Paroxysmal Supraventricular Tachycardia - Causes, Symptoms, Diagnosis, and Treatment

Introduction

PSVT, Paroxysmal Supraventricular Tachycardia, is an abnormal and irregular heart rhythm. Any irregular heart rhythm is called arrhythmia. Paroxysmal supraventricular tachycardia develops in an individual when a short-lived circuit type of rhythm passes in the heart's upper chamber, called the atrium. This particular circuit results in an irregular but rapid heartbeat that suddenly stops and starts. The heart is divided into four different compartments. There are two chambers above and two chambers below. The upper two heart sections are the right and left atrium, and the lower two are the right and left ventricles.

What Happens During a Paroxysmal Supraventricular Tachycardia?

A normal heartbeat starts with an electric impulse from the sinus node. The sinus node is a tiny heart area in the upper right section. Paroxysmal supraventricular tachycardia begins due to a small short circuit, an abnormal electrical signal made up of cardiac or heart cells. These abnormal cardiac cells allow the electrical signal to circulate at high speed over and over again. The results of this nonstop wrong-signaled circulation; the heart's chambers start to work extremely fast and contract swiftly. This high-speed contraction may cause problems in the heart’s function, and this entire cardiac scenario is called paroxysmal supraventricular tachycardia.

What Are the Causes of Paroxysmal Supraventricular Tachycardia?

There are three main reasons for the occurrence of paroxysmal supraventricular tachycardia. This condition generally tends to have a different location and will present itself in various forms depending on the cause of its event. The three primary reasons for paroxysmal supraventricular tachycardia are given as follows:

• AVNRT, or atrioventricular nodal reentrant tachycardia, is one of the most common causes of paroxysmal supraventricular tachycardia. It occurs when a tiny extra impulse leaves the atrioventricular node or near the atrioventricular node. AV, or atrioventricular node, is the gateway that allows signals to pass from the heart's upper section to the heart's lower area. An electrical signal that finds the entry into this pathway will circulate quickly. This rapid circulation leads to paroxysmal supraventricular tachycardia.

• In a healthy heart, the AV node or the atrioventricular node is the primary link that connects the upper chamber of the heart (atrium) with the lower chamber of the heart (ventricle). Through this node, all the impulses get transferred between the two sections. A syndrome where an additional muscle or fibered muscle links to the upper chamber and the lower chamber of the heart is referred to as WPW or the Wolff-Parkinson-White syndrome. Due to an extra muscle fiber, as in this syndrome, the electric signal keeps repeating or forms a short circuit leading to paroxysmal supraventricular tachycardia. Wolff-Parkinson-White syndrome develops in the fetus and thus is congenital. Fortunately, they take a decade to crop up as a significant issue.

• Atrial tachycardia is another common cause of paroxysmal supraventricular tachycardia. This generally occurs due to a short circuit kind of phenomenon. This happens when an electrical signal short is a breakneck speed from outside the heart's upper chamber and then circulates.

What Are the Symptoms of Paroxysmal Supraventricular Tachycardia?

The general features of paroxysmal supraventricular tachycardia are parallel to that of a panic attack.

A few of the clinical manifestations of this condition are mentioned below.

• Palpitations.

• Fatigue.

• Syncope.

• Chest pain or chest discomfort.

• Weakness.

• Lightheadedness.

• High blood pressure.

• Dizziness.

• Rapid pulse rate.

• Difficulty in breathing.

• Chest tightness.

• Pounding kind of heartbeat.

• A fluttering feeling in the neck.

How to Diagnose Paroxysmal Supraventricular Tachycardia?

Paroxysmal supraventricular tachycardia must be diagnosed only after thorough medical history. An electrocardiograph is a vital diagnostic tool for this condition. It so happens that paroxysmal supraventricular tachycardia occurs suddenly or seldom. In such cases, one cannot rely solely on electrocardiography. To catch an episode of paroxysmal supraventricular tachycardia, an electrocardiogram monitor such as a Holter monitor needs to be placed with the patient to record the heart rhythm over a long period of time.

Below are some investigative and diagnostic techniques used for paroxysmal supraventricular tachycardia.

• A portable electrocardiograph, such as a Holter monitor, can be worn continually by the patient for up to a week. This records the heart rhythm throughout.

• An event monitor is a portable electrocardiographic monitor that can be worn for up to a month and will trigger any abnormality in the heart’s functions, such as abnormal rhythm.

• A cardiac implantable loop monitor is a device that has to be inserted into the patients and remains there for around seven years. This may then be taken out surgically in the same way that it was placed inside.

Keeping the above in mind, the best test that has proven to show excellent results in diagnosing paroxysmal supraventricular tachycardia is an elaborated electrophysiological or EP study. This will not only diagnose but also help locate the precise zone and cause of the disease. Catheter ablation comes hand in hand with this study.

How to Treat Paroxysmal Supraventricular Tachycardia?

There are three general treatment modalities for paroxysmal supraventricular tachycardia.

• Valsalva maneuver is when the patient's carotid artery is slightly rubbed to reduce the tachycardia episode.

• Medications prescribed by the doctors after considering the risk and side effects are given.

• Catheter ablation is another successful way to treat paroxysmal supraventricular tachycardia. It is a mature technique that requires expertise.

Conclusion

Paroxysmal supraventricular tachycardia is an abnormal heart rhythm leading to the heart's fast beating. It has no complications, but it needs to be diagnosed early and treated promptly. The first line of treatment is catheter therapy and then medications. Post-treatment, a patient can lead a comfortable everyday life without any after-effects.