Embryotoxicity Study of Monomeric 4,4'-Methylenediphenyl Diisocyanate (MDI) Aerosol after Inhalation Exposure in Wistar Rats

One of the uses of MDI is as an alternative to formaldehydein the manufacture of furniture, its main route of exposureto humans being by inhalation. There have been no previous studieson the potential prenatal toxic effects of this compound. Toclose this gap in information, gravid Wistar rats, Crl:(WI)BR,were exposed by whole-body inhalation to clean air (control)and to 1, 3, and 9 mg/m3 MDI, respectively, for 6 hr per dayfrom Days 6 to 15 post conception (p.c). Rats were killed onDay 20 p.c. and the following results were obtained: Treatmentcaused a dose-dependent decrease in food consumption in allsubstance-treated groups during exposure, returning to normalvalues after cessation of treatment. The lung weights in thehigh-dose group were significantly increased compared to thesham-treated control animals. Treatment did not influence anyother maternal and/or fetal parameters investigated (maternalweight gain, number of corpora lutea, implantation sites, pre–and postimplantation loss, fetal and placental weights, grossand visceral anomalies, degree of ossification), although aslight but significant increase in litters with fetuses displayingasymmetric sternebra(e) was observed after treatment with thehighest dose of 9 mg/m³. Although the relevance of an increaseof this minor anomaly in doses which cause toxic effects indams (reduced food consumption, increased lung weights) is limitedand the number observed is within the limits of biological variability,a substance-induced effect in the high-dose group cannot beexcluded with certainty. Consequently, a no embryotoxic effectlevel of 3 mg/m³ was determined.     

Fast transmission of alterations in plasma phosphatidylcholine/sphingomyelin ratio and lyso phosphatidylcholine levels into changes of red blood cell membrane phospholipid composition after low density lipoprotein apheresis

Abstract. In order to evaluate whether changes in plasma phospholipid composition are rapidly transmitted to the red blood cell membrane (RBCM) under in vivo conditions, the levels of major phospholipids in plasma, low density and high density lipoproteins (LDL and HDL) as well as in RBCM were determined before (pre), directly after (post) and 2 days after (48 h post) LDL apheresis in six patients with severe hypercholesterolaemia. LDL apheresis induced a 30–70% decrease in plasma and LDL cholesterol and total phospholipid levels within 2–3 h. Concomitantly, the percentages of plasma phosphatidylcholine (PC) and the PC/sphingomyelin (SM) ratio were increased compared to initial values. The percentage of plasma lyso PC (LPC) determined before apheresis in the patients was 30% lower with respect to the mean level of LPC in a normolipidaemic control. For LPC of LDL no differences were observed between normolipidaemia and hypercholesterolaemia. LDL apheresis induced a rise by about one third in the percentage of plasma LPC. At 48 h post, plasma LPC levels reapproached pre-apher-esis levels, while the percentages of PC and the PC/SM ratio remained elevated. The pattern of changes induced by apheresis in plasma PC, SM and LPC levels was mimicked by changes in RBCM phospholipids. Strong positive relationships were noted for PC, SM and PC/SM as determined at pre, post and 48 h post between plasma and RBCM. In summary, changes in plasma PC, LPC, and PC/SM ratios as induced by LDL apheresis are rapidly transmitted to the RBCM under in vivo conditions, most probably as a result of phospholipid transfer between both compartments. In addition, the percentages of LPC in plasma and LDL particles of patients with severe hypercholesterolaemia are certainly below the levels of LPC reported to mediate biological effects of in vitro oxidized LDL.     

Catheter Ablation of Chronic Atrial Fibrillation with Noncontact Mapping:

SEIDL, K., et al .: Catheter Ablation of Chronic Atrial Fibrillation with Noncontact Mapping: Are Continuous Linear Lesions Associated with Ablation Success? Catheter-based, right and left atrial compartmentalization procedure was evaluated using a noncontact mapping (NCM) system. Its usefulness to identify and close discontinuities in linear lesions in both atria was evaluated. The impact of linear lesion continuity on ablation success of chronic AF was also investigated. Nineteen patients with symptomatic, drug refractory chronic AF were studied. Right atrial ablation with three predefined lines was attempted in all patients. In 18 patients, left atrial ablation was performed with four linear lesions. During a follow-up of 12 ± 3 months , 6 of 19 patients remained in sinus rhythm (SR) without antiarrhythmic agents (AAs). In addition, four patients were maintained in SR with AA. Thirteen of 14 patients with gaps identified during off-line analysis had recurrence of AF. Only one patient with a gap was free of recurrence without AAs. In the remaining five patients without recurrence of AF, no gap was observed during off-line analysis. In all four patients who were free of AF with additional treatment of AAs, two gaps had been identified. In the remaining nine patients with chronic AF recurrence, a mean of 4.9 gaps were identified. Excluding the initial learning period (first five patients) the success rate increased to 43% (6/14 patients) without and to 71% (10/14 patients) with AA. NCM identifies discontinuities in lines of ablation. Successful ablation of chronic AF is associated with continuity of linear lesions and good clinical technique demands a vigilant search for and closure of every gap. (PACE 2003; 26[Pt. I]:534–543)     

