Ventricular filling during atrial contraction
Due to decreased ventricular compliance (CAD, AS, MR, HCM, Diabetic Cardiomyopathy)
****No S4 during Atrial Fibrillation
The S4 heart sound is associated with any process that increases the stiffness of the ventricle including:
–>hypertrophy of the ventricle
–>long-standing hypertension (causes ventricular hypertrophy)
–>aortic stenosis (causes ventricular hypertrophy)
–>overloading of the ventricle (causes ventricular hypertrophy)
–>fibrosis of the ventricle (eg. post-MI)
–>Congestive Heart Failure