A Faint – simple or complex?
Case : 15 years old young lady presents with parents after two episodes of syncope. The symptoms usually occurred during mid morning , there is history that she often skips breakfast. There is no family history of sudden deaths. These symptoms never occurred during exercise. She is completely conscious within 4-5 minutes of episode. There is no history of palpitation or chest heaviness along with syncope. What is next appropriate test to order ?
- a) Echocardiogram
- b) 24 hours Holter assessment
- c) ECG
- d) Tilt –table test
Neurocardiogenic syncope or vasovagal syncope is very common in the teenage years. It is also known as ‘simple faint’. It is characterized by inappropriate vasodilatation and bradycardia leading to neurally mediated systemic hypotension and subsequent decreased cerebral blood flow. There is history of extended period of upright position and dehydration. Patient can often experience light headedness, nausea , diaphoresis and visual changes.
In vasovagal events there is no history of post ictal drowsiness, which is mostly associated with syncope due to convulsion or stroke.
Such vasovagal syncope are often associated with growth spurts, menses and rapid weight loss.
Diagnosis is mostly history based in vasovagal syncope, however in case of frequent episodes Head up Tilt –table test is also ordered.
Typical management of vasovagal syncope includes reassurance, education ,increased fluid and salt intake and behavior modification such as positional adjustments when symptoms start. Rarely medications are advocated.
It must be differentiated from complex faint episode - other serious and potentially life threatening cardiac and neurological causes of loss of consciousness.
In above mentioned question answer is option (c), because in each case of benign looking syncope ECG needs to be done to rule out arrhythmic syncope.
Common Clinical and ECG features suggesting arrhythmic syncope:
- Syncope during exertion or supine
- Palpitation at the time of syncope
- Family history of sudden cardiac death
- Common ECG features ( describing all the ECG features is beyond the scope of this article)
- Bundle branch block (particularly Left bundle branch block) along with wide QRS duration (>120 msec)
- Sinus bradycardia ( <50 /min)
- Tachycardia (it can be SVT or VT particularly if HR >150/min)
- AV block /complete heart block
- Prolonged or Short QT syndrome
- Other patterns of Brugada syndrome or catecholamine polymorphic VT ( Rare)