scholarly journals Changes in mechanics of septal and lateral walls in patients with left bundle-branch block are related to extent of systolic dysfunction

2021 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
K Kupczynska ◽  
KA Nguyen ◽  
E Surkova ◽  
CH Palermo ◽  
F Sambugaro ◽  
...  

Abstract Funding Acknowledgements Type of funding sources: Public Institution(s). Main funding source(s): Karolina Kupczynska was supported by research grant awarded by the Club 30 of the Polish Cardiac Society Background Left bundle branch block (LBBB) affects left ventricular (LV) mechanics and promotes systolic dysfunction. Purpose To analyse myocardial work (MW) and myocardial work efficiency (MWE) of the septal and LV lateral wall in healthy controls and LBBB patients with various degrees of LV dysfunction using non-invasive method. Methods Our study involved 102 healthy controls (mean age 41.5 ± 15.7 years, 45% male) and 58 LBBB patients without coronary artery disease (mean age 65 ± 13 years, 60% male) divided into 3 groups based on their LVEF: preserved (n= 27), mid-range (n= 16) and reduced (n= 15). Myocardial work parameters were estimated in septal and lateral wall by LV pressure-strain loop obtained by echocardiography. Results There were no differences between septal and lateral MW and MWE in healthy controls (p = NS). We found lower septal MW in comparison to lateral MW (p < 0.0001), but there were no differences in MWE (p = NS) in LBBB patients with preserved LVEF. Patients with LBBB and mid-range or reduced LVEF had lower MW (p < 0.0001 in both subgroups) and lower MWE (p = 0.002 and p = 0.0001, respectively) in septum compared with lateral wall. There was a progressive decrease in septal MW and MWE with the occurring of LBBB and the worsening of LVEF (figure A). Interestingly in healthy controls there was significantly lower lateral MW but higher MWE in comparison to group with LBBB and preserved LVEF. We did not detect differences between LBBB groups with preserved and mid-range LVEF, but patients with reduced LVEF had significant reduction in terms of lateral MW and MWE (figure B). Conclusions Impairment in septal myocardial work escalated according to the appearance of LBBB and LVEF loss. Septal dysfunction was compensated by the effective myocardial work of the lateral wall in LBBB patients with preserved and mid-range LVEF. Mechanical dysfunction of the lateral wall was associated with severely reduced LVEF. Abstract Figure.

2020 ◽  
Vol 21 (Supplement_1) ◽  
Author(s):  
K Kupczynska ◽  
K A Nguyen ◽  
E Surkova ◽  
C H Palermo ◽  
F Sambugaro ◽  
...  

Abstract Funding Acknowledgements Karolina Kupczynska was supported by research grant awarded by the Club 30 of the Polish Cardiac Society Background Left bundle branch block (LBBB) impairs left ventricular (LV) mechanics and can lead to systolic dysfunction. However, LV mechanical changes that differentiate LBBB patients with preserved and reduced LV ejection fraction (LVEF) remain to be clarified. Purpose To measure myocardial work (MWI) and myocardial work efficiency (MWE) of the septal and LV lateral wall in patients with LBBB and various degrees of LV dysfunction using non-invasive strain-derived method. Methods Fifty-eight LBBB patients without coronary artery disease (mean age 65 ± 13 years, 60% male) were divided into 4 groups based on their LVEF according to current recommendations for cardiac chamber quantification (figure A): normal (n= 25), mildly (n= 16), moderately (n= 11), and severely (n= 6) reduced LVEF. Septal and lateral wall MWI and MWE were estimated by LV pressure-strain loop obtained by echocardiography. Results Both MWI (787 mmHg%, 95% CI 651-924 vs 1956 mmHg%, 95% CI 1758-2154; p < 0.0001) and MWE (71%, 95% CI 66-76 vs 85%, 95% CI 82-87; p = 0.0001) were lower in the septum than in the lateral wall. There was a progressive decrease in septal MWI and MWE with the worsening of LVEF (figure B). Conversely, MWI and MWE of the lateral wall were preserved in patients with normal, mildly and moderately reduced LVEF groups. A significant reduction of MWI and MWE in the lateral wall was detected only in patients with severely reduced LVEF (figure C). Conclusion In patients with LBBB, impairment in septal myocardial work escalates according to LVEF loss. Septal dysfunction was compensated by the effective myocardial work of the lateral wall in patients with normal, mildly and moderately reduced LVEF. Mechanical dysfunction of the lateral wall was associated with severe reduction of LVEF. Abstract 102 Figure.


2021 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
OJ Sletten ◽  
JM Aalen ◽  
H Izci ◽  
J Duchenne ◽  
EW Remme ◽  
...  

