Sinus arrest is characterized by a temporary absence of electrical activity generated by the sinoatrial node, resulting in pauses in the cardiac rhythm that are visible on the electrocardiogram (ECG). These pauses appear as prolonged RR intervals without corresponding P waves or QRS complexes, indicating a failure in the generation or transmission of the sinus impulse.

Electrocardiographic Criteria

  • Temporary absence of sinus activity lasting more than 1.5 times the baseline PP cycle

ECG in Sinus Arrest

Electrocardiogram with sinus arrest

Sinus arrest. Note the pauses in the long lead II rhythm strip, with no P waves. The temporary absence of sinus activity exceeds 1.5 times the baseline PP cycle, which characterizes sinus arrest.

References

  1. Samesima N, God EG, Kruse JCL, Leal MG, et al. Diretriz da Sociedade Brasileira de Cardiologia sobre a Análise e Emissão de Laudos Eletrocardiográficos – 2022. Arq Bras Cardiol. 2022;93(3 Suppl 2):2–19.