Clinical and Prognostic Implications of Electrocardiography and Holter Monitoring Findings in Patients with Light chain Cardiac Amyloidosis

Background: Cardiac involvement in light chain amyloidosis (AL-CA) represents an infiltrative heart disease. The aim of the study was to recognize differences between patients suffering from light chain amyloidosis with and without cardiac involvement in 12-lead electrocardiography (ECG) and 24-hour Holter ECG monitoring. Methods: We prospectively analyzed clinical profile, echocardiographic pattern, ECG and 24hr Holter monitoring findings in 39 (median 66 [IQR 62;71] years, 62% males) consecutive patients with AL amyloidosis. Results: Out of all patients, AL-CA was confirmed in 26 (67%) subjects. All patients with AL-CA manifested at least one pathology on 12-lead ECG, which contrasted with a low prevalence of abnormal ECG findings in patients without cardiac involvement (54%), p < 0.001. Abnormal Holter ECG findings were documented in 77% and 62% of patients with and without AL-CA. During 19 (7; 59) months of follow-up, 19 (73%) patients with AL-CA died. The mortality rate was significantly lower in patients with QRS < 100ms and QTc < 450ms (both p < 0.05), respectively. The absence of any pathology on 12-lead ECG had a negative predictive value of 100% for the presence of AL-CA. Conclusion: Standard 12-lead ECG seems to be a method with a relevant negative predictive value for the exclusion of AL-CA. The duration of QRS as well as QTc intervals seem to be a marker of early mortality of patients with AL-CA.