| Objective:To study the characteristics of 12-lead vectorcardiogram of hypertensive left ventricular hypertrophy(LVH)and to explore the value of 12-lead vectorcardiogram in the diagnosis of hypertensive LVH.Methods:111 patients with hypertension admitted to our hospital from November 2019 to January 2020 were examined by echocardiography within 3 months,indicating that interventricular septum thickness and/or left ventricular posterior wall thickness≥12mm and left ventricular mass index Male>125g/m2,Female>110g/m2.At the same time,52 patients with normal physical examination were selected as the control group.During the period of hospitalization,50 patients underwent both 12-lead vectorcardiogram examination and Frank lead vectorcardiogram examination,which were divided into Frank group.According to the different hypertrophy sites of 111 patients in the observation group,they were divided into interventricular septal thickening group,left ventricular posterior wall and interventricular septal thickening group.By using the ECG Workstation V.3.4.2 software system of Kangtai Medical Co.,Ltd.,the electrocardiogram of all patients was converted into 12-lead vectorcardiogram,and the maximum QRS vector amplitude,maximum QRS vector angle,QRS-T vector angle,T-ring angle,T/R ratio,P vector area and QRS vector area were recorded in three planes of LVH patients with hypertension.To compare and analyze the diagnostic results of LVH disease of hypertension by 12-lead vectorcardiogram and electrocardiogram,and to compare and analyze the diagnostic results of LVH disease of hypertension by 12-lead vectorcardiogram and Frank lead vectorcardiogram.Results:1.According to the diagnostic criteria by echocardiography,the sensitivity(74.77%),specificity(64.38%),accuracy(71.78%),positive predictive value(82.18%),negative predictive value(54.88%)and Jordan index(0.392).2.The diagnostic rate of LVH by 12-lead vectorcardiogram and electrocardiogram was statistically significant(P<0.05),while that of 12-lead vectorcardiogram and Frank lead vectorcardiogram was not statistically significant for LVH(P>0.05).3.In this study,there was no significant difference in the parameters of 12-lead vectorcardiogram in different thickening parts(P>0.05).4.The maximum QRS vector amplitude of frontal plane,sagittal plane and transverse plane,transverse plane T ring angle and frontal plane QRS-T vector angle of the observation group were significantly higher than those of the control group(P<0.05),and the frontal plane maximum QRS vector angle,sagittal plane T ring angle and sagittal plane QRS-T vector angle of the observation group were significantly lower than those of the control group(P<0.05).Sagittal plane and horizontal plane maximum QRS vector angle,frontal plane T ring angle and transverse plane QRS-T in observation group compared with the control group was no significant difference(P>0.05).The frontal plane and transverse plane maximum QRS vector amplitude,transverse plane maximum QRS vector angle,sagittal plane T-ring angle and sagittal plane QRS-T vector angle in the Frank group were significantly higher than those in the control group(P<0.05).The sagittal plane maximum QRS vector amplitude,the frontal plane maximum QRS vector angle and the frontal plane T-ring angle in the Frank group were significantly lower than those in the control group(P<0.05).The maximum QRS vector angle of sagittal plane and QRS-T vector angle of frontal plane and transverse plane in Frank group were not significantly different from those in control group(P>0.05).5.If the maximum amplitude ratio of T vector to QRS vector is less than 0.25 on at least two sides,it is positive,and vice versa.The positive rate in the observation group and Frank group was significantly higher than that in the control group,and the positive rate in the observation group was lower than that in the Frank group.6.The frontal and sagittal plane P vector area and the frontal plane QRS vector area of the observation group were significantly larger than those of the control group(P<0.05),while the transverse plane P vector area and the QRS vector area of the transverse plane and sagittal plane of the observation group were significantly lower than those of the control group(P<0.05).The frontal plane QRS vector area of the Frank group was larger than that of the control group,and the difference was statistically significant(P<0.05).The transverse plane P vector area of the Frank group was smaller than that of the control group(P<0.05),and there was no significant difference in the frontal and sagittal plane QRS vector area,sagittal and transverse plane QRS vector area between the Frank group and the control group(P>0.05).7.Logistics regression the frontal and sagittal plane maximum QRS vector amplitude and QRS vector area in sagittal plane were positively correlated with LVH(P<0.05),the frontal plane QRS-T angle was negatively correlated with the frontal plane and transverse plane QRS vector area(P<0.05),among which the maximum QRS vector amplitude in sagittal plane was the most significant.The maximum QRS vector amplitude in transverse plane,the maximum QRS vector angle in frontal plane,the T ring angle in sagittal plane and transverse plane,the QRS-T angle in sagittal plane and the area of P vector in frontal plane,sagittal plane and transverse plane were not correlated with LVH(P>0.05).8.The best diagnostic limits of ROC curve analysis were as follows:the frontal maximum QRS vector amplitude>0.98mV,the sagittal maximum QRS vector amplitude>1.57mV,the frontal QRS-T angle>44°,the frontal QRS area>107.28mm2.Conclusion:1.The diagnostic accuracy of LVH by conventional VCG is higher than that of ECG,and there is no difference between VCG and Frank according to the diagnostic criteria of this study.2.The maximum QRS vector amplitude of three planes,the maximum QRS vector angle of frontal plane,the T ring angle of sagittal and transverse plane,the QRS-T vector angle of frontal and sagittal plane,the area of P vector of three planes and the area of QRS vector of three planes in 12-lead vectorcardiogram were significantly changed during LVH.3.In 12-lead vectorcardiogram,the maximum QRS vector amplitude of frontal plane>0.98mV,sagittal plane maximum QRS vector amplitude>1.57mV,frontal QRS-T angle>44° and frontal QRS area>107.28mm2 have the highest sensitivity in the diagnosis of LVH. |
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