Page 21 - Clinical Pearls in Cardiology

History and General Examination 9

13. What is Stokes-Adams syndrome?
The Stokes-Adams syndrome is defined as an abrupt,
transient loss of consciousness due to sudden but
pronounced decrease in the cardiac output, which is
caused by a sudden change in the heart rate or rhythm.
“Arrhythmia-induced syncope” is a more specific term
for this condition. Most of the patients with Stoke-Adams
or arrhythmia induced syncope have some impairment
of atrioventricular (AV) conduction either during or in
between the attacks.
Characteristically, during the syncopal attack, there
is a stage of initial pallor. Following resumption of the
normal circulation, there is usually a facial flush due to
reactive hyperemia. The patient may resume a previous
conversation or activity without being aware of the pause
produced by the brief period (usually less than 1 minute)
of unconsciousness. Typically a slow or rarely a very
rapid pulse during the period of unconsciousness points
towards the correct diagnosis. Electrocardiographic
monitoring during the syncopal episode or Holter
monitoring may demonstrate the underlying rhythm
and make appropriate therapy possible.
14. What is meant by “obstructive” cardiac syncope?
Some types of structural abnormalities of the heart
can interfere with effective cardiac output and result in
syncopal attack. This type of cardiac syncope is known as
“obstructive” syncope. The obstructive syncope usually
occurs on exertion. The structural abnormalities of
the heart that are commonly associated with syncope
include the following:
Causes of “Obstructive” syncope
• Aortic stenosis
• Hypertrophic obstructive cardiomyopathy (HOCM)
• Atrial myxoma.