From the Guidelines
PVCs occur due to abnormal electrical signals in the heart, often triggered by factors such as caffeine, alcohol, stress, fatigue, or certain medications, as well as underlying heart conditions like coronary artery disease, heart failure, cardiomyopathy, or valve disease 1.
Causes of PVCs
PVCs can be caused by a variety of factors, including:
- Triggers like caffeine, alcohol, stress, fatigue, or certain medications that stimulate the heart
- Underlying heart conditions such as coronary artery disease, heart failure, cardiomyopathy, or valve disease that create areas of damaged heart tissue initiating abnormal electrical signals
- Electrolyte imbalances, particularly potassium, magnesium, and calcium, that disrupt the heart's electrical system
- Thyroid disorders and certain medications that can trigger PVCs
Risk Factors and Treatment
While most PVCs are benign and don't require treatment, especially in people with healthy hearts, frequent PVCs (more than 10-15% of total heartbeats) or those occurring in people with structural heart disease may require treatment with beta-blockers, calcium channel blockers, or antiarrhythmic medications 1. In some cases, catheter ablation may be recommended to eliminate the source of problematic PVCs. It's essential to note that very frequent PVCs (>10,000 to 20,000 a day) can be associated with depressed LV function, reversible with control of the PVCs, and has been referred to as PVC-induced cardiomyopathy 1.
Clinical Considerations
In clinical practice, PVCs that occur during an exercise test are associated with a higher risk of death, and PVCs occurring during recovery are a stronger predictor of death than those occurring only during exercise 1. However, in trained athletes without other cardiovascular abnormalities, PVCs may not appear to increase the risk of death 1. An electrophysiological study may be needed to assess patients' arrhythmogenic risk, especially in cases of complex PVCs or those with underlying heart conditions 1.
From the Research
Causes of PVCs
- PVCs arise from an ectopic focus within the ventricles 2
- They can be caused by underlying structural heart disease, electrolyte abnormalities, and substance use 2, 3, 4
- PVCs may also be a marker of underlying pathophysiologic processes such as myocarditis 4
- In some cases, PVCs can be benign and occur in structurally normal hearts, but they can also indicate increased risk of sudden death in the presence of structural heart disease 4
Risk Factors for PVCs
- Underlying coronary artery disease, hypertension, or left ventricular hypertrophy can increase the risk of PVCs 3
- High PVC burden can induce cardiomyopathy and left ventricular dysfunction or worsen underlying cardiomyopathy 2, 4
- PVCs are independently linked to an increased risk of stroke and sudden cardiac death 3
Diagnosis and Treatment of PVCs
- Diagnostic workup for PVCs includes electrocardiogram (ECG), 24-h Holter monitor, and transthoracic echocardiogram (TTE) 2
- Management of PVCs should focus on identifying and treating underlying causes, and beta-blockers are first-line therapy for symptomatic PVCs 2
- Nondihydropyridine calcium channel blockers, classic antiarrhythmic agents, and amiodarone can be considered as second-line agents 2
- Catheter ablation of the PVC focus can be recommended for patients who have failed medical therapy or have a high burden of PVCs 2, 4