Lasing at K Points of a Honeycomb Plasmonic Lattice.

We study lasing at the high-symmetry points of the Brillouin zone in a honeycomb plasmonic lattice. We use symmetry arguments to define singlet and doublet modes at the K points of the reciprocal space. We experimentally demonstrate lasing at the K points that is based on plasmonic lattice modes and two-dimensional feedback. By comparing polarization properties to T-matrix simulations, we identify the lasing mode as one of the singlets with an energy minimum at the K point enabling feedback. Our results offer prospects for studies of topological lasing in radiatively coupled systems.

Lasing in dark and bright modes of a finite-sized plasmonic lattice.

Lasing at the nanometre scale promises strong light-matter interactions and ultrafast operation. Plasmonic resonances supported by metallic nanoparticles have extremely small mode volumes and high field enhancements, making them an ideal platform for studying nanoscale lasing. At visible frequencies, however, the applicability of plasmon resonances is limited due to strong ohmic and radiative losses. Intriguingly, plasmonic nanoparticle arrays support non-radiative dark modes that offer longer life-times but are inaccessible to far-field radiation. Here, we show lasing both in dark and bright modes of an array of silver nanoparticles combined with optically pumped dye molecules. Linewidths of 0.2 nm at visible wavelengths and room temperature are observed. Access to the dark modes is provided by a coherent out-coupling mechanism based on the finite size of the array. The results open a route to utilize all modes of plasmonic lattices, also the high-Q ones, for studies of strong light-matter interactions, condensation and photon fluids.

Ultrasound Screening of Men with Coronary Artery Disease for Abdominal Aortic Aneurysms: A Prospective Dual Center Study.

BACKGROUND AND AIMS: According to the heterogeneous results of previous studies, the prevalence of abdominal aortic aneurysm seems high among men with coronary artery disease. The associating risk factors for abdominal aortic aneurysm in this population require clarification. Our objective was to assess the prevalence of non-diagnosed abdominal aortic aneurysms in men with angiographically verified coronary artery disease and to document the associated co-morbidities and risk factors. MATERIAL AND METHODS: Altogether, 407 men with coronary artery disease were screened after invasive coronary angiography in two series at independent centers. Risk factor data were recorded and analyzed. RESULTS AND CONCLUSION: The mean age of the study cohort was 70.0 years (standard deviation: 11.0). The prevalence of previously undiagnosed abdominal aortic aneurysms in the whole screened population of 407 men was 6.1% (n = 25/407). In a multivariate analysis of the whole study population, the only significant risk factors for abdominal aortic aneurysm were age (odds ratio: 1.04, 95% confidence interval: 1.00-1.09) and history of smoking (odds ratio: 3.13, 95% confidence interval: 1.26-7.80). Non-smokers with abdominal aortic aneurysm were significantly older than smokers (mean age: 80.7 (standard deviation: 8.0) vs 68.0 (standard deviation: 11.1), p = 0.003), and age was a significant risk factor only among non-smokers (p = 0.011; p = 0.018 for interaction). Among smokers, the prevalence of abdominal aortic aneurysm was 8.8%, and 72% (n = 18/25) of all diagnosed abdominal aortic aneurysm patients were smokers. Prevalence of undiagnosed abdominal aortic aneurysms among patients with coronary artery disease is high, and history of smoking is the most significant risk factor for abdominal aortic aneurysm. Effectiveness of selective screening of abdominal aortic aneurysm in male patients with coronary artery disease warrants further studies.

Surface lattice resonances and magneto-optical response in magnetic nanoparticle arrays.

Structuring metallic and magnetic materials on subwavelength scales allows for extreme confinement and a versatile design of electromagnetic field modes. This may be used, for example, to enhance magneto-optical responses, to control plasmonic systems using a magnetic field, or to tailor magneto-optical properties of individual nanostructures. Here we show that periodic rectangular arrays of magnetic nanoparticles display surface plasmon modes in which the two directions of the lattice are coupled by the magnetic field-controllable spin-orbit coupling in the nanoparticles. When breaking the symmetry of the lattice, we find that the optical response shows Fano-type surface lattice resonances whose frequency is determined by the periodicity orthogonal to the polarization of the incident field. In striking contrast, the magneto-optical Kerr response is controlled by the period in the parallel direction. The spectral separation of the response for longitudinal and orthogonal excitations provides versatile tuning of narrow and intense magneto-optical resonances.

Magnetic resonance imaging has no role in diagnosing the origin of pain in patients with overwhelmingly painful inguinal hernia.

