Ventricular Tachycardia

Ventricular tachycardia is an abnormally fast heart rate. The abnormal heart rate originates in one of the heart's lower chambers (ventricles). It is diagnosed when there are three or more beats in succession originating from a ventricle. The heart beats at a rate greater than 100 beats per minute, but less than 200 beats per minute. Ventricular tachycardia is considered sustained if it lasts more than 30 seconds. When this condition is sustained, the ventricles are not able to fill with enough blood for the heart to keep blood flowing properly through the body. This can result in lowered blood pressure, heart failure , and death.

  • Causes


    Damage to the ventricles can cause ventricular tachycardia. This damage to the heart muscle may be due to conditions like
    heart attack
    or
    cardiomyopathy
    .

  • Definition

    Ventricular tachycardia is an abnormally fast heart rate. The abnormal heart rate originates in one of the heart's lower chambers (ventricles). It is diagnosed when there are three or more beats in succession originating from a ventricle. The heart beats at a rate greater than 100 beats per minute, but less than 200 beats per minute.


    Ventricular tachycardia is considered sustained if it lasts more than 30 seconds. When this condition is sustained, the ventricles are not able to fill with enough blood for the heart to keep blood flowing properly through the body. This can result in lowered blood pressure,
    heart failure
    , and death.

    Heart Chambers and Valves
    heart anatomy
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  • Diagnosis

    This condition can be challenging to diagnose. Ventricular tachycardia often happens in emergency situations. It must be identified and treated very quickly.

    To make the diagnosis, the doctor will order tests, such as:

    • Electrocardiogram
      (ECG)
    • Exercise stress test
      to test the heart’s performance
    • Electrophysiology test
      to study the electrical signals of the heart

  • Prevention

    If you are at risk for ventricular tachycardia, your doctor may make these recommendations:

    • Take beta-blockers to manage blood pressure.
    • Take medicine to control heart rate.
    • Get proper treatment for any underlying heart conditions that you may have.
    • Avoid certain substances, such as caffeine, cocaine, and alcohol.
    • Take steps to avoid heart disease, such as maintaining a healthy weight and exercising.

    • If you smoke,
      quit
      .

  • Risk Factors

    The following factors may increase your chance of ventricular tachycardia:

    • Coronary artery disease
    • History of heart attacks

    • Heart abnormalities (eg, cardiomyopathy,
      mitral valve prolapse
      , valvular heart disease, ion channel disorders)
    • Diagnosis of electrical instability
    • Sarcoidosis

    • Beginning treatment for
      hypothyroidism
    • Use of certain medicines (eg, digitalis, antipsychotics, anti-arrhythmic drugs)
    • Extreme physical or emotional overstimulation
    • Low oxygen levels in the blood
    • Very high levels of acid in bodily fluids (eg, due to kidney disease or
      diabetes)

    • Stimulants (eg, caffeine,
      cocaine
      ,
      alcohol
      )
    Coronary Artery Disease
    Coronary Artery plaque
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  • Symptoms

    Symptoms may include:

    • A sensation of the heart beating very rapidly
    • Feeling dizzy
    • Feeling short of breath
    • Fainting
    • Chest discomfort
    • Pale skin color

  • Treatment


    In an emergency situation,
    CPR
    or a defibrillator may be required.

    Other treatment options may include:


    • Medicine, such as:

      • Drugs to lower the heart rate (eg, lidocaine, procainamide, amiodarone)

      • Beta-blockers to manage
        high
        blood pressure

        or heart rate

    • Surgery, such as:

      • Radiofrequency ablation
      • Open heart surgery


    If other approaches fail, an
    automatic defibrillator
    will be inserted into the heart to deliver shocks as needed to keep the heart rate steady.