scholarly journals Left bundle branch block causes left atrial dyssynchrony: a result of atrio-ventricular mechanical interaction

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

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.


Kardiologiia ◽  
2021 ◽  
Vol 61 (8) ◽  
pp. 68-75
Author(s):  
E. K. Serezhina ◽  
A. G. Obrezan

This systematic review is based on 19 studies from Elsevier, PubMed, Embase, and Scopus databases, which were found by the following keywords: LA strain (left atrial strain), STE (speckle tracking echocardiography), HF (heart failure), and HFpEF (heart failure with preserved ejection fraction). The review focuses on results and conclusions of studies on using the 2D echocardiographic evaluation of left atrial (LA) myocardial strain for early diagnosis of HFpEF in routine clinical practice. Analysis of the studies included into this review showed a significant decline of all LA functions in patients with HFpEF. Also, multiple studies have reported associations between decreased indexes of LA strain and old age, atrial fibrillation, left ventricular hypertrophy, left and right ventricular systolic dysfunction, and LV diastolic dysfunction. Thus, the review indicates significant possibilities of using indexes of LA strain in evaluation of early stages of both systolic and diastolic myocardial dysfunction. Notably, LA functional systolic and diastolic indexes are not sufficiently studied despite their growing significance for diagnosis and prognosis of patients with HFpEF. For this reason, in addition to existing models for risk stratification in this disease, including clinical characteristics and/or echocardiographic data, future studies should focus on these parameters. 


Author(s):  
Michael Henein ◽  
Krister Lindmark ◽  
Andrew Coats ◽  
Per Lindqvist

The common pathophysiology contributing to fluid retention and dyspnoea in heart failure is a non-compliant and stiff myocardium with raised left ventricular end-diastolic pressure. With the rapid development of newer imaging technologies, particularly echocardiography, our understanding of the syndrome of heart failure has significantly changed. The most important imaging sign in the early eighties was reduced ejection fraction (HFrEF), with low values being used as an explanation for the development of signs and symptoms.  In the early 2000s, similar Doppler echocardiographic signs became frequently recognised in patients with heart failure symptoms and signs who proved to have  a relatively maintained ejection fraction (EF) of >40%, hence the description of the syndrome of “diastolic heart failure”.  This was later rephrased as heart failure with normal ejection fraction (HFnEF) and more recently as heart failure with preserved ejection fraction (HFpEF). Since then, HFpEF has attracted the interest of many cardiologists and scientists worldwide, searching for specific features and treatment options for the syndrome. As for the features, two important findings have now been established, the first showed that LV systolic function mainly at the subendocardial level was abnormal in HFpEF, particularly manifesting during stress/exercise when the increase in heart rate was not associated with a commensurate increase in stroke volume and a second observation of a significant impairment of left atrial function (i.e. myocardial strain) and emptying fraction associated with increased left atrial pressures and the potential development of atrial arrhythmia in HFpEF. Such atrial abnormalities have been shown to be commonly associated with cavity enlargement and poor compliance. The latter observation has similarly been reported in patients with reduced EF.  Despite the above similarities in cardiac physiology between HFpEF and HFrEF, treatments of the two conditions differ markedly. When comparing HFrEF and HFpEF, we can easily see that some patients fall into the grey area on the EF spectrum with values fluctuating above and below 40%, suggesting that the substrate for the expected drug effect may differ, possibly explaining the lack of consistent response in these patients.. In addition, it should not be forgotten that most heart failure medications work on the circulation rather than the heart itself, hence the need for shared circulatory disturbances between the two conditions before we can reasonably expect identical treatment benefits when using the same medications in different clinical settings.  Therefore, it is clear that classifying heart failure patients according to a single measure of LV function i.e. ejection fraction fails to help at least 50% of patients presenting with this syndrome. In contrast, aggregating such patients based on clear evidence for raised LA pressures, irrespective of EF, might show evidence for a more consistent response to vasodilators and conventional heart failure therapy, particularly those patients currently described as HFpEF. 


2010 ◽  
Vol 120 (5) ◽  
pp. 207-217 ◽  
Author(s):  
Miriam T. Rademaker ◽  
Christopher J. Charles ◽  
Iain C. Melton ◽  
A. Mark Richards ◽  
Christopher M. Frampton ◽  
...  

Monitoring of HF (heart failure) with intracardiac pressure, intrathoracic impedance and/or natriuretic peptide levels has been advocated. We aimed to investigate possible differences in the response patterns of each of these monitoring modalities during HF decompensation that may have an impact on the potential for early therapeutic intervention. Six sheep were implanted with a LAP (left atrial pressure) sensor and a CRT-D (cardiac resynchronization therapy defibrillator) capable of monitoring impedance along six lead configuration vectors. An estimate of ALAP (LAP from admittance) was determined by linear regression. HF was induced by rapid ventricular pacing at 180 and 220 bpm (beats/min) for a week each, followed by a third week with daily pacing suspensions for increasing durations (1–5 h). Incremental pacing induced progressively severe HF reflected in increases in LAP (5.9 ± 0.4 to 24.5 ± 1.6 mmHg) and plasma atrial (20 ± 3 to 197 ± 36 pmol/l) and B-type natriuretic peptide (3.7 ± 0.7 to 32.7 ± 5.4 pmol/l) (all P<0.001) levels. All impedance vectors decreased in proportion to HF severity (all P<0.001), with the LVring (left ventricular)-case vector correlating best with LAP (r2=0.63, P<0.001). Natriuretic peptides closely paralleled rapid acute changes in LAP during alterations in pacing (P<0.001), whereas impedance changes were delayed relative to LAP. ALAP exhibited good agreement with LAP. In summary, impedance measured with an LV lead correlates significantly with changes in LAP, but exhibits a delayed response to acute alterations. Natriuretic peptides respond rapidly to acute LAP changes. Direct LAP, impedance and natriuretic peptide measurements all show promise as early indicators of worsening HF. ALAP provides an estimate of LAP that may be clinically useful.


