Au-decorated Sb2Se3 photocathodes for solar-driven CO2 reduction.

Photoelectrodes with FTO/Au/Sb2Se3/TiO2/Au architecture were studied in photoelectrochemical CO2 reduction reaction (PEC CO2RR). The preparation is based on a simple spin coating technique, where nanorod-like structures were obtained for Sb2Se3, as confirmed by SEM images. A thin conformal layer of TiO2 was coated on the Sb2Se3 nanorods via ALD, which acted as both an electron transfer layer and a protective coating. Au nanoparticles were deposited as co-catalysts via photo-assisted electrodeposition at different applied potentials to control their growth and morphology. The use of such architectures has not been explored in CO2RR yet. The photoelectrochemical performance for CO2RR was investigated with different Au catalyst loadings. A photocurrent density of ∼7.5 mA cm-2 at -0.57 V vs. RHE for syngas generation was achieved, with an average Faradaic efficiency of 25 ± 6% for CO and 63 ± 12% for H2. The presented results point toward the use of Sb2Se3-based photoelectrodes in solar CO2 conversion applications.

Comparison of TiO2 and ZnO for Heterogeneous Photocatalytic Activation of the Peroxydisulfate Ion in Trimethoprim Degradation.

The persulfate-based advanced oxidation process is a promising method for degrading organic pollutants. Herein, TiO2 and ZnO photocatalysts were combined with the peroxydisulfate ion (PDS) to enhance the efficiency. ZnO was significantly more efficient in PDS conversion and SO4•- generation than TiO2. For ZnO, the PDS increased the transformation rate of the trimethoprim antibiotic from 1.58 × 10-7 M s-1 to 6.83 × 10-7 M s-1. However, in the case of TiO2, the moderated positive effect was manifested mainly in O2-free suspensions. The impact of dissolved O2 and trimethoprim on PDS transformation was also studied. The results reflected that the interaction of O2, PDS, and TRIM with the surface of the photocatalyst and their competition for photogenerated charges must be considered. The effect of radical scavengers confirmed that in addition to SO4•-, •OH plays an essential role even in O2-free suspensions, and the contribution of SO4•- to the transformation is much more significant for ZnO than for TiO2. The negative impact of biologically treated domestic wastewater as a matrix was manifested, most probably because of the radical scavenging capacity of Cl- and HCO3-. Nevertheless, in the case of ZnO, the positive effect of PDS successfully overcompensates that, due to the efficient SO4•- generation. Reusability tests were performed in Milli-Q water and biologically treated domestic wastewater, and only a slight decrease in the reactivity of ZnO photocatalysts was observed.

Ultrasound guidance for femoral venous access in patients undergoing pulmonary vein isolation: A quasi-randomized study.

INTRODUCTION: Routine ultrasound (US) guidance for femoral venous access to decrease vascular complications of atrial fibrillation (AF) ablation procedures has been advocated. However, the benefit has not been unequivocally demonstrated by randomized-trial data. METHODS: Consecutive patients undergoing pulmonary vein isolation (PVI) on uninterrupted anticoagulant treatment were included. A quasi-random allocation to either US-guided or conventional puncture group was based on which of the two procedure rooms the patient was scheduled in, with only one of the rooms equipped with a US machine including a vascular transducer. The same four novice operators in rotation, with no relevant previous experience in US-guided vascular access performed venous punctures in both rooms. Major and minor vascular complications and the rate of prolonged hospitalization were compared. Major vascular complication was defined as groin hematoma, arteriovenous fistula, or pseudoaneurysm. Hematoma was considered as a major vascular complication if it met type 2 or higher Bleeding Academic Research Consortium criteria (requiring nonsurgical, medical intervention by a health care professional; leading to hospitalization or increased level of care, or prompting evacuation). RESULTS: Of the 457 patients 199 were allocated to the US-guided puncture group, while the conventional, palpation-based approach was performed in 258 cases. Compared with the conventional technique, US guidance reduced the rate of any vascular complication (11.63% vs. 2.01%, p < .0001), including both major (4.26% vs. 1.01%, p = .038) and minor (7.36% vs. 1.01%, p = .001) vascular complications. In addition, the rate of prolonged hospitalization was lower in the US-guided puncture group (5.04% vs. 1.01%, p = .032). CONCLUSION: The use of US for femoral vein puncture in patients undergoing PVI decreased the rate of both major and minor vascular complications. This quasi-randomized comparison strongly supports adapting routine use of US for AF ablation procedures.

