The frequency of cardiac amyloidosis among patients presenting with a so-called left ventricular hypertrophy remains unknown. This problem is especially relevant in the Caribbean's, where an amyloidosis-prone mutation of transthyretin gene might be frequent.

Cardiac amyloidosis is a very poorly known disease, in its frequency, its mechanisms, its treatment. This lack of knowledge is a major limitation to the improvement, indispensable, of the care of the patients. In clinical routine, particularly in West Indies-Guyana, cardiac amyloidosis is a disease poorly identified, whose management remains to be optimized. Concordant observations suggest that the frequency of the disease could be significant in the Antilles-Guyana: aging of the population, high frequency of an amyloidogenic mutation (Val122Il mutation of the transthyretin gene) found in 4% of the Afro-American population, recent identification in Martinique by a neurology team of a new founding mutation of the transthyretin gene that may cause the disease.

These elements justified the setting up of a multidisciplinary group whose objective is to contribute to the improvement of screening, treatment, and follow-up of patients with cardiac amyloidosis.

An identical diagnostic algorithm will be followed in all centers. Therapeutic management will be left to the discretion of the health care teams, who will be communicated regularly, the latest management recommendations.

A frequency of 30% is expected and will be assessed with a power of 80% and an alpha risk of 0.05. Quantitative and qualitative data will be described as usual. Differences between groups will be assessed with parametric or non-parametric tests.

Inclusion Criteria:

• Age > 18 years,
• Residency in French Caribbean Regions
• Access to healthcare coverage,
• Written informed consent obtained

Exclusion Criteria:

• Evidence of another cause for left ventricular hypertrophy (uncontrolled severe high blood pressure, untreated severe aortic stenosis, family history of hypertrophic cardiomyopathy)
• Inability to deliver informed consent,
• Presence of a known severe disease impending participation in the study

All collected IPD, all IPD that underlie results in a publication.

After the main publication of the results, for not limited time.

The conditions for the transfer of all or part of the database of the research are decided by the investigator coordinator / sponsor of the research and are the subject of a written contract.