When P waves cannot be identified, the decision as to whether a wide complex tachycardia is supraventricular in origin but conducted with aberration or ventricular in origin is more difficult. For this reason, guidelines have been suggested to aid in this differentiation. Some are general and primarily clinically based and others are ECGbased and quite specific.
Some general guidelines are proposed here. Remember that these are only guidelines to assist in the initial approach to the patient and that their sensitivity and specificity are low.
