Animal study on left bundle branch current of injury and anatomic location of leads in His-purkinje conduction system pacing / 中华心血管病杂志

Objective: Explore the relationship between tip of the left bundle branch pacing lead and anatomic location of left bundle branch as well as the mechanism of left bundle branch current of injury. To clarify the clinical value of left bundle branch current of injury during operation. Methods: The pacing leads were implanted in the hearts of two living swines. Intraoperative electrophysiological study confirmed that the left bundle branch or only the deep left ventricular septum was captured at low output. Immediately after operation, the gross specimen of swine hearts was stained with iodine to observe the gross distribution of His-purkinje conduction system on the left ventricular endocardium and its relationship with the leads. Subsequently, the swine hearts were fixed with formalin solution, and the pacing leads were removed after the positions were marked. The swine hearts were then sectioned and stained with Masson and Goldner trichrome, and the relationship between the anatomic location of the conduction system and the tip of the lead was observed under a light microscope. Results: After iodine staining of the specimen, the His-purkinje conduction system was observed with the naked eye in a net-like distribution, and the lead tip was screwed deeply and fixed in the left bundle branch area of the left ventricular subendocardium in the ventricular septum. Masson and Goldner trichrome staining showed that left bundle branch pacing lead directly passed through the left bundle branch when there was left bundle branch potential with left bundle branch current of injury, while it was not directly contact the left bundle branch when there was left bundle branch potential without left bundle branch current of injury. Conclusion: The left bundle branch current of injury observed on intracardiac electrocardiogram during His-purkinje conduction system pacing suggests that the pacing lead directly contacted the conduction bundle or its branches, therefore, the captured threshold was relatively low. Left bundle branch current of injury can be used as an important anatomic and electrophysiological evidence of left bundle branch capture.

Animal study on left bundle branch current of injury and anatomic location of leads in His-purkinje conduction system pacing / 中华心血管病杂志

Objective: Explore the relationship between tip of the left bundle branch pacing lead and anatomic location of left bundle branch as well as the mechanism of left bundle branch current of injury. To clarify the clinical value of left bundle branch current of injury during operation. Methods: The pacing leads were implanted in the hearts of two living swines. Intraoperative electrophysiological study confirmed that the left bundle branch or only the deep left ventricular septum was captured at low output. Immediately after operation, the gross specimen of swine hearts was stained with iodine to observe the gross distribution of His-purkinje conduction system on the left ventricular endocardium and its relationship with the leads. Subsequently, the swine hearts were fixed with formalin solution, and the pacing leads were removed after the positions were marked. The swine hearts were then sectioned and stained with Masson and Goldner trichrome, and the relationship between the anatomic location of the conduction system and the tip of the lead was observed under a light microscope. Results: After iodine staining of the specimen, the His-purkinje conduction system was observed with the naked eye in a net-like distribution, and the lead tip was screwed deeply and fixed in the left bundle branch area of the left ventricular subendocardium in the ventricular septum. Masson and Goldner trichrome staining showed that left bundle branch pacing lead directly passed through the left bundle branch when there was left bundle branch potential with left bundle branch current of injury, while it was not directly contact the left bundle branch when there was left bundle branch potential without left bundle branch current of injury. Conclusion: The left bundle branch current of injury observed on intracardiac electrocardiogram during His-purkinje conduction system pacing suggests that the pacing lead directly contacted the conduction bundle or its branches, therefore, the captured threshold was relatively low. Left bundle branch current of injury can be used as an important anatomic and electrophysiological evidence of left bundle branch capture.

Current pattern of Chinese dialysis units: a cohort study in a representative sample of units / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Understanding the characteristics of Chinese dialysis patients and the current practice trends is the first step to evaluate the association between practice pattern and outcome in these populations. In the present study, we evaluated the status of medical treatment and characteristic features of chronic dialysis patients in China.</p><p><b>METHODS</b>Through a clustering sampling, we selected 9 centers from the largest dialysis facilities in 6 cities around China. All adult undergoing dialysis in the selected units were screened. A total of 2388 (1775 on hemodialysis (HD) and 613 on peritoneal dialysis (PD)) patients were finally enrolled. All data were collected at enrollment on the bases of review of medical records.</p><p><b>RESULTS</b>In this cohort, 1313 (55.0%) were male. The mean age was 54 years old. The median time for dialysis was 26 months (12 - 51 months). Seventy-five percent of patients were on HD and 25.0% on PD. Among PD patients, about 21% patients did not receive dialysis adequacy. For HD patients, about 14.0% of them did not achieve dialysis adequacy when the target of kt/V was set as 1.2. Only 44.7% of patients achieved blood pressure target of 140/90 mmHg. About 60% of patients did not reach the hemoglobin target of 110 g/L even though 85.0% of them were treated with erythropoietin. In addition, 48.5% of the patients had uncontrolled mineral metabolism revealed by the high calcium-phosphate product. Compared with HD patients, higher level of serum glucose, triglyceride, and total and low density lipoprotein cholesterol were more common in PD patients.</p><p><b>CONCLUSIONS</b>This observational study suggests that many Chinese dialysis patients did not achieve the therapeutic target, particularly in blood pressure control, anemia correction, and mineral balance. PD patients were more likely to suffer metabolic disturbance.</p>