High-Density Circumferential Pulmonary Vein Mapping with a 20-Pole Expandable Circular Mapping Catheter

The differentiation of pulmonary vein (PV) electrograms from atrial far-field signals during PV isolation (PVI) for atrial fibrillation (AF) may be difficult. In addition, owing to highly variable PV ostial sizes, current fixed-diameter circular PV mapping catheters may not yield optimal electrograms. We evaluated an expandable, circular 15–25 mm diameter, 20-pole mapping catheter for PV mapping during sustained AF in 25 patients. After selective PV angiography to define the ostial position and size, the catheter was introduced into each PV and withdrawn to the most stable proximal position, with optimal wall contact ensured by progressive loop expansion. At each PV ostium, electrograms recorded at high resolution (HR) were compared with those recorded at a resolution similar to that of a standard 10-pole Lasso catheter. After PVI performed during ongoing AF, the presence of residual far-field potentials (FFP) under both set-ups was compared. We mapped 97 PV, including 4 pairs with common ostia. In the HR recordings, the PV potentials had greater amplitude (0.5 ± 0.1 vs 0.3 ± 0.1 mV, P = 0.001) and fragmentation, whereas left atrial FFP were minimized. After successful isolation of all PV, FFP were observed in 33% of left superior and 28% of left inferior PV on the HR recordings, compared to 66% and 61%, respectively under normal resolution. Catheter stability and optimal wall contact, in combination with HR electrograms can optimize circumferential PV mapping during AF and improve the discrimination of FFP postablation.     

A protease inhibitor attenuates gastric erosions and microcirculatory disturbance in the early period after thermal injury in rats

The effects of camostat mesilate, a synthetic serine protease inhibitor on gastric microcirculation and active oxygen species generated by leucocytes from the gastric and jugular veins in the early period after thermal injury were assessed. Male Wistar rats were anaesthetized and a 30% full skin-thickness dorsal burn was inflicted. Camostat mesilate (100 mg/kg) was dissolved in distilled water and administered orally to rats 40 min before thermal injury (the camostat group). The control animals (the vehicle group) were administered distilled water orally. Rolling leucocytes as well as Monastral blue B deposits in venules were observed using in vivo microscopy. Active oxygen species were measured by chemiluminescence. Camostat mesilate decreased the total length of gastric erosion, venular deposits of Monastral blue B, and rolling of leucocytes in venules, and relatively increased luminol-dependent chemiluminescence activity generated by zymosan-stimulated leucocytes 15 min after thermal injury. These results suggest that serine proteases are involved in the formation of gastric erosions and gastric microcirculatory disturbance in the early period after thermal injury.     

A Sensitive and Simple Determination of Human α-fetoprotein by Enzyme-electroimmunodiffusion

A simple and sensitive determination method of α-fetoprotein was developed by introducing α-fetoprotein horseradish peroxidase conjugate into electroimmunodiffusion.
The precipitin line formed was directly visualized by staining for peroxidase activities. The sensitivity was 32 ng/ml. Electrophoretic activities of AFP were analyzed by two dimensional electrophoresis applying the present method to the second electrophoresis.
AFP from normal adults and several patients was confirmed to migrate as an α-globulin as AFP of hepatoma, yolk sac tumor and fetuses did.
AFP-like activities were detected in β-γ-globulin region in some samples but these were not due to AFP-anti-AFP interactions.     

Successful Catheter Ablation of Reentrant Junctional Tachycardia in a Patient with Asplenia Syndrome before Total Cavo‐Pulmonary Connection

Asplenia syndrome is commonly associated with complex structural cardiac malformations, and junctional tachycardia (JT), which may compromise hemodynamic status, has been reported in association with asplenia syndrome. 1 We report successful radiofrequency catheter ablation of reentrant JT in a patient with asplenia syndrome. (PACE 2010; e43–e45)     

Incidence and Prevention of Cardiac Tamponade Complicating Ablation for Atrial Fibrillation

