Are classic predictors of voltage valid in cardiac amyloidosis? A contemporary analysis of electrocardiographic findings.
BACKGROUND
Low voltage electrocardiography (ECG) coupled with increased ventricular wall thickness is the hallmark of cardiac amyloidosis. However, patient characteristics influencing voltage in the general population, including bundle branch block, have not been evaluated in amyloid heart disease.


METHODS
A retrospective analysis was performed of patients with newly diagnosed cardiac amyloidosis from 2002 to 2014. ECG voltage was calculated using limb (sum of QRS complex in leads I, II and III) and precordial (Sokolow: S in V1 plus R in V5-V6) criteria. The associations between voltage and clinical variables were tested using multivariable linear regression. A Cox model assessed the association of voltage with mortality.


RESULTS
In 389 subjects (transthyretin ATTR 186, light chain AL 203), 30% had conduction delay (QRS >120ms). In those with narrow QRS, 68% met low limb, 72% low Sokolow and 57% both criteria, with lower voltages found in AL vs ATTR. LV mass index as well as other typical factors that impact voltage (age, sex, race, hypertension, BSA, and smoking) in the general population were not associated with voltage in this cardiac amyloidosis cohort. Patients with LBBB and IVCD had similar voltages when compared to those with narrow QRS. Voltage was significantly associated with mortality (p<0.001 for both criteria) after multivariable adjustment.


CONCLUSIONS
Classic predictors of ECG voltage in the general population are not valid in cardiac amyloidosis. In this cohort, the prevalence estimates of ventricular conduction delay and low voltage are higher than previously reported. Voltage predicts mortality after multivariable adjustment.
Department of Cardiovascular Medicine, Cleveland Clinic Foundation, Cleveland, OH 44195, USA. Electronic address: sperryb@ccf.org.
Brett W
BW
Sperry
Department of Cardiovascular Medicine, Cleveland Clinic Foundation, Cleveland, OH 44195, USA.
Michael N
MN
Vranian
Department of Cardiovascular Medicine, Cleveland Clinic Foundation, Cleveland, OH 44195, USA.
Rory
R
Hachamovitch
Department of Internal Medicine, Cleveland Clinic Foundation, Cleveland, OH 44195, USA.
Hariom
H
Joshi
Department of Internal Medicine, Cleveland Clinic Foundation, Cleveland, OH 44195, USA.
Meghann
M
McCarthy
Department of Cardiovascular Medicine, Cleveland Clinic Foundation, Cleveland, OH 44195, USA.
Asad
A
Ikram
Department of Cardiovascular Medicine, Cleveland Clinic Foundation, Cleveland, OH 44195, USA.
Mazen
M
Hanna
D000368:Aged; D000369:Aged, 80 and over; D000686:Amyloidosis / Q000150:complications*; D004562:Electrocardiography / Q000379:methods*; D005260:Female; D006331:Heart Diseases / Q000175:diagnosis* / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012307:Risk Factors
Bundle branch block; Cardiac amyloidosis; Electrocardiography; Infiltrative cardiomyopathy; Voltage