First hea sound is soft in all, except:
Sho PR interval
Ventricular septal defect
Mitral regurgitation
Calcified valve
Answer is A (Sho PR interval) Sho PR interval is associated with a Loud S,. SI is produced as a result of closure of AV valves. In sho PR interval mitral leaflets are at a greater distance from neutral as decreased interval between atrial contraction and ventricular systole does not allow them to return towards neutral before the ventricular contraction