The S3 heart sound occurs as the mitral valve opens and allows blood to fill the left ventricle passively. The sound happens as a result of blood striking the left ventricle during early diastole. An ...

An S4 heart sound cannot be present during atrial fibrillation (atrial kick is required). An S3 heart sound cannot be present in the setting of severe mitral stenosis. An S3 heart sound can be present ...

Complete heart block means that there’s a complete separation of electrical activity between the upper and lower chambers of the heart. Without prompt medical attention, it can be fatal. Your heart ...

First-degree heart block is the mildest type and often requires no treatment. Third-degree heart block is the most severe and often needs a pacemaker to regulate the heartbeat. Many different causes ...