News
Sep 5, 2018

ESC Congress 2018, Sunday 26th of August


 

.....

"Detection of mechanical activation of the left ventricle using high frame rate ultrasound imaging" with first author Kaja Kvåle, M.Sc, PhD fellow, was selected for best poster screen on Sunday.

"Ventricular volume changes are more accurate markers of acute response to CRT than contraction indices" with first author Espen Bøe, MD, PhD was selected for best poster presentation the same day.

CCI has been cooperating with renowned cardiologists from Brazil and results from the study "Association between ventricular arrhythmogenicity and myocardial mechanical dispersion assessed by strain echocardiography in chagas cardiomyopathy" were presented during the Congress.

CCI is also cooperating with experts in Japan, and results from the experimental study "Estimation of filling pressure by E/e’ in left bundle branch block: why is it so difficult?" were presented. It is a matter of debate if E/e' should be used in patients with left bundle branch block (LBBB). As suggested by the clinical data and strongly supported by this experimental study, septal E/e' should not be used for estimation of LV filling pressure in patients with LBBB.

Copyright: John Aalen / OUH
Category: General
Posted by: Piritta
Sunday 26th of August

Contributions


Azevedo ACA, Barros MV, Klaboe LG, Edvardsen T, Nunes MCP, Costa HS, Paixao GMM,  Martins JPP, Bernardes HR, Santos Junior OR, Rocha MOC
Association between ventricular arrhythmogenicity and myocardial mechanical dispersion assessed by strain echocardiography in chagas cardiomyopathy.

Introduction: Endemic Chaga's disease is a major health concern in Latin America. Ventricular arrhythmias (VA) is a hallmark of Chagas cardiomyopathy (ChD) associated with worse prognosis. Myocardial mechanical dispersion (MD) by speckle tracking echocardiography reflects heterogenous ventricular contractions and is a sensitive marker of ventricular arrhythmias in several cardiomyopathies. We aimed to verify the possible association between ventricular arrhythmias and mechanical dispersion in patients with chronic Chagas cardiomyopathy (ChD).

Methods: We included otherwise healthy patients with chronic ChD in a cross sectional echocardiographic study. MD was defined as the standard deviation of time from onset of Q/R on ECG to peak longitudinal strain in 16 segments. Non-sustained ventricular tachycardia (NSVT) by Holter monitoring was defined as complex ventricular arrhythmia. Included patients were split into two groups according to absence (GROUP 0) or presence (GROUP 1) of NSVT by Holter.

Results: We included 76 ChD patients (55±10 years, 60% men). GROUP 0 had 44 patients and GROUP 1 had 32 patients. Patients with NSVT (GROUP 1) had more pronounced MD (59±15ms vs. 87±49ms, p=0.006) and worse GLS (-14.4±2.9% vs. -12.5±4.2, p=0.02) than patients without NSTV (GROUP 0), while LVEF (44±6% vs 42±9%, p=0.57), end-diastolic diameter (61±6 mm vs 62±7 mm, p=0.9) and diastolic function (E/e' 10.2±4.4 vs. 11.7±4.9, p=0.19) were similar. Both MD and GLS were univariate predictors of CVA (P<0.01). MD was independently associated with non-sustained ventricular tachycardia (OR 1.04; 95% CI, 1.00–1.20; p=0.031) in a multivariate analysis

Conclusion: MD was the only echocardiography parameter associated with NSVT in Chagas disease cardiomyopathy and may add important information in the risk stratification of those patients. Better knowledge of pathophysiological and pathogenetic mechanisms, through new methodologies, should allow better therapeutic management and knowledge of earlier risk factors to worse prognosis and stratification of patients.

Copyright: Eigil Samset / GE Vingmed Ultrasound

Best poster screen

Kvaale K, Bersvendsen J, Salles S, Aalen J, Remme EW, Brekke PH, Edvardsen T, Samset E
Detection of mechanical activation of the left ventricle using high frame rate ultrasound imaging.

Introduction: A non-invasive method for regional mapping of mechanical activation could be useful in the diagnosis of pathologies affecting cardiac contraction patterns. With the advent of high frame rate echocardiography, there is potential to uncover rapid events not seen by conventional imaging. Novel echo acquisition and signal processing methods were tested for the assessment of mechanical activation.

Purpose: To assess the feasibility of using high frame rate ultrasound imaging to determine spatio-temporal information about onset of mechanical activation in the left ventricle.

Methods: High frame rate ultrasound imaging (1000 to 1200 fps) was performed on 3 anesthetized open chest dogs during epicardial right ventricle (RV) and left ventricle (LV) free wall pacing. Combined sonomicrometry and electromyography (EMG) was recorded simultaneously.

The activation of the LV was mapped by tracking the propagation of the mechanical wave that occurred in the tissue after pacing. The wave propagation was estimated using Clutter Filter Wave Imaging (CFWI). CFWI was configured to highlight tissue moving at a velocity above 2.5 cm/s. An activation map showing the arrival times of the propagating activation wave, as estimated by CFWI, was computed for each pacing experiment.