Pressure‐Guided Cryoballoon Isolation of the Pulmonary Veins for the Treatment of Paroxysmal Atrial Fibrillation

Pressure‐Guided Cryoballoon Pulmonary Vein Isolation. Background: Pulmonary vein (PV) isolation using a balloon‐mounted cryoablation system is a new technology for the percutaneous treatment of atrial fibrillation (AF). Complete PV occlusion during balloon ablation has been shown to predict successful electrical isolation. The aim of this study was to correlate mechanical PV occlusion with changes in a pressure curve recorded at the distal tip of the cryoballoon catheter. Methods and Results: We analyzed 51 PVs in 12 patients (61 ± 6 years old) with paroxysmal AF. At first, PV occlusion via the cryoballoon was documented by changes in the pressure curve. Once the PV is occluded, the pressure curve registered in the vein converts from a left atrial pressure curve to a pulmonary artery pressure curve: the PV wedge curve. Occlusion was then confirmed by transesophageal echocardiography (TEE). Following 2 cryoablation applications, electrical PV isolation was assessed with a circumferential mapping catheter. Under the exclusive guidance of changes in the pressure curve at the tip of the cryoballoon, mechanical occlusion confirmed by TEE was achieved in 47 of 51 PVs (92%). Three PVs required further TEE guidance to achieve occlusion. All 50 occluded veins were electrically isolated after cryoablation. One right inferior vein, which could not be occluded with the balloon, displayed conduction post cryoablation and was isolated by focal ablation. Conclusions: Occlusion and electrical isolation of PVs during cryoballoon ablation can be predicted by the appearance of a PV wedge curve at the tip of the catheter. This new straightforward parameter may facilitate the procedure. (J Cardiovasc Electrophysiol, Vol. 21, pp. 120‐125, February 2010)     

Ventricular Oversensing:

WERETKA, S., et al. : Ventricular Oversensing: A Study of 101 Patients Implanted with Dual Chamber Defibrillators and Two Different Lead Systems . Modern dual chamber ICD systems are able to overcome various sensing problems. However, improvement of their performance is still required. The aim of this study was to assess the sensing function in 101 consecutive patients (84 men, 17 women; mean age 63 ± 12 years; mean follow-up 24 ± 4 months) implanted with dual chamber defibrillators and integrated (IB) or dedicated bipolar (DB) lead systems. Follow-up data were analyzed for the presence of ventricular oversensing. Oversensing occurred in 25 (25%) patients, significantly more frequent in patients implanted with IB compared to DB lead systems (21/52 vs 4/49, P = 0.0002). Patients with cardiomyopathies (CMs) were more prone to sensing malfunctions than patients with no CM (12/30 vs 13/71, P = 0.04). T wave oversensing (n = 14), respirophasic ventricular oversensing (n = 4), and P wave oversensing (n = 6) were the most common pitfalls of ventricular sensing. P wave oversensing was unique to the IB lead system. CT scans performed in these patients disclosed the position of the RV coil to be proximal to the tricuspid area. Four patients received inappropriate ICD shocks due to oversensing. In all but two patients who received lead revision, oversensing was resolved by noninvasive means. In conclusion: (1) ventricular oversensing is a common problem occurring in up to 25% of patients with dual chamber ICDs; (2) P wave oversensing is a ventricular sensing problem affecting function of 11% of dual chamber devices with IB lead systems; (3) IB leads are significantly more susceptible to T wave and P wave oversensing than DB leads; and (4) patients with cardiomyopathies are more prone to oversensing than patients with other heart diseases. (PACE 2003; 26[Pt. I]:65–70)     

3 Tesla MRI‐Detected Brain Lesions after Pulmonary Vein Isolation for Atrial Fibrillation: Results of the MACPAF Study

MRI Results of the MACPAF Study. Background: Left atrial catheter ablation (LACA) is an established therapeutic approach to abolish symptomatic atrial fibrillation (AF). Objective: Based on the prospective MACPAF study (clinicaltrials.gov NCT01061931) we report the rate of ischemic brain lesions postablation and their impact on cognitive function. Methods: Patients with symptomatic paroxysmal AF were randomized to LACA using the Arctic Front® or the HD Mesh Ablator® catheter. All patients underwent brain MRI at 3 Tesla, neurological, and neuropsychological examinations within 48 hours prior and after the ablation procedure. Results: There was no clinically evident stroke in 37 patients (mean age 62.4 ± 8.4 years; 41% female; median CHADS2 score 1 [IQR 0–2]) after LACA but high‐resolution diffusion‐weighted imaging (DWI) detected new ischemic lesions in 15 (41%) patients after LACA. Four (27%) of the HD Mesh Ablator® patients and 11 (50%) of the Arctic Front® patients suffered a silent ischemic lesion (P = 0.19). In these 15 patients, there was a nonsignificant trend toward lower cardiac ejection fraction (P = 0.07) and AF episodes during LACA (P = 0.09), while activated clotting time levels, number of energy applications, periprocedural electrocardioversion or CHADS₂ score had no impact. Lesion volumes varied from 5 to 150 mm³ and 1 to 5 lesions were detected per patient. However, acute brain lesions had no effect on cognitive performance immediately after LACA. Of the DWI lesions postablation 82% were not detectable on FLAIR images 6–9 months postablation. Conclusions: According to 3 Tesla high‐resolution DWI, ischemic brain lesions after LACA were common but not associated with impaired cognitive function after the ablation procedure. (J Cardiovasc Electrophysiol, Vol. 24, pp. 14‐21, January 2013)     

