scholarly journals Regional myocardial work as determinant of heart failure in left bundle branch block

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.


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.


EP Europace ◽  
2021 ◽  
Vol 23 (Supplement_3) ◽  
Author(s):  
N Shirokov ◽  
V Kuznetsov ◽  
V Todosiichuk ◽  
A Soldatova ◽  
D Krinochkin

Abstract Funding Acknowledgements Type of funding sources: None. Background Left bundle branch block (LBBB) assessed by electrocardiography (ECG) is used in current clinical guidelines for patient selection to cardiac resynchronisation therapy (CRT). But percentage of non-responders among patients with congestive heart failure is high. Super-response (SR) to CRT was not enough described in clinical guidelines. We hypothesized that mechanical patterns of LBBB and parameters of mechanical dyssynchrony could be used as predictors of SR to CRT. Aim To assess a relationship of LBBB patterns defined by ECG and echocardiography with SR to CRT. Materials and methods 60 patients (mean age 54.5 ± 10.4 years) were examined at baseline and during follow-up: 10.6 ± 3.6 months. Patients were divided into groups: I group (n = 31) with decrease of left ventricular end-systolic volume (ESV) ≥30% (super-responders) and II group (n = 29) - decrease of LV ESV <30% (non-super-responders). Three strain-markers of LBBB assessed by Tissue Doppler Imaging (TDI) and Speckle Tracking Echocardiography (STE) were used: (1) early contraction of basal or midventricular segment in the septal wall and early stretching of basal or midventricular segment in the lateral wall (yellow arrows); (2) the early peak contraction of the septal wall occurred in the first 70% of the systolic ejection phase (blue arrow); (3) the early stretching wall that showed peak contraction after aortic valve closure (red arrows). The classic LBBB pattern was defined if all three strain-markers were present. The heterogeneous LBBB pattern was defined if two from three strain-markers were present. Results At baseline groups did not differ in main clinical characteristics, including QRS width and LBBB assessed by ECG. Mechanical abnormalities were found only in group I: SF (32.3% vs 0.0%; p = 0.001) and apical rocking (19.4% vs 0.0%; p = 0.024), as well as classic LBBB mechanical pattern (20.8% vs 0.0%; p = 0.05). The complex of heterogeneous LBBB mechanical pattern (HR 7.512; 95% CI 1.434 – 39.632; р=0.025), interventricular mechanical delay (HR 1.037; 95% CI 1.005 – 1.071; р=0.017) and longitudinal strain of interventricular septum mid segment (HR 0.726; 95% CI 0.540 – 0.977; р=0.035) had an independent relationship with SR. According to the ROC analysis the sensitivity and specificity of model in the prediction of SR were 77.3% and 91.3% (AUC = 0.862; p < 0.001). Conclusion SR is associated with both LBBB mechanical patterns assessed by STE and TDI. LBBB defined by ECG did not have significant association with SR to CRT. Abstract Figure.


2021 ◽  
Vol 42 (Supplement_1) ◽  
Author(s):  
L E R Hammersboen ◽  
M Stugaard ◽  
E W Remme ◽  
E Donal ◽  
J Duchenne ◽  
...  

Abstract Introduction Left bundle brach block (LBBB) leads to left ventricular (LV) mechanical dyssynchrony with septal flash and delayed lateral wall contractions. Since atrium and ventricle are anatomically connected, dyssynchronous LV contractions may be transmitted to the left atrium, thereby disturbing left (LA) function. Purpose To test the hypothesis that patients with LBBB have LA dyssynchrony induced by tethering to the dyssynchronous left ventricle. Methods Myocardial strain was measured by speckle-tracking echocardiography in 20 non-ischaemic heart failure patients with LBBB, before and 6 months after cardiac resynchronization therapy (CRT), and in 20 healthy controls. For the LA, dyssynchrony was measured as time delay between onset of the interatrial septum and the lateral wall, and for the LV, between onset septal flash and onset lateral wall contraction. White arrows in Figure indicate onset LA stretch. Results As shown in the Figure, patients with LBBB and HF had marked LA reservoir phase dyssynchrony. Before CRT time delay from onset LA septal stretch to onset lateral wall stretch was 125±71 ms (mean±SD), and decreased to 23±70 (p<0.0001) with CRT. In controls there was a small delay of 34±56 ms. The LA dyssynchrony correlated with LV dyssynchrony (r=0.50, p=0.033), supporting the hypothesis that LA dyssynchrony in LBBB represents mechanical interaction due to tethering between the respective walls. Conclusions Patients with LBBB had marked LA reservoir phase dyssynchrony, which was abolished with CRT. The LA dyssynchrony was attributed to direct LV-LA mechanical interaction. The observed LA resynchronization by CRT represent an additional benefit of CRT in patients with heart failure. FUNDunding Acknowledgement Type of funding sources: None. Left atrial and ventricular dyssynchrony


Author(s):  
Alberto Aimo ◽  
Alessandro Valleggi ◽  
Andrea Barison ◽  
Sara Salerni ◽  
Michele Emdin ◽  
...  

AbstractPatients with non-ischaemic systolic heart failure (HF) and left bundle branch block (LBBB) can display a wide or narrow pattern (WP/NP) of the systolic phase of the left ventricular (LV) volume/time (V/t) curve in cardiac magnetic resonance (CMR). The clinical and prognostic significance of these patterns is unknown. Consecutive patients with non-ischaemic HF, LV ejection fraction < 50% and LBBB underwent 1.5 T CMR. Maximal dyssynchrony time (time between the earliest and latest end-systolic peaks), systolic dyssynchrony index (standard deviation of times to peak volume change), and contractility index (maximum rate of change of pressure-normalized stress) were calculated. The endpoint was a composite of cardiovascular death, HF hospitalization, and appropriate defibrillator shock. NP was found in 29 and WP in 72 patients. WP patients had higher volumes and NT-proBNP, and lower LVEF. WP patients had a longer maximal dyssynchrony time (absolute duration: 192 ± 80 vs. 143 ± 65 ms, p < 0.001; % of RR interval: 25 ± 11% vs. 8 ± 4%, p < 0.001), a higher systolic dyssynchrony index (13 ± 4 vs. 7 ± 3%, p < 0.001), and a lower contractility index (2.6 ± 1.2 vs 3.2 ± 1.7, p < 0.05). WP patients had a shorter survival free from the composite endpoint regardless of age, NT-proBNP or LVEF. Nonetheless, WP patients responded more often to cardiac resynchronization therapy (CRT) than those with NP (24/28 [86%] vs. 1/11 [9%] responders, respectively; p < 0.001). In patients with non-ischaemic systolic HF and LBBB, the WP of V/t curves identifies a subgroup of patients with greater LV dyssynchrony and worse outcome, but better response to CRT.


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