A Decrease in Pulmonary Vein Diameter After Radiofrequency Ablation Predicts the Development of Severe Stenosis

A decrease in ostial pulmonary vein (PV) diameter was observed in patients on the day after radiofrequency ablation of atrial fibrillation (AF). This study examined whether a relative reduction in PV diameter on day 1 (RRPVD1) after the procedure predicts the late development of severe PV stenosis (PVS). The study included 104 consecutive patients (mean age = 55 years, range 46–61, 34 women) with drug refractory AF. Pulmonary vein diameter was measured using MR angiography (MRA) on the day before and on day 1 after the ablation procedure. The MRA was repeated every 3 months after the procedure. Severe PVS was defined as a >70% diameter reduction from the initial ostial diameter. The cut-off of RRPVD1 was prespecified as 25% decrease in initial diameter. The data are presented as medians and interquartile range. A total of 357 PV were treated. The RRPVD1 was 0.0% (0.0–11.1%). Severe PVS was found in 18 PV during a follow-up of 12 months (range 6–13). The log-rank analysis confirmed a strong association between a RRPVD1 ≥25% and the development of PVS (hazard ratio: 7.1; 95% confidence interval 3.8–13.5, P < 0.0001). By multivariate Cox regression model, after adjustment of procedure variables, RRPVD1 was the strongest predictor of development of severe PVS. RRPVD1 ≥25% was a strong independent predictor of development of severe PVS.     

Seminal Fluid and the Expression of MHC Class I Antigens in the Placenta of the Rat

PROBLEM : To determine whether seminal fluid influences the expression of MHC class I antigens on the surface of basal trophoblast cells in the placenta of the rat. METHODS : Transfer of DA × DA embryos into a WF (allogeneic) or DA (syngeneic) recipient made pseudopregnant by hormonal treatment followed by mating with a vasectomized male (seminal fluid) or by mechanical stimulation (no seminal fluid). Antigen expression was determined by electron microscopic immunocytochemistry using the appropriate gold-labeled monoclonal antibodies. RESULTS : Seminal fluid did not affect the expression of MHC class I antigens on the surface of the basal trophoblast in either allogeneic or syngeneic matings. CONCLUSIONS : The suppression of the expression of paternal class I antigens on the surface of the basal trophoblast cells in allogeneic pregnancies most likely occurs at the genome level shortly after fertilization.     

STRUCTURED THERAPY INTERRUPTION (STI) AND DECEPTIVE IMPRINTING

The immune response in individuals chronically infected with HIV-1 is unable to prevent progression of disease. Diversion of immune recognition via ‘Deceptive Imprinting’ allows virus variants to continue the infection. Stuctured Interrupting of (HAART) therapy (STI) causes rebound of virus with ‘wild-type’ strains that stimulate the immune system. Combining STI with suppression of the dominant response against anti-wild–type virus is proposed to enhance the beneficial effects of STI.     

Early preventive attachment-oriented psychotherapeutic intervention program with parents of a very low birthweight premature infant: Results of attachment and neurological development

The birth of a very small preterm infant ( 1500 grams) can be a traumatizing experience for many parents. A developmental risk model is presented that is the background to an early attachment-oriented preventive psychotherapeutic intervention. This comprehensive parent-centered intervention program is composed of supportive group psychotherapy, attachment-oriented focal individual psychotherapy, a home visit and video-based sensitivity training. The intervention aims at improving parental coping, the process of attachment and parent-infant interaction. In a prospective longitudinal design mothers were randomly assigned to a control (N = 44) and an intervention group (N = 43) after preterm delivery. Results show that the percentage of secure (control vs. intervention group: 77.8% vs. 59.4%) and insecure (control vs. intervention group: 8.3% vs. 31.3% avoidant, 13.9% vs. 9.4% ambivalent) attachment quality in high-risk preterm infants is comparable to results from studies with term infants. There was no significant statistical difference in terms of quality of attachment of the preterm infants between the control group and the intervention group. However, only in the control group, impaired neurological development corresponded significantly with an insecure quality of attachment, but not in the intervention group, although there were significantly more neurologically impaired infants in the intervention group. This result is discussed as an effect of the intervention program.     

AIRWAY MANAGEMENT IN A CASE OF NECK IMPALEMENT: USE OF THE OESOPHAGEAL TRACHEAL COMBITUBE AIRWAY

A patient presented with neck impalement after a traffic accident.Respiratory arrest demanded immediate trachead intubation, whichwas impossible as a wooden splinter had partially obstructedthe pharynx and prevented laryngoscopy. An oeso-phageal tracheadCombitube airway was inserted successfully and the patient'slungs were ventilated adequately until tracheotomy was performed.     

