Hypertrophic Cardiomyopathy, Mechanical Hyper-synchronicity
Conditions
Keywords
Hypertrophic cardiomyopathy, hyper-synchronicity, outflow-tract obstruction, dual chamber pacing
Brief summary
Hypertrophic cardiomyopathy (HCM) is a common genetic cardiovascular disease. Outflow-tract gradient of 30 mmHg or more under resting conditions is an independent determinant of symptoms of progressive heart failure and death. The investigators hypothesize that the electrical approach by dual chamber pacing could improve symptoms and reduce outflow-tract obstruction in a specific sub-group of selected patients with a mechanical hyper-synchronicity. The aim of the study is to identify and describe this phenomenon in HCM with (O-HCM) and without (NO-HCM) outflow-tract obstruction thanks to innovative multi-imaging approach.
Detailed description
The concept of physiological ventricular desynchrony was described recently with technics of myocardial deformation analysis applied in animal models. Authors confirmed the existence of a time delay in the contraction of the apical walls before basal walls. In O-HCM, the outflow-tract obstruction could be explained by a mechanical hyper-synchronicity between apical and basal walls. This study aims to describe the possible hyper-synchronized contraction in O-HCM and NO-HCM patients unlike the physiological desynchrony observed in healthy volunteers (HV) For this purpose, three imaging tests will be used at baseline: echocardiography (TEE), magnetic resonance imaging (MRI) with gadolinium enhancement only in HCM, and 3-dimensional electrocardiographic mapping (ECM) combined with computed tomography-scan. No follow-up is planned for this study.
Interventions
PROCEDUREEchocardiography (TEE)
DEVICEMagnetic resonance imaging (MRI) with gadolinium enhancement
DEVICEMagnetic resonance imaging (MRI) without gadolinium enhancement
PROCEDURE3D electrocardiographic mapping (ECM)
Sponsors
University Hospital, Bordeaux
Study design
Allocation
NON_RANDOMIZED
Intervention model
PARALLEL
Primary purpose
BASIC_SCIENCE
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
* HCM: Adults aged more than 18 years with sarcomeric hypertrophic cardiomyopathy under optimal medical therapy, isolated septal hypertrophy, sinus rhythm, exploitable acoustic window. For women of childbearing age, effective contraception and required negative pregnancy test. * O-HCM : outflow-tract gradient more than 30 mmHg at rest and during exercise * NO-HCM : outflow-tract gradient less than 30 mmHg at rest and during exercise * HV: Adults aged more than 18 years, without cardiovascular disease. For women of childbearing age, effective contraception and required negative pregnancy test.
Exclusion criteria
\- HV: unusable acoustic window
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Mechanical time delay in contraction between basal and apical walls in TEE and MRI in O-HCM, NO-HCM and healthy volunteers | Day 1 | The main interest variable is the delay value (ms) of the contraction between basal and apical walls measured by TEE and MRI. |
Secondary
| Measure | Time frame |
|---|---|
| Relationship between each mesure with hyper-synchronicity and outflow-tract gradient | Day 1 |
| Electrical time delay in ECM between basal and apical walls and relationship with hyper-synchronicity and outflow tract gradient. | Day 1 |
| Mechanical time delay between septal and lateral walls in MRI and TEE. | Day 1 |
| Evolution of mechanical time delay between basal and apical walls at rest and exercise in O-HCM and NO-HCM and relationship with outflow-tract gradient. | Day 1 |
| Delay between peaks of basal and apical radial displacement in MRI | Day 1 |
| Apical-basal phase on a phase analysis of the radial displacement data in MRI | Day 1 |
| Delay between apical and basal peaks circumferential strain in MRI | Day 1 |
| Delay between the beginning of the apical and basal circumferential deformation in MRI | Day 1 |
| Twist angle between the base and the apex in MRI | Day 1 |
| Delay between the beginning of the apical and basal radial displacement in MRI | Day 1 |
Countries
France
Outcome results
None listed