To diagnose ventricular tachycardia, your doctor may review your symptoms and your family and medical history and conduct a physical examination.
Your doctor may order several tests to diagnose your condition, determine the cause and severity of your condition, and determine the most appropriate treatment.
In some cases, ventricular tachycardia may be a medical emergency and require an urgent diagnosis and prompt treatment.
Several heart tests also may be necessary to diagnose ventricular tachycardia.
An electrocardiogram, also called an ECG or EKG, is the most common tool used to diagnose ventricular tachycardia. It's a painless test that detects and records your heart's electrical activity using small sensors (electrodes) attached to your chest and arms.
An ECG records the timing and strength of electrical signals as they travel through your heart. Your doctor can look for patterns among these signals to determine what kind of tachycardia you have and how abnormalities in the heart may be contributing to a fast heart rate.
Your doctor may also ask you to use portable ECG devices at home to provide more information about your heart rate. These devices include:
Holter monitor. This portable ECG device is carried in your pocket or worn on a belt or shoulder strap. It records your heart's activity for an entire 24-72 hour period, which provides your doctor with a prolonged look at your heart rhythms.
Your doctor will likely ask you to keep a diary during the same 24 hours. You'll describe any symptoms you experience and record the time they occur.
Event monitor. This portable ECG device is intended to monitor your heart activity over a few weeks to a few months. You wear it all day, but it records only at certain times for a few minutes at a time.
With many event monitors, you activate them by pushing a button when you experience symptoms of a fast heart rate. Other monitors automatically sense abnormal heart rhythms and then start recording. These monitors allow your doctor to look at your heart rhythm at the time of your symptoms.
- Transtelephonic monitor. This device provides continuous heart rhythm monitoring but must be worn continuously. It may or may not include wires.
- Implantable loop recorder. This is an implantable device that has no wires and can sit underneath your skin for up to three years to continuously monitor your heart rhythm.
Imaging of the heart may be performed to determine if structural abnormalities are affecting blood flow and contributing to ventricular tachycardia.
Types of cardiac imaging used to evaluate V-tach include:
- Echocardiogram (echo). An echocardiogram creates a moving picture of your heart using sound waves via a transducer placed on the chest that emits and detects these waves. An echo can identify abnormalities in the heart valves and heart muscle that contribute to poor blood flow.
- Magnetic resonance imaging (MRI). A cardiac MRI provides still or moving pictures of how the blood is flowing through the heart and detects irregularities. It is often used to evaluate potential causes of ventricular tachycardia.
- Computerized tomography (CT). CT scans combine several X-ray images to provide a more detailed cross-sectional view of the heart.
- Coronary angiogram. This may be used to study the flow of blood through your heart and blood vessels. Your doctor may use a coronary angiogram to reveal potential blockages or abnormalities. It uses a dye and special X-rays to show the inside of your coronary arteries.
- Chest X-ray. This painless test is used to take still pictures of your heart and lungs and can detect if your heart is enlarged.
Your doctor may recommend a stress test to see how your heart functions while it is working hard during exercise or when medication is given to make the heart beat faster.
In an exercise stress test, electrodes are placed on your chest to monitor heart function while you exercise, usually by walking on a treadmill. Other heart tests may be performed in conjunction with a stress test.
Your doctor may recommend an electrophysiological test to confirm the diagnosis or to pinpoint the location of problems in your heart's circuitry.
During this test, a doctor inserts thin, flexible tubes (catheters) tipped with electrodes into an access point, usually your groin or neck, and guides them through your blood vessels to various spots in your heart.
Your doctor may order additional tests as needed to diagnose an underlying condition that is contributing to ventricular tachycardia and judge the condition of your heart.