Paroxysmal Supraventricular Tachycardia: Understanding the Condition
Paroxysmal Supraventricular Tachycardia (PSVT) is a heart rhythm disorder that causes sudden episodes of rapid heartbeat. The term “paroxysmal” refers to its sudden onset and ending, while “supraventricular” indicates that the abnormal rhythm starts above the heart’s ventricles, usually in the atria or the atrioventricular (AV) node. Although PSVT is not always life-threatening, it can be distressing and may require medical attention depending on its frequency and severity.
Causes and Mechanism
PSVT occurs when electrical signals in the heart follow abnormal pathways, leading to rapid heartbeats. Normally, the heart’s rhythm is controlled by the sinoatrial (SA) node, which sends signals in a regular pattern. In PSVT, reentry circuits or extra pathways create a loop, causing the heart to beat much faster than normal. Triggers may include stress, caffeine, alcohol, nicotine, or certain medications, although in many cases, episodes happen without a clear cause.
Symptoms of PSVT
The hallmark symptom of PSVT is a sudden and unexpected increase in heart rate, often ranging between 150 to 250 beats per minute. Episodes can last from a few seconds to several hours. Common symptoms include:
Palpitations or the sensation of a racing heartbeat
Dizziness or lightheadedness
Shortness of breath
Chest discomfort or tightness
Fatigue following an episode
In some cases, people may experience anxiety due to the sudden and intense nature of the rapid heartbeat.
Risk Factors
PSVT can occur in healthy individuals, but certain factors increase the risk. These include congenital heart defects, structural heart abnormalities, thyroid disorders, and a family history of arrhythmias. Athletes and younger individuals may also experience PSVT, even without underlying heart disease.
Diagnosis
Diagnosis typically involves monitoring the heart’s electrical activity through an electrocardiogram (ECG). Since episodes may not occur during a doctor’s visit, portable monitoring devices such as Holter monitors or event recorders are often used. In some cases, electrophysiological studies are performed to identify abnormal electrical pathways inside the heart.
Treatment Options
Management of PSVT depends on the frequency and severity of episodes. For occasional and mild cases, no treatment may be necessary other than lifestyle adjustments. During an episode, certain physical maneuvers called vagal maneuvers (such as coughing, bearing down, or applying cold water to the face) can sometimes slow the heart rate and stop the arrhythmia.
When episodes are frequent or severe, medications such as beta-blockers, calcium channel blockers, or antiarrhythmic drugs may be prescribed. In more persistent cases, a procedure called catheter ablation can be performed. This minimally invasive treatment uses radiofrequency energy to destroy the abnormal electrical pathway, offering a long-term solution for many patients.
Outlook and Lifestyle Considerations
Although PSVT can be alarming, the long-term outlook is generally favorable, especially with proper management. Avoiding triggers such as excessive caffeine, alcohol, or stimulant medications can reduce the likelihood of episodes. Maintaining heart health through regular exercise, stress management, and a balanced diet is also beneficial.
