Incidence of and Risk Factors for Sick Sinus Syndrome in the General Population

Abstract

Background Little is known about the incidence of and risk factors for sick sinus syndrome (SSS), a common indication for pacemaker implantation. Objectives To describe the epidemiology of SSS. Methods This analysis included 20,572 participants (mean baseline age 59 years, 43% male) in the Atherosclerosis Risk in Communities (ARIC) study and the Cardiovascular Health Study (CHS), who at baseline were free of prevalent atrial fibrillation and pacemaker therapy, had a heart rate of ≥50 bpm unless using beta blockers, and were identified as white or black race. Incident SSS cases were identified by hospital discharge ICD-9-CM code 427.81 and validated by medical record review. Results During an average 17 years of follow-up, 291 incident SSS cases were identified (unadjusted rate 0.8 per 1,000 person-years). Incidence increased with age (HR 1.73, 95% CI: 1.47–2.05 per 5-year increment), and blacks had a 41% lower risk of SSS than whites (HR: 0.59, 95% CI: 0.37–0.98). Incident SSS was associated with greater baseline body mass index, height, NT-proBNP, and cystatin C, with longer QRS interval, with lower heart rate, and with prevalent hypertension, right bundle branch block, and cardiovascular disease. We project that the annual number of new SSS cases in the United States will increase from 78,000 in 2012 to 172,000 in 2060. Conclusions Blacks have a lower risk of SSS than whites, and several cardiovascular risk factors were associated with incident SSS. With the aging of the population, the number of Americans with SSS will increase dramatically over the next 50 years.

Sinus Node and Atrial Arrhythmias

“…13,14 Its incidence increases with age, occurring in 1 of every 600 patients >65 years of age. 15 SND accounts for significant healthcare use, including the need for hospitalization and pacemaker implantation (accounting for ≈50% of implant indications in the United States).…”

“…15 SND accounts for significant healthcare use, including the need for hospitalization and pacemaker implantation (accounting for ≈50% of implant indications in the United States). 13 The natural history of SND is characterized by progressive rhythm disturbances and adverse cardiovascular events. The time course can be lengthy and unpredictable; progression from bradycardia to sinoatrial block or sinus arrest can extend over an average of 13 years (range, 7-29 years).…”

G protein-gated I KACh channels as therapeutic targets for treatment of sick sinus syndrome and heart block

“…SSS accounts for about half of all pacemaker implantations in the United States (5,6). The incidence of SSS has been forecasted to increase during the next 50 y, particularly in the elder population (7). Furthermore, it has been estimated that at least half of SSS patients will need to be electronically paced (7).…”

“…The incidence of SSS has been forecasted to increase during the next 50 y, particularly in the elder population (7). Furthermore, it has been estimated that at least half of SSS patients will need to be electronically paced (7). Although pacemakers are continuously ameliorated, they remain costly and require lifelong follow-up.…”

Understanding the ECG Part 4: Conduction blocks

“…The most common cause of sick sinus syndrome is age related degeneration of the sinus node, resulting in fibrosis or ion-channel dysfunction, although it may also be due to coronary heart disease (Monfredi et al, 2010). Its symptoms include dizziness, loss of consciousness, palpitations, breathlessness, and exercise intolerance (Jensen et al, 2014). Permanent pacemaker implantation is necessary in symptomatic individuals, especially if there is a history of syncope (Bennett, 2013).…”