Long-term arrhythmia variability after monomorphic ventricular tachycardia in patients with an implantable cardioverter defibrillator

Background: Arrhythmia burden in patients receiving an implantable cardioverter defibrillator (ICD) after monomorphic ventricular tachycardia (mVT) is higher than in patients with other indications. We investigated the long‐term arrhythmia profile in this subset of patients. Methods: Fifty‐two patients with an ICD implanted after mVT were followed up for at least 3 months. The cycle lengths (CLs) of the tachycardias recovered from the device memory were compared with the CL of the index arrhythmia. Morphological analysis of the intracardiac electrograms was performed and the response to antitachycardia pacing (ATP) was also assessed. Results: A total of 833 mVT episodes with intracardiac electrograms occurred during the follow‐up (3–58 months; mean: 30.3 months) in 41 of the 52 patients analyzed. mVTs with different CLs as compared with the index mVT were found in 26 (50.0%), and at least two different mVT morphologies were observed in 28 (53.8%) patients. Multiple mVT morphologies were predictive of lower ATP efficacy (95.6%, 85.0%, and 70.3% in the patients with 1, 2, and 3 or more mVT morphologies, respectively; P < 0.0001) and a higher shock burden (4.2%, 19.3%, and 24.7% in the patients with 1, 2, and 3 or more mVT morphologies, respectively; P < 0.0001). Conclusion: A high mVT burden was demonstrated with marked variability of the arrhythmias as concerns both CL and morphology in patients with an ICD implanted for mVT. Multiple mVT morphologies during the follow‐up were predictive of lower ATP efficacy and a higher shock burden. (PACE 2011; 34:1185–1191)     

The specific panoramic radiographic signs and their relation with inferior alveolar nerve injuries after mandibular third molar surgery

The aim of the authors was to describe the classic specific panoramic signs (indicating a close spatial relationship between dental canal and third molar's root) on panoramic radiographic images and determine their role in the risk assessment, predicting inferior alveolar nerve (IAN) paresthesia after lower third molar removal. The authors represented an informative case, where the IAN was visible during the surgery. The exact knowledge of classic panoramic radiographic signs should help the determination of "high risk" cases predicting IAN paresthesia after mandibular third molar removal. The authors keep panoramic radiography rather a routine than the most superior diagnostic tool in third molar surgery.     

Male reproductive tract abnormalities: More common after assisted reproduction?

Background

In this era of increased use of assisted reproduction (AR) techniques, the prevalence rates of hypospadias, cryptorchidism, poor semen quality have been increasing in parallel with a rising incidence of testicular cancer. It is suggested that these problems result from the disruption of gonadal development during fetal life causing the testicular dysgenesis syndrome (TDS).

Aim

The aim of our study was to evaluate the influence of conventional in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI), on the development of male genital tract abnormalities. Study design and subjects: We analyzed a cohort of 15,206 neonates born from January 1, 1999 through December 31, 2008 at the Department of Obstetrics and Gynecology, Medical School, University of Pécs, including 890 children (5.9%) born after IVF or ICSI. We examined the association between these AR methods and developmental abnormalities of the genital tract (hypospadias, cryptorchidism), after controlling for potential confounding factors, such as prematurity, low birthweight and twinning.

Results

Preterm birth and low birthweight are risk factors for hypospadias and cryptorchidism (p < 0.001), twinning increases the risk of hypospadias (p < 0.001). ICSI was revealed as a risk factor for hypospadias in singletons (OR: 3.190, 95%CI: 1.266-8.042) and in normal birthweight (> 2500 g) infants (OR: 3.966, 95%CI: 1.193-13.181, respectively). Similar but not nonsignificant trends were seen for cryptorchidism.

Conclusion

IVF and ICSI, by increasing the risks of prematurity, low birthweight, and multiple gestation, are indirect risk factors for developing male genital malformations. In infants with normal birhtweight or from singleton pregnancies, ICSI is a specific risk factor for hypospadias.     

Metal deposition and functional neurotoxicity in rats after 3-6 weeks nasal exposure by two physicochemical forms of manganese

Airborne manganese represents a major risk of nervous system damage first of all in industrial settings. The resulting effects may depend on the dose and physicochemical form of Mn. To compare the effect of soluble and nanoparticulate Mn, adult male rats received daily instillation of MnCl(2) solution or MnO(2) nanoparticle suspension (dose: 2.53mg Mn per rat) into the nasal cavity for 3 and 6 weeks. At the end of treatment, spontaneous open field motility was tested, electrophysiological recording was done in anesthesia, and brain tissue Mn level was determined. Metal level increase in the rats' brain, body weight gain reduction, and decrease of open field motility was significant in the MnCl(2), but not nano-Mn, treated rats. Most evoked cortical activity parameters were significantly altered in both groups, but spontaneous cortical activity spectrum only in the rats receiving MnCl(2). There was fair correlation between brain Mn levels and certain neuro-functional parameters, underlining the causal relationship. Electrophysiological tests might be more sensitive to the effects of Mn than general toxicological or neurobehavioral tests.     

Neurotoxic effects of subchronic intratracheal Mn nanoparticle exposure alone and in combination with other welding fume metals in rats

Manganese (Mn) is a toxic heavy metal exposing workers in various occupational settings and causing, among others, nervous system damage. Metal fumes of welding, a typical source of Mn exposure, contain a complex mixture of metal oxides partly in nanoparticle form. As toxic effects of complex substances cannot be sufficiently understood by examining its components separately, general toxicity and functional neurotoxicity of a main pathogenic welding fume metal, Mn, was examined alone and combined with iron (Fe) and chromium (Cr), also frequently found in fumes. Oxide nanoparticles of Mn, Mn?+?Fe, Mn?+?Cr and the triple combination were applied, in aqueous suspension, to the trachea of young adult Wistar rats for 4?weeks. The decrease of body weight gain during treatment, caused by Mn, was counteracted by Fe, but not Cr. At the end of treatment, spontaneous and evoked cortical electrical activity was recorded. Mn caused a shift to higher frequencies, and lengthened evoked potential latency, which were also strongly diminished by co-application of Fe only. The interaction of the metals seen in body weight gain and cortical activity were not related to the measured blood and brain metal levels. Fe might have initiated protective, e.g. antioxidant, mechanisms with a more general effect.