Premature ventricular contractions (PVCs) are extra, abnormal heartbeats that begin in one of your heart’s two lower pumping chambers (ventricles). These extra beats disrupt your regular heart rhythm, sometimes causing you to feel a fluttering or a skipped beat in your chest.
For many people, PVCs are occasional and don’t require treatment. But for some people, frequent PVCs are bothersome or can be a sign of an underlying heart condition. PVCs can be triggered by stress, exercise, caffeine, alcohol, nicotine, sleep deprivation or underlying heart disease. But why do PVCs tend to get worse when lying down?
The increase in PVCs when lying down is due to vagal tone
The vagus nerve is one of the cranial nerves that originates in the brainstem. It interacts with the parasympathetic nervous system to slow heart rate, facilitate digestion, and perform other involuntary functions. The constant pressure exerted by the vagus nerve to slow the heart’s pacemaking activity is known as vagal tone.
When you lie down, vagal tone increases. This increased vagal stimulation can sometimes trigger PVCs in susceptible individuals by slowing parts of the heart’s electrical conduction system. The slowing of electrical signaling through the heart increases the chance that an early beat will occur.
Gravity and body position affects vagal tone
When you’re upright, gravity causes blood to pool in the veins of your legs and abdomen. This reduces the amount of blood returning to your heart. To compensate, your heart rate and blood pressure increase. This counters the effects of gravity to keep blood circulating adequately.
When lying down, gravity no longer causes blood to pool in the lower half of your body. More blood returns to the heart, stimulating an increase in vagal tone to slow the heart rate. This vagal surge can trigger PVCs in some people.
Other factors that increase PVCs while lying down
In addition to increased vagal tone, other factors may contribute to worsening PVCs when lying down:
- Improved blood flow to the heart while lying down may irritate irritable areas and trigger beats.
- Less pressure on the diaphragm while lying down allows the heart to enlarge slightly. This may stretch sensitive areas and induce PVCs.
- Sleeping triggers changes in breathing patterns, carbon dioxide levels, and autonomic tone, which may provoke beats.
Tips to reduce PVCs while lying down
If your PVCs tend to worsen when you lie down, certain measures may help prevent or reduce them:
- Avoid lying flat. Prop up your head and upper body with pillows or raise the head of your bed.
- Try lying on your left or right side instead of your back.
- Practice relaxing breathing techniques before bed.
- Avoid caffeine, alcohol, and heavy meals before bedtime.
- Take medications as prescribed. Your doctor may adjust timing or dosages.
- Consider an evaluation for underlying heart disease if frequent PVCs persist.
When to see a doctor
Occasional, brief bursts of PVCs when lying down usually aren’t cause for concern in healthy people. But contact your doctor if you experience:
- Frequent PVCs — more than 10 per minute
- Noticeable, prolonged pauses between PVCs and normal beats
- Lightheadedness or fainting associated with PVCs
- Chest pain or tightness along with PVCs
- Shortness of breath with exertion
Evaluation may include an electrocardiogram (ECG) patch monitor to record your heart rhythm over an extended time. Your doctor can check for any underlying heart disease and determine if treatment is needed.
Treatment options for PVCs that worsen when lying down
If lifestyle measures don’t alleviate frequent PVCs while lying down, treatment options may include:
- Medications: Beta blockers or calcium channel blockers may help suppress problematic PVCs.
- Ablation: A minimally invasive procedure destroys small areas of heart tissue triggering PVCs. Highly effective when PVCs originate from one area.
- Implantable defibrillator: For people at risk of abnormal heart rhythms and sudden cardiac arrest. Shocks the heart back into proper rhythm when dangerous beats occur.
Talk to your doctor about the benefits and risks of these PVCs treatments for your situation.
The bottom line
Lying down increases vagal tone, which can trigger PVCs in some people. Try elevating your upper body while sleeping and avoiding triggers near bedtime. See your doctor promptly if PVCs are frequent or cause symptoms, as treatment may be needed.
| Cause | Explanation |
|---|---|
| Increased vagal tone | The vagus nerve exerts greater slowing effects on the heart when lying down. |
| Effects of gravity | When upright, gravity causes blood to pool in the lower body, increasing heart rate. Lying down removes this effect. |
| Improved blood flow | Better coronary blood flow when lying down may irritate sensitive areas. |
| Diaphragm pressure | Less pressure on the diaphragm allows the heart to enlarge slightly. |
| Breathing pattern changes | Sleep causes changes in respiration that influence heart rhythms. |
| Tip | Explanation |
|---|---|
| Elevate upper body | Prop head and torso up with pillows when lying down. |
| Avoid lying flat | Lying on the left or right side puts less vagal pressure on the heart. |
| Practice relaxation techniques | Deep breathing before bed may reduce PVCs. |
| Avoid triggers | Caffeine, alcohol, and heavy meals can provoke PVCs. |
| Take medications appropriately | Follow prescribed timing and dosing instructions. |
| Evaluate for heart disease | Check for any underlying problems if PVCs persist. |
