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.