Abstract Funding Acknowledgements Type of funding sources: Public Institution(s). Main funding source(s): The Norwegian Health Association Background Left bundle branch block (LBBB) worsen prognosis in heart failure patients. LBBB may also cause heart failure in otherwise healthy individuals. The mechanical changes induced by LBBB are potential determinants of heart failure in these patients, but their relation to left ventricular (LV) systolic function is incompletely understood. Purpose This study investigates the contribution of regional contractile function to heart failure in patients with LBBB. Methods In 76 patients with LBBB and 11 healthy controls, myocardial strain was measured by speckle-tracking echocardiography and myocardial work by pressure-strain analysis. Patients with ischemic heart disease or myocardial scarring were excluded. LBBB patients were stratified by LV ejection fraction (EF) >50% (EFpreserved), 36-50% (EFmid), and ≤35% (EFlow). 62 LBBB patients subsequently underwent cardiac resynchronization therapy (CRT) implantation and was re-examined at 6 months. Results Septal work was significantly and successively reduced from controls, EFpreserved, EFmid, to EFlow (1977 ± 506, 1025 ± 342, 601 ± 494 and -41 ± 303 mmHg·%, respectively, all p < 0.01) (Figure 1). There was a strong correlation (R = 0.84, p < 0.01) between septal work and LVEF. In contrast, work in the LV lateral wall was preserved in both EFpreserved (2367 ± 459 mmHg·%) and EFmid (2252 ± 449 mmHg·%) vs controls (2062 ± 459 mmHg·%, all NS). In the EFlow group, however, LV lateral wall work was reduced (1473 ± 568 mmHg·%, p < 0.01 vs controls). Thus, lateral wall function was not correlated with LVEF in patients with LVEF >35% (NS). At six month CRT septal work was markedly increased (165 ± 485 vs 1288 ± 523 mmHg·%, p < 0.01) and LV lateral wall work reduced (1730 ± 620 vs 1264 ± 490 mmHg·%, p < 0.01). LVEF increased from 32 ± 8 to 47 ± 10 % (p < 0.01). Conclusions Heart failure in LBBB patients is determined by degree of septal dysfunction. LV lateral wall function, on the other hand, is preserved in the early phase of heart failure and was only reduced in patients with severe heart failure. Further clinical studies should investigate if measuring LV lateral wall function can increase precision in patient selection for CRT. Abstract Figure.


2021 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
OJ Sletten ◽  
JM Aalen ◽  
EW Remme ◽  
H Izci ◽  
J Duchenne ◽  
...  

Abstract Funding Acknowledgements Type of funding sources: Public Institution(s). Main funding source(s): The Norwegian Health Association Background Septal dysfunction is a main feature of left bundle branch block (LBBB), and increasing wall stress is a proposed mechanism of heart failure development in LBBB patients. To try to reveal the pathophysiologic pathway from dyssynchrony to heart failure, we investigated the relationship between septal and left ventricular (LV) lateral wall stress in patients with LBBB. Hypothesis Increased septal wall stress causes septal dysfunction in LBBB. Methods We included 24 LBBB-patients (65 ± 11 years, 11 males) with LV ejection fraction (EF) ranging from 18 to 67%, and 8 healthy controls (58 ± 10 years, 4 males). Wall stress was calculated at peak LV pressure (LVP) according to the law of La Place ([LVP x radius]/[wall thickness]). Wall thickness was measured using M-mode, and regional curvature was measured in mid-ventricular shortaxis from 2D echocardiographic images. We used a previously validated non-invasive method to estimate LVP from brachial blood pressure and adjusted for valvular events. Myocardial scar was ruled out by late gadolinium enhancement cardiac magnetic resonance imaging. Results Wall stress was significantly higher in septum than LV lateral wall at peak LVP (48 ± 12 vs 37 ± 11 kPa, p < 0.01) in LBBB patients, while no difference was seen in the controls (Figure A). In patients, septal wall thickening showed a strong correlation with LVEF (r = 0.77, p < 0.01) (Figure B). Similar correlation was not significant for the LV lateral wall (r = 0.13, NS). Attenuation of septal wall thickening in LBBB-patients correlated well with increasing septal wall stress (r=-0.60, p < 0.01). Wall thickening and stress did not correlate in the LV lateral wall (r=-0.14, NS). Conclusion Increased septal wall stress is associated with reduced systolic thickening in patients with LBBB. Septal wall thickening, in contrast to LV lateral wall thickening, was correlated to global LV function. These findings suggest that septal remodeling which could have normalized septal wall stress, was not achieved and heart failure may develop. Abstract Figure.


