Which cardiac arrhythmia is most commonly associated with palpitations accompanied by syncope?

- Ventricular tachycardia is most commonly associated with palpitations and syncope because it is a rapid, potentially unstable ventricular arrhythmia that can lead to severely decreased cardiac output.
- This reduction in cerebral perfusion explains the occurrence of syncope.
- Unlike atrial fibrillation or premature atrial contractions, ventricular tachycardia originates from the ventricles and poses a high risk of hemodynamic compromise and sudden cardiac death.
- Sinus tachycardia is generally a physiological response and rarely causes syncope.
- Thus, ventricular tachycardia's ability to disrupt effective cardiac pumping links it directly to palpitations accompanied by syncope.

Reference: Davidson’s Principles and Practice of Medicine, 24th Edition, Chapter: Disorders of Cardiac Rhythm, Page 540.