Spatial separation of left and right ventricular leads adjusted to the left ventricular end-diastolic dimension does not affect the acute change of the paced QRS complex duration in resynchronization therapy

Background: Cardiac resynchronization therapy has been shown to improve left ventricular performance in patients with left ventricular dysfunction and a left-sided interventricular conduction delay. This is performed by placing a pacing lead on the lateral left ventricular wall to stimulate the area normally stimulated by the left bundle branch. In patients with right bundle branch block (RBBB), pacing the right bundle branch could also result in resynchronization. Previous studies have shown that right ventricular outflow septal (RVOS) pacing does, in fact, utilize the native conduction system. Methods: 62 consecutive patients, 46 male/16 female, aged 75 +/− 10.5 yr, with RBBB and indications for pacing, underwent RVOS lead placement using commercially available pacing systems. The patients subsequently underwent bedside A-V optimization to achieve the narrowest QRS duration and most “normal” QRS complex. Echocardiography was performed to evaluate changes in wall motion comparing baseline with optimal pacing. Results: Baseline mean QRS duration 146 +/− 20.9 ms Optimized mean QRS duration 111 +/− 20.5 ms Average decrease in QRS duration -35 +/− 21.5 ms p < 0.001 Echocardiography demonstrated improvement in septal contraction abnormalities. Conclusions: 1) RVOS pacing in RBBB patients can significantly narrow the QRS complex on ECG. 2) Septal contraction abnormalities due to RBBB can be improved with RVOS pacing and optimal A-V timing. 3) Further studies are warranted to evaluate this therapy in a heart failure population.

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Importance of systematic right ventricular assessment in cardiac resynchronization therapy candidates: a machine-learning approach

European Heart Journal - Cardiovascular Imaging ◽

10.1093/ehjci/jeaa356.044 ◽

2021 ◽

Vol 22 (Supplement_1) ◽

Author(s):

E Galli ◽

V Le Rolle ◽

OA Smiseth ◽

J Duchenne ◽

JM Aalen ◽

...

Keyword(s):

Machine Learning ◽

Heart Failure ◽

Cardiac Resynchronization Therapy ◽

Right Ventricular ◽

Systolic Heart Failure ◽

Left Ventricular ◽

Supervised Machine Learning ◽

Cardiac Resynchronization ◽

Resynchronization Therapy ◽

Crt Response

Abstract Funding Acknowledgements Type of funding sources: None. Background Despite having all a systolic heart failure and broad QRS, patients proposed for cardiac resynchronization therapy (CRT) are highly heterogeneous and it remains extremely complicated to predict the impact of the device on left ventricular (LV) function and outcomes. Objectives We sought to evaluate the relative impact of clinical, electrocardiographic, and echocardiographic data on the left ventricular (LV) remodeling and prognosis of CRT-candidates by the application of machine learning (ML) approaches. Methods 193 patients with systolic heart failure undergoing CRT according to current recommendations were prospectively included in this multicentre study. We used a combination of the Boruta algorithm and random forest methods to identify features predicting both CRT volumetric response and prognosis (Figure 1). The model performance was tested by the area under the receiver operating curve (AUC). We also applied the K-medoid method to identify clusters of phenotypically-similar patients. Results From 28 clinical, electrocardiographic, and echocardiographic-derived variables, 16 features were predictive of CRT-response; 11 features were predictive of prognosis. Among the predictors of CRT-response, 7 variables (44%) pertained to right ventricular (RV) size or function. Tricuspid annular plane systolic excursion was the main feature associated with prognosis. The selected features were associated with a very good prediction of both CRT response (AUC 0.81, 95% CI: 0.74-0.87) and outcomes (AUC 0.84, 95% CI: 0.75-0.93) (Figure 1, Supervised Machine Learning Panel). An unsupervised ML approach allowed the identifications of two phenogroups of patients who differed significantly in clinical and parameters, biventricular size and RV function. The two phenogroups had significant different prognosis (HR 4.70, 95% CI: 2.1-10.0, p < 0.0001; log –rank p < 0.0001; Figure 1, Unsupervised Machine Learning Panel). Conclusions Machine learning can reliably identify clinical and echocardiographic features associated with CRT-response and prognosis. The evaluation of both RV-size and function parameters has pivotal importance for the risk stratification of CRT-candidates and should be systematically assessed in patients undergoing CRT. Abstract Figure 1

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Left ventricular assist device support normalizes left and right ventricular beta-adrenergic pathway properties

Journal of the American College of Cardiology ◽

10.1016/j.jacc.2004.11.042 ◽

2005 ◽

Vol 45 (5) ◽

pp. 668-676 ◽

Cited By ~ 71

Author(s):

Stefan Klotz ◽

Alessandro Barbone ◽

Steven Reiken ◽

Jeffrey W. Holmes ◽

Yoshifumi Naka ◽

...

