Heart Rhythm Disorders (cont.)
Ventricular Fibrillation (V Fib)
Ventricular Fibrillation is technically not a rapid heart rhythm because the
heart has ceased to beat. In ventricular fibrillation, the ventricles do not have a coordinated
electrical pattern and the ventricles, instead of beating, just jiggle. Since
the heart doesn't beat, the body dies. This rhythm is often associated with a
heart attack in which the ventricular muscle doesn't get enough blood supply
(myocardial ischemia), becomes irritated, and causes the whole ventricle to stop
beating. The only treatment for this is defibrillation with an electrical shock.
Automated External Defibrillators (AEDs) in public places have helped decrease
the mortality from sudden cardiac death, but prevention remains the mainstay to
survive this event. Some people, such as those with a very weak heart muscle or
who have a prior history of ventricular fibrillation will require an
implantable defibrillator to
prevent future episodes of sudden death and treat this rhythm. Aside from
myocardial ischemia, other causes of ventricular fibrillation may include severe
weakness of the heart muscle, electrolyte disturbances,
drug overdose, and poisoning.
Ventricular Flutter
Ventricular Flutter is another rapid heart rate that originates in the
ventricle. The causes are the same as ventricular fibrillation, but because of the electrical
conduction pattern in the heart pathways, an organized signal is provided to the
ventricles, allowing them to beat. This remains an emergency, because without
treatment, this rhythm will degenerate to ventricular fibrillation.
Paroxysmal supraventricular tachycardia (PSVT)
Paroxysmal supraventricular tachycardia (PSVT) occurs when the pathways in
the AV node or atrium allow an altered conduction of electricity, and the atrium begins
firing in a regular - fast rate, sometimes more than 150 -200 times per minute. The
ventricle, sensing the electrical activity coming through the AV node, beats
along with each stimulation, and this tachycardia occurs.
This is rarely a life threatening event, but most people feel uncomfortable
when PSVT occurs. They may become lightheaded, weak, have
shortness of breath,
and describe a feeling of fullness in the throat. PSVT is usually tolerated
and can even stop on its own. If this is a first time event, activating EMS
(emergency medical services) and
calling 911 is important, since other tachycardias can be life threatening.
The treatment for PSVT are attempts at stimulating the vagus nerve to slow the
heart (see vasovagal syncope above) by holding one's breath and bearing down as
if to have a bowel movement. Intravenous medications are often used to break the
episode. Many patients have PSVT due to congenital abnormalities in the
conduction system. External causes can include hyperthyroidism,
electrolyte imbalances, and the use of
caffeine, alcohol, over-the-counter cold medications containing stimulants, or
illegal drugs like cocaine and methamphetamine.
Next: Wolf-Parkinson-White Syndrome »
- Beta Blockers - Learn more about Beta Blockers, a drug that treats angina and other heart rhythm disorders, migraines, high blood pressure, panic attacks, and tremors. Generic and brand names are included in the article.
- Electrolytes - Read about blood electrolytes (sodium, potassium, chloride, and bicorbonate) and the effects of electrolyte imbalances like kidney failure, low blood pressure, hypokalemia, and hyperkalemia.
- Low Blood Pressure - Learn about low blood pressure (hypotension). Low blood pressure is blood pressure below normal and symptoms may include: lightheadedness, dizziness, fainting upon standing (orthostatic hypotension). There are many causes of low blood pressure, and treatment is dependant upon the cause.
Latest Medical News
Heart RSS