Predictive value of QT interval dynamicity for sudden death in patients with idiopathic dilated cardiomyopathy.
- Author:
Ming-Wei BAO
1
;
Tuan-Tuan TAN
;
Sheng-Bo YU
;
Kui CHEN
;
Cong-Xin HUANG
Author Information
- Publication Type:Journal Article
- MeSH: Adult; Aged; Aged, 80 and over; Cardiomyopathy, Dilated; complications; diagnosis; physiopathology; Case-Control Studies; Death, Sudden, Cardiac; etiology; Electrocardiography, Ambulatory; Female; Heart Rate; Humans; Long QT Syndrome; complications; diagnosis; Male; Middle Aged; Predictive Value of Tests; Prognosis; Risk Factors
- From: Chinese Journal of Cardiology 2010;38(12):1093-1097
- CountryChina
- Language:Chinese
-
Abstract:
OBJECTIVETo explore the predictive value of QT interval dynamicity for sudden death in patients with idiopathic dilated cardiomyopathy (DCM).
METHODSFifty-five patients with DCM (DCM group) and 27 healthy subjects (Control group, Con) were enrolled. Investigations included history collection, clinical examination, echocardiography, electrocardiogram and 24 h ambulatory electrocardiogram. Following indexes were determined: left ventricle end diastolic dimension (LVEDD), left ventricle ejection fraction (LVEF), QT dispersion (QTd), SDNN, the slope of QT/RR plots of the linear regression, ventricular premature beats (VPB) and non-sustained ventricular tachycardia (NSVT). Primary end point for patients with DCM was all cause death.
RESULTSLVEDD, QTd, VPB/24 h, NSVT/24 h, QTe/RR slope and QTp/RR slope were significantly higher while LVEF and SDNN were significantly lower in DCM group than in Con group (all P < 0.05). LVEDD, LVEF, QTd, SDNN, QTe/RR slope and QTp/RR slope were significantly different among DCM sudden death group, DCM non sudden death group and Con group (P < 0.05). LVEF, SDNN, QTe/RR slope and QTp/RR slope were significantly different between DCM sudden death and non sudden death group (P < 0.05). LVEF, QTd, VPB/24 h, QTe/RR slope and QTp/RR slope were significantly different between DCM with NSVT and DCM without NSVT group (P < 0.05). The sudden death rate of DCM patients with QTe/RR slope ≥ 0.210 was significantly higher than DCM patients with QTe/RR slope < 0.210 (54.5% vs. 21.1%, P < 0.05). Sudden death rate of QTp/RR slope ≥ 0.190 was also higher than those < 0.190 (52.2% vs. 21.9%, P < 0.05). The sudden death rate of DCM patients with both LVEF ≤ 35% and NSVT+ was 62.5%. Combining QTe/RR ≥ 0.210 with NSVT+ or LVEF ≤ 35%, the sudden death rates were 62.5% or 66.7%. Combining QTp/RR ≥ 0.190 with NSVT+ or LVEF ≤ 35%, the sudden death rates were 66.7% or 61.5%. Combining QTe/RR ≥ 0.210 or QTp/RR ≥ 0.190 with NVST+ and LVEF ≤ 35%, the sudden death rates were 77.8% or 70.0%.
CONCLUSIONSHigh QT/RR slope is a risk factor for sudden death of DCM patients. QT/RR slope is a useful predictor for sudden death in DCM patients either independently or combined with NSVT or LVEF.
