Ostial PV Isolation:

Pulmonary vein (PV) isolation by elimination of spike potentials has been reported to cure drug refractory atrial fibrillation. Because of the heterogenous morphology of the PVs, sequential electroanatomic reconstruction of the PVs was performed in 39 patients (group A), who underwent subsequent PV isolation by interruption of all conductive myocardial fibers by distinct RF current applications using a "lasso" approach. In group B (157 patients), only biplane two-dimensional fluoroscopy was performed to guide the diagnostic and the ablation catheters. After reprocedures (in 7% of patients in group A and 22% of group B), which depicted a recurrence of a spike potential inside or at the ostium of  >1 previously isolated PV in all restudied patients, stable sinus rhythm was documented in 69% of patients in group A and 60% of patients in group B. Reasons for the relapse of the previously eliminated spike potentials include a temporary ablation effect and a too distal interruption of the conducting myocardial fiber. Detailed knowledge of the individual three-dimensional morphology enhanced the clinical success rate of PV isolation but is time-consuming using CARTO   (8.0 ± 1.7 vs 5.0 ± 1.6, P < 0.001)   . Further technical improvement to fuse the individual three-dimensional anatomy and the electrophysiological markers to a composed "electroanatomic" map may overcome this limitation in the future. (PACE 2003; 26[Pt. II]:1624–1630)     

Perinatal epidemiology in Belgium

Data on the civil registration of all births and deaths recordedin 1987 in Belgium were analysed following WHO rules. The followingstatistics with significant regional variations were recorded:2.5% of teenage pregnancies, 7% of late pregnancies (35 years),6.1% of low birth weights and 5.3% of preterm deliveries. Pretermbirth rates did not improve during the last decade and are higherthan in neighbouring countries. Infant mortality rate is 9.74per 1000. This rate has remained unchanged since the early 1980sbut the relative importance of post-neonatal mortality is increasing.Congenital anomalies account for 26% of all infant deaths followedby the sudden infant death syndrome (17%). Maternal conditionssuch as eclampsia are related to 29% of the infants' deaths.     

Effects of Continuous-Wave (670-nm) Red Light on Wound Healing

BACKGROUND Recent work suggests that injuries can heal faster if treated by lasers emitting 670-nm red light. LED lights emitting 670-nm light are now available. This suggests that inexpensive and easy-to-use 670-nm LED lights might help accelerate cutaneous wound healing.
OBJECTIVE The objective was to evaluate the effect of 670-nm LED light on wound healing in SKH-1 hairless mice.
METHODS To study 670-nm light effects on incisional injury, animals were left unexposed or exposed to equal doses of high-, medium-, or low-flux light. Burn injuries were treated with high-flux light or left unexposed. Healing was assessed by measurement of the burn area and the gap remaining to closure of incisional injury.
RESULTS Mice exposed to 670-nm red light showed significantly faster healing than control mice. High, medium, and low fluxes of light were all effective after incisional injury. In burn injury, there was improvement in wound healing initially, but the time to repair was unchanged.
CONCLUSIONS A 670-nm LED red light source accelerates healing in skin of SKH-1 hairless mice after incisional injuries, but is not as effective for burn injuries. These data that suggest red light exposure may be helpful in postoperative wound repair.     

Bird migration--An energy-based analysis of costs and benefits

We look at a model of migration as part of a whole ecologicalsystem. The purpose is to investigate the mutual relationshipof population dynamics and migration strategies. In particular,we deal with the question of justifying the cost and dangerof migration. We evaluate the flight costs in terms of energyand try to model annual events that influence migration ratherthan emphasizing single aspects. We apply estimates of the totalannual energy budget to assess the motivation for migration.We give simulation runs of our model for the migration behaviourof one bird-of-prey species (Houbara bustard, Chlamydotis undulatamacqueenii) and of one passerine species (stonechat, Saxicolatorquata). In our model the most important factors determiningmigration success are overwinter survival and reproductive success.This is in agreement with experimental studies. The model allowsstrategies to be checked with respect to evolutionary stabilityin simulating species with very small initial values for thepopulation size. During a period of warm winters a nonmigratorybehaviour can be an evolutionary-stable strategy (ESS), butspecies which do not migrate are endangered and they can easilybe extinguished during seasons with food supply below the averageminimum (strong winters), even if such seasons are rare.     

Safe and Rapid Isolation of Pulmonary Veins Using a Novel Circular Ablation Catheter and Duty-Cycled RF Generator

Background: Ablation of atrial fibrillation (AF) has been one of the most difficult and time-consuming electrophysiological procedures. Due to the rapidly increasing demand for ablation procedures, technical advances would be helpful to reduce complexity and procedure time in AF ablation. Therefore, we investigated the feasibility of a single-catheter technique for pulmonary vein (PV) isolation utilizing a decapolar catheter combined with a duty-cycled, unipolar–bipolar radiofrequency (RF) generator.
Methods: AF mapping and ablation was performed in 21 consecutive patients (mean age 59 ± 12 years, 9 males) with paroxysmal AF (n = 17) and persistent AF (n = 4). The ablation catheter was forwarded to the LA via single-transseptal puncture. All electrodes were energized in 2 to 5 applications per vein, followed by segmental RF applications, as needed, to achieve electrical isolation. To assess left atrial anatomy for purposes of catheter manipulation, and later evaluate the possibility of asymptomatic PV-stenosis, CT or MR imaging was performed both prior to ablation and at 6-month follow-up.
Results: Isolation could be achieved in 85/86 veins (99%). Procedure time for ablation was 81 ± 13 minutes, and fluoroscopy time was 30 ± 11 minutes. There were no procedural complications. Success rate at 6 months was 86% (18/21). MR or CT imaging excluded asymptomatic PV-stenosis.
Conclusion: Mapping and ablation of PVs can be performed in a safe and efficient manner using a single-catheter technique, with short procedure times and minimal learning curve. Thus, this system may be of high interest not only for high volume but all centers performing AF ablation.