Phylogenetic observations on specialized cardiac tissues.
D000818:Animals; D001145:Arrhythmias, Cardiac / Q000209:etiology*; D005075:Biological Evolution; D001717:Birds / Q000033:anatomy & histology*; D004562:Electrocardiography; D006329:Heart Conduction System / Q000033:anatomy & histology*; D008322:Mammals / Q000033:anatomy & histology