Is prophylactic ablation of the cavotricuspid and peri-incisional isthmus justified in patients with postoperative atrial flutter after right atriotomy?

BACKGROUND: The two most common postoperative atrial flutter (AFL) circuits after right atriotomy are the cavotricuspid isthmus (CTI) dependent and the lateral, peri-incisional. We investigated whether radiofrequency ablation (RFA) of both circuits results in more favorable long-term outcomes. METHODS: Single-center retrospective cohort study of consecutive patients who underwent RFA of AFL after open-heart surgery. The effect of surgery type and RFA strategy on AFL recurrence was evaluated. RESULTS: One hundred and forty-two patients (mean age 64.5 ± 12.7 years, 65.% male) were enrolled. Patients with right atrial (RA) flutter (n = 124) were divided into two groups based on the index RFA procedure: only one RA circuit was ablated (Group 1, n = 84, 67.7%) or both the CTI and the peri-incisional circuit ablated (Group 2, n = 40, 32.3%). The previous open-heart surgery was categorized based on the extension of the RA incision: limited (Type A) or extended (Type B) atriotomy. After a mean follow-up of 36 ± 28 months, flutter recurrence was not different among patients with limited RA atriotomy (25% vs. 22% in Groups 1A and 2A, respectively, p = 1.0). However, after type B surgery, ablation of both AFL circuits was associated with a reduced recurrence rate (63% vs. 26% in Groups 1B and 2B, respectively, p = .002). CONCLUSIONS: In patients with postoperative RA flutter after extended right atriotomy, ablation of both the CTI and the peri-incisional isthmus significantly reduces the AFL recurrence rate. Prophylactic ablation of both isthmi, even if not proven to support reentry, is reasonable in this population.

Implantation of a VDD implantable cardioverter-defibrillator lead via a persistent left superior vena cava.

A persistent left superior vena cava (LSVC) represents a challenging congenital abnormality for transvenous cardiac device implantation. In the current case a secondary prophylactic VDD implantable cardioverter-defibrillator (ICD) implantation was planned in a 75-year-old woman presenting with ischemic cardiomyopathy and elevated stroke risk. Since no venous communication to the right side was identified intraoperatively, the lead was placed via the persistent LSVC. The far-field signal on the floating atrial dipole could be successfully blanked out, and appropriate device function with high and stable atrial sensing was demonstrated at follow-up.

Randomized trial of intracardiac echocardiography-guided slow pathway ablation.

PURPOSE: Radiofrequency (RF) catheter ablation of the slow pathway (SP) in atrioventricular nodal reentry tachycardia (AVNRT) is highly effective; however, it may require prolonged fluoroscopy and RF time. We postulated that visualization of the SP region with intracardiac echocardiography (ICE) could decrease ablation time, minimize radiation exposure, and facilitate SP ablation compared to the standard, fluoroscopy-guided approach. METHODS: In our study, we randomized 91 patients undergoing electrophysiologic study and SP ablation for AVNRT into 2 groups: fluoroscopy-only (n = 48) or ICE-guided (n = 43) group. Crossover to ICE-guidance was allowed after 8 unsuccessful RF applications. RESULTS: Mapping plus ablation time (mean ± standard deviation: 18.8 ± 16.1 min vs 11.6 ± 15.0 min, p = 0.031), fluoroscopy time (median [interquartile range]: 4.9 [2.93-8.13] min vs. 1.8 [1.2-2.8] min, p < 0.001), and total ablation time (144 [104-196] s vs. 81 [60-159] s, p = 0.001) were significantly shorter in the ICE group. ICE-guidance was associated with reduced radiation exposure (13.2 [8.2-13.4] mGy vs. 3.7 [1.5-5.8] mGy, p < 0.001). The sum of delivered RF energy (3866 [2786-5656] Ws vs. 2283 [1694-4284] Ws, p = 0.002) and number of RF applications (8 [4.25-12.75] vs. 4 [2-7], p = 0.001) were also lower with ICE-guidance. Twelve (25%) patients crossed over to the ICE-guided group. All were treated successfully thereafter with similar number, time, and cumulative energy of RF applications compared to the ICE group. No recurrence occurred during the follow-up. CONCLUSIONS: ICE-guidance during SP ablation significantly reduces mapping and ablation time, radiation exposure, and RF delivery in comparison to fluoroscopy-only procedures. Moreover, early switching to ICE-guided ablation seems to be an optimal choice in challenging cases.

