Incidence and Predictors of Permanent Pacemaker Requirement after Transcatheter Aortic Valve Implantation with a Self‐Expanding Bioprosthesis

Background: Previous reports have suggested the occurrence of cardiac conduction disorders and permanent pacemaker (PPM) requirement after transcatheter aortic valve implantation (TAVI). Based on a single‐center experience, we aim to assess the incidence of postprocedural conduction disorders, need for PPM, and its determinants after TAVI with a self‐expanding bioprosthesis. Methods: From August 2007 to October 2009, 32 consecutive patients underwent TAVI with the Medtronic CoreValve (MCV) System (Medtronic Inc., Minneapolis, MN, USA). Three patients paced at baseline and two cases of procedure‐related mortality were excluded. We analyzed the 12‐lead electrocardiogram at baseline, immediately after procedure and at discharge. Requirements for PPM were documented and potential clinical, electrophysiological, echocardiographic, and procedural predictors of PPM requirement were studied. Results: After TAVI, eight patients (29.6%) required PPM implantation due to high‐grade atrioventricular (AV) block. The prevalence of left bundle branch block increased from 13.8% to 57.7% directly after implantation (P = 0.001). Need for PPM was correlated to the depth of prosthesis implantation (r = 0.590; P = 0.001). At a cutoff point of 10.1 mm, the likelihood of pacemaker could be predicted with 87.5% sensitivity and 74% specificity and a receiver operator characteristic curve area of 0.86 ± 0.07 (P = 0.003). Of the seven patients with preexisting right bundle branch block (RBBB), four (57.1%) required PPM implantation after TAVI. Conclusions: High‐grade AV block requiring PPM implantation is a common complication following TAVI and could be predicted by a deeper implantation of the prosthesis. Patients with preexisting RBBB also seem to be at risk for the development of high‐grade AV block and subsequent pacemaker implantation. (PACE 2010; 1364–1372)     

Male diabetes mellitus and assisted reproduction treatment outcome

The long-held view that diabetes has little effect on male reproductive function has been challenged by findings that the condition influences fertility in numerous previously undetected ways. This retrospective chart review of 3000 couples determined the incidence of couples with a male diabetic seeking assisted reproduction treatment and assessed any relationship between male diabetes and IVF/intracytoplasmic sperm injection (ICSI) outcome. Eight (2.7%) couples were found with a diabetic male partner, of which 18 couples underwent assisted reproduction treatment (five IVF, 12 ICSI, one both), with fertilization rates (IVF 68%, ICSI 62%) similar to non-diabetic patients (IVF 70%, ICSI 71%) and no difference in embryo quality. Two men had retrograde ejaculation and two were azoospermic. Other than reduced sperm motility, the remaining 14 had normal World Health Organization semen parameters. Embryo transfers produced one pregnancy (5% combined IVF/ICSI pregnancy rate/cycle) giving a lower-than-expected rate (28.8%). The pregnancy rate from seven FETs (29%) was comparable to the expected (21.3%). Compared with non-diabetics, approximately three times more couples with diabetic men sought treatment, with a larger percentage having 'unexplained' infertility. Fertilization rates and embryo quality did not differ but pregnancy rates were lower in couples with a diabetic male.     

Modulation of disease severity of dystrophic epidermolysis bullosa by a splice site mutation in combination with a missense mutation in the COL7A1 gene

Dystrophic epidermolysis bullosa (EBD) is a clinically heterogeneous skin disorder, characterized by abnormal anchoring fibrils (AF) and loss of dermal-epidermal adherence. EBD has been linked to the COL7A1 gene at chromosome 3p21 which encodes collagen VII, the major component of the AF. Here we investigated two unrelated EBD families with different clinical phenotypes and novel combinations of recessive and dominant COL7A1 mutations. Both families shared the same recessive heterozygous 14 bp deletion at the exon-intron 115 boundary of the COL7A1 gene. The deletion caused in-frame skipping of exon 115 and the elimination of 29 amino acid residues from the pro-alpha1(VII) polypeptide chain. As a result, procollagen VII was not converted to collagen VII and the C-terminal NC-2 propeptide which is normally removed from the procollagen VII prior to formation of the anchoring fibrils was retained in the skin. All affected individuals also carried missense mutations in exon 73 of COL7A1 which lead to different glycine- to-arginine substitutions in the triple-helical domain of collagen VII. Combination of the deletion mutation with a G2009R substitution resulted in a mild phenotype. In contrast, combination of the deletion with a G2043R substitution led to a severe phenotype. The G2043R substitution was a de novo mutation which alone caused a mild phenotype. Thus, different combinations of dominant and recessive COL7A1 mutations can modulate disease activity of EBD and alter the clinical presentation of the patients.      

HELICOBACTER PYLORI-SPECIFIC TUMOUR-INFILTRATING T CELLS PROVIDE CONTACT DEPENDENT HELP FOR THE GROWTH OF MALIGNANT B CELLS IN LOW-GRADE GASTRIC LYMPHOMA OF MUCOSA-ASSOCIATED LYMPHOID TISSUE

Previous studies have shown that tumour cells from low-grade B-cell gastric lymphomas of mucosa-associated lymphoid tissue (MALT) type proliferate in vitro in response to heat-killed whole cell preparations of Helicobacter pylori , but only in the presence of tumour-infiltrating T cells. This response is strain-specific in that the tumours studied responded optimally to different strains of H. pylori . It was unclear from these studies, however, whether the ability to recognize the specific stimulating strains of H. pylori was a property of the tumour cells or the tumour-infiltrating T cells. This study shows that whereas the tumour cells do not respond to H. pylori , both freshly isolated tumour-infiltrating T cells and a T cell line derived from these cells proliferate in response to stimulating strains of H. pylori . T cells from the spleen of one of the patients do not share this property. These results suggest that B-cell proliferation in cases of low-grade gastric lymphoma of MALT type in vitro in response to H. pylori is due to recognition of H. pylori by tumour-infiltrating T cells, which in turn provide help for tumour cell proliferation. The observations provide an explanation for properties of gastric MALT-type lymphoma, such as regression following eradication of H. pylori and the tendency of the tumour to remain localized to the primary site.     

Zinc and Vitamin A in Liver of Foetuses and Infants

ABSTRACT. The association of zinc and vitamin A levels was studied in liver of foetuses and infants which were stillborn or died of various causes between the age of 26 weeks of gestation up to 16 weeks post-partum. No correlation between zinc and vitamin A was observed ( r =0.07). Although smaller infants had more hepatic vitamin A than larger infants no significant difference was observed between these groups for liver zinc values.     

Aetiology of chronic suppurative lung disease

Forty one (1%) of 4000 children referred for respiratory disease had chronic suppurative lung disease not due to cystic fibrosis. Further investigations showed congenital malformations in six (15%), primary ciliary dyskinesia syndrome in seven (17%), 11 had immunological abnormalities (27%), and two bronchiectasis due to aspiration (5%). Therefore the underlying cause for the disease was found in 63%. Identification of predisposing causes may facilitate prevention of further bronchial damage.