What other conditions can be associated with a loud S1?
In addition to mitral stenosis and the hyperkinetic heart syndrome, a loud S1 is often encountered in:
Hypertrophic ventricles
Holosystolic mitral valve prolapse with regurgitation (where the prolapse delays the tension of the
redundant mitral leaflet, thus allowing it to occur at peak of ventricular contraction, which makes it
louder). A similar mechanism takes place in:
A left-atrial myxoma. Here it is the tumor that delays the closure of the mitral valve, thus allowing it to
occur at peak of ventricular contraction and making it, therefore, louder. As a result, 80% of patients with
this condition will have a loud S1.
Short P-R interval, as in the pre-excitation syndromes of Wolff-Parkinson-White and Ganong-Levine
syndromes.
In addition to mitral stenosis and the hyperkinetic heart syndrome, a loud S1 is often encountered in:
Hypertrophic ventricles
Holosystolic mitral valve prolapse with regurgitation (where the prolapse delays the tension of the
redundant mitral leaflet, thus allowing it to occur at peak of ventricular contraction, which makes it
louder). A similar mechanism takes place in:
A left-atrial myxoma. Here it is the tumor that delays the closure of the mitral valve, thus allowing it to
occur at peak of ventricular contraction and making it, therefore, louder. As a result, 80% of patients with
this condition will have a loud S1.
Short P-R interval, as in the pre-excitation syndromes of Wolff-Parkinson-White and Ganong-Levine
syndromes.