Keyword(s):

Right Ventricular ◽

Left Ventricular Assist Device ◽

Ventricular Assist Device ◽

Left Ventricular ◽

Assist Device ◽

Beta Adrenergic ◽

Ventricular Assist ◽

Left Ventricular Assist ◽

Left And Right

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P797 Assessment of right ventricular systolic function with 3D echocardiography following cardiac resynchronization therapy

European Heart Journal - Cardiovascular Imaging ◽

10.1093/ehjci/jez319.453 ◽

2020 ◽

Vol 21 (Supplement_1) ◽

Author(s):

C Jenei ◽

E Papp ◽

M Clemens ◽

Z Csanadi

Keyword(s):

Cardiac Resynchronization Therapy ◽

Right Ventricular ◽

Systolic Function ◽

Left Ventricular ◽

3D Echocardiography ◽

Cardiac Resynchronization ◽

Resynchronization Therapy ◽

S Wave ◽

Ventricular Systolic Function ◽

Significant Difference

Abstract Background In approximately 30-40% of cases, the left ventricular systolic function does not improve following cardiac resynchronization therapy (CRT; non-responders). Currently, the role of right ventricular (RV) systolic function is not yet completely clear in the background. Our aim was to assess the RV systolic function with 3D echocardiography in CRT patients. Methods We selected 19 patients who received CRT in our department between May and June 2017, and whose 1-year follow-up data were available. We characterized several 2D parameters of RV systolic function, such as RV free wall strain (RV GLSFW), annular s’ wave velocity (TDI s), tricuspid annulus plane systolic excursion (TAPSE), RV fractional area change (RV FAC). A number of 3D parameters were also assessed, such as RV ejection fraction (EF), end-diastolic (EDV) and end-systolic (ESV) volumes, using a dedicated RV analysis software. Moreover, we measured the LV EF and considered the patients "responder", when the LV EF improved with at least 10% after CRT implantation. Results From 19 patients, 12 was identified as responders (R) and 7 as non-responders (NR). No significant difference was seen in the mean age of patients in the two groups (NR: 68 ± 6 year; R: 67 ± 9 year, p = 0.76), however, the proportion of male individuals was higher in the NR group (8/12 vs. 1/7). The RV EF was higher in the R group (41 ± 8% vs.29 ± 10%; p = 0.012), while the EDV or ESV did not differ between the two groups. The RV GLSFW (–21.2 ± 7% vs.–13.9 ± 7%, p = 0.045) and the TAPSE (16.8 ± 5 mm vs.11.4 ± 3 mm, P = 0.03) values were significantly different between the two groups. Based on logistic regression analysis, the RV EF was an independent predictor of non-respondence. Conclusions The lower RV EF indicates non-respondence to CRT, however, it is not associated with RV dilation, i.e.adverse remodelling. These results suggest mechanical abnormality of RV function in the background of impaired EF.

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Regulation of β myosin heavy chain, c-myc and c-fos proto-oncogenes in thyroid hormone-induced hypertrophy of the rat myocardium

Clinical Science ◽

10.1042/cs0840061 ◽

1993 ◽

Vol 84 (1) ◽

pp. 61-67 ◽

Cited By ~ 9

Author(s):

N. K. Green ◽

M. D. Gammage ◽

J. A. Franklyn ◽

A. M. Heagerty ◽

M. C. Sheppard

Keyword(s):

Thyroid Hormone ◽

Right Ventricular ◽

Myosin Heavy Chain ◽

Heavy Chain ◽

Molecular Mechanisms ◽

Left Ventricular ◽

Transcriptional Level ◽

Messenger Rnas ◽

Hypertrophic Response ◽

Left And Right

1. In order to investigate the molecular mechanisms determining the hypertrophic response of the ventricular myocardium to thyroid hormone administration, changes in left and right ventricular expression of the c-myc, c-fos and H-ras proto-oncogenes in response to treatment with 3,3′,5-tri-iodothyronine were defined. 2. Adult female Wistar rats were treated with daily subcutaneous injections of 3,3′,5-tri-iodothyronine (50 μg) for 1, 3, 7 or 14 days (n = 6 in each treatment group) and the results from 3,3′,5-tri-iodothyronine-treated animals were compared with those obtained from untreated controls (n = 6). Changes in the weight of the left and right ventricles in response to 3,3′,5-tri-iodothyronine treatment were measured; changes in expression of the c-myc, c-fos and H-ras proto-oncogenes were determined in parallel by measurement of specific messenger RNAs by Northern and dot hybridization, as well as changes in expression of β myosin heavy chain messenger RNA. 3. Treatment with 3,3′,5-tri-iodothyronine resulted in increases in both left and right ventricular weights after 3 days, an effect maintained up to 14 days. Despite an increase in left ventricular weight, levels of β myosin heavy chain, c-myc, c-fos and H-ras mRNAs in the left ventricle were unchanged; in contrast, an increase in right ventricular weight was associated with increased expression of β myosin heavy chain, c-myc and c-fos messenger RNAs. 4. These specific ventricular changes in gene expression, in the face of a hypertrophic response of both ventricles to 3,3′,5-tri-iodothyronine, suggest that the cardiac growth response to thyroid hormones reflects the well-documented secondary haemodynamic influences rather than direct gene regulatory actions of 3,3′,5-tri-iodothyronine at the transcriptional level on the genes studied. Changes in right ventricular proto-oncogene and β myosin heavy chain expression may in turn reflect an increase in right ventricular pressure load.

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