Electrocardiographic features and need for pacemaker in cardiac amyloidosis: Analysis of 58 cases

Abstract

Aim: Amyloidosis is a disease in which amyloid fibrils can be deposited in different cardiac structures, and several electrocardiographic abnormalities can be produced by this phenomenon. The objective of this study was to describe the most common basal electrocardiographic alterations in patients diagnosed with cardiac amyloidosis (CA) and to determine if these abnormalities have an impact on the need of pacemaker.

Methods: This retrospective study included patients who had an established diagnosis of CA [light-chain cardiac amyloidosis (LA-CA) or transthyretin cardiac amyloidosis (TTR-CA)] between January 2013 and March 2021. The baseline heart rate, the percentage of patients with a pseudo-infarct pattern, low-voltage pattern or cardiac conductions disturbances, and the impact of these factors on the need of pacemaker were analysed.

Results: Fifty-eight patients with CA (20 with LA-CA and 38 with TTR-CA) were included, and the majority were male (69.0%). Twenty-one patients had atrial fibrillation (AF) at diagnosis. Thirty-five patients had a pseudo-infarct pattern, 35% had a low-voltage pattern, and 22% had criteria for ventricular hypertrophy. Two hirds had a conduction disorder: 18 patients with first degree atrioventricular block, 12 right bundle branch block, 3 left bundle branch block and 25 with a branch hemiblock. There were no differences between LA-CA and TTR-CA. Patients with TTR-CA had a greater need for pacemakers in the folow-up (39±40 meses). Bundle branch block was a predictor of the need for a permanent pacemaker (HR: 23.43; CI 95%: 4.09.134.09; P=.01).

Conclusions: Electrocardiographic abnormalities in patients diagnosed wich CA are heterogeneus. Most frecuent is the presence of conduction disorders, the pseudoinfarction pattern, followed by the low voltage pattern. Patients with any bundle branch block at the baseline electrocardiogram need more frecuent to require a pacemaker during follow-up, especially in TTR-CA.

Keywords: Amiloidosis cardiaca; Bajo voltaje; Cardiac amyloidosis; Electrocardiogram; Electrocardiograma; Low voltage; Marcapasos; Pacemaker; Pseudo-infarct; Pseudoinfarto.