Ventricular Tachycardia (Arrhythmia): Symptoms, Causes, Diagnosis And Treatment

Arrhythmia is a group of conditions that cause an abnormal heartbeat, usually because of damage to the electrical system that controls the heart’s beats. Although you may not hear about it much, or only hear about it when growing older, it covers some worryingly severe conditions. In the United States, arrhythmic disturbances are considered to be the leading cause of death (cardiac arrest).

With all these very scientific names, it’s hard to picture what is happening in these conditions. Your heart has two sections; the atria at the top of the heart, and the ventricles at the bottom. The atria are responsible for getting blood into your heart, whereas the ventricles are responsible for getting blood out.

Ventricular tachycardia strikes when the electrical system in the lower part of the heart has either become damaged or malfunctioned, and it results in a heartbeat that is too quick. This is especially dangerous because if blood does not leave the heart, the body will not receive enough oxygen, which can lead to death. A more severe form of this is ventricular fibrillation, where the ventricles attempt to beat even more quickly, with over 300 beats per minute, and blood is no longer pumped from the heart. This results in sudden cardiac arrest.

What symptoms should you look out for?

Because ventricular tachycardia is episodic, these symptoms can appear during periods in which you have a fast heart beat. These symptoms can stop and start suddenly, and there are even some who experience no symptoms at all.

Here are some symptoms to watch out for:

• Chest discomfort, owing to reduced blood flow through the blood vessels in the heart
• Fainting, due to decreased blood flow to your brain. Sometimes you will feel weak, nauseous, or like your senses are constricting before fainting.
• Lightheadedness and dizziness
• Feeling your heart pounding or racing
• Shortness of breath

If you have ventricular fibrillation, an episode can be fatal, as blood no longer reaches vital parts of the body and you will lose consciousness. However, about an hour before collapsing, these symptoms may be present:

• Chest discomfort
• Lightheadedness and dizziness
• Nausea
• Feeling your heart pounding, racing, or beating abnormally
• Shortness of breath

What causes these conditions?

Ventricular tachycardia and ventricular fibrillation are caused by abnormal electrical signals at the bottom of the heart. Many different conditions and diseases that do damage to the heart or speed it up can culminate in ventricular tachycardia.

Here’s a list of things that can lead to both ventricular fibrillation and ventricular tachycardia:

• Scarring that results from a heart attack
• Electrocution accidents or a heart injury, e.g. a hard blow above the heart
• Congenital heart disease
• A heart muscle disease, where the muscles become weakened or thickened
• Heart surgery
• Sudden cardiac death
• Certain medications
• Potassium levels in the blood that are too high or low
• Heart failure

Other blood-related causes can lead to ventricular tachycardia, like changes in your blood’s pH level (acid/base). A lack of the proper amount of oxygen is also a cause both of these conditions.

What will a doctor use to diagnose ventricular tachycardia?

When doing tests for ventricular tachycardia, doctors will generally try to look for things like an absent pulse, previous times of losing consciousness, low blood pressure, or a rapid pulse. There are several different tests they can use besides the common stethoscope. After doing a physical exam, and ECG or electrophysiology study (EPS) can be used to analyze the electrical activity of the heart and find arrhythmias.

For ventricular fibrillation, this should show a chaotic heartbeat, and the doctors will then attempt to find the cause. For ventricular tachycardia, symptoms may not always be present. In this case, they can use something called a Holter monitor to monitor the patient’s heart for 24 to 48 hours. If symptoms are even more scarce, an event recorder or implanted loop recorder will be the best tests, for weekly and monthly symptoms respectively.

What would treatment involve?

If someone has a particularly severe case of ventricular tachycardia, they may need CPR, electric shock, or certain medicines given through the blood. This will temporarily restore their heart, but steps should be taken beyond that to prevent further incidents. Medications can be used for long term treatment but are being used less because of their side effects. A procedure called ablation that can destroy problematic parts of the heart is another long term solution. Something called an implanted cardioverter defibrillator (ICD) may also be recommended by a doctor. It’s implanted in the chest and detects life-threatening abnormal heartbeats, then uses an electric shock to restore the heart to normal.