MS. The OS is followed by a low-pitched, rumbling, diastolic murmur, heard best at the apex with the patient in the left lateral recumbent position; it is accentuated by mild exercise e.g.. a few rapid sit-ups carried out just before auscultation.- Harrison 18e p1930Third Heart Sound S3: Ventricular Diastolic Gallop, Protodiastolic Gallop, and Pericardial KnockPhysiologic S3Pathologic S3 ChildrenQ High cardiac output- AtheletesQ- FeverQ- PregnancyQ- ThyrotoxicosisQ- AV fistulasQ Ventricular dysfunction LVFRVF: Poor systolic function increased end-diastolic and end-systolic volume, decreased ejection fraction, and high filling pressure.- Idiopathic dilated cardiomyopathy, Ischemic heart disease- Valvular heart disease, Congenital heart disease- Systemic and pulmonary hypertension Excessively rapid early diastolic ventricular filling:- Hyperkinetic states, Anemia, ThyrotoxicosisQ- Arteriovenous fistula, Atrioventricular valve incompetenceQ- Left to right shuntsQ VSD, PDA and ASD Restrictive myocardial or pericardial diseaseQ Constrictive pericarditisQ pericardial knock Restrictive cardiomyopathyQ Hypertrophic cardiomyopathyQ Mitral stenosisAuscultatory findingsX-Ray findings S1: AccentuatedQ S2: Normally split S2Q with accentuated P2Q Murmur: Low-pitchedQ, rumbling diastolic murmur with Pre-systotic accentuation, heard best at the apex in left lateral recumbent positionQ. Opening snap: Brief, high pitchedQ, early diastolicQ sound, best heard at the lower left sternal borderQ. Features suggesting severe MS- Proximity of S2-OS gapQ- Longer duration of mid-diastolic murmurQ Straightening of the left border of cardiac silhouette Prominence of main pulmonary artery Dilation of upper lobe pulmonary veinsQ Kerley B linesQ Backward displacement of the esophagusQ 