Literature reports indicate that primary systemic amyloidosis is a rare disease with poor prognosis[1]. It is usually caused by abnormal proliferation of plasma cells, and most often it involves the heart, kidney and skin soft tissue. Restrictive cardiomyopathy and refractory heart failure are the main manifestations when the heart is involved.
In this study, It is worth noting that there was no serious obstruction in each branch of coronary angiography, The electrocardiogram limb lead QRS voltage did not match the thickness of the chamber wall, and the chamber wall was obviously hypertrophic[2], but the limb lead was low voltage, which is a typical "quality/electricity" contradiction. This feature is an important clue in diagnosing CA. Researchers have established that when the ratio of RI voltage to left ventricular posterior wall thickness is < 0.4, the sensitivity and specificity of primary CA are 91 and 100 %, respectively. Moreover, when this ratio is < 0.36, the sensitivity and specificity of primary CA are 97 and 89%, respectively.
The appearance of myocardial amyloidosis in echocardiography is morphologically characterized by diffuse hypertrophy of the myocardium and increased echogenicity[3], scattered patchy or scintillating granule, including decreased diastolic function of the heart, decreased ejection fraction, systemic edema caused by heart failure, multiple serous cavity effusion (pericardium, thorax and abdominal cavity); pulmonary hypertension, and widened inferior vena cava. The typical manifestations on electrocardiogram are limb lead low voltage, T wave, ST segment change, and chest lead false infarct waveform.
A clear diagnosis of CA depends largely on endomyocardial biopsy. Congo red staining indicates positive, but this procedure is expensive and highly risky. Besides, some basic hospitals cannot carry it out. Thus, by the time the cause is identified, it is usually late and treatment options are limited. The classification of CA is related to the clinical symptoms. The survival of CA patients is low, their mortality is high, and the prognosis is poor, especially in primary CA. Once the symptoms of heart failure, usually restrictive cardiomyopathy, begin to appear, conventional heart failure medications may not be effective. The monitoring of daily fluid intake and diuretic dose is key to managing CA-induced heart failure. Cardiac involvement has become a serious risk factor affecting the prognosis of the disease. In recent years, a number of clinical studies in China and abroad have confirmed that good clinical benefits for the diagnosis and differential diagnosis of CA can result from linking the parameters of echocardiography and electrocardiogram (two well-established and widely used cardiovascular techniques), with comprehensive analysis of "progressive refractory heart failure +" quality/electricity "contradiction + ventricular wall hypertrophy and flare sign" based on medical history[4]. Early detection, early diagnosis and early treatment are important for improving the prognosis.