Wavelength Dependence of the Transformation Mechanism of Sulfonamides Using Different LED Light Sources and TiO2 and ZnO Photocatalysts.

The comparison of the efficiency of the commercially available photocatalysts, TiO2 and ZnO, irradiated with 365 nm and 398 nm light, is presented for the removal of two antibiotics, sulfamethazine (SMT) and sulfamethoxypyridazine (SMP). The •OH formation rate was compared using coumarin, and higher efficiency was proved for TiO2 than ZnO, while for 1,4-benzoquinone in O2-free suspensions, the higher contribution of the photogenerated electrons to the conversion was observed for ZnO than TiO2, especially at 398 nm irradiation. An extremely fast transformation and high quantum yield of SMP in the TiO2/LED398nm process were observed. The transformation was fast in both O2 containing and O2-free suspensions and takes place via desulfonation, while in other cases, mainly hydroxylated products form. The effect of reaction parameters (methanol, dissolved O2 content, HCO3- and Cl-) confirmed that a quite rarely observed energy transfer between the excited state P25 and SMP might be responsible for this unique behavior. In our opinion, these results highlight that "non-conventional" mechanisms could occur even in the case of the well-known TiO2 photocatalyst, and the effect of wavelength is also worth investigating.

Impact of Reaction Parameters and Water Matrices on the Removal of Organic Pollutants by TiO2/LED and ZnO/LED Heterogeneous Photocatalysis Using 365 and 398 nm Radiation.

In this work, the application of high-power LED365nm and commercial, low-price LED398nm for heterogeneous photocatalysis with TiO2 and ZnO photocatalysts are studied and compared, focusing on the effect of light intensity, photon energy, quantum yield, electrical energy consumption, and effect of matrices and inorganic components on radical formation. Coumarin (COU) and its hydroxylated product (7-HC) were used to investigate operating parameters on the •OH formation rate. In addition to COU, two neonicotinoids, imidacloprid and thiacloprid, were also used to study the effect of various LEDs, matrices, and inorganic ions. The transformation of COU was slower for LED398nm than for LED365nm, but r07-HC/r0COU ratio was significantly higher for LED398nm. The COU mineralization rate was the same for both photocatalysts using LED365nm, but a significant difference was observed using LED398nm. The impact of matrices and their main inorganic components Cl- and HCO3- were significantly different for ZnO and TiO2. The negative effect of HCO3- was evident, however, in the case of high-power LED365nm and TiO2, and the formation of CO3•- almost doubled the r07-HC and contributes to the conversion of neonicotinoids by altering the product distribution and mineralization rate.

Is adenosine useful for the identification of atrial fibrillation triggers?

