case_images: PMC11390494_01
case_images: (A) Initial EKG at obtained in the emergency department at time of patient presentation with evidence of junctional escape rhythm and noted absence of p-waves indicative of sinoatrial dysfunction in all but the last sinus complex. (B) Repeat EKG 30-minutes after administration of atropine showing normal sinus rhythm with emergence of p-waves and bigeminal premature atrial complexes indicative of sinus node and atrial conduction recovery. There is noted lead misplacement of V1 indicated by only positive deflection of QRS complexes not consistent with antecedent and subsequent studies. (C) Repeat EKG obtained 12-hours after atropine administration revealing complete dissipation of sinus node recovery with re-emergence junctional escape rhythm and noted absence of p-waves indicative. (D) Sequential progression of telemetry-capture approximately 12-hours after initial Theophylline dose revealing progressively shortening sinus pauses ranging from sinus arrest of 3.8 s to a briefer pause of 1.12 s to eventual complete resolution of SND with return to normal sinus rhythm. (E) EKG obtained approximately 24 h after theophylline administration with evidence of sustained normal sinus rhythm and regular p-waves with normal sinoatrial conduction pattern.
case_images: fcvm-11-1412376-g001.jpg
case_images: PMC11390494_01_fcvm-11-1412376-g001.jpg
case_images: F1
case_images: Initial EKG Figure 1(s) obtained upon presentation showed evidence of sinoatrial block with junctional escape rhythm. Repeat EKG (Figure 1B) after the administration of atropine exhibited slight recovery of sinus function with emergence of p-waves and bigeminal premature atrial complexes indicative of improvement in atrial conduction. Approximately 12 h after atropine administration, the patient suffered deteriorating sinus node function with redevelopment of junctional bradycardia with a ventricular rate of 31 bpm (Figure 1C). Theophylline 300 mg was trialed. 12-hours subsequent to theophylline dosing, telemetry-capture (Figure 1D) revealed progressively shortening sinus pauses from sinus arrest of 3.8 s to a briefer pause of 1.32 s to eventual complete resolution of SND with return to normal sinus rhythm. The following morning, a repeat EKG (Figure 1E) was obtained that confirmed the patient had reverted to normal sinus rhythm, with a heart rate of 74 bpm:an increase of 43 bpm from the prior EKG.