An interventional study of LBBAP CRT device implantation and BVP-CRT in Left Bundle Branch Block, Left Bundle Branch Area Pacing and Biventricular Pacing, sponsored by Faculty Hospital Kralovske Vinohrady. Recruiting at 1 site in Czechia. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2025-07-14.
Sponsored by Faculty Hospital Kralovske Vinohrady · Not applicable, Interventional, and Treatment
The main objective of the project is to demonstrate that in patients with heart failure and QRS complex of nonRBBB morphology lasting over 130 ms, UHF-ECG can differentiate patients with trueLBBB from IVCD better than existing approaches based on the assessment of QRS complex morphology and duration from 12-lead ECG.
Another goal of the proposed study is to demonstrate that trueLBBB patients will benefit more from CRT using left bundle branch pacing than from CRT using biventricular pacing.
The final aim of the project is to demonstrate that the echocardiographic and clinical response in patients with intraventricular conduction disturbance will be dependent on the degree of reduction in ventricular dyssynchrony after CRT.
Since the introduction of cardiac resynchronization therapy (CRT), a way to better define the patients who will benefit from it most has been sought. Their selection based on the duration of the QRS complex or its morphology fails in some of them. Current data demonstrate that CRT done by pacing the conduction system below the site of the left bundle branch block may be a better therapy than biventricular pacing. A prerequisite for a better effect of conduction system pacing is to perform it in patients in whom a conduction block is present in the left bundle branch block ("true" LBBB) and not in the patients with a more distal left ventricular conduction problem (IVCD). The criteria derived from the surface standard ECG are insufficient to differentiate "true" LBBB from IVCD, and thus it is not possible to determine the optimal treatment in some patients. The sequence of ventricular activation can be visualized within a few minutes using ultra-highfrequency ECG (UHF-ECG) in virtually all patients. It is a non-invasive method that shows ventricular dyssynchrony as a time difference between the activation of the ventricles or their individual segments. Pilot data show that patients with "true" LBBB are likely to have greater ventricular dyssynchrony and a different pattern of ventricular depolarization than patients with IVCD. The aim of this project is to test the hypothesis that UHF-ECG can distinguish "true" LBBB from IVCD in patients with heart failure and left ventricular conduction disturbance better than using standard criteria assessing QRS duration and morphology. Other aim is to demonstrate that in patients with trueLBBB resynchronization using conduction system pacing will lead to better echocardiographic and clinical outcomes than biventricular pacing. Finally, the echocardiographic and clinical response of IVCD patients will depend on the reduction of UHF-ECG ventricular dyssynchrony after CRT.
94 studies on the registry are indexed under Bundle-Branch Block; 30 are open to participants now.
This study's planned enrollment of 200 is above the median of 60 across 59 interventional studies indexed under Bundle-Branch Block.
Browse Bundle-Branch Block studies →Faculty Hospital Kralovske Vinohrady is the lead sponsor of 30 studies on the registry; 6 are open to participants now.
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Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The New York Heart Association’s four classes of how much heart failure limits physical activity.
Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.
The share of blood the heart’s main pumping chamber (the left ventricle) pushes out with each beat, measured by an echocardiogram (heart ultrasound) or a MUGA scan. About 50–70% is normal.
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
NYHA class (heart failure)
The New York Heart Association’s four classes of how much heart failure limits physical activity.
Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
LVEF (left ventricular ejection fraction)
The share of blood the heart’s main pumping chamber (the left ventricle) pushes out with each beat, measured by an echocardiogram (heart ultrasound) or a MUGA scan. About 50–70% is normal.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Life expectancy
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
In this arm, LBBAP CRT will be performed
Device: LBBAP CRT device implantation
In this arm, BVP CRT will be performed.
Device: BVP-CRT
Pacing system with a lead implanted in the left bundle branch area will be done.
Implantation of biventricular device
Left ventricular end-systolic volume
Left ventricular end-systolic volume reduction
Time frame: 6 and 18 months since randomization
Plan to share: Undecided
No publications or documents are linked to this record.
Started May 2024 (actual). Primary completion is estimated for Dec 2027, 43 months after the start.
Of 32 interventional studies with no phase under Bundle-Branch Block, half reached primary completion within 50 months of starting (the median), counting those still running; a quarter within 33 and three quarters within 61. This study's planned 43 months is below that.
How these figures are worked out, and which studies are left out of them.
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Faculty Hospital Kralovske Vinohrady