title: Influence of positional change on pulsus alternans.
mesh_terms: D002339:Carotid Arteries; D004452:Echocardiography; D004562:Electrocardiography; D006801:Humans; D007702:Kinetocardiography; D008297:Male; D008875:Middle Aged; D010490:Pericardial Effusion / Q000175:diagnosis*; D011187:Posture; D011674:Pulse