Paroxysmal Atrial Tachycardia (PAT) with Block

Electrocardiographic Findings

 * 1) The P wave morphology is different than that of Normal Sinus Rhythm (NSR).
 * 2) The atrial rate is between 150 and 250 Beats Per Minute (BPM).
 * 3) * It is less than 200 in most cases.
 * 4) * In atrial flutter the rate is > 250 BPM in most cases.
 * 5) There is an isoelectric baseline between P waves in all leads.
 * 6) * In atrial flutter there is a sawtooth appearance to the P waves.
 * 7) AV block
 * 8) * Usually 2:1, but can be 3:1, and can even be variable and resemble atrial fibrillation.
 * 9) Digoxin toxicity caused 73% of cases in the Lown series. Other reports put the number at 40 to 82%.