Paroxysmal atrial tachycardia (PAT) is a type of abnormally fast heart rhythm (tachycardia) that starts and stops suddenly in the upper chambers of the heart (atria).
Understanding PAT
Here's a more detailed explanation of PAT:
- Paroxysmal: This term indicates that the tachycardia begins and ends abruptly. The rhythm isn't constantly present; rather, it occurs in episodes.
- Atrial: The abnormal electrical activity that causes the rapid heart rate originates in the atria, which are the two upper chambers of the heart. These chambers receive blood from the body and lungs before it's pumped to the ventricles.
- Tachycardia: Tachycardia refers to a heart rate that is faster than normal. Generally, a heart rate above 100 beats per minute at rest is considered tachycardia. In PAT, the heart rate can be significantly higher.
Key Characteristics of PAT
- Sudden Onset and Termination: PAT episodes start and stop without warning.
- Rapid Heart Rate: The heart beats very quickly, often between 150 and 250 beats per minute.
- Regular Rhythm: While fast, the heart rhythm during an episode of PAT is generally regular.
- Symptoms: Symptoms can vary from mild to severe and may include palpitations (a fluttering or racing feeling in the chest), dizziness, lightheadedness, shortness of breath, chest pain, and anxiety. Some individuals may experience no symptoms at all.
How PAT Differs From Other Arrhythmias
PAT is just one type of supraventricular tachycardia (SVT), which is a broad category of arrhythmias originating above the ventricles. Other types of SVT include atrial fibrillation, atrial flutter, and AV nodal reentrant tachycardia (AVNRT). The precise mechanism and location of the abnormal electrical circuit distinguish each type.
Causes of PAT
PAT can be triggered by:
- Stress
- Caffeine
- Alcohol
- Nicotine
- Lack of sleep
- Certain medications
- Underlying heart conditions
In some cases, the cause of PAT is unknown.
Diagnosis and Treatment
Diagnosis typically involves an electrocardiogram (ECG or EKG) to record the heart's electrical activity during an episode.
Treatment options may include:
- Vagal maneuvers: These are simple techniques, such as holding your breath and straining or applying ice to the face, which can sometimes slow the heart rate.
- Medications: Antiarrhythmic drugs can help to control the heart rate or prevent episodes of PAT.
- Cardioversion: This involves delivering an electrical shock to the heart to restore a normal rhythm.
- Catheter ablation: This is a procedure that uses radiofrequency energy to destroy the abnormal electrical pathway causing the PAT.
