<prompt> A patient in regular rhythm presents with absent P waves on ECG. Leads II, III and AVF reveal a Saw-Tooth Pattern. Which of the following is the most likely diagnosis:Atrial FibrillationAtrial Flutter with Variable BlockAtrial Flutter with Fixed BlockMultifocal Atrial Tachcardia  <response>: Answer is C Atrial Flutter with Fixed Block The absence of any discernible P waves on ECG, together with the presence of Saw Tooth Flutter waves in inferior leads Leads II, III and AVF strongly suggests a diagnosis of Atrial Flutter. The presence of a regular rhyti,,o suggests a Fixed Block . FindingsFeatures Diagnosis Irregular Rhythm with no discernible P wave Chaotic base line with fibrillary f waves Atrial Fibrillation Irregular rhythm with no discernible P wave Saw tooth ,Ilutter waves especially in inferior leads and VI Atrial Flutter with variable block Regular rhythm with no discernible P waves Saw tooth flutter waves especially in inferior leads and V1 Atrial Flutter with fixed block Irregular Rhythm with multiple P wave morphologies P waves Discernible and Varying PR intervals Multifocal Atrial Tachycardia 