Coronary Angiographic Features In Patients With Coronary Artery Disease And Normal Resting Electrocardiogram

Objective: Coronary artery disease (CAD) is the heart disease which iscaused by coronary atherosclerosis leading to vascular cavity stenosis orobstruction, or (and) myocardial ischemia and hypoxia，or necrosis becauseof coronary functional changing (spasm). The prevalence and mortality ofCAD is increasing year by year and its onset age is getting younger. Diagnosisand standardized treatment of CAD to the effective prevention ofcardiovascular events in the early stage is of great significance. It is based oncertain method, including the history, physical examination, electrocardiogram(ECG), the detection of serum markers and so on. ECG has been widely usedbecause of its convenience, simplicity, speediness, low-cost and otheradvantages. However, with the advent of new technology, especially theprevalence of coronary angiography (CAG), its dominance has been shaken.CAG is currently considered the ‘gold standard’ in the diagnosis of CAD,comparing to which the limitation of the ECG is even more obvious,especially the inconsistency of ECG manifestation and the result of CAG ishighly concerned. In this study, by observing the results of CAG andassociated clinical data in patients with CAD and normal resting ECG, we areplanned to analyze the features in CAD and then explore the mechanism toimprove people’s awareness of it and improve the diagnostic levels of it inclinic.Methods: A total of49cases of patients with normal ECG and coronarymeaningful (≥50%) stenosis by selective CAG from January2011toDecember2012are going to be studied, and100cases of patients withabnormal ECG over the same period will be taken as control group. Collectthe results of all cases of CAG, including the number of stenosed coronaryartery branches, the degree of coronary artery lesions, the place of coronary artery lesions, coronary artery anatomic patterns, collateral circulationsituation and so on, which are going to be compared in patients with normaland abnormal ECG. Analyze the features of CAG of patients with CAD andnormal resting12-lead surface ECG.Results:1The number of stenosed coronary artery branches：to coronarylesions of1,2,3branches, the normal ECG group respectively were25cases(51.0%),15patients (30.6%),9patients (18.4%); abnormal ECG group were28cases (28.0%),38patients (38.0%),34cases (34.0%). There werestatistically differences (P <0.05) between the two groups. Hence, the lesionsof coronary artery in patients with CAD and normal ECG are mostly singlelesion.2Coronary artery stenosis: the normal ECG group in coronarystenosis with moderate (50%to75%), and severe (75%to90%), very severe(90to99%)(100%), total occlusion were13cases (26.5%),18cases (36.7%),16cases (32.7%),2cases (4.1%); the other group were3cases (3.0%),21cases (21.0%),50cases (50.0%),26cases (26.0%). Between the two groupthere were significant differences (P <0.01). The stenosis of coronary artery inpatients with CAD and normal ECG are mostly moderate to severe stenosis.3Coronary artery anatomic patterns: normal ECG group of rightpattern, left pattern and balanced pattern who were39cases (79.6%),9cases(18.4%),1(2.0%); abnormal ECG group respectively95cases (95.0%),5cases (5.0%),0cases (0.0%). According to statistical analysis of the twogroups（P＜0.05）, the right pattern is majority, followed by the left andbalanced patterns.4Coronary artery lesions: normal ECG group of coronary arterydisease involving the LM, LAD, LCX and RCA respectively1(2.0%),39cases (79.6%),17cases (34.7%),24patients (49.0%); the other grouprespectively were2cases (2.0%),86patients (86.0%),59cases (59.0%),59cases (59.0%). There were no statistical differences between the two groups（P>0.05）. 5Collateral circulation: normal ECG group with or without collateralcirculation were2cases (4.1%), and47patients (95.9%); the other group wereeight cases (8.0%),92patients (92.0%).6Differences between the number of coronary lesions branches withcoronary stenosis: to the single vessel lesion, the proportion of moderatestenosis is highest in normal ECG group (44.0%), and the proportion of theother group with severe stenosis is highest (53.6%)(P <0.01); to double vessellesions, severe stenosis, the proportion of the patients with normal ECG ishighest stenosis, the proportion of abnormal ECG patients with extremelysevere stenosis is of the maximum (57.9%)(P <0.05); to tree-vessel lesions,there were no significant differences (P>0.05).7Comparison Differences the number of coronary lesions brancheswith coronary artery lesions: both single and double vessel lesions which weredifferent coronary branches in ECG normal and abnormal group were nosignificant differences (P>0.05). Coronary multi-vessel disease, with thepresence or absence of the mirror corresponding places, the normal ECGpatients were16cases (66.7%),8(33.3%), and the others were44cases(61.1%),28cases (38.9%).There were no significant differences between thetwo (P>0.05). And the proportion of mirror corresponding areas with normalECG was higher.Conclusion:1The lesions of coronary artery in patients with CAD and normalECG are mostly single lesion. The single vessel lesion is mild, and themulti-vessel lesions may be related to the mirror corresponding area.2The proportion of single coronary lesion with moderate in patientswith CAD and normal ECG is highest, which showed decreasing trend along.3The coronary artery anatomic patterns in patients with CAD andnormal ECG is the majority of right pattern, followed by the left and balancedpatterns.4In terms of the place of coronary lesions, the lesion of LAD is themost in coronary artery branches, or6to8segments mostly. The lesions of LAD and RCA are most of double-vessel in coronary artery lesions.5Some patients with the ECG normal may be related to collateralcirculation.