scholarly journals Premature ventricular contractions of the right ventricular outflow tract: Upward displacement of the ECG unmasks ST elevation in V1 associated with the presence of low voltage areas

2019 ◽  
Vol 38 (2) ◽  
pp. 83-91 ◽  
Author(s):  
Leonor Parreira ◽  
Rita Marinheiro ◽  
Pedro Carmo ◽  
Pedro Amador ◽  
Tiago Teixeira ◽  
...  
Author(s):  
Leonor Parreira ◽  
Pedro Carmo ◽  
Rita Marinheiro ◽  
Dinis Mesquita ◽  
José Farinha ◽  
...  

Background and aims: Activation wavefront is rapid and uniform in normal myocardium. Fibrosis is associated with deceleration zones (DZ) and late activated zones. Our aim was to study the right ventricular outflow tract (RVOT) endocardial activation duration (EAD) in sinus rhythm, and assess the presence of DZs, in patients with PVCs and controls. Methods: We studied 29 patients with idiopathic PVCs from the outflow tract, subjected to catheter ablation and an activation and voltage map of the RVOT in sinus rhythm. A control group of 15 patients without PVCs that underwent ablation of supraventricular arrhythmias was also studied. The RVOT EAD and number of 10 ms isochrones were assessed. DZ were defined as a zone with>3 isochrones within 1 cm radius. Low voltage areas (LVA) defined as areas with local electrogram amplitude <1.5mV. Results: The two groups did not differ in relation to age, gender or number of points in the map. EAD and number of 10 ms isochrones were higher in the PVC group; 56 (41-66) ms vs 39 (35-41) ms, p=0.001 and 5 (4-8) vs 4 (4-5), p=0.001. Presence of DZs and LVAs were more frequent in the PVC group; 20 (69%) vs 0 (0%), p<0.0001 and 21 (72%) vs 0 (0%), p<0.0001. Patients with LVAs had longer EAD 60 (52-67) vs 36 (32-40) ms, p<0.0001. Conclusions: EAD was longer and DZs were more frequent in patients with PVCs and were associated with presence of LVAs.


EP Europace ◽  
2021 ◽  
Vol 23 (Supplement_3) ◽  
Author(s):  
A Parreira ◽  
P Carmo ◽  
D Mesquita ◽  
R Marinheiro ◽  
A Goncalves ◽  
...  

Abstract Funding Acknowledgements Type of funding sources: None. Background and aims Activation wavefront is rapid and uniform in normal myocardium. Fibrosis is associated with deceleration zones (DZ) and late activated zones. The presence of low voltage areas (LVAs) in the right ventricular outflow tract (RVOT) of patients with premature ventricular contractions (PVCs) from this origin has been described previously. The aim of this study was to evaluate in sinus rhythm, the RVOT endocardial activation duration (EAD) and the presence of DZs, in patients with PVCs and in controls. Methods Consecutive patients with frequent (&gt;10.000/24 h) idiopathic PVCs with inferior axis subjected to ablation that had an activation and voltage map of the RVOT performed in sinus rhythm. A control group of patients without PVCs that underwent ablation of supraventricular arrhythmias was also studied. Patients with structural heart disease, previous ablation or conduction disease were excluded. The RVOT EAD was measured as the time interval between the earliest and the latest activated region. Also evaluated the number of 10 ms isochrones throughout the RVOT and the maximal number of 10 ms isochrones within 1 cm, and a DZ was defined as a zone with &gt; 3 isochrones within 1 cm. Low voltage areas (LVA) were defined as areas with local electrogram amplitude &lt;1.5 mV. Results 42 patients, 29 in the PVC group and 13 control subjects. The site of origin of the PVCs was the RVOT in 23 patients and the LVOT in 6. The characteristics of the two groups are displayed in the Table. Patients with PVCS had longer RVOT EAD, total number of isochrones and presence of DZ was also significantly higher (See table).  LVAs were more frequent in PVCs from the RVOT than from the LVOT (83% vs 33%, p = 0.033). Patients with LVA had longer EAD 60 (52-67) vs 36 (34-40) ms, p &lt; 0.0001 (Figure A) and more DZ than patients without LVA 95% vs 0%, p &lt; 0.0001 (Figure B and C). Conclusions The velocity of the wavefront propagation was slower and DZs were more frequently present in patients with PVCs and were associated with presence of LVAs. All sampleN= 42PVCsN = 29ControlsN = 13p-valueAge in years, median (Q1-Q3)56 (35-65)58 (38-66)53 (28-67)0.648Male gender, n (%)19 (45)14 (48)5 (39)0.401Nº points in the map, median (Q1-Q3)410 (338-589)467 (345-660)345 (333-465)0.056Activation duration in ms, median (Q1-Q3)41.8 (36-61)56 (41-66)39 (35-41)0.001Nº isochrones, median (Q1-Q3)4 (4-6)5 (4-6)4 (4-4)0.037Presence of DZs, n (%)20 (48)20 (69)0 (0)&lt;0.0001Presence of LVAs, n(%)21 (50)21 (72)0 (0)&lt;0.0001Abstract Figure.


Sign in / Sign up

Export Citation Format

Share Document