Cardiac tamponade complicating catheter ablation of atrial fibrillation (AF) occurs in approximately 1% of pulmonary vein isolation (PVI), and up to 6% of linear ablation procedures. We reviewed 348 consecutive AF ablation (including repeat) procedures over 1 year, which all included PVI, with additional linear lesions at the mitral isthmus in 73%, and cavotricuspid isthmus (CTI) in 76%. An irrigated-tip ablation catheter was used, with power limited to 25–35 W for PVI and 45–60 W for linear lesions. Tamponade occurred in seven men and three women (2.9% of the population) during the creation of linear ablation lesions. Mechanical perforations occurred in two patients, and "popping" during radiofrequency (RF) energy delivery at the mitral isthmus in six, and at the CTI in two patients. Peak RF power was significantly higher in patients with than without tamponade (53 ± 4 W vs 48 ± 7 W; P = 0.02), and was greater than 48 W in all cases of "popping." In the following year, RF power for linear ablation was limited to ≤42 W. Among 398 procedures, tamponade occurred in four patients (1.0%; P = 0.047 vs first year), three from "popping" and one from mechanical trauma. Procedural success rate remained the same despite reduction of power. Risk of tamponade was highest during linear ablation, mainly associated with high energy delivery and "popping." Reducing the energy limited, though did not eliminate this complication.     

Catheter Ablation of Atrial Fibrillation in Patients With Valvular Heart Disease: Long‐Term Follow‐Up Results

AF Ablation in Patients With Valvular Heart Disease . Background: The purpose of this study is to evaluate the efficacy of atrial fibrillation (AF) ablation in patients with moderate valvular heart disease (VHD). Methods: In total, 534 consecutive patients who underwent AF ablation were enrolled. Patients with a history of valve surgery or other structural heart disease were excluded. Patients with clinically moderate VHD (group‐1, n = 45) were compared with those without VHD (control group‐2, n = 436). Ipsilateral pulmonary vein antrum isolation (PVAI) was performed with a double Lasso technique in all the patients. Left atrial (LA) linear ablation was undertaken in persistent AF patients, if AF was inducible after PVAI. Results: Patients in group‐1 were significantly older and had a larger LA. PVAI was successfully achieved in all the patients. Patients in group‐1 received LA linear ablation more frequently during the index procedure. After a median of 26 months from the index procedure, the freedom from AF was significantly lower in group‐1 than group‐2 off antiarrhythmic drugs (AADs) (47% vs 69%, P = 0.002). Although there were more number of total procedures in group‐1 than group‐2, the freedom from AF was lower at median 24 months after the last procedure (78% vs 87%, P = 0.038). There was no significant difference in the freedom from AF on AADs (91% vs 95%, P = 0.356) or complication rate between the 2 groups. Atrial tachycardia following the index procedure was observed more frequently in group‐1 (P = 0.001). Conclusion: The patients with VHD undergoing AF ablation are less likely to remain in sinus rhythm at long term without AADs than those without VHD. (J Cardiovasc Electrophysiol, Vol. 21, pp. 1193‐1198, November 2010)     

Serum hyaluronic acid reflects the effect of interferon treatment on hepatic fibrosis in patients with chronic hepatitis C

Changes in serum hyaluronic acid (HA) in 35 patients treated with interferon (IFN) were studied and the histological change in fibrosis was analysed. Serum HA levels and hepatitis C virus (HCV) RNA were followed from the start of therapy to 12 months after completion of treatment. Histological changes in pre- and post-treatment liver biopsies were assessed using a modified Knodell's scoring system. The serum levels of HA (r = 0.79; P<0.0001) correlated with the degree of fibrosis more closely than with that of amino terminal peptides of type III procollagen (PIIIP; r = 0.45; P<0.05) or type IV collagen (IV-C; r = 0.42; P<0.05). Only complete responders (CR) had a significant decrease in serum levels of HA and IV-C (P<0.05), in parallel with histological improvement (P<0.01). Neither partial responders (PR) nor non-responders (NR) had significant changes in histological scores and in serum levels of fibrotic markers. Significant differences were observed between CR and NR, both in HA levels (P<0.01) and PIIIP levels (P<0.05) 12 months after the cessation of treatment. These results suggest that serum HA is an indicator of the extent of fibrosis in chronic hepatitis C. Serial determinations of serum HA levels may be of use for monitoring the histological response of hepatic fibrosis to IFN treatment in chronic hepatitis C.