Abstract：Objective To investigate the clinical features and mechanism of non-specific intraventricular block. Methods We selected 28 patients with non-specific intraventricular block as the observation group (group A) , 30 patients with complete left bundle branch block as the control group 1 (group B) and 62 patients with complete right bundle branch block as the control group 2 (group C). We observed their general clinical data, cardiac function, and characteristic manifestations of ECG, 24-hour ambulatory electrocardiographic and cardiac echocardiographic examination results. Results There are statistically significant differences of the number of patients with NYHA cardiac function grading of Ⅲ or above, QRS duration, and the number of patients with over 4 kinds of premature ventricular contractions (PVCs), over two types of extra wide PVCs and Lown grading of 4B or above among the three groups (P＜0.01). There is statistically significant difference of QRS duration between group B and group A or C (P＜0.01). The number of patients with over 4 kinds of PVCs varies significantly among the three groups (P＜0.01). There is statistically significant difference of the number of patients with over two types of extra wide PVCs between group A and group B or C (P＜0.01). The number of patients with Lown grading of 4B or above varies significantly between group A, B and group C (P＜0.01). The left ventricular ejection fraction, left ventricular diameter and the number of patients with abnormalities of left ventricular wall motion are significantly different among the three groups (P＜0.01), and between group A or B and group C (P＜0.05). Conclusion Patients with non-specific intraventricular block is poorer in cardiac functions than those with simple bundle branch block, and the former are high risky of ventricular arrhythmia. Therefore, it is clinically significant to effectively distinguish non-specific intraventricular block from general bundle branch block.
