🫀 Introduction
Premature ventricular complexes (PVCs)—extra heartbeats originating in the ventricles—are among the most commonly detected cardiac arrhythmias on 24-hour ECG monitoring. While often considered benign in individuals without structural heart disease (SHD), their true clinical significance has remained controversial.
Several previous studies have linked PVCs to poor outcomes such as cardiomyopathy, atrial fibrillation (AF), stroke, and even sudden cardiac death. But these studies often included patients with underlying heart disease, leaving a gap in understanding whether PVCs independently contribute to cardiovascular events in otherwise structurally normal hearts.
A new retrospective cohort study from Sweden, published in 2024, now offers clarity. This large study aimed to isolate PVCs as a variable by including only those patients who had no evidence of SHD, confirmed via echocardiography and stress testing.
🧪 Study Design and Methodology
This observational cohort study followed 751 patients diagnosed with PVCs and compared them to 3,041 matched controls from the general Swedish population. The PVC patients were seen between 2010 and 2016 at cardiology centers in Stockholm and had normal:
- Echocardiograms (EF ≥ 55%, normal wall thickness and dimensions)
- Stress tests (no ischemia or exercise-induced arrhythmias)
Importantly, all patients with prior diagnoses of AF, stroke, TIA, or any structural heart disease were excluded to reduce confounding.
Patients were monitored until 2018, and the primary outcomes were:
- Development of new-onset atrial fibrillation (AF)
- Occurrence of transient ischemic attack (TIA) or stroke
📊 Key Findings
1. PVCs and Risk of Atrial Fibrillation (AF)
- Incidence of AF:
- PVC group: 4.1% (31 patients)
- Control group: 2.0% (61 patients)
- Unadjusted risk: PVC patients had double the risk (HR 2.08, p < 0.01)
- Adjusted analysis (after propensity score weighting): No statistically significant difference (HR 1.45, p = 0.14)
Conclusion: PVCs in structurally normal hearts were not associated with a significantly higher risk of AF when comorbidities and medications were accounted for.
2. PVCs and Risk of TIA or Stroke
- Incidence of TIA/Stroke:
- PVC group: 2.9%
- Control group: 2.3%
- Adjusted analysis: No significant difference in cumulative risk (HR 1.31, p = 0.27)
Conclusion: There was no strong evidence that PVCs independently raise stroke or TIA risk in patients without SHD.
🔍 PVC Burden and Trends
Among PVC patients:
- 76% had >1,000 PVCs/day
- 29% had ≥10,000 PVCs/day
There was a trend toward higher AF incidence in patients with higher PVC burdens, but due to low event counts, these trends did not reach statistical significance.
Interpretation: High PVC burden may increase AF risk, but more robust studies are needed.
🧠 What Makes This Study Unique?
- Exclusion of SHD confirmed via imaging and stress tests
Most prior studies relied on self-reported or administrative data to rule out heart disease, which may have missed subclinical cases. - Matched control group from national registries
Patients were compared to a large sample of the general Swedish population. - Use of inverse probability weighting (IPW)
Ensured balanced comparison by adjusting for comorbidities and medications.
🩺 Clinical Implications
- PVCs in healthy hearts may not require aggressive intervention
- If structural heart disease is ruled out, the presence of PVCs alone is not a strong predictor of AF or stroke.
- Consider full cardiac workup in symptomatic PVC patients
- Echocardiography and stress testing remain essential to rule out SHD before risk stratification.
- Monitor patients with high PVC burden closely
- There may be a dose-dependent effect of PVCs on long-term AF risk.
📉 Limitations to Consider
- PVC burden was missing in 19% of patients
- Lack of long-term Holter data post-inclusion
- Controls may have had unrecognized SHD or PVCs
- Outcome data only available until 2018
Despite these, the study remains the most rigorous to date in isolating PVCs as an independent variable in AF/stroke risk.
🧾 Final Verdict
This landmark Swedish study provides reassuring evidence that PVCs in structurally normal hearts do not significantly increase the risk of AF or stroke, challenging prior assumptions that PVCs are always a red flag for arrhythmic complications.
It reinforces the importance of cardiac imaging and stress testing in differentiating benign from pathologic PVCs and encourages physicians to adopt a more individualized approach when counseling patients with these common arrhythmias.
📚 References
- Full study: [BMJ Open Heart, 2024]
- National Patient Register, Sweden
- Rujirachun et al. Meta-analysis on PVCs and AF risk (2022)