2020 ◽  
Author(s):  
João Ferreira ◽  
Célia Marques Domingues ◽  
Susana Isabel Costa ◽  
Maria Fátima Franco Silva ◽  
Lino Manuel Martins Gonçalves

Abstract Background Implantable cardiac defibrillators (ICD) are a popular and effective option in heart failure with left ventricular systolic dysfunction patients. Although frequently underdiagnosed, inadvertent malposition can lead to endocardial damage and thrombotic events. As ICD implants tend to increase in the following years, the recognition of their complications is critical. Case presentation The authors present a case of a 64-year-old woman with advanced heart failure and ICD malposition. This accidental discovery was denounced by the presence of a right bundle branch block pattern and later confirmed by echocardiography which showed the lead tip in contact with the mid segment of the left ventricular antero-lateral wall. As the patient hospitalisation was complicated with refractory ascites and cardiogenic shock, she underwent cardiac transplantation, with no recurrence of heart failure symptoms. Conclusions An electrocardiogram showing a right bundle branch block pattern during VVI pacing should arise the suspicion of inadvertent placement of a pacing/ICD lead. The many facets of echocardiography should be used for the diagnosis of this complication, as they were paramount in this case, as highlighted.


EP Europace ◽  
2021 ◽  
Vol 23 (Supplement_3) ◽  
Author(s):  
I Chung

Abstract Funding Acknowledgements Type of funding sources: None. Background Background: In 1982, Goldberger described an electrocardiographic triad (SV1 or SV2 +RV5 or RV6 ≥3.5mV, total QRS amplitude in limb leads ≤0.8mV, and R/S ratio < 1 in lead V4) that was 70% sensitive and >90% specific for detecting severe left ventricular (LV) dysfunction. The pathophysiology of this highly specific ECG triad probably relates to a number of mechanical and vectorial factors associated with congestive heart failure of a variety of etiologies. Left ventricular enlargement causes increased precordial voltage. The horizontal plane vector shifts posteriorly, orthogonal to the frontal plane, causing poor R wave progression and low limb lead voltage. Finally, increased extracellular fluid may preferentially attenuates QRS voltage in the limb leads. Objective To test the sensitivity of this triad in patients with non-ischaemic cardiomyopathy and severe left ventricular systolic dysfunction Methods Methods: 386 patients mean age 62.45 ± 13.96 years, male 72%, NYHA II-IV, with non-ischaemic cardiomyopathy, 70 had bundle branch block (18%) and mean left ventricular ejection fraction(EF) 22.57 ± 8.62%. 76% hypertension, 39% diabetes mellitus, 32% atrial fibrillation. The electrocardiographic triad was sought in the ECG recorded at time of the echocardiographic study. The mean LV end-diastolic diameter was 5.81 ± 1.53 cm. Result Results: 56% patients had SV1 or SV2 +RV5 or RV6 ≥3.5mV, 85% patients had R/S ratio < 1 in lead V4, 19% had total QRS amplitude in limb leads ≤0.8mV. 50% patients had SV1 or SV2 +RV5 or RV6 ≥3.5mV and R/S ratio < 1 in lead V4. Only 6% patients fulfilled the triad. Conclusions Conclusion: Goldberger"s triad is an insensitive marker for severe LV dysfunction. Using SV1 or SV2 +RV5 or RV6 ≥3.5mV and R/S ratio < 1 in lead V4 had a sensitivity of 50%. 85% patients had R/S ratio < 1 in lead V4. R/S ratio < 1 in lead V4 is a simple way to select dilated LV.


2011 ◽  
Vol 301 (6) ◽  
pp. H2334-H2343 ◽  
Author(s):  
Kristoffer Russell ◽  
Otto A. Smiseth ◽  
Ola Gjesdal ◽  
Eirik Qvigstad ◽  
Per Andreas Norseng ◽  
...  

During left bundle branch block (LBBB), electromechanical delay (EMD), defined as time from regional electrical activation (REA) to onset shortening, is prolonged in the late-activated left ventricular lateral wall compared with the septum. This leads to greater mechanical relative to electrical dyssynchrony. The aim of this study was to determine the mechanism of the prolonged EMD. We investigated this phenomenon in an experimental LBBB dog model ( n = 7), in patients ( n = 9) with biventricular pacing devices, in an in vitro papillary muscle study ( n = 6), and a mathematical simulation model. Pressures, myocardial deformation, and REA were assessed. In the dogs, there was a greater mechanical than electrical delay (82 ± 12 vs. 54 ± 8 ms, P = 0.002) due to prolonged EMD in the lateral wall vs. septum (39 ± 8 vs.11 ± 9 ms, P = 0.002). The prolonged EMD in later activated myocardium could not be explained by increased excitation-contraction coupling time or increased pressure at the time of REA but was strongly related to dP/d t at the time of REA ( r = 0.88). Results in humans were consistent with experimental findings. The papillary muscle study and mathematical model showed that EMD was prolonged at higher dP/d t because it took longer for the segment to generate active force at a rate superior to the load rise, which is a requirement for shortening. We conclude that, during LBBB, prolonged EMD in late-activated myocardium is caused by a higher dP/d t at the time of activation, resulting in aggravated mechanical relative to electrical dyssynchrony. These findings suggest that LV contractility may modify mechanical dyssynchrony.


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