The timing of mechanical activation from CFWI was compared to electrical activation and to mechanical activation in terms of strain rate measured by sonomicrometry.

Results: Figure 1a shows the mechanical activation map from pacing of the RV free wall. Early activation can be seen in the mid to apical septum, then spreading bilaterally with the latest activation in the basal lateral wall. The delays between activation of the basal septum and the lateral wall, measured using EMG and CFWI were 24.3±4.3 and 23.6±1 ms, respectively, with a difference of 0.7±4.4 ms. The difference between mechanical activation measured by sonomicrometry and CFWI was 1.7±6.7 ms.

Figure 1b shows the mechanical activation map from pacing of the LV lateral wall. Mechanical activation started in the mid lateral wall, then spreading bilaterally with the latest activation in the basal septum. The delays between activation of the basal septum and the lateral wall, measured using EMG and CFWI were 35.4±10.01 and 33.5±8.04 ms, respectively, with a difference of 1.9±12.8 ms. The difference between mechanical activation measured by sonomicrometry and CFWI was 3.4±4.1 ms.

Conclusion: This pilot study showed that mechanical activation measured by CFWI had good agreement with invasive measurements. Thus, this novel CFWI method shows potential as a non-invasive tool for LV mechanical activation mapping.

Copyright: John Aalen / OUH

Best poster

Boe E, Smiseth OA, Storsten P, Andersen OS, Aalen J, Eriksen M, Krogh M, Kongsgaard E,  Remme EW, Skulstad H
Ventricular volume changes are more accurate markers of acute response to CRT than contraction indices.

Background: Cardiac resynchronisation therapy (CRT) improves systolic function in left bundle branch block (LBBB). However, the magnitude of acute improvements in global ventricular contraction indices do not correlate consistently with long-term response to CRT.

Purpose: To determine the effect of CRT on contraction indices and ventricular volumes during LBBB by pressure-volume analysis.

Methods: In eight anaesthetised dogs, we measured left ventricular (LV) pressure by micromanometry and LV volume by sonomicrometry to calculate stroke work (SW), stroke volume (SV), peak rate of LV pressure rise (LV dP/dtmax) and ejection fraction (EF). LBBB was induced by radiofrequency ablation. Transient caval constrictions were performed to compare data at similar preloads.

Results: CRT decreased LV volumes significantly shown by a reduction in end-diastolic volume (EDV) from 83.2±21.4 to 79.5±21.1 (P<0.05) and end-systolic volume from 67.0±20.5 to 63.8±20.4 (P<0.05). There were negligible changes in SV, SW and EF whereas LV dP/dtmax increased moderately (Figure, left panels). When correcting for the reduction in preload, SV, SW and EF increased significantly (Figure, right panels). The magnitude of change in LV dP/dtmax was 3 times larger when using preload-corrected data.

Conclusions: CRT reduced preload shown by a significant reduction in EDV with little changes in EF, SW and SV. These findings suggest that LV volume changes rather than conventional contraction indices should be used to evaluate acute CRT response. These observations may explain some of the apparent inconsistency between acute response and long-term response to CRT.

 

...

Havneraas Kvisvik BA, Aagaard EN, Morkrid L, Rosjo H, Smedsrud MK, Eek C, Benz B, Haugaa KH, Edvardsen T, Gravning J
Mechanical dispersion as marker of left ventricular dysfunction and prognosis in stable coronary artery disease

Background: Assessment of global longitudinal strain (GLS) is superior to ejection fraction (EF) in evaluation of left ventricular (LV) dysfunction in patients with stabile coronary artery disease (CAD). However, the role of mechanical dispersion (MD) in this context is unresolved.

Objectives: We aimed to evaluate the potential role of MD as marker of subtle LV dysfunction and long-term prognosis in patients with stable CAD.

Methods: EF, GLS and MD were assessed in 160 patients with stable CAD, one year after successful coronary revascularization. Serum levels of high-sensitivity cardiac troponin I and amino-terminal pro B-type natriuretic peptide were quantified as markers of LV dysfunction. The primary end point was defined as all-cause mortality, whereas the secondary end point was defined as the composite of all-cause mortality and hospitalization for acute myocardial infarction or heart failure during follow-up.

Results: MD was successfully quantified in 98% of the patients (46±14 ms, [mean±SD]). There were no significant associations between EF and the biochemical markers of LV dysfunction, while both MD and GLS correlated with hs-cTnI (R=0.450 and R=0.307, p<0.01) and NT-proBNP (R=0.379 and R=0.202, p<0.05). During a mean (±SD) follow-up of 8.5±0.4 years, 14 deaths and 29 secondary events occurred. Only MD was significantly increased in nonsurvivors, and also associated with both the primary and secondary end point in a Cox regression model, after adjustment for EF and GLS.

Conclusions: In patients with stable CAD, MD may be a promising marker of subtle LV dysfunction and adverse prognosis.