Sexual function before and after mesh repair of inguinal hernia

AIM: Several factors having an influence on the quality of life after an inguinal hernia repair have been studied, yet little has been reported on sexual function before and after this operation. METHODS: In a prospective follow-up study from January 1999 to July 2002, 210 men and 14 women were asked to answer an anonymous questionnaire of 40 questions before elective inguinal hernia repair to assess pre- and postoperative sexual function (preoperatively, 3 months postoperatively and every 6 months afterwards). Inguinal hernia repair was performed using a standardized Plug and Patch mesh technique. RESULTS: Fifty-two (23.2%) patients mentioned preoperative sexual dysfunction related to the groin hernia. Postoperatively, the surgical repair had a positive influence on the sexual function in these patients. Thirty-six (16%) patients complained of postoperative sexual dysfunctions, which improved or disappeared over the next few months. All patients suffered surgical complications, which were surgically treated in six cases. Symptoms specifically associated with inguinal hernias can cause certain limitations in the sexual life. CONCLUSIONS: In most cases, and in the absence of postoperative complications, the operative repair can lead to a recovery of the sexual life in patients with preoperative sexual dysfunction, while, in most cases, it does not affect patients with a preoperative normal sexual life.     

Balloon Expandable Sheath for Transfemoral Aortic Valve Implantation: A Viable Option for Patients with Challenging Access

Background and Objectives

Transcatheter aortic valve replacement (TAVR) via femoral access is a new option for patients with severe aortic valve stenosis considered to be at high risk for conventional open‐heart surgery. This procedure requires peripheral arteries that are able to accommodate the large sheaths required for valve delivery. We present a series of patients with suboptimal vascular conditions, who received a self‐expandable vascular sheath.

Methods and Results

From January 2009 to September 2011, a total of 96 patients (43% male) were treated with the 18F Medtronic CoreValve (Medtronic, Minneapolis, MN, USA). The patients' average age was 82.5 ± 4.6 years, and the mean EuroSCORE was 29%. In eight cases, vascular conditions were inadequate either due to advanced atherosclerotic disease (n = 5, 62.5%), or an arterial diameter ≤7 mm (n = 3, 37.5%). Instead of the standard 18F sheath, a balloon‐expandable transfemoral introducer (SoloPath?‐Introducer, Onset Medical Corporation, Irvine, CA, USA) was delivered and removed without complications in all but one (87.5%) patient. In the last case, rupture of the right femoral artery occurred after removal of the sheath with the need of vascular surgery.

Conclusion

The SoloPath sheath is a feasible alternative to conventional sheaths for transfemoral TAVR patients with difficult femoral vascular access.

     

Semi‐elective intraosseous infusion after failed intravenous access in pediatric anesthesia1

Background: Intraosseous (IO) infusion is a well‐established intervention to obtain vascular access in pediatric emergency medicine but is rarely used in routine pediatric anesthesia. Methods: In this observational study, we report on a series of 14 children in whom semi‐elective IO infusion was performed under inhalational anesthesia after peripheral intravenous (IV) access had failed. Patient and case characteristics, technical details, and estimated timings of IO infusion as well as associated complications were reviewed. Data are median and range. Results: IO infusion was successfully established in fourteen children [age: 0.1–6.00 years (median 0.72 years); weight: 3.5–12.0 kg (median 7.0 kg)]. The majority suffered from chronic cardiac, metabolic, or dysmorphic abnormalities. Estimated time taken from inhalational induction of anesthesia until insertion of an intraosseous needle was 26.5 min (15–65 min). The proximal tibia was cannulated in all patients. The automated EZIO? IO system was used in eight patients and the manual COOK? system in six patients. Drugs administered included hypnotics, opioids, neuromuscular blocking agents and reversals, cardiovascular drugs, antibiotics, and IV fluids. The IO cannulas were removed either in the operating theatre (n = 5), in the recovery room (n = 5), or in the ward (n = 4), after 73 min (19–225 min) in situ. There were no significant complications except one accidental postoperative dislocation. Conclusions: IO access represents a quick and reliable alternative for pediatric patients with prolonged difficult or failed IV access after inhalational induction of anesthesia.