Stokes-Adams attack

Classical description of a Stokes Adams attack is of collapse without warning associated with a loss of consciousness lasting a seconds not minutes

• loss of consciousness can occur in any posture and is abrupt
• individual is pale initially
  • though the patient is pale and pulseless; respiration continues
• on recovery the patient becomes flushed; this is due to well-oxygenated blood which has been in the pulmonary capillaries during the period of circulatory arrest being flung into systemic capillaries which are widely dilated as a result of the accumulation of vasodilator metabolites.
• respiration continues during the attack
• flushing does not always occur
• after about 15-20 seconds twitching may begin due to cerebral anoxia
• attack usually lasts for about 30 seconds but may last longer and death may result
• occasionally, if the attacks occur when the patient is asleep, the only complaint may be of the face feeling hot and flushed on waking.
• Stokes Adams attacks are typically associated with complete heart block - however this condition also been described in other diseases such as tachy-brady syndrome

Notes:

• the term Stokes Adams attack is still commonly used by non-specialist doctors although rarely used by cardiologists and doctors specialising in the management of syncope (1)
• heart block still causes syncope but is rare (<3% of cases)
  • heart block does not often present with classical Stokes Adams attacks
    • other cardiovascular disorders can present with sudden, transient loss of consciousness - these collapses might previously have been described clinically as Stokes Adams attacks, but improved understanding of cardiovascular physiology and pathology and techniques for investigation, and the development of specific diagnostic classifications have left the term increasingly redundant (1)
      • common causes of cardiovascular syncope to consider include:
        • vasovagal syncope
          • commonest cause of the simple faint - caused by hypotension resulting from sudden dilatation of venous capacitance vessels sometimes associated with vagally mediated bradycardia
        • orthostatic hypotension
          • sudden fall in blood pressure occurring on standing - can be secondary to hypovolaemia resulting from drugs, dehydration, or from vasodilators and is associated with atherosclerosis, diabetes, and long-lasting confinement to bed
        • carotid sinus hypersensitivity (three types)
          • 1) cardioinhibitory, resulting in symptomatic asystole of longer than 3 s.
          • 2) vasodepressor, resulting in systolic blood pressure fall 50 mm Hg
          • 3) Mixed, a combination of 1) and 2)
        • cardiac arrhythmias
          • tachyarrhythmias (eg, ventricular tachycardia) and bradyarrhythmias (eg, sinus arrest and complete heart block) can cause syncope through loss of cardiac output

Reference:

1. Harbison JL et al. Stokes Adams attacks and cardiovascular syncope. Lancet 2002; 359(9301):158-160
2. Sigurd B, Sandoe E.Management of Stokes-Adams syndrome. Cardiology 1990;77:195–208.