5,371
edits
No edit summary |
No edit summary |
||
Line 1: | Line 1: | ||
'''Sick sinus syndrome''' (SSS) or '''sinus node dysfunction''' (SND) refers to any condition where the [[Sinoatrial node|SA node]] is dysfunctional. This causes intermittent [[sinus bradycardia]], sinus pauses (pauses <3 seconds), [[sinus arrest]] (pauses >3 seconds), tachycardia-bradycardia syndrome, [[chronotropic incompetence]], or [[Sinoatrial block|SA block]]. Patients present with intermittent complaints of fatigue, dizziness, palpitations, syncope, etc. | '''Sick sinus syndrome''' (SSS) or '''sinus node dysfunction''' (SND) refers to any condition where the [[Sinoatrial node|SA node]] is dysfunctional. This causes intermittent [[sinus bradycardia]] (< 40 bpm when awake), sinus pauses (pauses <3 seconds), [[sinus arrest]] (pauses >3 seconds), tachycardia-bradycardia syndrome, [[chronotropic incompetence]], or [[Sinoatrial block|SA block]]. Patients present with intermittent complaints of fatigue, dizziness, palpitations, syncope, etc. | ||
SSS is usually idiopathic, due to SA node degeneration, but it can also be due to [[Ischaemic heart disease|ischaemia]] or structural cardiac abnormalities like [[Cardiomyopathies|cardiomyopathy]]. It mostly affects elderly. | SSS is usually idiopathic, due to SA node degeneration, but it can also be due to [[Ischaemic heart disease|ischaemia]] or structural cardiac abnormalities like [[Cardiomyopathies|cardiomyopathy]]. It mostly affects elderly. | ||
Line 6: | Line 6: | ||
== Tachycardia-bradycardia syndrome == | == Tachycardia-bradycardia syndrome == | ||
Tachycardia-bradycardia syndrome | '''Tachycardia-bradycardia syndrome''', usually called simply '''tachy-brady syndrome''', refers to when a patient both has alternating atrial tachyarrhythmias (like [[atrial fibrillation]]) and symptomatic sinus bradycardia. This occurs in 50% of those with SSS. The atrial tachyarrhythmia may spontaneously convert to sinus rhythm, but because the sinus node is sick, there may be a pause before the sinus node kicks in, which can be symptomatic. | ||
The syndrome can cause dizziness, syncope, palpitations, and chest pain. Pacemaker implantation is usually necessary. | The syndrome can cause dizziness, syncope, palpitations, and chest pain. Pacemaker implantation is usually necessary, especially if the atrial tachyarrhythmia has a rapid ventricular response. The ideal treatment would be rate-limiting drugs, like [[beta blockers]] or [[calcium channel blockers]], but these would worsen the sinus bradycardia when it occurs. Implantation of a pacemaker (which prevents symptomatic bradycardia) can allow for administration of rate-limiting drugs to reduce the rapid ventricular response of the tachyarrhythmia, alleviating the symptoms. | ||
[[Category:Cardiology]] | [[Category:Cardiology]] | ||
[[Category:Internal Medicine (POTE course)]] | [[Category:Internal Medicine (POTE course)]] |