The role of frontal plane cardiac axis shift in the diagnosis of wide QRS tachycardia / 实用医学杂志

Objective To explore the value of axis shift between the baseline normal sinus rhythm (NSR) and WCT in diagnosis of wide QRS-complex tachycardia (WCT). Methods 390 surface ECGs of 186 patients with WCT were obtained from April 2012 to April 2018 at Ningbo Medical Center Lihuili Hospital at which the arrhythmia diagnosis was proven by intracardiac electrophysiological study. The axis shift between the baseline NSR and WCT was calculated by table lookup method. Then we analyzed the role of axis shift in diagnosis of WCT. Results Among the 186 patients with WCT, 147 (79.03％) were ventricular tachycardia (VT) , and 39 (20.97％) were supraventricual tachycardia (SVT) with conduction abnormalities. In the 95％ confidence interval, the axis shift showed an outstanding discrimination performance. The area under the ROC curve is 0.708 (0.579-0.817, P =0.007). Compared with left axis deviation, right axis deviation, the right axis deviation of LBBB morphology, the axis shift> 68 degree is more sensitive (53.06％) , and the specificity (91.43％) is also more desirable. Moreover, if the axis shift set> 130 degree, the specificity can reach 100％, and the sensitivity (12.24％) is equivalent to northwestern axis. Conclusion A significant axis shift between the baseline NRS and WCT can distinguish WCT accurately. Given the ease of grasping, it can probably be feasible to popularize as a routine diagnosis method for WCT in primary hospitals.

Analysis of clinical phenotype and genotype of unstable Hemoglobin Rush / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To analyze the hematological and genetic characteristics of unstable hemoglobin Rush (Hb Rush) and compound heterozygote of Hb Rush and thalassemia.</p><p><b>METHODS</b>Peripheral blood samples and genomic DNA from three patients (including two ethnic Dai and one Han Chinese) with anemia of undetermined origin were collected. Hematological phenotypes of these patients were determined through red blood cell analysis and hemoglobin electrophoresis. Genotypes of alpha- and beta-globin genes, -158 XmnⅠ polymorphic site ofγ promoter region, and haplotypes of 7 polymorphic restriction sites in the beta-globin gene cluster were determined using PCR-based methods and DNA sequencing.</p><p><b>RESULTS</b>All patients have presented hypochromic microcytic anemia and hemoglobin fraction with significant increased measurement (30.5%-59.2%) in the region of fetal hemoglobin during alkaline medium electrophoresis. DNA analysis suggested that all patients have carried mutations leading to the unstable hemoglobin Rush (HBB codon 101, GAG>CAG, Glu>Gln). Two of them were compound heterozygotes of Hb Rush and thalassemia mutations of -α,CD17 and Hb E, respectively. Hb Rush mutation was associated with various haplotypes of the β-globin gene cluster. No significant association was found between increased abnormal hemoglobin fraction in the region of Hb F and the polymorphism ofγ promoter or large deletion of the beta-globin gene cluster.</p><p><b>CONCLUSION</b>This study has confirmed the distribution of Hb Rush among various Chinese populations and is the third report of its kind. Hb Rush can result in increased measurement of hemoglobin fraction in the region of fetal hemoglobin (Hb F) during routine hemoglobin electrophoresis under alkaline condition. Hb Rush heterozygote alone can lead to hypochromic microcytic anemia and thalassemia-like phenotype. Prenatal diagnosis of Hb Rush is necessary for carriers.</p>

Genotypic diagnosis of long QT syndrome by analysis of candidate genes / 药物分析学报

Objective To diagnose 6 LQTS families by genetic analysis. Methods A total aof 6 LQTS pedigrees with 43 family members were brought together for genetic diagnosis by using short-sequence tandem-repeat (SIR) markers or sequencing. Genomic DNA was extracted from blood samples by standard procedure. STR markers or KCNQ1, KCNH2 and SCN5A were amplified. The haplotype analysis for LQTS was performed. If the family got the negative haplotype analysis, the sequencing was performed. Results LQTS patients were always linkaged with the SCNSA gene in family 1. KCNH2 was linkaged with the disease in family 2 to 5.21 gene carriers were identified from these 5 families. A mutation (A561V-KCNH2) was only found in the proband of family 6 and an SNP (G1691A) was found in all the members of the family. Conclusion Genetic diagnosis can not only improve presymptomatic diagnosis,bnt also provide the basis for personal therapy and research on disease-causing mutations.