Sick Sinus Syndrome SSS Flashcards
What is sick sinus syndrome (SSS)?
Sick Sinus Syndrome is a group of arrhythmias caused by dysfunction of the sinoatrial (SA) node, resulting in abnormal heart rhythms.
What are the common types of arrhythmias seen in Sick Sinus Syndrome?
Sinus bradycardia, sinus arrest, sinoatrial exit block, and alternating bradycardia-tachycardia syndrome.
What are the typical symptoms of Sick Sinus Syndrome?
Symptoms include fatigue, dizziness, syncope, palpitations, and dyspnoea.
What is the aetiology of Sick Sinus Syndrome?
Causes include fibrosis of the SA node, ischaemic heart disease, cardiomyopathies, medications, and electrolyte imbalances.
What is the pathophysiology of Sick Sinus Syndrome?
Dysfunction of the SA node leads to impaired impulse initiation, resulting in bradycardia, pauses, or irregular heart rhythms.
What are the risk factors for developing Sick Sinus Syndrome?
Ageing, ischaemic heart disease, heart surgery, hypothyroidism, and the use of rate-slowing medications like beta-blockers or calcium channel blockers.
What investigations are used to diagnose Sick Sinus Syndrome?
ECG, Holter monitoring, event recorders, and electrophysiological studies.
What are the characteristic ECG findings in Sick Sinus Syndrome?
Sinus bradycardia, sinus pauses, sinus arrest, SA block, or alternating bradycardia-tachycardia patterns.
What is the role of Holter monitoring in Sick Sinus Syndrome?
Holter monitoring records continuous ECG over 24-48 hours to detect intermittent arrhythmias.
What are the complications of untreated Sick Sinus Syndrome?
Complications include syncope, falls, thromboembolism (e.g., stroke), and heart failure.
What are the differential diagnoses for Sick Sinus Syndrome?
Atrioventricular block, atrial fibrillation, hypothyroidism, and medication-induced bradycardia.
How is Sick Sinus Syndrome managed in symptomatic patients?
Management includes the implantation of a permanent pacemaker to regulate heart rhythm.
What are the indications for a pacemaker in Sick Sinus Syndrome?
Symptomatic bradycardia, syncope due to sinus pauses, and alternating bradycardia-tachycardia syndrome.
What are the non-pacemaker management options for Sick Sinus Syndrome?
Discontinuing or adjusting medications that exacerbate bradycardia and addressing reversible causes like electrolyte imbalances or hypothyroidism.
What lifestyle advice is given to patients with Sick Sinus Syndrome?
Avoidance of excessive caffeine and alcohol, regular follow-up, and monitoring for symptoms like syncope or palpitations.
What is the role of anticoagulation in Sick Sinus Syndrome?
Anticoagulation may be indicated in patients with atrial fibrillation or other arrhythmias to reduce the risk of thromboembolism.
What is tachycardia-bradycardia syndrome?
A subtype of Sick Sinus Syndrome where periods of bradycardia alternate with episodes of supraventricular tachycardia, such as atrial fibrillation.
What is the prognosis of Sick Sinus Syndrome?
Prognosis is generally good with appropriate management, particularly with pacemaker implantation, though underlying heart disease may affect outcomes.
How is Sick Sinus Syndrome related to ageing?
Ageing leads to fibrosis and degeneration of the sinoatrial node, making Sick Sinus Syndrome more common in older adults.
What is the role of electrophysiological studies in Sick Sinus Syndrome?
These studies are used to assess SA node function and identify conduction abnormalities in unclear cases.
What medications can exacerbate Sick Sinus Syndrome?
Beta-blockers, calcium channel blockers, digoxin, and antiarrhythmics can worsen bradycardia or conduction abnormalities.
What are the clinical signs of Sick Sinus Syndrome on physical examination?
Signs may include a slow or irregular pulse, hypotension, and evidence of underlying heart disease.
What is sinus arrest?
Sinus arrest is a pause in sinus node activity resulting in the absence of P waves for a period, often followed by escape rhythms.
What is sinoatrial exit block?
SA exit block occurs when impulses generated by the SA node fail to conduct to the atria, leading to dropped beats on ECG.
