Lateral Wall Dysfunction Signals Onset of Progressive Heart Failure in Left Bundle Branch Block

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.

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Elevated septal wall stress - a driver of left ventricular dysfunction in left bundle branch block?

European Heart Journal - Cardiovascular Imaging ◽

10.1093/ehjci/jeaa356.032 ◽

2021 ◽

Vol 22 (Supplement_1) ◽

Author(s):

OJ Sletten ◽

JM Aalen ◽

EW Remme ◽

H Izci ◽

J Duchenne ◽

...

Keyword(s):

Heart Failure ◽

Wall Thickness ◽

Left Bundle Branch Block ◽

Wall Stress ◽

Lateral Wall ◽

Left Ventricular ◽

Public Institution ◽

Wall Thickening ◽

Bundle Branch Block ◽

Septal Wall

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.

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Associations between left bundle branch block with different PR intervals, QRS durations, heart rates and the risk of heart failure: a register-based cohort study using ECG data from the primary care setting

Open Heart ◽

10.1136/openhrt-2020-001425 ◽

2021 ◽

Vol 8 (1) ◽

pp. e001425

Author(s):

Marc Meller Søndergaard ◽

Johannes Riis ◽

Karoline Willum Bodker ◽

Steen Møller Hansen ◽

Jesper Nielsen ◽

...

Keyword(s):

Heart Failure ◽

Primary Care ◽

Heart Rate ◽

Left Bundle Branch Block ◽

Bundle Branch Block ◽

Increased Risk ◽

Pr Interval ◽

Qrs Duration ◽

The Impact

AimLeft bundle branch block (LBBB) is associated with an increased risk of heart failure (HF). We assessed the impact of common ECG parameters on this association using large-scale data.Methods and resultsUsing ECGs recorded in a large primary care population from 2001 to 2011, we identified HF-naive patients with a first-time LBBB ECG. We obtained information on sex, age, emigration, medication, diseases and death from Danish registries. We investigated the association between the PR interval, QRS duration, and heart rate and the risk of HF over a 2-year follow-up period using Cox regression analysis.Of 2471 included patients with LBBB, 464 (18.8%) developed HF during follow-up. A significant interaction was found between QRS duration and heart rate (p<0.01), and the analyses were stratified on these parameters. Using a QRS duration <150 ms and a heart rate <70 beats per minute (bpm) as the reference, all groups were statistically significantly associated with the development of HF. Patients with a QRS duration ≥150 ms and heart rate ≥70 bpm had the highest risk of developing HF (HR 3.17 (95% CI 2.41 to 4.18, p<0.001). There was no association between the PR interval and HF after adjustment.ConclusionProlonged QRS duration and higher heart rate were associated with increased risk of HF among primary care patients with LBBB, while no association was observed with PR interval. Patients with LBBB with both a prolonged QRS duration (≥150 ms) and higher heart rate (≥70 bpm) have the highest risk of developing HF.

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

European Heart Journal - Cardiovascular Imaging ◽

10.1093/ehjci/jeaa356.152 ◽

2021 ◽

Vol 22 (Supplement_1) ◽

Author(s):

K Kupczynska ◽

KA Nguyen ◽

E Surkova ◽

CH Palermo ◽

F Sambugaro ◽

...

Keyword(s):

Left Bundle Branch Block ◽

Systolic Dysfunction ◽

Lateral Wall ◽

Left Ventricular ◽

Public Institution ◽

Healthy Controls ◽

Bundle Branch Block ◽

Funding Sources ◽

Lv Dysfunction ◽

Artery Disease

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.

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