Objective: Primary cardiac amyloidosis (CA) is associated with poor prognosis. However, the noninvasive diagnostic tools are limited. The aim of the study is to assess the utility of combined indexes of electrocardiography (ECG) and echocardiography (ECHO) in the diagnosis of primary CA.
Methods: A total of 20 consecutive patients (7 men, mean age 50 ± 12 years) referred for endomyocardial biopsy (EMB) were included. Eleven of these patients (55%) confirmed primary CA, the rest of 9 patients were EMB negative and used for the control.
Results: The voltage of SV1+ RV6 < 1.2 mV has a sensitivity of 91% and specificity of 89% for the identification of primary CA, yields the positive and negative predictive values of 91% and 89%, respectively. Among ECHO parameters, there were no significant differences between the 2 groups, except for left ventricular ejection fraction (47 ± 12% in primary CA vs 67 ± 11% in the control, P < 0.001). However, the combined indexes of ECG and ECHO parameters, including the ratio of RI/LVPW as well as RV5/LVPW and RV6/LVPW, were significantly lower in the patients with primary CA than the control. The ratio of RI/LVPW < 0.4 has the sensitivity of 91% and specificity of 100%, yields the positive and negative predictive values of 100% and 91%, respectively. The ratios of RV5(6)/LVPW < 0.7 have the sensitivity of 91% and specificity of 89%, yield the positive and negative predictive values of 91% and 89%, respectively.
Conclusion: Patients with clinically suspected primary CA, combined indexes of ECGs and ECHOs could be used as the noninvasive diagnostic tools.
Ann Noninvasive Electrocardiol 2011;16(1):25–29