Syncope due to unexpected paroxysmal sinus arrest

Area of Science:

• Cardiology
• Electrophysiology

Background:

• Sick sinus syndrome (SSS) can present with unpredictable sinus pauses.
• Syncope is a concerning symptom that warrants thorough investigation into cardiac causes.

Purpose of the Study:

• To describe two unique cases of prolonged sinus arrest leading to syncope.
• To differentiate these events from other causes of syncope and propose a classification.

Main Methods:

• Case report of two patients presenting with syncope.
• Clinical evaluation and electrophysiological assessment (implied).

Main Results:

• Two patients had unexpected, long sinus arrest causing syncope.
• No pre-existing signs of SSS or increased vagal tone were noted.
• The prolonged asymptomatic pauses resembled paroxysmal sub-AV nodal block.

Conclusions:

• The presented cases are suggested to be classified as paroxysmal sinus arrest.
• Paroxysmal sinus arrest is proposed as a potential manifestation of sick sinus syndrome.