Sinus Node Syndrome: Contemporary Therapeutic Approaches

• DOI: https://doi.org/10.22533/at.ed.1595332520115

• Palavras-chave: Sinus Node Syndrome; Artificial Pacemaker; Bradycardia; Therapy; Cardiac Electrophysiology; Sinoatrial Node Dysfunction.

• Keywords: Sinus Node Syndrome; Artificial Pacemaker; Bradycardia; Therapy; Cardiac Electrophysiology; Sinoatrial Node Dysfunction.

• Abstract:

  Sinus node syndrome (SNS) is a heterogeneous set of disorders that compromise the generation and conduction of electrical impulses by the sinoatrial node, resulting in sinus bradycardia, pauses, chronotropic incompetence, and brady-tachy syndrome. Its pathophysiology involves the interaction between intrinsic mechanisms—such as progressive fibrous degeneration and atrial remodeling—and extrinsic factors, including drugs, metabolic disorders, autonomic dysfunctions, and genetic predisposition. Clinically, it manifests as symptoms of cerebral and systemic hypoperfusion, notably dizziness, syncope, and exercise intolerance. This narrative review analyzed recent evidence on pharmacological therapies, permanent pacemaker indication, and emerging strategies. The data confirm that agents such as theophylline and cilostazol can alleviate symptoms in specific scenarios, but they do not replace pacemakers, which remain the most effective intervention in symptomatic SSS, with a consistent impact on reducing syncope and improving quality of life, although with no proven effect on mortality. New approaches, such as leadless pacemakers, physiological stimulation of the conduction system, and cell/gene therapies, show potential but still lack robust studies, especially in populations with SSS. It is concluded that the management of SSS should be individualized, with exclusion of reversible causes, careful therapeutic evaluation, and use of a pacemaker when indicated. Important gaps remain regarding the role of atrial fibrillation, comorbidities, emerging therapies, and pharmacomodulation of automatism, reinforcing the need for prospective research to improve risk stratification and clinical decision-making.