The Relation Between The QRS Wave Duration On Admission And The Prognosis Of In-patient In People Who Suffered Acute Myocardial Infarction

Object: To investigate the relation between the QRS wave duration on admission (QRS d) and the prognosis in the near future in people who suffered acute myocardial infarction;to ascertain whether we can use QRS wave duration on admission-a simple,easy-accessed clinical definition to evaluating the prognosis in the near future in people who suffered acute myocardial infarction, through this, we can distinguish high-risk patients,perform some treatment in time,reduce mortality of acute myocardial infarction in the near future and improve the recent prognosis of patients who suffered acute myocardial infarction.Methods:Randomly selected 88 patients suffered acute myocardial infarction who were hospitalized in cardiovascular department of the first hospital affiliated to Jilin University from January 1, 2002 to January 1, 2008; 55 of them were male, All the patients conform to WHO diagnostic criteria about acute myocardial infarction (1979 year): meet the following three criteria at least two ; 1) typical ischemic chest pain lasts more than 30 minutes; 2) ECG ST-T dynamic evolution; 3) enzyme markers of myocardial injury and their dynamic evolution. Exclusion criteria: 1) established cerebral infarction in past history, or cerebral hemorrhage in history; 2) complete atrioventricular block; 3) different intraventricular conduction or other clinical conditions that could interfere with the accurate measurement of QRS wave duration, such as early repolarization syndrome; 4) implanting permanent pacemaker in history; 5) patients who do not agree with coronary angiography; In order to facilitate the analysis, all the patients are acute ST-segment elevation myocardial infarction and all the patients accept coronary angiography. Divide enrolled patients into three different groups according to their QRS duration on admission: group A: QRS wave duration on admission lies between 0.06s to 0.08s; group B: QRS wave duration on admission lies between 0.08s to 0.10s; group C: QRS wave duration on admission was longer than 0.10s; Observe and record cardiovascular events in each groups respectively when patients are in hospital; Cardiovascular events are defined as sudden cardiac death, cardiac shocks, Adam-Strokes syndrome, cardiac insufficiency or cardiac Doppler ultrasound examination confirmed that LVEF≤40%, low blood pressure that must use vasoactive drugs such as dopamine or hydroxylamineto to maintain blood pressure, serious arrhythmias, such as worse than degree II atrioventricular block, paroxysmal or sustained ventricular tachycardia, ventricular fibrillation, and atrial fibrillation that can influence hemodynamics.Data process: Data use the mean plus or minus the standard deviation, enumeration data use chi square check; measurement data use analysis of variance (ANOVA), After statistical process, we define P<0.05 as statistically significant.Results: Common clinical informations such as age, sex ratio, hypertension, type 2 diabetes, previous history of angina and other related histories has no significant differences among each groups; the type of myocardial infarction, cardiac function on admission (assessed by Killip classification) also have no significant difference among each groups; When the patients were in hospital, compared patients in A group and in C group, we found that the patients in C group received lessβ-blocker therapy, the reasons may lies in thatβ-blockers have negative inotropic, negative role of conductivity; Compare with patients in A group, patients in C group with longer QRS duration had worse cardiac function, so patients in C group received lessβ-blocker treatment; Using chi-square check among the three groups, we find that: B group and A group, C group and A group have statistically significant differences in the incidence of cardiovascular events when in hospital(chi-square check P value<0.05),but B group and C group do not have statistically significant differences, (chi-square check P value>0.05); There is no significant difference in the incidence of cardiovascular events between B group and C group,which suggests that turnover point of QRS wave duration associated with cardiovascular events lies in 0.08-0.10s;All patients enrolled in the study accept coronary angiography; Through analyzing coronary angiography ,we find that: comparing with A group, patients in B group and C group have more coronary artery lesions, meanwhile, coronary artery lesions are more severe in B group and C group than A group, the differences have statistically meaning (by chi-square check P value<0.05), while comparing B group with C group, the differences have no statistically meaning, (by chi-square check P value>0.05).Conclusion: The study confirmed that there is relation between QRS wave duration on admission and the prognosis in the near future in people who suffered acute myocardial infarction, after adjusting other factors such as age, sex, history of hypertension, mellitus diabetes, history of angina pectoris, and cardiac function on admission (assessed by Killip classification), those factors are thought to have influences on prognosis in patients who suffered acute myocardial infarction. Patients with QRS duration on admission lies in 0.06-0.08s have less cardiovascular events when they are in-patient, thus have a better prognosis in the near future, while those patients with QRS duration on admission lies in 0.08-0.10s or longer than 0.10s have more cardiovascular events when they are in-patient, which lead to a worse prognosis in the near future, After statistical process, the difference in incidence of cardiovascular events has statistically meanings, (by chi-square check P value<0.05);When comparing patients with QRS duration on admission lies in 0.08-0.10s with those QRS duration on admission longer than 0.10s,the cardiovascular events incidence difference have no statistically meaning,(by chi-square check P value>0.05), It suggests that turn-over point of QRS wave duration associated with cardiovascular events lies in 0.08-0.10s. So we can draw a conclusion that QRS wave duration on admission is a useful indicator that help to evaluate prognosis of acute myocardial infarction in the near future,and patients with QRS duration on admission lies in 0.06-0.08s have a better prognosis.