Atrioventricular reentrant tachycardia

Atrioventricular Reentrant Tachycardia

Atrioventricular reentrant tachycardia (AVRT) is a type of supraventricular tachycardia characterized by an abnormal electrical pathway in the heart. This condition causes rapid heart rates and can lead to symptoms such as palpitations, dizziness, and shortness of breath. AVRT is a relatively common cardiac arrhythmia and can occur in individuals of all ages.

Pathophysiology

AVRT occurs due to the presence of an accessory pathway in the heart, known as the atrioventricular (AV) bypass tract. This abnormal pathway allows electrical signals to bypass the normal conduction system of the heart, resulting in a reentrant circuit. The reentrant circuit causes the electrical signals to continuously loop between the atria and ventricles, leading to a rapid heart rate.

The most common type of AVRT is known as Wolff-Parkinson-White syndrome (WPW). In WPW, the accessory pathway is called the bundle of Kent, which connects the atria and ventricles. This pathway allows electrical signals to bypass the AV node, resulting in a short PR interval on an electrocardiogram (ECG).

Symptoms

The symptoms of AVRT can vary from person to person. Some individuals may experience no symptoms at all, while others may have severe symptoms. Common symptoms include:

- Palpitations: A rapid and irregular heartbeat that may feel like a fluttering sensation in the chest. - Dizziness or lightheadedness: Feeling faint or lightheaded due to the rapid heart rate. - Shortness of breath: Difficulty breathing due to the increased heart rate. - Chest pain: Some individuals may experience chest discomfort or pain during episodes of AVRT. - Fatigue: Feeling tired or exhausted due to the increased workload on the heart.

Diagnosis

The diagnosis of AVRT is typically made based on the patient's symptoms and an electrocardiogram (ECG). The ECG will show characteristic findings, such as a short PR interval and a delta wave, which indicates the presence of an accessory pathway.

Additional tests may be performed to further evaluate the condition and rule out other causes of tachycardia. These tests may include:

- Holter monitor: A portable device that records the heart's electrical activity over a 24-hour period. - Echocardiogram: An ultrasound of the heart to assess its structure and function. - Electrophysiology study: A specialized test that involves the insertion of catheters into the heart to map the electrical pathways and identify the location of the accessory pathway.

Treatment

The treatment of AVRT aims to control the rapid heart rate and prevent future episodes. The choice of treatment depends on the severity of symptoms and the individual's overall health. Treatment options include:

- Vagal maneuvers: Simple techniques, such as bearing down or coughing, that can help slow down the heart rate. - Medications: Antiarrhythmic medications may be prescribed to control the heart rate and prevent future episodes of AVRT. - Catheter ablation: A minimally invasive procedure that involves the destruction of the accessory pathway using radiofrequency energy. This procedure has a high success rate and can provide a long-term cure for AVRT. - Implantable cardioverter-defibrillator (ICD): In rare cases, an ICD may be recommended for individuals with severe symptoms or those at high risk of life-threatening arrhythmias.

Prognosis

The prognosis for individuals with AVRT is generally good, especially with appropriate treatment. Most individuals can lead normal lives with minimal restrictions. However, it is important to manage the condition and follow up with regular check-ups to monitor for any recurrence or complications.

Conclusion

Atrioventricular reentrant tachycardia is a common cardiac arrhythmia characterized by an abnormal electrical pathway in the heart. It can cause rapid heart rates and various symptoms. Early diagnosis and appropriate treatment are essential for managing the condition and improving the quality of life for individuals with AVRT.