Paroxysmal Supraventricular Tachycardia (PSVT) is a common type of abnormally fast heart rhythm, also known as an arrhythmia. These episodes begin and end suddenly, often without warning. While a PSVT episode can be alarming due to the rapid heart rate, the condition is generally not life-threatening for most individuals. It involves an electrical issue within the heart, leading to temporary periods of accelerated heart activity.
What is PSVT?
The heart’s normal electrical system coordinates its pumping action. Electrical impulses typically originate in the sinus node, the heart’s natural pacemaker in the upper right chamber (atrium), then travel through the atria to the atrioventricular (AV) node, before reaching the ventricles. During a PSVT episode, the heart rate can suddenly jump to between 120 and 250 beats per minute.
PSVT refers to a rapid heart rate originating from “supraventricular” areas (above the ventricles), typically in the atria or the AV node. This fast rhythm is caused by an electrical “short circuit” within these upper chambers or the AV node. This short circuit often involves an abnormal electrical pathway or dual pathways allowing signals to loop rapidly.
The most common form, atrioventricular nodal reentrant tachycardia (AVNRT), occurs when two electrical pathways within or near the AV node allow an impulse to loop rapidly. Another type, atrioventricular reciprocating tachycardia (AVRT), involves an accessory pathway bypassing the AV node, creating a similar re-entry circuit. PSVT is an electrical abnormality, not typically associated with underlying structural heart disease.
Recognizing PSVT
Individuals experiencing a PSVT episode often report a sudden onset of a rapid, pounding heartbeat, described as palpitations. This sensation can feel like fluttering in the chest, throat, or neck. Other symptoms may include dizziness, lightheadedness, shortness of breath, chest discomfort, anxiety, or weakness.
Episodes can vary in duration, lasting from a few minutes to several hours, and end as abruptly as they begin. While the exact cause is not always known, certain factors can trigger episodes. Common triggers include stress, caffeine, alcohol, and certain medications or stimulant drugs.
Seek medical attention if PSVT symptoms are severe, prolonged, or accompanied by concerning signs. Immediate evaluation is advisable for fainting, significant chest pain, or extreme shortness of breath. While generally not dangerous for those with healthy hearts, persistent or severe symptoms warrant professional assessment to rule out more serious conditions and discuss management options.
Diagnosing and Treating PSVT
Diagnosis often begins with a medical history and physical examination. The primary diagnostic tool during an active episode is an Electrocardiogram (ECG), which records the heart’s electrical activity and captures the rapid rhythm. Since episodes come and go, an ECG performed during a symptom-free period may appear normal.
For intermittent episodes, a portable heart monitor (e.g., Holter or event recorder) may be recommended. In some cases, an Electrophysiology (EP) study may be performed. This involves inserting wires into the heart to map electrical pathways and locate the abnormal rhythm’s source, aiding treatment guidance.
For acute episodes, vagal maneuvers (e.g., bearing down, coughing, splashing cold water on the face) can sometimes help slow the heart rate and restore a normal rhythm by stimulating the vagus nerve. These should be attempted under medical guidance. If ineffective, intravenous medications like adenosine can quickly interrupt the abnormal electrical circuit in a hospital setting.
Long-term management focuses on preventing future episodes. Lifestyle modifications, such as avoiding triggers like excessive caffeine or alcohol, can be helpful. Medications like beta-blockers or calcium channel blockers may be prescribed to control heart rate and reduce episode frequency. For frequent or disruptive episodes, catheter ablation is often considered. This procedure uses heat or cold energy to create small scars in heart tissue, blocking the electrical pathway.