2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
M V Kostyukevich ◽  
P Van Der Bijl ◽  
N M Vo ◽  
N Ajmone Marsan ◽  
V Delgado ◽  
...  

Abstract Background Myocardial work, assessed by speckle tracking echocardiography, reflects mechanical efficiency of the left ventricle. In heart failure patients, characterization of acute changes in regional (septal and lateral) left ventricular (LV) myocardial walls after cardiac resynchronization therapy (CRT) may enhance understanding of CRT response. Objective To evaluate the interaction between CRT response and components of myocardial work of the lateral wall and septum in patients with heart failure. Methods Regional LV myocardial work was calculated by integrating non-invasive blood pressure measurements, timing of mitral and aortic valve opening and closure and speckle tracking-derived LV longitudinal strain. From pressure-strain loops, constructive work (CW) and wasted work (WW) were calculated. CRT response was defined as a decrease in LV end-systolic volume ≥15% at 6 months follow-up. Changes in CW and WW of the septal and lateral walls prior to (baseline) and within the first 5 days after CRT implantation were compared between CRT responders and non-responders. Results At baseline, measurement of regional CW and WW was performed in 168 patients treated with CRT (71% men, 66±10 years). At 6 months, 59% of patients were CRT responders. CRT responders more frequently had non-ischemic heart failure than non-responders (54% vs 36%; p=0.027). At baseline, CRT responders were characterized by a significantly higher septal WW (270.5 [160.0; 451.5] mmHg% vs. 210.5 [106.3; 336.5] mmHg%; p=0.038) and lateral CW (989.5 [574.0; 1439.0] mmHg% vs. 689.0 [463,3; 1140.0] mmHg%; p=0.005). On multivariable analysis, only CW of the lateral wall at baseline was independently associated with CRT response (HR 1.001; 95% CI, 1.000–1.001; p=0.048). Immediately after CRT implantation, measurement of regional CW and WW was feasible in 115 patients. CRT responders showed improvement in CW (433.0 [254.5; 686.5] mmHg% to 664.5 [424.5; 977.8] mmHg%; p<0.001) and WW (305.0 [169.0; 461.3] mmHg% to 145.0 [80.0; 306.3] mmHg%; p=0.005) of the septum whereas the lateral wall demonstrated a significant decrease in CW (1036.5 [561.0; 1402.0] to 818.0 [491.0; 1154.3] mmHg%; p=0.005) and increase in WW (132.5 [80.3; 269.3] to 198.5 [107.5; 331.0] mmHg%; p=0.025). Non-responders showed only a decrease in WW of the septum (202.8 [102.9; 332.5] to 168.5 [67.6; 258.4] mmHg%; p=0.049). Conclusion CRT responders are characterized by increased WW of the septum and CW of the lateral wall at baseline, which are corrected immediately after CRT implantation. Constructive work of the LV lateral wall at baseline is independently associated with CRT response. Acknowledgement/Funding Study was supported by ESC Research grant 2018


2020 ◽  
Vol 21 (Supplement_1) ◽  
Author(s):  
J Aalen ◽  
E Donal ◽  
C K Larsen ◽  
J Duchenne ◽  
M Cvijic ◽  
...  

Abstract Funding Acknowledgements The study was supported by Center for Cardiological Innovation. Introduction Septal dysfunction is the dominant mechanism of left ventricular (LV) failure in left bundle branch block (LBBB). We hypothesize that, provided septum is viable, septal function can recover and hence LV function improve after cardiac resynchronization therapy (CRT). Purpose To determine if combined assessment of septal function and viability identifies responders to CRT. Methods In a prospective multicenter study of 200 unselected patients referred for CRT, we measured myocardial strain by speckle-tracking echocardiography and regional work by pressure-strain analysis before and 7 ± 1 months after CRT. Viability was assessed by late gadolinium enhancement cardiac magnetic resonance imaging (n = 123). CRT response was defined as ≥15% reduction in LV end-systolic volume. Results Before CRT, septal work was 258 ± 463 and LV lateral wall work 1469 ± 674 mmHg·% (p &lt; 0.0001). In CRT responders, septal work was restored to 1243 ± 495 mmHg·%, whereas non-responders showed less marked improvement (p &lt; 0.0001). The figure illustrates a typical CRT responder with negative septal work and a large difference between work in the LV lateral wall and septum (panel A). There was no septal scar (panel B) and, after 6 months with CRT, septal work was recovered (panel C). Pressure-strain loops illustrate that CRT converted inefficient septal contractions with substantial negative (wasted) work to positive work throughout systole. For the entire study population, the difference between work in the LV lateral wall and septum predicted CRT response with area under the curve (AUC) 0.75 (95% CI: 0.68-0.83) and was feasible in 98% of patients. Furthermore, septal scar predicted non-response to CRT with AUC 0.76 (95% CI: 0.65-0.86). Combining work difference and septal viability improved AUC for CRT response to 0.85 (95% CI: 0.76-0.94) (figure panel D). The AUC was similar for QRS 120-150 and &gt;150 ms. Conclusions The proposed combined approach with assessment of septal work and viability identified CRT responders with high precision. Abstract 561 Figure.


Sign in / Sign up

Export Citation Format

Share Document