title: Influence of atrial systole on first derivative of the apexcardiogram.
mesh_terms: D000368:Aged; D001146:Arrhythmia, Sinus / Q000503:physiopathology; D002306:Cardiac Volume; D006325:Heart Atria / Q000503:physiopathology; D006352:Heart Ventricles / Q000503:physiopathology; D006801:Humans; D007702:Kinetocardiography; D008297:Male