Fragmented surface ECG was a poor predictor of appropriate therapies in patients with Chagas' cardiomyopathy and ICD implantation (Fragmented ECG in CHAgas' Cardiomyopathy Study).
BACKGROUND
Main causes of death in chronic Chagas' cardiomyopathy (CChC) are progressive congestive heart failure and sudden cardiac death. Implantable cardioverter defibrillators (ICD) have been proved an effective therapy to prevent sudden death in patients with CChC. Identification of predictors of sudden death remains a challenge.


OBJECTIVE
To determine whether surface fragmented ECG (fQRS) helps identifying patients with CChC and ICDs at higher risk of presenting appropriate ICD therapies.


METHODS
Multicenter retrospective study. All patients with CChC and ICDs were analyzed. Clinical demographics, surface ECG, and ICD therapies were collected.


RESULTS
A total of 98 patients were analyzed. Another four cases were excluded due to pacing dependency. Mean age was 55.5 ± 10.4 years, male gender 65%, heart failure New York Heart Association class I 47% and II 38%. Mean left ventricular ejection fraction (LVEF) 39.6 ± 11.8%. The indication for ICD was secondary prevention in 70% of patients. fQRS was found in 56 patients (59.6%). Location of fragmentation was inferior (57.1%), lateral (35.7%), and anterior (44.6%). Rsr pattern was the more prevalent (57.1%). Predictors of appropriate therapy in the multivariate model were: increased age (P = 0.01), secondary prevention indication (P = 0.01), ventricular pacing >50% of the time (P = 0.004), and LVEF <30% (P = 0.01). The presence of fQRS did not identify patients at higher risk of presenting appropriate therapies delivered by the ICD (P = 0.87); regardless of QRS interval duration.


CONCLUSIONS
fQRS is highly prevalent among patients with CChC. It has been found a poor predictor of appropriate therapies delivered by the ICD in this population.
Queen's University, Kingston, Ontario, Canada.
Adrian
A
Baranchuk
Francisco
F
Femenia
Juan Cruz
JC
López-Diez
Claudio
C
Muratore
Mariana
M
Valentino
Enrique
E
Retyk
Nestor
N
Galizio
Darío
D
Di Toro
Karina
K
Alonso
Wilma M
WM
Hopman
Rodrigo
R
Miranda
D001145:Arrhythmias, Cardiac / Q000150:complications / Q000175:diagnosis*; D053840:Brugada Syndrome; D000075224:Cardiac Conduction System Disease; D002598:Chagas Cardiomyopathy / Q000150:complications / Q000601:surgery*; D016757:Death, Sudden, Cardiac / Q000517:prevention & control; D017147:Defibrillators, Implantable; D004562:Electrocardiography / Q000379:methods* / Q000706:statistics & numerical data; D005260:Female; D006329:Heart Conduction System / Q000002:abnormalities*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome
Chagas' disease; fragmented ECG; implantable cardioverter defibrillator; sudden death; ventricular arrhythmias