SPC365

Three-dimensional late gadolinium enhancement increases the diagnostic yield of cardiovascular magnetic resonance to detect low voltage in the right ventricular outflow tract

Session: Posters - C. Arrhythmias and Device Therapy
Speaker: Leonor Parreira

Congress: CPC 2021
Topic: C. Arrhythmias and Device Therapy
Theme: 04. Arrhythmias, General
Subtheme: 04.3 Arrhythmias, General – Diagnostic Methods
Session Type: Posters
FP Number: ---
Authors: Leonor Parreira; Antonio Ferreira; Pedro Carmo; Dinis Mesquita; Rita Marinheiro; Pedro Amador; José Farinha; Ana Esteves; Silvia Nunes; Duarte Chambel; Marta Fonseca; Diogo Cavaco; Francisco Costa; Hugo Marques; Pedro Adragao

<p style="text-align:justify"><span style="font-size:12pt"><span style="font-family:&quot;TN web use only&quot;,sans-serif"><span style="color:black"><strong><span style="font-size:10.0pt"><span style="font-family:&quot;Times New Roman&quot;,serif">Background:</span></span></strong><span style="font-size:10.0pt"><span style="font-family:&quot;Times New Roman&quot;,serif"> Cardiac magnetic resonance (CMR) using late gadolinium enhancement (LGE) fails to detect scar tissue in patients with abnormalities on the three-dimensional (3D) electroanatomical map and biopsy-proven structural heart disease. It has shown conflicting data regarding existence of structural abnormalities in patients with idiopathic premature ventricular contractions (PVCs) from the right ventricular outflow tract (RVOT). 3D-LGE enables high-spatial resolution more appropriate to the thin-walled right ventricle than two-dimensional (2D) LGE. </span></span></span></span></span></p>

<p style="text-align:justify"><span style="font-size:12pt"><span style="font-family:&quot;TN web use only&quot;,sans-serif"><span style="color:black"><strong><span style="font-size:10.0pt"><span style="font-family:&quot;Times New Roman&quot;,serif">Objective:</span></span></strong><span style="font-size:10.0pt"><span style="font-family:&quot;Times New Roman&quot;,serif"> Our aim was to evaluate if the use of 3D-LGE would improve the performance of CMR to detect low voltage areas in the RVOT of patients with PVCs. </span></span></span></span></span></p>

<p style="text-align:justify"><span style="font-size:12pt"><span style="font-family:&quot;TN web use only&quot;,sans-serif"><span style="color:black"><strong><span style="font-size:10.0pt"><span style="font-family:&quot;Times New Roman&quot;,serif">Methods:</span></span></strong><span style="font-size:10.0pt"><span style="font-family:&quot;Times New Roman&quot;,serif"> Since May 2020 we performed 3D-LGE CMR in 11 consecutive patients that underwent ablation of frequent PVCs. A control group of 11 consecutive patients that underwent catheter ablation by the same operator and had a 2D-LGE CMR performed before ablation was also studied. All patients had normal 2D-LGE CMR. A 3D electroanatomical bipolar voltage map of the RVOT was performed in sinus rhythm (0.5 mV-1.5 mV colour display). Areas with electrograms &lt;1.5 mV represented the low voltage areas (LVAs). The area adjacent to the pulmonary valve usually displays voltage between 0.5 and 1.5 mV and is classified as transitional-voltage zone. Presence of LVAs outside this transitional-voltage zone were estimated. We compared the accuracy of CMR for detecting LVA in the two groups: 3D LGE and 2D LGE. </span></span></span></span></span></p>

<p style="text-align:justify"><span style="font-size:12pt"><span style="font-family:&quot;TN web use only&quot;,sans-serif"><span style="color:black"><strong><span style="font-size:10.0pt"><span style="font-family:&quot;Times New Roman&quot;,serif">Results:</span></span></strong><span style="font-size:10.0pt"><span style="font-family:&quot;Times New Roman&quot;,serif"> The median number of points used for the voltage map was 344 (242-450). The site of origin of the PVCs was the RVOT in 17 patients and the left ventricular outflow tract (LVOT) in 5. The two groups did not differ in relation to age, gender, site of origin of the PVCs and number of points used for the voltage map. LVAs were present in 18 patients (82%), 9 in the 3D-LGE group and 9 in the 2D-LGE group, p=0.707. In the 2D LGE group CMR failed to demonstrate abnormalities of the RVOT in all patients that presented with LVAs. In the 3D-LGE group CMR showed presence of fibrosis (Figure) in 3 out of 9 patients with LVAs (33%). </span></span></span></span></span></p>

<p style="text-align:justify"><span style="font-size:12pt"><span style="font-family:&quot;TN web use only&quot;,sans-serif"><span style="color:black"><strong><span style="font-size:10.0pt"><span style="font-family:&quot;Times New Roman&quot;,serif">Conclusion:</span></span></strong><span style="font-size:10.0pt"><span style="font-family:&quot;Times New Roman&quot;,serif"> CMR using 3-D LGE techniques showed an increased power to diagnose structural abnormalities. This technique may be a better choice in initial stages of RVOT disease.</span></span></span></span></span></p>