INTRODUCTION: Both isoproterenol (Iso) and adenosine (Ado) are used to induce atrial fibrillation (AF) in the electrophysiology lab. However, the utility of Ado has not been systematically established. OBJECTIVE: The purpose of this study was to compare Ado to Iso for the induction of paroxysmal AF. METHODS: Forty patients (16 women; mean age, 60 ± 12 years) with paroxysmal AF, presenting for ablation were prospectively included of whom 36 (90%) received Ado (18-36 mg) and/or Iso (3-20 µg/min incremental dose) in a randomized order (26 [72%] received both drugs). RESULTS: AF was induced with Iso in 15 of 32 (47%) and with Ado in 12 of 30 (40%) patients (P = 0.9). Iso-triggered AF started from the left pulmonary veins (PVs) in 11 of 15 (73%), from the right PVs in 3 of 15 (20%), and from the coronary sinus (CS) in 1 of 15 (7%) cases. Ado-induced AF episodes originated from the left PVs in 6 of 12 (50%), from the right atrium (RA) in 4 of 12 (33%), and from the CS in 2 of 12 (17%) cases. Altogether, Iso-induced AF was more likely initiated from the PVs (93%) compared with Ado (50%) ( P = 0.02). Ado-induced non-PV triggers were not predictive of arrhythmia recurrence after PV isolation. CONCLUSION: Ado much more frequently induces non-PV triggers, especially from the RA. The clinical significance of these foci, however, is questionable.

[The first use of iv. idarucizumab for dabigatran reversal in Hungary]. / A dabigatran-antidótum, az intravénás idarucizumab elso hazai alkalmazása.

At present, the direct thrombin inhibitor dabigatran is the only one amongst the new direct anticoagulants which has an effective, specific reversal agent. The novel agent idarucizumab is a humanized, monoclonal antibody fragment binds to dabigatran within minutes thereby offers an opportunity to induce a safe, long-lasting reverse of the anticoagulant effects of dabigatran. The authors describe the first use of idarucizumab in Hungary (23. 05. 2016) in an old female patient with non-valvular paroxysmal atrial fibrillation of high stroke risk-score and renal dysfunction who was taking dabigatran (2 x 110 mg/day) when an acute abdomen developed requiring emergency cholecystectomy. Patient received the antidote (idarucizumab 2 x 2.5 g/50 ml iv.) two hours before the surgical intervention, and she did not have any uncontrollable, life-threatening bleeding during the surgery. The high activated partial thromboplastin time relating to anticoagulative influence before the surgery normalized completely after administration of the antidote. Antagonizing dabigatran with idarucizumab was feasible and safe without any side effects. The patient received dabigatran therapy again after her recovery. Orv. Hetil., 2017, 158(10), 387-392.

Should the Aortic Root Be the Preferred Route for Ablation of Focal Atrial Tachycardia Around the AV Node?: Support From Intracardiac Echocardiography.

OBJECTIVES: The purpose of this study was to determine the optimal approach to focal atrial tachycardia originating from around the atrioventricular node. BACKGROUND: Focal atrial tachycardia (FAT) demonstrating earliest activation around the atrioventricular (AV) node during right atrial (RA) mapping has been eliminated by ablation at the RA para-Hisian region, from the left atrium (LA) or the noncoronary aortic cusp (NCC). However the optimal approach has not been determined. METHODS: We conducted a retrospective analysis of a consecutive series of 148 patients undergoing catheter ablation for FAT between 2006 and 2014 in our institution. RESULTS: Earliest activation was recorded in the peri-AV nodal region during RA mapping in 34 patients (23%). Of these, 7 patients (20.5%) had successful ablation at the RA septum, using either radiofrequency (n = 4) or cryoenergy (n = 3). Seven FATs (20.5%) were ablated from the LA at the region of the aortomitral continuity, and 20 patients (59%) had successful ablation in the NCC, including 1 patient with a recurrence after a temporarily successful cryoablation from the RA. The proportion of the 3 approaches in this series showed a significant temporal evolution and overall frequency favoring ablation in the NCC (p = 0.011 for time trend and 0.013 for actual vs. expected frequencies). Intracardiac echocardiography proved superior catheter stability with the NCC approach. There were 2 cases of atrioventricular block and 1 recurrence after RA ablation versus no complications or recurrent FAT with NCC and LA approaches. CONCLUSIONS: Most peri-AV nodal FATs can be safely and effectively ablated from the NCC. The strategy of preferential NCC approach avoids RA para-Hisian ablation with the accompanying risk of AV block.

