Rules for Second Degree Block Type 2 (Mobitz II)
Regularity: If there is a consistant conduction ratio, then the R-R interval will be regular. If the conduction ratio is not constant, the R-R interval will be irregular. Rate: The atrial rate will be normal. The ventricular rate will be slower, usually 1/2 to 1/3, than the atrial rate. P WAVE: P waves are upright and uniform. There is not a QRS following every P wave. PRI: PRI can only be measured on conducted beats, and it is usually constant across the strip. It may or may not be longer than a normal PRI (0.12 seconds). QRS: Measures less than 0.12 seconds. 