Copyright: John Aalen / OUH

 

Masuda K, Aalen J, Andersen OS, Krogh M, Odland HH, Stugaard M, Remme EW,  Nakatani S, Smiseth OA
Estimation of filling pressure by E/e’ in left bundle branch block: why is it so difficult?


Introduction: Current guidelines recommend the ratio between early-diastolic mitral flow velocity and mitral annular velocity (E/e') as a key parameter for noninvasive estimation of left ventricular (LV) filling pressure. It is debated, however, if E/e' should be used in patients with left bundle branch block (LBBB).

Purpose: To determine how LBBB modifies the relationship between E/e' and LV filling pressure.

Methods: Heart failure patients with wide QRS due to LBBB or right ventricular (RV) pacing (n=13) were compared to heart failure patients with narrow QRS (n=82). Mitral annular velocities were measured at septal (e'septal) and lateral (e'lateral) locations, and average (e'average) was calculated. LV filling pressure was measured as pulmonary capillary wedge pressure (PCWP). In 6 anaesthetized dogs we induced LBBB activation pattern by RF ablation and by RV pacing, measured pressures by micromanometers and E and e' by echocardiography.

Results: In heart failure patients with narrow QRS there was good correlation between E/e' and PCWP with r values 0.54 and 0.46, for e'average and e'septal, respectively (p<0.0001.) In heart failure patients with LBBB, however, neither e'average nor e'septal correlated with PCWP (r=0.32 and 0.28 respectively, NS).

In the dog model, induction of LBBB and RV pacing caused QRS widening and septal motion similar to patients with LBBB. Septal e' decreased from 6±2 to 3±2 cm/s (mean±SD) (P<0.05), but e'lateral was unchanged at 6±1 cm/s. Septal E/e' increased from 8±2 to 15±6 (p<0.05), whereas E/e'average showed no significant change (8±2 and 9±2, respectively). There was no significant change in mean left atrial pressure (7.4±3.2 vs. 9.0±2.8 mmHg, respectively).

Conclusions: Induction of LBBB markedly increased septal E/e' due to reduction in septal e', but this did not reflect elevation of LV filling pressure. As suggested by the clinical data and strongly supported by the experimental study, septal E/e' should not be used for estimation of LV filling pressure in patients with LBBB. Whether the average of septal and lateral E/e' is useful, should be explored further in larger patient populations with LBBB.

 

Massey RJ, Diep PP, Ruud E, Aakhus S, Beitnes JO
Left ventricle systolic dysfunction in young survivors after allogeneic haematopetic stem cell transplantation.

Introduction: Allogeneic haematopetic stem cell transplantation (allo-HSCT) is a potential curative therapy for young sufferers of hematological malignant and non malignant diseases. This intensive proceedure usually involves pretransplantation myeloablative chemotherapy and / or radiation therapy, both well documented to cause adverse effects to the heart. In addition, allo-HSCT patients are at risk of graft-versus-host-disease (GVHD).

Purpose: In the last decade there has been increasing awareness of heart related disease in survivors of cancer therapy. The main aim of this study is to describe the total burden of the cardiovascular late effects in young survivors of allo-HSCT.

Methods: This cross sectional, multidisciplinary survey was conducted between 2013 and 2016. The study included, 104 individuals, of whom 53.8% were female. Age at allo-HSCT was (mean±SD) 17.8±9.6 years. Age at follow-up was 35.0±11.7 years, and follow-up time from allo-HSCT was 17.2±5.6 years. The majority (98,1%) of individuals received myeloablative chemotherapy, 12.5% received radiation therapy and 1.9% received neither. Cardiovascular function was evaluated by comprehensive echocardiography (GE E9), including Speckle Tracking (2DSTE) and three dimensional echocardiography (3D). Left ventricular systolic dysfunction was defined by left ventricular ejection fraction (2D EF) ≤53% and Global Longitudinal Strain (GLS) ≤-17 (as recommended by the EACVI).

Results: LV systolic dysfunction defined by either by 2D EF ≤53% or GLS≤-17 or both was observed in 48.1%. The average 2D EF was 55.2±5.8%. 2D EF ≤53% was found in 35.6% of patients. Evaluation with GLS gave an average of -17.5±2.2% and 32.7% of the patients had a GLS ≤-17%. In 21.2% of the patients, a combination of GLS ≤-17% and 2D EF ≤53% was found.

Conclusion: Left ventricle systolic dysfunction is highly prevalent in long term survivors after allo-HSCT. These patients may be asymptomatic and unaware of their potential risk. Monitoring and screening regimes including echocardiography are important in allo-HSCT patients to ensure early detection of heart disease, early medical intervention and prevention against progressive heart failure.

2D EF

2D LVEDV index

2D LVESV index

3D EF

Fractional shortening

LVIDd index

GLS mean

%

(ml/m2)

(ml/m2)

%

%

(cm/m2)

%

55.2±5.8

63.1±13.9

28.6±8.5

54.0±5.0

30.6±5.7

2.7±0.32

-17.5±2.2


Heart SFI