Association between dissociated firing in isolated pulmonary veins and the initiation and maintenance of atrial fibrillation.

BACKGROUND: Whether dissociated firing (DiFi) in isolated pulmonary veins (PVs) implies arrhythmogenicity of the particular PVand, therefore, a better outcome of PV isolation (PVI) for paroxysmal atrial fibrillation (PAF) is debated. METHODS: Thirty-one patients undergoing their first PVI for PAF were studied. Isoproterenol was infused for induction, and the triggering PV was identified. During sustained PAF, sequential recordings were made with a decapolar circular mapping catheter from each PV. The dominant frequency (DF) was determined using fast Fourier transformation. Spontaneous DiFi was monitored for 30 min after PVI. RESULTS: PAF was triggered by the PVs in all patients. Fourteen (45 %) patients had DiFi after PVI in at least one PV. It was recorded most commonly from the left upper (84 %) and lower (67 %), less commonly from the right upper (31 %) PV. Out of the 23 PVs with DiFi, 13 (57 %) showed sporadic ectopic beats while 10 (44 %) had sustained ectopic rhythm or isolated tachycardia. There was no difference in size between PVs with or without DiFi (5.9±1.2 vs. 5.6±1.0 cm ostial perimeter, p=0.40). Triggering PVs more commonly showed any DiFi, compared to nontriggering PVs (68 vs. 27 %, p=0.003) and more commonly had sustained DiFi (53 vs. 0 %, p<0.001). During PAF PVs with any DiFi showed faster maximal DF compared to PVs without DiFi (7.1±1.3 vs. 5.9±1.1 Hz, p=0.001). Higher maximal DF was recorded in PVs with sustained versus sporadic DiFi versus PVs without DiFi (7.5 ±0.9 vs. 6.8±1.6 vs. 5.9±1.1 Hz, respectively, p=0.002). Patients with DiFi after PVI had a longer mean time to recurrent PAF compared to those without DiFi (52 vs. 32 months, p=0.048). CONCLUSIONS: Dissociated firing in isolated PVs is associated with their role in the initiation and maintenance of PAF.

Impaired adaptation to left atrial pressure increase in patients with atrial fibrillation.

BACKGROUND OR PURPOSE: Episodes of left atrial (LA) pressure increase predispose to atrial fibrillation (AF). The adaptation of LA mechanical function and electrophysiology to pressure elevation in healthy adults, and in patients with AF, is largely unknown. METHODS: Eleven patients with left-sided accessory pathway (controls) and 16 patients with paroxysmal AF undergoing catheter ablation were studied. LA pressure (LAP) was recorded through transseptal catheterization, while speckle tracking-derived peak LA longitudinal strain (PALS) was measured using transthoracic echocardiography. Stiffness index (SI) was calculated as mean LAP/PALS. Effective refractory period (ERP) of the LA was determined during simultaneous atrioventricular (AV) pacing and during atrial pacing. RESULTS: At baseline, AF patients had higher LA pressure (mean LAP 8.3 ± 4.7 vs. 5.1 ± 3.1 mmHg, p = 0.048), reduced LA mechanical function (PALS 15.1 ± 5.1 vs. 21.6 ± 6.2 %, p = 0.006, SI 0.69 ± 0.75 vs. 0.28 ± 0.22, p = 0.015), and longer LA ERP (242.3 ± 33.4 vs. 211.7 ± 15.6 ms, p = 0.017). Mean LAP was increased to the same extent by AV pacing in controls and AF patients (mean change 12.6 ± 7.4 vs. 12.6 ± 7.5 mmHg, p = 0.980). At the same time PALS decreased (from 15.1 ± 5.1 to 11.6 ± 3.3 %, p = 0.008), SI increased (from 0.69 ± 0.75 to 1.29 ± 1.17, p < 0.001) and ERP shortened (from 242.3 ± 33.4 to 215.9 ± 26.3 ms, p = 0.003) in AF patients, while they remained unchanged in controls. CONCLUSIONS: The stiffened LA in patients with AF responds to acute pressure elevation with an exaggerated increase in wall tension and decrease in ERP, which is not seen in the normal LA. This may underlie the propensity for AF during episodes of atrial stretch in these patients.

