What is syncope?
The term syncope means cessation, cutting short or pause. In medical practice, syncope refers to an episodic loss of consciousness and postural tone and an inability to stand, due to diminished flow of blood to the brain. It is synonymous in everyday language with fainting. Feeling faint and feeling of faintness are also commonly used terms to describe sudden loss of strength and other symptoms that characterize the impending or incomplete fainting spell. Incomplete fainting spell is called presyncope. Syncope is abrupt in onset, lasts for a brief period and it recovery is complete and spontaneous without any specific resuscitative measures.
Faintness and syncope are among the most common of all medical phenomenons. In day-to-day life, every person has experienced some syncopal or presyncopal attacks. The patient may refer to the symptoms as light-headedness, giddiness, dizziness, a drunken feeling or a blackout.
Clinical features of syncope:
The commonest type of faint is the vasovagal syncope. It is also called vaso depressor syncope. The person is usually standing or sitting at the beginning of the attack. The patient may feel certain symptoms (called prodromal symptoms) before the attack, like giddiness or apprehension and sway. Sometimes he may develop a headache and pallor of the face. There is sweating over the body and face. Salivation, stomach discomfort, nausea and sometimes vomiting can occur. Vision may dim and there may be ringing sound in the ear. The prodromal symptoms vary from a few seconds to minutes. At this time, if the patient lies down, there will not be loss of consciousness and he will recover completely. If the prodromal symptoms progress into an attack of syncope, the consciousness is lost and the person will fall to the ground. The patient lies motionless and the pulse is weak. Blood pressure is reduced. There is striking facial pallor and breathing is shallow. Once the patient is lying down, the blood flow to the brain is no longer reduced. The color of the skin becomes pink, breathing becomes quicker and deeper and consciousness is regained. There is no confusion, headache and drowsiness after the attack.
Causes of syncope:
What are the tests required to diagnose syncope?
- Neurogenic vasodepressor reactions:
- Vasovagal syncope, carotid sinus hypersensitivity
- Diminished venous return to the heart during urination, coughing, straining, weightlifting
- Intrinsic psychic stimuli like fear, anxiety, and sight of blood.
- Sympathetic nervous system innervation failure leading to postural-Orthostatic hypotension
- Gullain Barre syndrome
- Antihypertensive medications
- Spinal cord trauma
- Diminished cardiac output due to
- Disease of heart
- Reduced blood volume form dehydration or blood loss.
- Other causes
- Anxiety attacks
- Environmental overheating
- Conditions that may mimic syncope:
- Anxiety attacks and hyperventilation syndrome: Here there is light-headedness but there is no loss of consciousness. There is no facial pallor.
- Acute blood loss
- Transient cerebral ischemic attacks
- Drop attacks: the patient falls frequently to the ground without warning symptoms and without loss of consciousness. There is no dizziness. The usual cause for this is diminished blood flow causing ischemia to the brainstem
A detailed physical examination is necessary to rule out medical diseases. Blood pressure and pulse should be checked in standing and lying down procedures to rule out orthostatic hypotension. ECG should be taken to rule out cardiac disease. Continuous electrocardiogram monitoring is helpful in ruling out arrhythmias as a cause of syncopal attack. Tilt table test is more useful.
What are the treatments available for syncope?
When patient is seen in the initial stages of fainting, he should be placed in such away that blood flow to the brain is maximal. He should be made to lie down with legs elevated. All tight clothing should be loosened. He must be turned to side to prevent aspiration if he vomits and to keep the airway intact. Nothing should be given to the patient through mouth till he is fully conscious. The patient should be made to rise only after he fully recovers and be watched carefully for a few minutes.
Myocardial infarction and hemorrhage should be rule out. In postural hypotension, patient is advised not to get up from bed suddenly. Elastic stocking may be helpful. The foot end of the bed should be kept raised by wooden blocks. Special corticosteroids like fludrocortisone and increased salt intake may be helpful in chronic orthostatic hypotension .In carotid sinus syncope; the patient is advised to wear dresses with loose collar and not to turn the head suddenly. In elderly patients, trauma due to fall is frequent. So the rooms should be carpeted. Out door walking should be on soft ground rather than hard surfaces.