ECG scar quantification correlates with cardiac magnetic resonance scar size and prognostic factors in Chagas' disease.
OBJECTIVE
To test the hypothesis that 12-lead ECG QRS scoring quantifies myocardial scar and correlates with disease severity in Chagas' heart disease.


METHODS
Patients underwent 12-lead ECG for QRS scoring and cardiac magnetic resonance with late gadolinium enhancement (CMR-LGE) to assess myocardial scar.


METHODS
University of São Paulo Medical School, São Paulo, Brazil.


METHODS
44 Seropositive patients with Chagas' disease without a history of myocardial infarction and at low risk for coronary artery disease.


METHODS
Correlation between QRS score, CMR-LGE scar size and left ventricular ejection fraction. Relation between QRS score, heart failure (HF) class and history of ventricular tachycardia (VT).


RESULTS
QRS score correlated directly with CMR-LGE scar size (R=0.69, p<0.0001) and inversely with left ventricular ejection fraction (R=-0.54, p=0.0002), which remained significant in the subgroup with conduction defects. Patients with class II or III HF had significantly higher QRS scores than those with class I HF (5.1±3.4 vs 2.1±3.1 QRS points (p=0.002)) and patients with a history of VT had significantly higher QRS scores than those without a history of VT (5.3±3.2% vs 2.6±3.4 QRS points (p=0.02)). A QRS score ≥2 points had particularly good sensitivity and specificity (95% and 83%, respectively) for prediction of large CMR-LGE, and a QRS score ≥7 points had particularly high specificity (92% and 89%, respectively) for predicting significant left ventricular dysfunction and history of VT.


CONCLUSIONS
The wide availability of 12-lead ECG makes it an attractive screening tool and may enhance clinical risk stratification of patients at risk for more severe, symptomatic Chagas' heart disease.
Division of Cardiology, Johns Hopkins Hospital, 600 N. Wolfe Street/Carnegie 568, Baltimore, MD 21287, USA.
David G
DG
Strauss
Sávio
S
Cardoso
João A C
JA
Lima
Carlos E
CE
Rochitte
Katherine C
KC
Wu
D000328:Adult; D000368:Aged; D002598:Chagas Cardiomyopathy / Q000473:pathology*; D002921:Cicatrix / Q000473:pathology*; D004562:Electrocardiography; D005260:Female; D006801:Humans; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012680:Sensitivity and Specificity; D018487:Ventricular Dysfunction, Left