RESUMO
To analyse the endocardial activation of typical counter clock wise atrial flutter [CCW]. A retrospective study of 24 cases admitted over a period of 5 years for atrial flutter ablation at St. Georges Hospital, London. The electrophysiological study were reviewed from optical disc and right atrial activation analysed in all cases of typical CCW atrial flutter. In all the 24 cases of typical CCW atrial flutter the right atrial activation is in upward direction along the septum and downward along the right atrial lateral wall, the inferior leads on ECG represent it as "F" waves. In CCW atrial flutter the negative flutter wave in inferior leads represent lateral and anterior right atrial activation while descending limb represents septal activation