What is Loud SI present in: and explain in detail?
Ans: A (MS) MS with calcified valve, MR & TR cause soft S1S1 normal in AS"-O.P. Ghai 7th/418"AS: The cardiac impulse is heaving and sustained in character, and there may be a palpable fourth heart sound (S4). An aortic systolic thrill is often present at the base of the heart. In 80 to 90 percent of adult patients with severe AS, there is an S4 gallop sound, a midsystolic ejection murmur that peaks late in systole, and a single second heart sound (S2) because A2 and P2 are superimposed or A2, is absent or soft"- Hurst 12th/261Intensity of S1The primary factors determining intensity of S, are (1) integrity of valve closure, (2) mobility1 of the valve, (3) velocity of valve closure, (4) status of ventricular contraction, (5) transmission characteristics of the thoracic cavity and chest %vall, and (6) physical characteristics of the vibrating structures.S1 in Mitral StenosisA loud, late M1 is the hallmark of hemodynamically significant mitral stenosis. When M, is loud, it is associated with a loud opening snap, and the intensity of both M, and the opening snap correlates with valve motility. When calcific fixation of the stenotic mitral valve occurs, M1 is soft, and the opening snap is absentS1 in Acute Aortic RegurgitationOne of the important auscultatory findings in acute AR is attenuation or absence of M1 Severe regurgitation into a left ventricle that has not had time to adapt to the acute volume overload causes a marked increase in the LV end-diastolic pressure, resulting in premature closure of the normal mitral valve in mid-diastole. With the onset of LV systole, minimal mitral valve excursion occurs, causing a marked reduction in the intensity of M1