An Adams-Stokes episode initially manifests with significant pallor, followed by impairment of consciousness that ranges from a fainting tendency to a complete loss of consciousness. The aforementioned episode is elicited by a sudden change in the heart rhythm, that may involve tachyarrhythmia or bradyarrhythmia.

Epileptic seizures without an aura may or may not accompany the Adams-Stokes related episode; their onset is usually acute and unexpected, as is their resolution. Patients tend to resume their prior activity without realizing that epileptic activity has taken place. After the individual has fully regained consciousness, flushing is observed, that can be attributed to reactive hyperemia. The episodes described above may develop regardless of the posture of the patient and may be experienced up to multiple times each day.

Approximately 10% to 20% of all Adams-Stokes syndrome episodes are induced by third-degree sinoatrial block paroxysms [1] [2]. A variety of supraventricular arrhythmias can also be held accountable for the syncopic events observed in Adams-Stokes syndrome and can even co-exist in the same patient [3] [4] [5]. The presence of a well-defined dysrhythmic condition leads to additional symptoms that can aid in the diagnosis of the underlying cause; symptoms most commonly associated with dysrhythmias that can lead to an Adams-Stokes episode include fatigue, palpitations, and discomfort.

Any patient presenting with a syncopic event is required to undergo multiple tests and examinations in order to detect the precise cause of the loss of consciousness. A fainting spell raises suspicion towards Adams-Stokes syndrome, when the patient reports a sudden-onset fainting tendency or loss of consciousness, following otherwise unexplained pallor. After the episode is resolved, the patient typically reports flushing.

For the physician to establish an accurate diagnosis of Adams-Stokes syndrome, many of the following tests should be carried out and evaluated:

• A comprehensive medical history, including underlying cardiovascular or other pathologies, prior similar episodes and their characteristics, as well as medication history. Digoxin is particularly known for its potential to lead to toxicity, a state which may further cause a third-degree atrioventricular block, amongst others, and an Adams-Stokes episode [6].
• Blood pressure and heart rate measurement.
• Electrocardiography (ECG): Although it may appear normal after the resolution of the episode, a 24-hour ECG monitoring will help to illustrate multiple types of dysrhythmia associated with the syndrome [7].
• Blood tests: Digoxin can be directly measured in the blood. Furthermore, blood tests can detect enzymes associated with myocardial infarction.
• Cardiac catheterization.
• Electrophysiologic studies.

A potential Adams-Stokes episode, complicated by convulsions should prompt neurological evaluation as well.

1. Rasmussen K. Chronic sinoatrial heart block. American Heart journal. 1971; 81:38.
2. Jensen G, Sigurd B, Meibom J, Sandoe E. Adams-Stokes syndrome caused by paroxysmal third-degree atrioventricular block. British Heart Journal, 1973;35: 5I6.
3. Ferrer MI. The sick sinus syndrome in atrial disease. Journal of the American Medical Association, 1968; 206: 645-46.
4. Slama R, Waynberger M, Motte G, Bouvrain Y. La maladie rhythmique auriculaire. Archives des Maladies du Coeur et des Vaisseaux, 1969; 62 (3): 297.
5. Eraut D, Shaw DB. Sinus bradycardia. British Heart Journal, 1971; 33:742.
6. Eichhorn EJ, Gheorghiade M. Digoxin. Prog cardiovasc dis. 2002; 44 (4): 251–66.
7. Schlant RC, Adolph RJ, DiMarco JP, et al. Guidelines for electrocardiography. A report of the American College of Cardiology/American Heart Association Task Force on Assessment of Diagnostic and Therapeutic Cardiovascular Procedures (Committee on Electrocardiography). Circulation. 1992 Mar; 85(3):1221-8.