Diagnosis of cardiac involvement in systemic amyloidosis by state-of-the-art echocardiography: where are we now?

ABSTRACT

Introduction: Echocardiography is the first-line imaging modality used to characterize heart compromise in systemic infiltrative diseases and to evaluate response to therapy. Cardiac amyloidosis results in progressive heart failure due to restriction of ventricular filling. However, in early stages, typical findings may not be evident, even when symptoms and signs of heart failure with preserved ejection fraction are already present. Identification of early compromise is now made possible with the advent of new echocardiography techniques as two-dimensional strain imaging.

Areas covered: Diagnostic and prognostic parameters that can be assessed by echocardiography are discussed, including M-mode, two-dimensional and Doppler echocardiography, as well as by new tools as tissue Doppler imaging and strain imaging.

Expert opinion: Systemic amyloidosis is a rare disorder resulting from the production of misfolded proteins, primarily light-chain (AL) immunoglobulins and transthyretin (ATTR). The prognosis of affected subjects depends mainly on the presence and the degree of cardiac involvement. Early diagnosis and treatment are mandatory in order to improve survival. We present here a proposal for structured diagnosis, an algorithm based peak systolic longitudinal left ventricular strain, combined with parameters including typical myocardial texture, increased ventricular wall thickness and the presence of some degree of left ventricular diastolic dysfunction.

KEYWORDS:

• Systemic amyloidosis
• cardiac involvement
• echocardiography
• strain imaging

Article highlights

• Systemic amyloidosis is a rare disorder resulting from the production of misfolded proteins in which cardiac compromise is one of the most important determinants of survival.

• Echocardiography is the first-line imaging modality used to define heart compromise in systemic amyloidosis.

• Diagnostic criteria for CA include morphological and functional findings: thickening of left ventricular (LV), right ventricular (RV) and atrial walls, increased myocardial wall echogenicity, pericardial effusion, diastolic dysfunction.

• Impairment of myocardial longitudinal function is a paramount finding, even in early stages of myocardial infiltration, when ventricular walls are not evidently thickened. Longitudinal strain is typically diminished, with emphasis on the basal ventricular segments. Clear identification is possible by two-dimensional high-definition speckle tracking strain imaging.

• Predictors of prognosis in CA have been defined with echocardiography. Most significant ones are severe diminished longitudinal LV strain, Doppler restrictive diastolic pattern, RV enlargement with severe impairment of RV function, as well as pericardial effusion.

• Clinical presentation should be taken into consideration, since incidental finding of mild but typical changes during diagnostic work-up of patients with dyspnea on exertion may lead to suspicion of CA, which may be decisive for early treatment and consequent improvement in outcome.

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Declaration of interest

The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.