Novel strategies in the ablation of typical atrial flutter: role of intracardiac echocardiography.

Radiofrequency ablation (RFA) of the cavo-tricuspid isthmus (CTI) is one of the most frequently performed procedures in electrophysiology. Despite a high success rate, ablation of the CTI can be unusually difficult in some cases. Multiple tools like angiography, 3D mapping, remote navigation and intracardiac echocardiography (ICE) have been introduced to facilitate typical flutter ablation. This review article summarizes the clinical value of different strategies and tools used for CTI ablation focusing on the importance of approaches utilizing ICE.

Incorporation of cobalt-ferrite nanoparticles into a conducting polymer in aqueous micellar medium: strategy to get photocatalytic composites.

In this study an easy strategy for conducting polymer based nanocomposite formation is presented through the deposition of cobalt-ferrite (CoFe(2)O(4)) containing poly(3,4-ethylenedioxythiophene) (PEDOT) thin layers. The electrochemical polymerization has been performed galvanostatically in an aqueous micellar medium in the presence of the nanoparticles and the surface active Triton X-100. The nanoparticles have been characterized by Transmission electron microscopy (TEM), the thin layers has been studied by applying Scanning electron microscopy (SEM), and X-ray diffraction (XRD), and the basic electrochemical properties have been also determined. Moreover, electrocatalytic activity of the composite was demonstrated in the electrooxidation reaction of dopamine (DA). The enhanced sensitivity - related to the cobalt-ferrite content - and the experienced photocatalyitic activity are promising for future application.

[Experience with implanted ports for venous access between 2005 and 2012]. / Vénás portkatéter beültetésével szerzett tapasztalataink 2005-2012 között.

INTRODUCTION: During chemotherapy of cancer patients, vein inflammation may develop which may lead to pain and difficulty in blood sampling. The use of implanted venous access ports may overcome these problems. With a correct use of needles, venous port membrane may be pierced 2000-2500 times. AIM: The aim of the authors was to analyze their experience with venous access ports and evaluate whether insertion of venous ports occurred in an optimal time. METHOD: A retrospective study of 63 patients who received venous access ports between 2005 and 2012 was carried out. Complication rate and the time of venous port insertion were analysed. RESULTS: Of the 63 patients, the venous access port was removed in 22 patients because it was no longer required (n = 14) due to the development of complications (n = 8). 24 patients died from the underlying disease and 17 patients are still alive with the venous port in place. CONCLUSIONS: In the period studied patients with venous access ports had an improved quality of life. However, the authors conclude that venous access ports were not inserted in an optimal time.

Photosynthetic reaction centers/ITO hybrid nanostructure.

Photosynthetic reaction center proteins purified from Rhodobacter sphaeroides purple bacterium were deposited on the surface of indium tin oxide (ITO), a transparent conductive oxide, and the photochemical/-physical properties of the composite were investigated. The kinetics of the light induced absorption change indicated that the RC was active in the composite and there was an interaction between the protein cofactors and the ITO. The electrochromic response of the bacteriopheophytine absorption at 771 nm showed an increased electric field perturbation around this chromophore on the surface of ITO compared to the one measured in solution. This absorption change is associated with the charge-compensating relaxation events inside the protein. Similar life time, but smaller magnitude of this absorption change was measured on the surface of borosilicate glass. The light induced change in the conductivity of the composite as a function of the concentration showed the typical sigmoid saturation characteristics unlike if the photochemically inactive chlorophyll was layered on the ITO. In this later case the light induced change in the conductivity was oppositely proportional to the chlorophyll concentration due to the thermal dissipation of the excitation energy. The sensitivity of the measurement is very high; few picomole RC can change the light induced resistance of the composite.

