Evidence for a shift from right ventricular to left ventricular outflow tract origin of idiopathic premature ventricular contractions with advancing age

Idiopathic premature ventricular contractions (PVCs) is a frequently encountered clinical arrhythmia. Current guidelines define idiopathic PVCs as those occurring in the absence of structural heart disease. Among the most frequent sites of PVCs origin are the right ventricular outflow tract (RVOT) and the left ventricular outflow tract (LVOT).

The study aimed to assess whether increasing age is associated with an RVOT or LVOT origin of PVCs.

We included 79 patients (29 women, men age 55.7 ± 16.2), who underwent successful idiopathic PVC ablation, originating from either RVOT or LVOT, as determined by 3-D electroanatomical mapping, from 2015 to 2024. Univariate logistic regression was applied, to correlate the patients age with the site of the arrhythmia origin.

The site of origin was identified as the RVOT in 37 patients and the LVOT in 42 patients. Advancing age was positively associated with an arrhythmia origin from the LVOT, rather the RVOT (Odds Ratio: 1.06, 95% C.I. 1.03- 1.11, p < 0.001, per year increase). The area under the curve was calculated to be 0.76 (Image 1). The age difference among the two sites of origin is also illustrated in Image 2. No differences were noted in the 24-hour burden among RVOT and LVOT originating arrhytmias (20.2% vs 19.0%, p = 0.9). Patients with RVOT-originating arrhythmia were more likely to be symptomatic on initial presentation (45.9% vs 20.0 %, p < 0.01). Procedural duration was similar (131.6 vs 127.8 min, p = 0.8) for RVOT and LVOT, respectively. Activation mapping depicted similar prematurity, irrespectively of RVOT or LVOT origin (30 vs 26 msec, p = 0.2).

Increasing age is positively correlated with LVOT- originating PVCs, compared with RVOT-originating aortic cusps. The finding is possibly attributed to increased calcium deposition within the aortic cusps and the aortic annulus with increasing age, which leads to micro- reentry circuits and arrhythmogenesis.

Area under the curve