SPC365

A CMR Myocardial Strain Patterns Analysis in Left Bundle Branch Block

Session: Comunicações Orais (Sessão 27) - Imagem 2 - Ecocardiografia e Strain
Speaker: M. Raquel Santos

Congress: CPC 2022
Topic: B. Imaging
Theme: 03. Imaging
Subtheme: 03.1 Echocardiography
Session Type: Comunicações Orais
FP Number: ---
Authors: m. Raquel Santos; Mariana da Silva Santos; Sara Guerreiro; Daniel a. Gomes; Gonçalo Lopes da Cunha; Bruno m. Rocha; Pedro Freitas; João Abecasis; Ana Santos; Carla Saraiva; Miguel Mendes; António Miguel Ferreira

<p><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif"><strong>INTRODUCTION:</strong></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif">Recently, a classification with four types of septal longitudinal strain patterns was described using a speckle tracking based strain analysis in echocardiography suggesting pathophysiological continuum of LBBB-induced LV remodeling. Little data exist on feature tracking cardiac magnetic resonance (FT-CMR) in LBBB patients, and whether such patterns could be reproduced in CMR is not established yet. Therefore, in this study, we aimed to: 1) Assess and reproduce the new strain patterns classification by CMR and 2) Evaluate its association with LV remodeling and myocardial scar in a LBBB cohort.</span></span></p>

<p><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif">&nbsp;</span></span></p>

<p><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif"><strong>METHODS:</strong></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif">Single center registry which included LBBB patients with septal flash (SF) referred to CMR to assess the structural cause of LV dysfunction. LBBB was defined according to Strauss criteria <span style="background-color:white"><span style="color:black">as strict LBBB, non-strict LBBB or<s> </s>nonspecific LV conduction delay. </span></span></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif"><span style="background-color:white"><span style="color:#333333">A semi-automated FT-CMR </span></span><span style="background-color:#fcfcfc"><span style="color:#333333">(Circle CVI42&reg;) </span></span><span style="background-color:white"><span style="color:#333333">was used</span></span> to quantify myocardial strain and detect the four septal longitudinal and radial strain patterns, according to the recent classification (LBBB-1 through LBBB-4) <strong>&ndash; Figure</strong>. Extent of SF was visually scored as mild, moderate, or prominent. </span></span></p>

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<p><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif"><strong>RESULTS:</strong></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif">A total of 115 patients were included (mean age 66&plusmn;11 years; 57% men; 38% with ischemic heart disease). Median duration of QRS was 150&plusmn; 26ms and majority of the patients (n=90, 78%) were classified as strict LBBB.</span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif">In longitudinal strain analyses LBBB-1 was observed in 23 (20%), LBBB-2 in 37 (32.1%), LBBB-3 in 25 (21.7%), and LBBB-4 in 30 (26%) patients. Patients at higher LBBB stages (longitudinal or radial pattern) had more prominent septal flash, greater LV volumes, lower LV ejection fraction and lower absolute global longitudinal, circumferential and radial strain values compared with patients in less advanced stages (p &lt; 0.05 for all).</span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif"><span style="background-color:white"><span style="color:black">There was no difference between patterns in clinical characteristics, </span></span>ischemic etiology, QRS duration<span style="background-color:white"><span style="color:black"> and time delay between septal and lateral LV wall.</span></span></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif">Late gadolinium enhancement (LGE) was found in 63 patients (54.8%), with a septal location in 34 (29.6%) patients, lateral in 4 (3.5%) patients, septal and lateral in 11 (9.6%) patients. Furthermore, no difference was found for LGE presence, distribution or location between the four strain patterns. </span></span></p>

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<p><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif"><strong>CONCLUSIONS:</strong></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif">Among patients with LBBB, our study found a good association between longitudinal and radial strain patterns with the degree of LV remodeling and LV dysfunction by FT-CMR analysis. Additionally, myocardial fibrosis didn&rsquo;t seem to interfere with the staged LBBB classification. </span></span></p>

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