Prevalence and Prognostic Value of Conduction Disturbances at the Time of Diagnosis of Cardiac AL Amyloidosis

Background and purpose: To evaluate the prevalence and the prognostic implications of conduction delays in a large cohort of cardiac AL patients. Methods: Echo Doppler and 12-lead ECG were collected in 344 consecutive patients in whom diagnosis of AL amyloidosis was concluded between 2008 and 2010. Patients were subdivided according to the presence (n= 240) or absence (n= 104) of cardiac involvement. Results: When compared with patients without myocardial involvement, cardiac AL was associated with prolonged PQ, QRS, QT and QTc intervals (P< 0.05), and with higher prevalence of intraventricular blocks (27.5% vs. 16.5%, P< 0.05), that was associated with higher wall thickness, worse diastolic and regional systolic function, higher NT-proBNP values (all P< 0.05), and higher mortality (P= 0.0001; median follow-up: 402 days). Conclusion: Intraventricular conduction delays have a negative prognostic impact in patients with cardiac AL amyloidosis. Their presence should not be overlooked in the diagnostic workup, prompting a more accurate cardiological support.