"Pseudo" late potentials unmasked by spectrocardiography

We present a patient with chronic obstructive pulmonary disease and sustained ventricular tachycardia in the setting of unstable coronary artery disease. Signal-averaged ECG (SAECG), inadvertently performed during an atrial tachycardia with 2:1 atrioventricular (AV) block, was abnormal by time-domain analysis, but was normal by a relatively new frequency analysis technique of the entire QRS (spectrocardiography). The patient was noninducible for sustained ventricular arrhythmias. Following cardioversion to sinus rhythm, SAECG was normal by time-domain analysis and spectrocardiography. This technique may show promise in the management of patients who are at risk for sustained ventricular arrhythmias, particularly those who cannot be evaluated by time-domain analysis.