BACKGROUND: Comparison of different stroke locations had been focused in past researches in electrocardiogram (ECG) changes of cerebral stroke patients. Some researches neglected the heart disease in the illness history. OBJECTIVE: To discuss ECG changes in different infarction locations and size of acute cerebral infarction and compare with healthy people. DESIGN: Contrast observation. SETTING: Shanghai Ninth People’s Hospital. PARTICIPANTS: A total of 57 patients with cerebral infarction were selected from the Neurological Department of Ninth People’s Hospital of Shanghai from March 2003 to September 2005. They were diagnosed according to the criteria revised in the 4th National Cerebral Disease Conference and brain images. Patients who had heart disease were excluded. There were 32 males and 25 females, who were 65-84 years old. Among them, 23 cases were involved in right hemisphere, 34 cases in left one, 23 in base ganglion, 11 in brain stem, 9 in frontal lobe and 14 in other parts. According to their infarction size (plus size in every different scan), they were divided into three different groups: large-size group (n = 10) with size larger than 3.5 cm3, medium-size group (n = 13) with size between 1.5-3.5 cm3, and small-size group (n = 34) with size smaller than 1.5 cm3. Another 50 healthy subjects were regarded as control group. There were 29 males and 21 females aged 40-82 years. All these cases knew and agreed of the examination. METHODS: Patients received 12-lead ECG examinations within the first 6-24 hours of onset while control group received it at the same time. The HR, PR, QTc, QRS, T wave and ST changes were compared between the two groups. MAIN OUTCOME MEASURES: The ECG changes and differences in two hemispheres, in different infarction locations and sizes. RESULTS: All 57 patients and 50 healthy subjects were involved in the final analysis. ① ECG changes in infarction group and control group. There were no differences in HR, QRS time and cases with opposite T wave of infarction group compared with control group (P > 0.05). PR and QTc [(0.167±0.010), (0.383±0.029) s] in infarction group were longer than those in control group [(0.159±0.008), (0.361±0.022) s, t = 1.982, 2.363, P < 0.05, 0.01]. ST changes cases were 77% (44/57), which was more than those in control group [46% (23/50), χ2 = 11.072, P < 0.01]. ② Comparison of infarction in two hemispheres. HR, PR interval, QRS time, cases with opposite T wave and ST changes showed no differences (P > 0.05), and QTc interval in right hemisphere infarction was longer than left one [(0.391±0.054), (0.380±0.034) s, t =1.673, P < 0.05]. ③ ECG changes in different infarction locations. HR, PR interval, QTc interval, QRS time, cases with opposite T wave and ST changes showed no statistically significantly differences (P > 0.05). ④ ECG changes in different infarction sizes. HR, PR interval, QRS time showed no differences (P > 0.05). QTc interval in large size group was longer than the others [(0.399±0.044), (0.388±0.073), (0.378±0.124) s, F = 3.19, P < 0.05]. Cases with opposite T wave and ST changes in large size group were 80% (8/10), 100% (10/10), which were higher than those in medium size group [46% (6/13), 69% (9/13)] and small size group [44% (15/34), 35% (12/34), χ2 = 8.495, 10.538, P < 0.05, 0.01]. CONCLUSION: ① PR interval and QTc interval prolonged in cerebral infarction patients. Furthermore, QTc interval was more obvious in large size infarction group and right hemisphere infarction group. ② Infarction location did not affect the changes of ECG. BACKGROUND: Comparison of different stroke locations had been focused in past researches in electrocardiogram (ECG) changes of cerebral stroke patients. Some researches neglected the heart disease in the illness history. OBJECTIVE: To discuss ECG changes in different infarction locations and size of acute cerebral SETTING: Shanghai Ninth People’s Hospital. PARTICIPANTS: A total of 57 patients with cerebral infarction were selected from the Neurological Department of Ninth People’s Hospital of Shanghai from March 2003 to September 2005. They were diagnosed according to the criteria revised in the 4th National Cerebral Disease Conference and brain images. Patients who had heart disease were excluded. hemisphere, 34 cases in left one, 23 in base ganglion, 11 in brain stem, 9 in frontal lobe and 14 in other parts According to their infarction size (plus size in every different scan), they were divided into three different groups: large-size group (n = 10) with size larger than 3.5 cm3, medium-size group (n = 13) with size Between 50-3.5 cm3, and small-size group (n = 34) with size smaller than 1.5 cm3. Another 50 healthy subjects were considered as control group. METHODS: Patients received 12-lead ECG examinations within the first 6-24 hours of onset while control group received it at the same time. The HR, PR, QTc, QRS, T wave and ST changes were compared Between the two groups. MAIN OUTCOME MEASURES: The ECG changes and differences in two hemispheres, in different infarction locations and sizes. RESULTS: All 57 patients and 50 healthy subjects were involved in the final analysis. ① ECG changes in infarction group and control group There were no differences in HR, QRS time and cases wit hopposite T wave of infarction group compared with control group (P> 0.05). PR and QTc [(0.167 ± 0.010), (0.383 ± 0.029) s] in infarction group were longer than those in control group [(0.159 ± 0.008), (0.361 ± 0.022) s, t = 1.982, 2.363, P <0.05, 0.01]. ST changes cases were 77% (44/57), which was more than those in control group [46% (23/50) = 11.072, P <0.01] .② Comparison of infarction in two hemispheres. HR, PR interval, QRS time, cases with opposite T wave and ST changes showed no differences (P> 0.05), and QTc interval in right hemisphere infarction was longer than left one [(0.391 ± 0.054), (0.380 ± 0.034) s, t = 1.673, P <0.05] .③ ECG changes in different infarction locations. HR, PR interval, QTc interval, QRS time, cases with opposite T wave HRT, PR interval, QRS time showed no differences (P> 0.05). QTc interval in large size group was longer tha n the others [(0.399 ± 0.044), (0.388 ± 0.073), (0.378 ± 0.124) s, F = 3.19, P <0.05]. Cases with opposite T wave and ST changes in large size groups were 80% 10%, 100% (10/10), which were higher than those in medium size group [46% (6/13), 69% (9/13)] and small size group [44% (15/34) P <0.05, 0.01]. CONCLUSION: ① PR interval and QTc interval was more significantly in large size infarction group and right hemisphere infarction group. ② Infarction location did not affect the changes of ECG.