Randomized trial of intracardiac echocardiography during cavotricuspid isthmus ablation.

UNLABELLED: Randomized Trial of ICE During CTI Ablation. INTRODUCTION: Despite a high success rate, radio-frequency ablation (RFA) of the cavotricuspid isthmus (CTI) can be unusually challenging in some cases. We postulated that visualization of the CTI with intracardiac echocardiography (ICE) could maximize the success rate, decrease the procedure and ablation time, and minimize the radiation exposure. METHODS AND RESULTS: In our prospective, randomized study, we included 102 patients scheduled for CTI ablation. We randomized patients in 2 groups: guided only by fluoroscopy (n = 52) or ICE-guided (n =50) group. Procedure time, fluoroscopy time, and the time spent for RFA were significantly shorter, radiation exposure (dose-area product-DAP) and the sum of delivered radio frequency energy were significantly lower in the ICE-group (68.06 ± 15.09 minutes vs 105.94 ± 36.51 minutes, P < 0.001, 5.54 ± 3.77 minutes vs 18.63 ± 10.60 minutes, P <0.001, 482.80 ± 534.12 seconds vs 779.76 ± 620.82 seconds, P = 0.001 and 397.62 ± 380.81 cGycm(2) vs 1,312.92 ± 1,129.28 cGycm(2) , P < 0.001, 10,866.84 ± 6,930.84 Ws vs 16,393.56 ± 13,995.78 Ws, P = 0.048, respectively). Seven patients (13%) from the fluoroscopy-only group crossed over to ICE-guidance because of prolonged unsuccessful RFA and were all treated successfully. Four vascular complications and 2 recurrences were equally distributed between the 2 groups. CONCLUSIONS: ICE-guided ablation of the CTI significantly shortens the procedure and fluoroscopy time, markedly decreases radiation exposure, and time spent for ablation in comparison with fluoroscopy-only procedures. At the same time, visualization with ICE allowed successful ablation in challenging cases. (J Cardiovasc Electrophysiol, Vol. 23, pp. 996-1000, September 2012).

Surgical technique and the mechanism of atrial tachycardia late after open heart surgery.

INTRODUCTION: Diverse atrial tachycardias (ATs) can develop after open heart surgery. The aim of our study was to examine the determinants of the mechanism of postoperative AT. METHODS AND RESULTS: One hundred patients with AT occurring at least 3 months after open heart surgery were studied. Patients were grouped according to the atrial incision applied at the time of surgery. During 127 electrophysiology procedures, 151 ATs were studied. Eighty-eight patients had cavotricuspid isthmus (CTI)-dependent atrial flutter (AFL), 49 patients had at least one non-CTI-dependent AFL and 11 patients had focal AT. While CTI-dependent AFL was equally prevalent across groups, the finding of a non-CTI-dependent AFL was progressively more common as more extensive atriotomy was applied (p < 0.001). Among patients who had right atrial (RA) operations, RA incisional tachycardia was the most common non-CTI-dependent circuit, while the finding of perimitral or left atrial (LA) roof-dependent AFL was associated with LA atriotomy (p = 0.002 and p = 0.041, respectively). After adjustment for possible confounders, surgical group remained independent predictor of non-CTI-dependent AFLs (p < 0.001). No predictor was identified for focal AT, which originated from typical predilection sites and in 36% from the vicinity of surgical scar. Radiofrequency ablation was highly effective for all ATs, but the recurrence rate of AFL and atrial fibrillation was high at 22% and 27%, respectively, during 19 ± 15 months of follow-up. CONCLUSION: While CTI-dependent AFL is the most common AT late after open heart surgery, atypical AFL becomes progressively more common with more extensive atriotomy. Right atrial incisional tachycardia is the dominant non-CTI-dependent AFL after opening of the RA, while a perimitral or roof-dependent LA circuit can be expected after LA operations.