From the Research
Sinus arrest can cause symptoms when it lasts for approximately 3 seconds or longer, as evidenced by a study published in 2023 1, which highlights the importance of prompt treatment to prevent mortality and morbidity. The duration of sinus arrest before symptoms start can vary depending on several factors, including the patient's underlying cardiac function, position, and cerebral autoregulation capabilities.
- Brief pauses of less than 2 seconds are often asymptomatic and may go unnoticed.
- As the duration increases beyond 3 seconds, patients typically begin experiencing lightheadedness, dizziness, or syncope (fainting).
- More prolonged episodes lasting 5-6 seconds or longer almost always produce noticeable symptoms and may lead to loss of consciousness. The mechanism behind these symptoms involves decreased cardiac output during the pause, resulting in reduced cerebral perfusion, as noted in a study on pacemaker implantation for persistent sinus node dysfunction in a patient with COVID-19 2. Patients with known sinus node dysfunction should be monitored for these pauses, and those experiencing symptoms should seek immediate medical attention, as hospitalization for permanent pacemaker implantation in the context of isolated sinus node dysfunction is associated with increased mortality compared with an outpatient strategy 1. Treatment may include medication adjustments or pacemaker implantation if pauses are symptomatic or prolonged, as seen in a case of prolonged sinus arrest due to the obstruction of a sinus node branch after percutaneous coronary intervention of the right coronary artery 3.