| Summary: | 碩士 === 國立臺灣大學 === 臨床醫學研究所 === 98 === Background
The most common underlying reason for patients to die suddenly from cardiac arrest is coronary heart disease (CHD). Although a large number of risk factors for Sudden Cardiac Death have been identified, translating these findings into a comprehensive risk stratification strategy is challenging. T wave morphology descriptors on standard twelve-lead electrocardiogram (ECG) have shown to predict arrhythmic events in patients with previous myocardial infarction or congestive heart failure. However, these descriptors have not been considered to determine the risk stratification in CHD patients with Implantable Cardioverter Defibrillator (ICD). This study was conducted to examine T wave morphology descriptors prognostic importance in CHD patients with ICD, comparison CHD patients without ICD.
Methods
41 CHD patients with ICD were compared with 55 CHD patients without ICD and 55 healthy patients using a case-control design. T wave morphology descriptors including (lead dispersion, T wave morphology dispersion, percentage of the loop area, percentage of the outer area, and the total cosine between QRS and T wave [TCRT] were studied in these patients
Results
A total of 41 CHD with ICD patients with a mean age of 65 ± 10 years were enrolled and followed-up for 3.1 ± 2.1 years. In the ICD group, the occurrence rate of HTN and DM were 73% and 50%. The mean left ventricular ejection fraction (LVEF) was 47% ± 14%. The total mortality rate in ICD group was 21.9%, shock within 1 year rate was 27% and shock rate was 32%. QRS duration and T wave morphology descriptors like TCRT, TMD were statistically significantly different in CHD patients and CHD patients with ICD patients.(P<0.001,<0.001 and <0.001 respectively). A stepwise backward Cox regression analysis showed that first shock rate was significantly associated with TMD(P = 0.05). On the basis of PL<0.64, PO>0.298 and TMD>74.1 as cutoff points, a significant difference in long-term survival were observed from a Kaplan-Meier survival curve (P < 0.022, P<0.032 and P<0.038 respectively). The Cox regression analysis showed that total mortality was significantly associated with LVEF (p=0.037), No. of diseased vessel(p=0.028) ,HTN(p=0.024), DM(p=0.033), Creatine (p=0.019), QRS duration (p=0.027), PO(p=0.032) and PL(p=0.032) (Table 5) and first shock was significantly associated with b-blocker use(p=0.046), sex(p=0.047), hypertension (p=0.027)and TMD (P = 0.031).
Conclusion
In conclusion, TCRT ,TMD and QRS duration may provide further risk stratification for CHD patients, and TMD,PO and PL may impact on the long term survival of CHD patients with ICD. Moreover, TMD may be a good predictor for shock rate in CHD patients with ICD.
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