Introduction:
AV-nodal reentrant tachycardia or atrioventricular nodal reentry tachycardia (AVNRT) is a common heart rhythm malfunctioning condition. In this condition, the heart rhythm is abnormally fast. This is a chain effect of tachycardia in the ventricles above the His-Purkinje fibers. Tachycardia means an unusually fast heart rhythm. The atrioventricular node also referred to as the AV node, is the area that controls the flow of electrical impulses from the atrium to the ventricles.
The heart is sectioned into four chambers, and the upper two compartments are called the right and left atriums. The lower two compartments are called the right and left ventricles. The His-Purkinje System or the HPS or simply this His- is responsible for the prompt transmission of electrical impulses into the lower chambers of the heart, the ventricles. Reentrant or reentry is an abnormal heart rhythm signal that continuously repeats the signals in a loop within the heart instead of jumping from one cell to another cell. The electrical signal keeps repeating in circles between two cells instead of transferring from one cell to the next to the third.
What Are the Symptoms of Atrioventricular Nodal Reentry Tachycardia?
The main sign and symptom of atrioventricular nodal reentry tachycardia is the unexpected occurrence of fast irregular palpitations.
Some of the other signs and symptoms are as follows:
-
A sensation of flutter in the neck.
-
Rapid heartbeat.
-
Panic attacks.
-
A momentary plunge in blood pressure.
-
Dizziness.
-
Loss of consciousness.
-
Atherosclerosis or narrowing of the heart arteries.
-
Chest pain and discomfort.
-
Angina is a pain that radiates to the left jaw and left arm.
When a patient goes through atrioventricular nodal dissociation, the heart rate is around 150 beats to 290 beats in a minute. The neck reveals visible pulsation of the jugular vein.
What Causes Atrioventricular Nodal Reentry Tachycardia?
Atrioventricular nodal reentry tachycardia can occur in any individual but is more commonly reported among young females. Additionally, it is present in some patients only in their last decades. There are multiple precipitating factors of atrioventricular nodal reentry tachycardia. Below are some of the elements.
-
Atrial contraction.
-
Premature ventricular contractions.
-
Emotional stress.
-
Caffeine.
-
Chronic heart disease.
What Are the Complications of Atrioventricular Nodal Reentry Tachycardia?
Around 95 % of the patients with atrioventricular nodal reentry tachycardia show no complications if treated correctly. If not, certain complications can occur. Below are some of the intricacies of atrioventricular nodal reentry tachycardia.
-
Syncope.
-
Angina.
-
Cardiomyopathy.
-
Myocardial ischemia.
-
Hemodynamic alterations.
-
Myocardial infarction.
How to Diagnose Atrioventricular Nodal Reentry Tachycardia?
There are several ways to diagnose atrioventricular nodal reentry tachycardia in patients who show symptoms and patients who do not show signs.
Following are some of the ways used to diagnose atrioventricular nodal reentry tachycardia.
-
An electrocardiograph presents changes in the intervals, specially QRS duration, that the healthcare provider can easily catch.
-
A Holter monitor is used to diagnose the reason for repeating palpitations.
-
An implantable loop recorder can also be attached to record the heart's functioning.
-
Every electrocardiograph-based technology has proven to be a vital diagnostic tool because it can easily differentiate between atrioventricular nodal reentry tachycardia and other cardiovascular rhythm conditions such as atrial fibrillation, ventricular tachycardia, atrial flutter, sinus tachycardia, all of which have symptoms parallel to atrioventricular nodal reentry tachycardia.
-
A thyroid function test to get a complete picture of the thyroid profile
-
Electrolyte imbalance may also lead to atrioventricular nodal reentry tachycardia; thus, it should also be checked, specifically the potassium, calcium, and magnesium levels.
-
Cardiac markers distinguish between a heart attack, chest pain, and atrioventricular nodal reentry tachycardia.
How Is Atrioventricular Nodal Reentry Tachycardia Treated?
The principal aim in managing a case of atrioventricular nodal reentry tachycardia is the complete termination of episodes of tachycardia and the prevention of such outbreaks. There are multiple ways to bring about these treatment modalities, such as medication therapy and even a surgical intervention if the case may arise.
-
Arrhythmia prevention and termination are vital aspects of managing atrioventricular nodal reentry tachycardia. Physical maneuvers can be used for this.
-
A medication that decreases the speed or stops the electrical conduction for a short time can also be prescribed. Such medications are beta-blockers, calcium channel blockers, or adenosine.
-
Cardioversion is another successful treatment choice to electrically terminate atrioventricular nodal reentry tachycardia.
-
Invasive procedures can also be considered a treatment plan to potentially cure atrioventricular nodal reentry tachycardia. Such surgical procedures are catheter ablation and electrophysiology.
-
Radiofrequency ablation has a hold of a high percentage of curing patients while putting them at nearly no or low risks.
It should be noted that any medication regarding the cardiovascular system or any other body system must only be taken after the healthcare provider's prescription and strictly under their guidance.
How Can the Patient Be Educated About Atrioventricular Nodal Reentry Tachycardia?
Patients with an underlying cardiovascular condition should be aware of atrioventricular nodal reentry tachycardia. Activities that put such patients at risk of acquiring atrioventricular nodal reentry tachycardia, which include swimming or driving, must be limited or avoided. Regular follow-up with the healthcare provider and up-to-date check-up of the cardiovascular system is crucial. Changes in their diet, such as avoiding coffee, caffeinated beverages, and a balanced meal, must be included.
Conclusion:
Atrioventricular nodal reentry tachycardia, or AVNRT, is one of the most common reentrant supraventricular tachycardia or SVT. With the latest technologies and enhanced knowledge about the diagnosed tool, especially electrocardiogram, atrioventricular nodal reentry tachycardia can be promptly diagnosed and differentiated from other similar cardiovascular rhythmic problems. Generally, atrioventricular nodal reentry tachycardia is tolerated well, and it usually occurs in patients with no clinical damage to the heart's structure. In the absence of underlying heart conditions, the prognosis of atrioventricular nodal reentry tachycardia is excellent. More than 94 % of the population responds positively to the different treatment modalities, along with a low rate of risks and complications.
