Impact of diabetes on QT dynamicity in patients with and without myocardial infarction: The KORA Family Heart Study.
BACKGROUND
Patients with diabetes mellitus (DM) have an unfavorable prognosis after myocardial infarction (MI), partially due to a higher risk of sudden cardiac death (SCD). QT dynamicity is an independent predictor of SCD in post-MI patients. However, the effects of diabetes on QT dynamicity in patients with MI have not been described.


METHODS
We studied 468 survivors of MI (67 with DM) from the population-based MONICA registry (KORA Family Heart Study), Augsburg, Germany, by standardized questionnaire, anthropometry, electrocardiogram (ECG), 30-minute-Holter-ECG-recordings and echocardiography. In addition, 422 siblings without prior MI (22 with DM) were studied by the same protocol.


RESULTS
Among post-MI patients, the QT/RR slope was significantly steeper in diabetics than in nondiabetics (0.096 +/- 0.057 vs 0.077 +/- 0.045; P = 0.002). Likewise, among siblings without MI, the QT/RR slope was steeper in diabetics than in nondiabetics (0.104 +/- 0.053 vs 0.080 +/- 0.042; P = 0.008). The association of DM with steeper QT/RR slope remained significant in multivariate models in post-MI patients (beta: -0.14; P = 0.004) as well as in individuals without MI (beta: -0.10; P = 0.047).


CONCLUSIONS
In a large population of survivors of MI and unaffected siblings, patients and siblings presenting with DM exhibited an abnormal QT rate-dependence, compared with individuals without DM in both groups. Thus, diabetes itself may be a major determinant of ventricular arrhythmias, independently of a previous MI. These observations might in part explain the higher incidence of sudden cardiac death and ventricular arrhythmias in patients with DM.
Lieb
Wolfgang
W
Medizinische Klinik 2, Universitatsklinikum Schleswig-Holstein, Campus Lubeck, Lubeck, Germany.
Voss
Christian
C
Ortak
Jasmin
J
Barantke
Melanie
M
Hengstenberg
Christian
C
Loewel
Hannelore
H
Holmer
Stephan
S
Erdmann
Jeanette
J
Schunkert
Heribert
H
Bonnemeier
Hendrik
H
D000368:Aged; D001145:Arrhythmias, Cardiac / Q000503:physiopathology*; D016022:Case-Control Studies; D016757:Death, Sudden, Cardiac / Q000209:etiology; D048909:Diabetes Complications; D003920:Diabetes Mellitus / Q000235:genetics / Q000503:physiopathology*; D004452:Echocardiography; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000235:genetics / Q000503:physiopathology*; D035781:Siblings; D017741:Survivors