Differential electrograms computed from unipolar endocardial recordings improve Purkinje activation identification

Recent studies have indicated that the Purkinje system plays a critical role in the onset and maintenance of certain arrhythmias. Unipolar electrograms were recorded at 8 KHz from the endocardium during sinus rhythm and ventricular fibrillation. Using the unipolar recordings, bipolar, quadipolar, and octapolar, and Laplacian electrograms were created. Purkinje potentials were more readily identified with bipolar and octipolar electrograms than with unipolar recordings. The first temporal derivatives of the electrograms aided in distinguishing Purkinje potentials. Differential electrograms and their temporal derivatives facilitate Purkinje potential identification by reducing common noise in the electrograms and far field effects recorded by the unipolar signal. Combined analysis of the unipolar electrograms, differential computed electrograms, and their derivatives improve identification of Purkinje activation from endocardial electrical recordings.