Figure 94-28c

Difficulties encountered in analysis of the rhythm in presence of hyperkalemia.A.An ECG recorded at plasma K level of 9.1 meq/liter with a blood urea level of 270mg/dl AND co2 of 10meq/liter.The P waves are absent,making a definitive diagnosis of the rhythm difficult, if not impossible.The possible atria rhythms include(1)SA rhythm without identifiable P waves with a 2:1 block in leads V1 and V6 ;(2)SA rhythm with 1:1 AV conduction in leads 1 and 111 with 2 : 1 conduction in VI andV6;(3)sinus slowing in V1 and V6;(4)SA arrest oratrial fibrillation with a juncctional tachycardia with 1:1 exit in leads 1 and 111 and 2:1 exit in leads VI andV6.The QRS IS PROLONGED TO 0.20 s with prolngation of the prolongation of both the initial and terminal portions,best seen in leads 111 and V6,respectively.B. Recorded after treatment of the hyperkalemia.