Arrhythmias & electrophysiology
Baseline QRS axis distinguishes para-Hisian premature ventricular contraction (PVC) from outflow tract PVCs
- retrospective analysis
Authors' conclusion
The axis of idiopathic OT-PVC can be influenced by baseline SR axis deviation. Comparison of SR and PVC axes is essential to distinguish true para-Hisian PVCs from other OT-PVCs.
Study context
- Population
- Idiopathic PVC cases without conduction abnormalitiespara-Hisian Seventeen · RVOT 84 · left ventricular outflow tract (LVOT) 59
- Participants
- 160 idiopathic PVC cases
- Exposure
- Differences between sinus rhythm (SR) and PVC axes were compared among para-Hisian, RVOT, and LVOT PVCs
- para-Hisiann = Seventeen
- RVOTn = 84
- LVOTn = 59
Main finding
As reported in the abstract
Mean difference between SR and PVC axes
para-Hisian
−4.9°
mean · ± 26.1°
RVOT
42.1°
mean · ± 21.0°
LVOT
61.2°
mean · ± 22.9°
Observational data: associations, not effects.
Further findings
| Outcome | para-Hisian | RVOT | LVOT | |
|---|---|---|---|---|
| RVOT or LVOT PVCs with QRS morphologies mimicking para-Hisian PVCs · As the SR axis deviated leftward | Not reported in the abstract | 14 of 84 events | 4 of 59 events | para-Hisian: not reported in the abstract |
Axis difference of ≤18° for para-Hisian PVC vs other outflow tract PVCs (OT-PVCs)
- area under the curve
- 0.94
- sensitivity
- 0.94
- specificity
- 0.82
RVOT or LVOT PVCs with QRS morphologies mimicking para-Hisian PVCs
- these PVCs exhibited a substantial difference between SR and PVC axes
- Para-Hisian PVCs consistently showed similarity between SR and PVC axes, regardless of baseline axis deviation
Original publication
Baseline QRS axis distinguishes para-Hisian PVC from outflow tract PVCs. Heart Rhythm. Published 30 April 2026. doi:10.1016/j.hrthm.2026.04.044
Summarised from the published abstract; every number is checked against it