Paroxysmal Ventricular Standstill: A Rare Cardiac Manifestation of Syncope

BACKGROUND Transient abrupt loss of consciousness due to sudden but pronounced decrease in cardiac output caused by a change in heart rate and rhythm is termed Stokes-Adams disease. Causes of Stokes-Adams syndrome are 1) transition from normal rhythm to high grade block, 2) slowing of idioventricular rhythm in the course of complete heart block, and 3) abnormal ventricular rhythm such as ventricular tachycardia and ventricular fibrillation. Paroxysmal ventricular standstill is one of the rarest causes of Stokes-Adams attack. It is well documented that some patients with a diagnosis of epilepsy actually have a cardiac cause for their convulsions. Brevity of these episodes sometimes makes diagnosis difficult. CASE REPORT We present a case of 40-year-old builder who was normally fit and healthy who developed paroxysmal ventricular standstill. He presented to the Emergency Department with multiple episodes of seizure-like activity. Blood tests which included antibody screen were normal except for hypophosphatemia. Computed tomography head scan was normal. He was commenced on intravenous phenytoin infusion which did not abort his seizure-like episodes. Eventually, ventricular standstill was recorded on cardiac monitoring. The seizure-like episodes were determined to be Stokes-Adams attacks. He underwent transcutaneous pacing and then transvenous pacing with eventual permanent pacemaker insertion. He did not have further episodes at yearly follow-up. CONCLUSIONS This case serves as a reminder of the diagnostic dilemma between syncope and seizures. Misdiagnosing cardiac dysrhythmia for epilepsy could lead to adverse consequences for the patient. It is incumbent upon the emergency physician to perform cardiac monitoring on all patients who present with syncope or convulsion in order that dysrhythmia is observed during such episode.