CLINICAL MASKS OF AMYLOIDOSIS WITH THE HEART INVOLVEMENT: MODERN DIAGNOSTIC ISSUES

Abstract

In amyloidosis AL-type the heart involvement is most common; this type is specific with predecessor proteins of light immunoglobulin chains, transthyretin (TTR), mutant and wild (senile) types. Most common clinical form is restriction cardiomyopathy.Aim. To assess the recent specifics of diagnostics, due to broader abilities of novel methods.Material and methods. Five 40-79-year old patients with various morphofunctional variants of heart involvement and typical ECG signs (low QRS voltage, QS, non-sufficient R increase, absence of left ventricle (LV) hypertrophy signs) to verify the suspected amyloidosis, underwent EchoCG, immunohistochemistry of blood and urine for light chains of immunoglobulines, biopsy of subcutaneous fat and mucose of the gum/gut; MDCT of the heart (n=3), MRI (n=1), scintigraphy with 99Tc-pyrophosphate with assessment in 1 hour after indicator injection (n=1), endomyocardial biopsy (n=2), titer of anticardial antibodies assessment (n=2), DNA-diagnostics (n=1).Results. The diagnosis of amyloidosis was confirmed in all cases. Its morpho-functional types were RSMP with LV hypertrophy, hypertrophic cardiomyopathy (HCMP) with no restriction but progressing fall of ejection fraction (EF), dilation cardiomyopathy (DCMP), severe hypertrophy with low EF, minimal hypertrophy with no restriction and systolic dysfunction. There was AL-type diagnosed (n=2, one case with myopathy mimicking “dermatomyositis”), mutant TTR (n=1, novel mutation Thr40Asn) and wild TTR (n=2) types. The leading clinical signs were biventricular heart failure and atrial rhythm disorders: sustained atrial fibrillation in 3 patients (in one, before amyloidosis verification, the RF-modification was done as “labyrinth” surgery, isthmus block with no established efficacy) and frequent supraventricular extrasystoly in one another. To the patient with mutant ATTR the ICD was implanted with further replacement by CRT-D, and increase of EF from 24% to 31% was achieved (patient is followed-up for 8 years). As the morphological equivalent of severe systolic dysfunction in this patient the amyloid deposition in myocardial arteries could be suspected. MDCT revealed typical subendocardial delayed deposition in 2 from 3 patients, in one case there was also diffuse deposition of 99Tc-pyrophosphate in myocardium. Antibodies to the nuclei of cardiomyocytes (specific ANF) was found in a female patient with AL-type and DCMP, which made not to rule out myocarditis.Conclusion. Cardiac amyloidosis might present as any structural and functional variant of cardiomyopathy, including DCMP. The most specific is diffuse hypertrophy with restriction and EF decrease, but with no LV dilation. Early fall of contractility, ischemia symptoms and LV dilation might be the result of amyloid lesion of small arteries. In the presence of any systemic presentations together with “HCMP”, “RCMP”, “DCMP” there must be amyloidosis ruled out. Myocardial scintigraphy with 99Tc-pyrophosphate is a method of use for the diagnosis of ATTR; MDCT of the heart — for any type of amyloidosis. Cardiac amyloidosis might be followed by significant type of the titer of specific ANF (secondary reaction or concomitance with myocarditis?).

Keywords

• cardiac amyloidosis
• restriction cardiopmyopathy
• hypetrophic cardiomyopathy
• dilation cardiomyopathy
• pyrophosphate scintigraphy of myocardium
• multispiral computed tomography of the heart