The Basis for Activity Controlled Rate Variable Cardiac Pacemakers: An Analysis of Mechanical Forces on the Human Body Induced by Exercise and Environment

We conducted tests on six healthy volunteers and six pacemaker patients. With the aid of three straight line frequency acceleration pickups attached to the body, the mechanical signals were recorded on the three axes during different activities. Along with standardized exercise on bicycle and treadmill ergometers, we tested the influence of household activities and interference influences. The results were analyzed in terms of the amplitude and frequency content of the signals. For walking activities, we found a signal amplitude increasing in a largely linear fashion with the walking speed, the signal amplitudes being approximately twice as high on the vertical axis as on the other two axes. Exercise on the bicycle ergometer produced mechanical signals of clearly lower amplitude than comparable walking activities. The Fast-Fourier analysis showed amplitude peaks in the low frequency range of 1 to 4 Hz for all forms of physiological exercise, while interference influences showed amplitude peaks mainly in the range above 8 Hz. The use of a straight line-frequency acceleration pickup and a corresponding low pass filter might be a way of reducing the effect of unphysiological interference influences on an activity controlled pacemaker system. A sensor measuring on the horizontal axis appears to be the most favorable compromise for the various types of exercise. However, due to the considerable difference in signal amplitude for different types of exercise of the same intensity, an activity controlled pacemaker system cannot entirely meet metabolic conditions and requirements.     

Chronic Ventricular Electrograms: Do Steroid-Eluting Leads differ from Conventional Leads?

SCHUCHERT, A., ET AL.: Chronic Ventricular Electrograms: Do Steroid-Eluting Leads differ from Conventional Leads? The aim of steroid-eluting leads is to reduce chronic pacing thresholds. Whether steroid-eluting leads also modify acute and chronic R wave amplitudes as well as R wave sensing of the pulse generator was investigated in 31 patients with a unipolar ventricular pacemaker. Four different leads were implanted: Two steroid-eluting leads with different electrode surface areas (8 mm² and 5.8 mm²) and two conventional leads (Target Tip, Elgiloy lead). At implantation filtered R wave amplitudes, peak-to-peak values, and slew rates were measured by a pacing system analyzer. One year after implantation R wave amplitudes were directly determined from intracardiac electrograms and compared to the peak-to-peak data at implantation. Additionally, R wave inhibition was evaluated at a sensitivity setting of 5 mV. There were no differences among the four leads in respect to any of the parameters studied at implantation. At follow-up, no differences in R wave amplitudes were found leading to an appropriate sensing in all leads. Steroid-eluting leads did not differ from conventional leads and a smaller electrode surface area of 5.8 mm² had no influence on ventricular electrogram. Together with a pacemaker with an input impedance of 37 kohms R wave sensing was a correct setting of 5 mV.     

Relation Between Left Atrial Size and Secondary Atrial Arrhythmias After Successful Catheter Ablation of Common Atrial Flutter

Catheter ablation ptovides an effective cure for patients with typical atrial flutter. However, these patients may have the potential to develop atrial tachyarrhythmias other than common atrial flutter. This study examines clinical and echocardiographic predictors for the occurrence of uncommon atrial flutter or atrial fibrillation after abolition of common atrial flutter. The study population comprised 17 patients (12 men, 5 women, age 32–74 years) who underwent successful radiofrequency catheter ablation of common atrial flutter. Common atrial flutter did not recur in any patient during a median follow-up time of 8 (range 1–25) months. Within a median of 7 (range 1–223) days, however, symptomatic atrial tachyarrhythmias occurred in 8 of 17 patients (47%): uncommon atrial flutter (n = 4); atrial fibrillation (n = 3); and both uncommon atrial flutter and atrial fibrillation in one patient. Preablation left atrial volume was significantly larger in patients who developed secondary arrhythmias compared with patients who remained in sinus rhythm (57.9 ± 15.6 vs 43.7 ± 16.4 cm³, P < 0.05). Enlarged left atrial volume dichotomized at 51 cm³ independently predicted postablation atrial arrhythmias (x²=5.11, rel. risk = 5.3, P < 0.05). On Kaplan-Meier analysis, time to occurrence of postablation atrial arrhythmias was significantly shorter in patietits with enlarged left atrium (P < 0.02). In conclusion, symptomatic uncommon atrial flutter and atrial fibrillation develops in a substantial proportion of patients after successful ablation of common atrial flutter. Out of a series of clinical and echocardiographic parameters, preablation left atrial size is the best predictor for the occurrence of these postablation atrial arrhythmias.