Conduction abnormalities and role of cardiac pacing in cardiac amyloidosis: A systematic review

Abstract

Cardiac amyloidosis (CA) is an increasingly recognized cause of heart failure, characterized by extracellular deposition of insoluble protein fibrils leading to progressive myocardial dysfunction. The most common types of cardiac amyloidosis are immunoglobin light-chain (AL) and transthyretin (ATTR). Conduction abnormalities are commonly encountered among patients with cardiac amyloidosis and are an important cause of morbidity and mortality. Abnormalities range from infra-Hisian intraventricular conduction delay and bundle branch block to complete atrioventricular block. Pacemaker placement in CA patients follows established guidelines, similar to those for patients without CA, with generally good efficacy. The role and appropriate timing of pacemakers for primary prevention of brady-arrhythmias in CA remains uncertain. While biventricular (BiV) pacing has been shown to improve clinical outcomes in patients with systolic heart failure without CA, there are few data examining the utility of BiV pacing in patients with CA. With the advent of effective treatments for AL and ATTR, appropriate application of pacing is important to support patients with CA and conduction disease through therapeutic trials. This systematic review summarizes the current literature examining the utility of pacing in CA.

The Silent Period for Small Fiber Sensory Neuropathy Assessment in a Mixed Cohort of Transthyretin-Mediated Amyloidosis

“…Historically, ATTR was considered a systemic disease involving small sensory fibers and leading to painful polyneuropathies. Small fiber neuropathy accounts for some of the most typical signs in ATTR [ 25 , 26 , 27 ], including painful neuropathy [ 28 ], orthostatic hypotension [ 29 ], erectile dysfunction [ 30 , 31 , 32 , 33 ], constipation or diarrhea [ 34 ], and heart autonomic dysfunction [ 35 , 36 , 37 ].…”

El electrocardiograma en la amiloidosis cardíaca: un arma para la sospecha diagnóstica de esta enfermedad

“…No obstante, el BRIHH aparece con menos frecuencia en pacientes con AC (< 5% en la mayoría de los estudios), sin diferencias significativas en la prevalencia entre estos pacientes y controles sin la enfermedad (18,19) . La presencia de estos hallazgos no varía de manera significativa entre los dos subtipos más frecuentes de AC, pero se ha descrito una mayor duración del QRS en pacientes con AC-ATTR, lo que refleja una mayor enfermedad del tejido de conducción infrahisiano en estos pacientes (21,25) . La presencia de QRS ancho en pacientes con AC se ha asociado con la incidencia de bloqueo auriculoventricular (BAV) avanza-do durante el seguimiento (24) .…”

Cardiac arrhythmias and amyloidosis

“…Diferentes bradiarritmias han sido descritas en la AC, en la totalidad de ellas el mecanismo que las origina no se restringe a la infiltración del miocardio; el reemplazo de tejido especializado por fibrosis y/o la presencia de defectos isquémicos microvasculares en ausencia de enfermedad coronaria epicárdica cumplen un rol en la mayoría de las bradicardias 42 . ( Figura 8 )…”