S1

S1 loud
- MS
- Hyperkinetic state ( anemia, thyrotoxicosis, beri beri )

S1 soft
- Valvular - Immobile MS, AR - regurgitant jet hitting the undersurface of MV
- LV - failure, hypertrophy
- Rhythm - AV block, LBBB

Split S1 ( M1-T1 )
- RV overload, hypertrophy
- Ebstein anomaly