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Background The incidence, predictors, and clinical impact of lead break during transvenous lead extraction (TLE) were previously unknown. Methods We included consecutive patients who underwent TLE between September 2013 and July 2019 at our institute. Lead break during removal was defined as lead stretching and becoming misshapen, as assessed by fluoroscopy. Results A total of 246 patients underwent TLE for 501 leads. At a patient level, complete success was achieved in 226 patients (91.9%). At a lead level, 481 leads (96.0%) were completely removed and 101 leads (20.1%) were broken during the procedure. Of 392 identified pacemaker leads, 71 (18.3%) were broken during the TLE procedure. A multivariable analysis confirmed high lead age (odds ratio [OR] 1.12, 95% confidence interval (CI) 1.07‐1.17; P, The extraction of cardiac implantable electronic device leads due to infections, malfunctions, and recalls is common, and can lead to complications such as lead break resulting in incomplete lead removal and cardiac tamponade. We found that older lead age, co‐radial leads, passive leads, and non‐polyurethane leads were independent predictors of lead break during extraction. These findings will guide clinicians to make appropriate choices of procedure and take greater care when these risk factors are present.

We report the case of a 74-year-old man with a previously implanted pacemaker lead. He had undergone Medtronic™ Micra Transcatheter Pacing System (TPS, Medtronic plc, MN, USA) implantation because of lead fracture. We implanted a new TPS and retrieved the dislodged one. We used a multiple-loop snare (EN snare®) and an 8.5F steerable sheath (Agilis NXT; St. Jude Medical, St Paul, MN, USA). The TPS was obstructed by the chordae tendineae of the tricuspid valve and the pacemaker lead. We pushed the TPS to the apex site; this enabled us to move the TPS away from the chordae tendineae and pacemaker lead. The TPS body was caught in the inferior vena cava and was successfully retrieved. To our knowledge, this is the first case reporting TPS retrieval in a heart with preexisting lead. Keywords: Dislodgement, Transcatheter pacing system, TPS retrieval

Cardiac rhythm management devices (pacemakers) are being increasingly implanted worldwide not only for symptomatic bradycardia, but also for the management of arrhythmia and heart failure. Despite the overall safety, transvenous lead extraction (TLE) remains a challenging procedure with inherent

As the population ages, the number of elderly patients with implantable cardiac devices referred for transvenous lead extraction will dramatically increase in Japan. We report the safety and effectiveness of transvenous lead extraction in octogenarians. Between 2005 and 2017, we collected data of

Catheter ablation (CA) is an effective and widely used treatment strategy for paroxysmal atrial fibrillation (PAF). According to some papers, PAF is associated with distinct mechanistic and prognostic criteria in different patient subgroups. Compared with men, women with PAF have greater

Radiofrequency (RF) ablation of the atrioventricular nodal slow pathway is the accepted treatment for atrioventricular nodal reentrant tachycardia (AVNRT), with success rates greater than 90%. The major risk is atrioventricular nodal block requiring permanent pacemaker implantation. Cryoablation is

Objectives To explore the possibility of a generally applicable tool for the immediate diagnosis of Parkinson's disease (PD) in its early stage, we compared the sensitivity and specificity of an acute levodopa challenge test with that of 123I-metaiodobenzylguanidine (MIBG) myocardial scintigraphy. Materials and methods A consecutive series of 45 patients with extrapyramidal symptoms were recruited to the acute levodopa challenge and evaluated for improvement by use of the Unified Parkinson's Disease Rating Scale motor scores. Of these patients, 32 of them were also examined by MIBG scintigraphy. The patients were followed up for at least 24 months, and 22 patients were diagnosed as having clinically definite PD. Results The sensitivity and specificity of the acute levodopa challenge test to predict clinical diagnosis of PD were 81.8% and 81.8%, respectively, which were better than those obtained by MIBG scintigraphy (62.5% and 62.5%). In both early- and middle-stages of PD, the test gave better sensitivity than MIBG scintigraphy. Conclusions Considering that the well-established and frequently referred clinical diagnostic criteria require longitudinal observation for at least 24 months, the acute levodopa challenge test can be used as an immediate diagnostic tool for PD with sensitivity and specificity comparable to those of MIBG.

The in vivo responsiveness of thyroid glands to TSH at various ages in novel 'growth-retarded' (grt/grt) mice derived from Snell's dwarf (DW/J) mice and in their normal counterparts were analysed by determining serum T4 concentrations before and after the administration of exogenous TSH. The serum T4 concentration in normal mice increased in response to TSH at 2, 4 and 12 weeks of age but not at 1 week of age. A transient augmentation of such thyroidal responsiveness to TSH was apparent in normal mice at 2 weeks of age, when the serum T4 level exhibits a peak and the pubertal growth of mice starts. In contrast to normal mice, at any age examined from 2 to 12 weeks after birth, exogenous TSH did not influence serum T4 concentrations in the grt/grt mice at all. On the other hand, serum TSH concentrations in young grt/grt mice were highly elevated compared with those in normal mice and they were normalized by a 2–3 week's treatment with T3. Morphological studies demonstrated degenerated thyroid glands in the grt/grt mice. These results suggest that the severe hypothyroidism and consequent growth retardation in growth-retarded mice are due to impairment of the thyroid glands of the mutant mice in producing and/or secreting thyroid hormones in response to TSH. Journal of Endocrinology (1995) 144, 209–214

A membrane protein with a molecular weight of 40,000 (40K protein) was induced concurrently with cell filamentation by cyclic AMP (cAMP) in a fic mutant. In the crp mutant and the wild-type strain, cell filamentation by cAMP was not observed, and the 40K protein was not induced. Induction of the 40K protein is regulated by the cAMP-cAMP receptor protein complex and is closely related to cell filamentation by cAMP in the fic mutant.

Persistent hyperkalaemia was found in a patient with vitamin B12 unresponsive methylmalonic acidaemia associated with hyperuricaemia. At 3 years and 8 months of age, a serum potassium level of 6.8 mmol L−1 was found when blood gas measurement was normal. One year later azotaemia was noted. At the age of 5 years, renal function studies disclosed hyperaldosteronism, decreased creatinine clearance, reduction of the reabsorption of sodium at distal diluting segments and inadequate concentration of urine at the collecting ducts. The reduction of the reabsorption of sodium, which may have resulted in decreased potassium excretion, and the decrease in glomerular filtration rate, together with the superimposed excess intake of potassium, appeared to be responsible for the hyperkalaemia. Dietary potassium restriction was effective in suppressing the hyperkalaemia.