High Resolution Three-dimensional Maps of the Right Chambers in Patient Diagnosed With Cardiac Amyloidosis

Study Overview
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Brief Summary
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Amyloid heart disease is an accumulation of fibrillar proteins in the extracellular sector of the heart. Identified on echocardiography as Ventricular hypertrophy. The investigation of a Left Ventricular hypertrophy (LVH) is the most frequent discovery circumstance of amyloid heart disease. Pathophysiological mechanisms poorly understood, resulting in late diagnosis. Transthyretin amyloid heart disease (CATTR) is the most common form of cardiac amyloidosis in the West Indies due to an abnormally high frequency of the Val122Ile and Val107Ile mutations of the transthyretin gene in this population. Val122Ile and Val107Ile mutated-transthyretin are the substitution of valine for isoleucine at codon 122 of the TTR gene ( V122I) and at codon 107 of the TTR gene (V107I). Complications of CATTR are functional changes in heart cells or even death due to mechanical abnormalities (loss of contractility and increased wall stiffness cardiac arousal and conduction disturbances). These disorders result from an electrical abnormality of the heart the reason why the cardiologist performs preventive performance of electrophysiological explorations with EnSite Precision™. It's a registration system used to detect foci of necrosis within the myocardium. Amyloid deposits are areas devoid of electrical activity. Do they detectable by the EnSite Precision™ recording system ?

Detailed Description
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Transthyretin's amyloid heart disease (CATTR) is a rare disease whose frequency is high in the Caribbean's due to a high frequency of Val122Ile, an amyloidosis prone mutation in the Transthyretin gene. The Val122Ile variant might be present in 15 to 20 000 subjects in Martinique, placing them at high risk to develop the CATTR. CATTR results from the accumulation of amyloid deposits between the intercellular spans, resulting in mechanical cardiac abnormalities, but also in latent excitation or conduction defects: atrial and ventricular hyperexcitability, bundle branch blocks, atrio-ventricular blocks. These abnormalities require systematic electrophysiological studies and if necessary, antiarrythmic medications or pacemaker placement. Electro-mapping of the cardiac chambers offers high-resolution three-dimensional maps of cardiac electrical activity which has been used recently to detect focal myocardial infarction. This anatomo-functional imaging, used only once in cardiac amyloidosis, showed a correlation between areas of low voltage of the left atrial myocardium and areas of late gadolinium enhancement, a marker of amyloidosis deposit, found in cardiac MRI.

Official Title
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Frequency and Severity of Cardiac Injury in Transthyretin Cardiac Amyloidosis : an Electro Mapping Study.

Conditions
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Cardiac Amyloidosis, Cardiac Disease

Intervention / Treatment
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* Radiation: Cardiac electro-mapping


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Controls: Aged 18 and more Have had an echocardiogram within 6 months prior to inclusion Have had a cardiac Holter in the 6 months prior to inclusion. Informed Consent given Cases : Aged 18 and over Presence of cardiac amyloidosis with Transthyretin Have had an echocardiogram within 6 months prior to inclusion Have had a cardiac Holter monitoring in the 6 months prior to inclusion. Informed Consent given Exclusion Criteria: Controls Known case of amyloidosis in the immediate family Patient known to have amyloidosis Left ventricular wall thickness greater than or equal to 14 mm Hyperechogenicity of the left ventricular walls Cardiac disease which may affect electro-anatomic mapping: Right ventricular dysplasia, myocardial infarction, congenital heart disease. Contraindication such as pregnancy to radiological exams Presence of an anomaly of the vena cava Presence of intracavitary thrombus at cardiac echocardiography Patients with a pacemaker Cases Cardiac disease which may affect electro-anatomic mapping: Right ventricular dysplasia, myocardial infarction, congenital heart disease. Contraindication such as pregnancy to radiological exams Presence of an anomaly of the vena cava Presence of intracavitary thrombus at cardiac echocardiography

