What defines sick sinus syndrome (SSS)?

What defines sick sinus syndrome (SSS)?

• A. An arrhythmia caused by AV node dysfunction
• B. An arrhythmia caused by SA node dysfunction
• C. A continuous rapid heart rate
• D. Intermittent episodes of ventricular tachycardia

Answer: (B)

Sick sinus syndrome (SSS) is primarily defined by dysfunction of the sinus node, which is responsible for generating and regulating the heart's electrical impulses. In SSS, the sinoatrial (SA) node fails to function properly, leading to irregular heart rhythms. This can manifest as bradycardia (slow heart rate), pauses in heart rhythm, or alternation between slow and fast heart rates.

The hallmark of SSS is the inability of the SA node to maintain a normal heart rhythm, making option B the correct choice. Understanding that the SA node's dysfunction is central to this syndrome helps in recognizing the clinical implications, which may include symptoms like fatigue, palpitations, or syncope due to inadequate heart rate control.

In contrast, the other provided options describe different types of arrhythmias or conditions that do not capture the essence of sick sinus syndrome. For instance, AV node dysfunction relates to a different set of arrhythmias known as heart block, which is distinct from SSS. Continuous rapid heart rates typically describe conditions like atrial fibrillation or supraventricular tachycardia, while intermittent episodes of ventricular tachycardia involve rapid heartbeats that originate from the ventricles, further differentiating them