Premature Ventricular Contractions – Symptoms and Causes
Overview
The heart has four chambers—two upper ones (atria) and two lower ones (ventricles). Heart rhythm normally starts in the right upper chamber at the sinus node, which acts as a natural pacemaker.
This node sends electrical signals across the atria, making them contract and push blood into the ventricles.
These signals then reach the atrioventricular (AV) node, where they pause briefly, allowing the ventricles time to fill with blood before contracting to pump blood to the lungs or throughout the body.
In a healthy heart, this process runs smoothly, maintaining a resting heart rate between 60 and 100 beats per minute.
Premature ventricular contractions (PVCs) occur when an abnormal electrical signal starts in the ventricles instead of following the normal conduction pathway.
These extra beats disrupt the heart’s rhythm by occurring earlier than expected, often followed by a pause that can feel like a skipped or fluttering heartbeat.
While PVCs are common and often harmless, some people may experience chest pain, shortness of breath, dizziness, or discomfort.
The exact cause of PVCs is not always clear, but several factors can increase the electrical instability in the ventricles, including:
- Medications: Some decongestants and antihistamines
- Substances: Alcohol, caffeine, tobacco, and certain drugs.
- Physical states: Exercise, anxiety, or other conditions that raise adrenaline levels.
- Heart conditions: Disease, scarring, or structural issues that disrupt normal electrical signals.
For most people, lifestyle modifications—such as reducing caffeine and alcohol intake or avoiding certain over-the-counter medications—can help manage PVCs.
However, if they are severe or frequent, a doctor may recommend beta-blockers, calcium channel blockers, or catheter ablation to regulate the heart’s rhythm.