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Patient who needs electro-mapping in routine care.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Patient free cardiac amyloidosis<br>Patient with heart disease (related with rhythm disorders or conduction disorders) but free cardiac amyloidosis. | Radiation: Cardiac electro-mapping<br>* Perform an high-resolution three-dimensional maps of cardiac electrical activity using EnSite Precision system.<br>|
| Experimental: Patient with Transthyretin cardiac amyloidosis<br>Patient with transthyretin cardiac amyloidosis plus heart disease (related with rhythm disorders or conduction disorders). | Radiation: Cardiac electro-mapping<br>* Perform an high-resolution three-dimensional maps of cardiac electrical activity using EnSite Precision system.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Percentage of zones with abnormal electrical activity | Percentage of subject with at least one area of electrical inactivity (<0.1 mV) or at least one area of continuous low-voltage activity | 1 month | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Characteristics of zones with electrical inactivity | Number of areas of electrical inactivity (<0.1 mV) | 1 month | 
| Zones with electrical inactivity | Area of surface of electrical inactivity (<0.1 mV) | 1 month | 
| Characteristics of zones with abnormal electrical activity | Number of areas of continuous low voltage activity | 1 month | 
| Zones with abnormal electrical activity | Surface of areas of continuous low voltage activity | 1 month | 
| Compare electrical activity anomaly to total longitudinal strain on cardiac ultrasound | Number of areas of electrical inactivity vs. total longitudinal strain on cardiac ultrasound. | 1 month | 
| Electrical activity anomaly and total longitudinal strain on cardiac ultrasound | Number of areas of continuous low voltage activity vs. Total longitudinal strain on cardiac ultrasound. | 1 month | 
| Compare electrical activity anomaly (surface) to total longitudinal strain on cardiac ultrasound | Surface of areas of electrical inactivity vs. Total longitudinal strain on cardiac ultrasound. | 1 month | 
| Electrical activity anomaly (continuous low voltage activity) and total longitudinal strain on cardiac ultrasound | Surface of areas of continuous low voltage activity vs. Total longitudinal strain on cardiac ultrasound. | 1 month | 
| Compare electrical activity anomaly to Brain Natriuretic Peptide (BNP) value | Number of areas of electrical inactivity vs. BNP value. | 1 month | 
| Electrical activity and Brain Natriuretic Peptide (BNP) value | Number of areas of continuous low voltage activity vs. BNP value. | 1 month | 
| Compare electrical activity anomaly (surface) to Brain Natriuretic Peptide (BNP) value | Surface of areas of electrical inactivity vs. BNP value. | 1 month | 
| Electrical activity anomaly (continuous low voltage activity) and Brain Natriuretic Peptide (BNP) value | Surface of areas of continuous low voltage activity vs. BNP value. | 1 month | 
| Compare electrical activity anomaly to the presence of severe ventricular arrhythmia | Number of areas of electrical inactivity vs. the presence of severe ventricular arrhythmia. | 1 month | 
| Electrical activity anomaly and presence of severe ventricular arrhythmia | Number of areas of continuous low voltage activity vs. the presence of severe ventricular arrhythmia. | 1 month | 
| Compare electrical activity anomaly (surface) to the presence of severe ventricular arrhythmia | Surface of areas of electrical inactivity vs. the presence of severe ventricular arrhythmia. | 1 month | 
| Electrical activity anomaly (continuous low voltage activity) and presence of severe ventricular arrhythmia | Surface of areas of continuous low voltage activity vs. the presence of severe ventricular arrhythmia. | 1 month | 
| Compare electrical activity anomaly and to the presence of an atrial arrythmia | Number of areas of electrical inactivity vs. the presence of an atrial fibrillation load. | 1 month | 
| Electrical activity anomaly and presence of an atrial arrythmia | Number of areas of continuous low voltage activity vs. the presence of an atrial fibrillation load. | 1 month | 
| Compare electrical activity anomaly (surface) to the presence of an atrial arrythmia | Surface of areas of electrical inactivity vs. the presence of an atrial fibrillation load. | 1 month | 
| Electrical activity anomaly (continuous low voltage activity) and presence of an atrial arrythmia | Surface of areas of continuous low voltage activity vs. the presence of an atrial fibrillation load. | 1 month | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Cardiac amyloidosis, Transthyretin, Val122Ile, Cardiac electro-mapping, EnSite Precision