Diagnosing Atrioventricular Nodal Reentry Tachycardia (AVNRT)
Atrioventricular nodal reentry tachycardia (AVNRT) is a type of abnormal heart rhythm, also called an arrhythmia. It happens when the heart suddenly starts beating too fast due to a problem with the heart's electrical signals. In AVNRT, the electrical signal gets stuck in a loop inside the atrioventricular (AV) node, which is a part of the heart that controls the timing of the heartbeat. This looping signal makes the heart pump too fast. AVNRT often happens in younger people without any known heart problems.
To diagnose AVNRT, several examinations, screening tests, and procedures may be done to help confirm the diagnosis of AVNRT. Specialists who may be involved in diagnosing AVNRT include cardiologists and electrophysiologists. Here are some of the examinations and tests that may be performed:
- Medical history: The doctor will ask about your symptoms, medical history, and any past episodes of fast heart rate.
- Physical examination: The doctor will perform a physical examination to check for any abnormal signs of the heart or other underlying conditions.
- Electrocardiogram (ECG): An ECG is a non-invasive test that records the electrical activity of your heart. It can help identify abnormal heart rhythms caused by AVNRT.
- Holter monitor: A Holter monitor is a portable device that records your heart's electrical activity over 24 to 48 hours. It can capture any episodes of rapid heart rate during your daily activities.
- Event monitor: An event monitor is similar to a Holter monitor but is worn for a longer period, usually up to 30 days. It can be activated when you experience symptoms, allowing for the recording of any abnormal heart rhythms during those times.
To determine the type, severity, or stage of AVNRT, additional examinations or tests may include:
- Electrophysiology (EP) study: An EP study is an aggressive procedure performed by an electrophysiologist. During this procedure, thin, flexible wires called catheters are inserted into blood vessels and guided to your heart. The catheters measure the electrical signals in your heart and can help identify the specific location and mechanism of AVNRT.
- Ablation procedure: In some cases, an ablation procedure may be performed during an EP study to treat AVNRT. This involves using heat or cold energy to destroy the abnormal pathway that causes the fast heart rate.
- Echocardiogram: This test uses sound waves to create images of your heart's structure and function. It can help check the overall health of your heart and find any hidden problems with its structure.
- Stress test: A stress test involves exercising on a treadmill or stationary bike while your heart activity is being watched. It can help determine how well your heart functions during physical activity and look for any exercise-induced arrhythmias.
- Cardiac magnetic resonance imaging (MRI): In some cases, a heart MRI may be ordered to obtain detailed images of your heart's structure and function. This test can provide more information about any hidden heart structure problems or damage to the heart muscle.
These examinations, tests, and procedures are crucial in diagnosing AVNRT and determining its characteristics. However, it's important to consult with a healthcare professional for an accurate diagnosis and personalized treatment plan tailored to your specific needs.