Cochin Cardiac Club

Health Blog by Dr.Uday Nair


 Partial or complete loss of consciousness with interruption of awareness of oneself and ones surroundings. When the loss of consciousness is temporary and there is spontaneous recovery, it is referred to as syncope or, in nonmedical quarters, fainting. Syncope accounts for one in every 30 visits to a casualty
Syncope is due to a temporary reduction in blood flow and therefore a shortage of oxygen to the brain. This leads to lightheadedness or a "black out" episode, a loss of consciousness. Temporary impairment of the blood supply to the brain can be caused by heart conditions and by conditions that do not directly involve the heart:

What causes fainting (syncope)?

Decreased blood flow to the brain can occur because

1) the heart fails to pump the blood;
2) the blood vessels don't have enough tone to maintain blood pressure to deliver the blood to the brain;
3) there is not enough blood or fluid within the blood vessels;
4) a combination of reasons one, two, or three above.
5)low blood sugar (often from diabetes),
6)seizures and panic attacks.
7)Severe blood loss can also cause fainting.

Cardiac syncope – when does syncope predict sudden death?

The cardiac causes of syncope can be fatal. There are two major varieties of cardiac syncope: obstructive cardiac lesions, and cardiac arrhythmias.

Obstructive cardiac lesions: Several heart disorders can result in an obstruction of blood flow through the heart. These include obstructed heart valves (aortic stenosis and mitral stenosis are the most common examples; obstructed blood vessels (such as a massive pulmonary embolus; and cardiac tumors (such as an atrial myxoma, a benign tumor that can obstruct the mitral valve). Most of these lesions are readily apparent to a physician taking a careful medical history and doing a careful cardiac examination. And for the most part, they are readily confirmed by performing a simple echocardiogram.

Far more common as a cause of syncope – and especially as a cause of sudden death – are the cardiac arrhythmias. Again, there are two major categories of life-threatening, syncope-producing cardiac arrhythmias: the bradycardias and the tachycardias.

Bradycardias, or slow heart rhythms, are treated effectively by inserting a cardiac pacemaker.

There are two varieties of tachycardia – ventricular tachycardias and supraventricular tachycardias (SVT). With rare exceptions, SVT does not cause syncope nor does it cause sudden death. (The most common exception to this rule is in patients with Wolff-Parkinson-White syndrome (W-P-W), in which, rarely, SVT can degenerate into the much more dangerous ventricular variety of tachycardia.)
Ventricular tachycardia, on the other hand, commonly causes sudden death. And unfortunately, ventricular tachycardia is common in people who have underlying heart disease, and is commonly overlooked by doctors. If it is missed once, neither the doctor nor the patient are likely to get a second chance to undo the error.While there are many kinds of tachycardia, only two produce syncope with any regularity – ventricular tachycardia (VT) and ventricular fibrillation (VF).

Signs and Symptoms:

You may have the following signs and symptoms before you faint:
  • Lightheadedness
  • Feeling warm
  • Blurred vision
  • Sweating
  • Heaviness in your lower limbs
  • Confusion
  • Yawning
  • Nausea, and sometimes vomiting
When you faint, in addition to loss of consciousness, you may have the following symptoms:
  • Turning very pale
  • Falling down or slumping
  • Spasmodic jerks of your body
  • Weak pulse
  • Drop in blood pressure

    Who's Most At Risk?

    People with the following conditions or characteristics are at risk for fainting:

  • Over 65 years of age
  • Already have heart disease, diabetes or high blood pressure
  • Recreational drug use
  • Taking certain medications such as blood pressure medication, insulin, oral diabetes medications, diuretics (water pills), antiarrhythmics, or blood thinners (anticoagulants)
  • Pregnancy

Diagnostic Tests;

Tests may include blood tests, electrocardiogram (ECG), and imaging of the brain, such as magnetic resonance imaging (MRI). Your doctor will focus on medications you take, preexisting medical conditions, and your description of any similar episodes you may have experienced in the past. This will help your doctor pinpoint why you fainted and identify or rule out particular health conditions. If seizures are suspected, your doctor may also perform a test called an electroencephalogram (EEG).

Treatment Options:


You may be able to avoid fainting, depending on the cause.
  • Avoid fatigue, hunger, and stress. Don' t skip meals.
  • Drink plenty of fluids.
  • Avoid changing positions quickly, especially getting up from a sitting or lying-down position.
  • Sleep with the head of your bed raised.
  • Avoid standing for long periods of time.
  • Wearing elastic stockings may keep blood from pooling in your legs, which may reduce blood flow to the brain.
  • Diuretics and other prescription and non-prescription medicines can contribute to the problem, so check with your doctor.
  • Avoid tight clothing around the neck.
  • Turn your whole body and not just your head when looking around.
  • To prevent injuries, cover floors with thick carpeting and avoid driving or operating mechanical equipment.
  • Avoid caffeine and alcohol.
If you feel like you are going to faint, lie down and raise your legs (that helps keep blood flowing to your brain). If you can' t lie down, sit down and put your head between your knees. Or stand with your legs crossed and thighs pressed together -- this can also help keep blood from pooling in your legs.

Drug Therapies

When an irregular heartbeat causes fainting, your doctor may prescribe medications such as beta-blockers or antiarrhythmics
A second form of treatment is ablation. Ablation consists of carefully mapping the electrical system of the heart (either in the electrophysiology laboratory or in the operating room), locating the part of the electrical system that is causing the arrhythmia, and ablating the offending area (by freezing it, burning it, or surgically excising it). Unfortunately, most forms of VT are very difficult to localize to a specific “culprit” area. This means that ablation is only infrequently an option for VT (and never for VF).

Please Note-

If fainting is caused by a heart condition, such as a slow or rapid heartbeat, you may need a pacemaker

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