Vectorcardiogram of Anguilla anguilla L. and Pleurodeles waltlii Mich.

PREVIOUS investigations1–3 on the epicardial electrocardiogram of fishes (Anguilla anguilla L., Ameiurus nebulosus Raf., Cyprinus carpio L., Salmo irideus Gibb., Acipenser sturio L., Scyliorhinus canicula L. and S. stellare L.), of larval Urodeles (Ambystoma tigrinum Green) and adult Urodela (Pleurodeles waltlii Mich., Triturus cristatus Laur. and Salamandra maculosa Laur.) showed that the general activation front in the epicardial layers moves approximately from the heart basis towards the apex in the fishes and in Ambystoma tigrinum, and from the apex towards the basilar region in Pleurodeles waltlii, Triturus cristatus and Salamandra maculosa.