PURPOSE: Clinical tools for predicting postoperative pain should be developed to provide better care for patients. The aims of this study were to evaluate preoperative magnetic resonance imaging (MRI) findings to reveal reasons for overwhelming pain in patients with inguinal hernia and to detect changes in quality-of-life (QoL) and pain scores preoperatively and following laparoscopic totally extraperitoneal (TEP) repair of inguinal hernia. METHODS: Twenty-two patients aged 18-50 years presenting with extremely painful inguinal hernias (highest pain scores >50, scale 0-100) were examined with MRI prior to operative treatment with TEP repair. Postoperative follow-up lasted 6 months and consisted of questionnaires regarding functional status, pain, QoL and possible complications. Postoperative MRI scans were performed only in cases of preoperative findings on the MRI or prolonged inguinal pain persisting over 6 months. RESULTS: Prolonged postoperative pain could not be predicted from preoperative MRI scans, because no signs of the pain's origin such as pubic periostal irritation, bone marrow edema, pelvic bone or hip joint abnormalities, or lower abdominal muscle hemorrhage were detected in MRI. TEP repair of inguinal hernia significantly improved the patients' quality of life and relieved pain symptoms. High preoperative pain scores were major predictors of prolonged postoperative pain. CONCLUSIONS: Carefully evaluated preoperative pelvic MRI was usually normal in patients with high pain scores prior to operation. Preoperative pain scores may serve as indicators of development of prolonged inguinal pain.

Spatial coherence properties of organic molecules coupled to plasmonic surface lattice resonances in the weak and strong coupling regimes.

We study spatial coherence properties of a system composed of periodic silver nanoparticle arrays covered with a fluorescent organic molecule (DiD) film. The evolution of spatial coherence of this composite structure from the weak to the strong coupling regime is investigated by systematically varying the coupling strength between the localized DiD excitons and the collective, delocalized modes of the nanoparticle array known as surface lattice resonances. A gradual evolution of coherence from the weak to the strong coupling regime is observed, with the strong coupling features clearly visible in interference fringes. A high degree of spatial coherence is demonstrated in the strong coupling regime, even when the mode is very excitonlike (80%), in contrast to the purely localized nature of molecular excitons. We show that coherence appears in proportion to the weight of the plasmonic component of the mode throughout the weak-to-strong coupling crossover, providing evidence for the hybrid nature of the normal modes.

Surgical wound infections after peripheral vascular surgery.

Surgical wound infection is one of the most common complications after peripheral vascular surgery. It increases the affected patient's risk for major amputation as well as mortality. Furthermore, surgical wound infection is an additional cost. Wound infections after vascular surgery are of multifactorial nature and generally result from the interplay of patient- and procedure-related factors. The use of systemic antibiotic prophylaxis may be the most important method in preventing surgical wound infections. In this review article, we report the current literature of surgical wound infections after peripheral vascular surgery.

The impact of surgical wound bacterial colonization on the incidence of surgical site infection after lower limb vascular surgery: a prospective observational study.

OBJECTIVE: To study the relationship between surgical wound bacterial colonization and the development of surgical site infection (SSI) after lower limb vascular surgery. SSI is a major problem after lower limb vascular surgery. Most SSIs in vascular surgery are caused by Staphylococcal species that are part of normal skin flora. A prospective observational investigator blind study to examine quantitative and qualitative analysis of surgical wound bacterial colonization and the correlation with the development of SSI has been conducted. METHODS: The study cohort comprised 94 consecutive patients with 100 surgical procedures. Swabs for microbiological analyses were taken from surgical wounds at four different time intervals: before surgery, just before the surgical area had been scrubbed, at the end of surgery, and on the first and second postoperative days. Postoperative complications were recorded. RESULTS: Three hundred and eighty-seven skin bacterial samples from 100 surgical wounds were analyzed. The most common bacteria isolated were coagulase-negative staphylococci (80%), Corynebacterium species (25%), and Propionibacterium species (15%). In 13 (62%) cases, the same bacterial isolates were found in the perioperative study samples as in the infected wounds. The incidence of SSI was 21%. Multivariate analysis revealed that high bacterial load on the second postoperative day and diabetes independently increased the risk of SSI. Elective redo surgery was protective against the development of SSI. CONCLUSIONS: A high bacterial load in the postoperative surgical wound independently increases the risk of the development of SSI after lower limb vascular surgery.

Preventive strategies for atrial fibrillation after cardiac surgery in Nordic countries.

BACKGROUND AND AIMS: Atrial fibrillation is a common arrhythmia after cardiac surgery. It increases morbidity, length of hospital stay, and costs of operative treatment. Beta-blockers, sotalol, amiodarone, corticosteroids, and biatrial pacing have been shown to be efficient in the prevention of postoperative atrial fibrillation. The aim of this study was to find out how widely different prophylactic strategies for postoperative atrial fibrillation are used in Scandinavian countries. MATERIAL AND METHODS: An online link for a questionnaire was emailed to (214) cardiac surgeons in Finland, Sweden, Norway, Denmark, and Estonia to assess the use of prophylactic methods for postoperative atrial fibrillation. RESULTS: A total of 97 surgeons responded to the survey. Oral beta-blockers were routinely used for atrial fibrillation prophylaxis by 62% of responders. The main reasons for nonuse of beta-blockers were that responders were unconvinced of the evidence of benefit or they preferred some alternative prophylaxis. Intravenous beta-blockers were used frequently by 6% of responders. Amiodarone was used for prophylaxis by 18% of responders. Nonusers were unconvinced of its efficacy, were afraid of its complications, or found its use too cumbersome. Other prophylactic atrial fibrillation strategies that were used are as follows: sotalol by 2%, magnesium by 17%, corticosteroids by 1%, and atrial pacing by 11% of respondents. CONCLUSIONS: There is still widely varying implementation of strategies for atrial fibrillation prophylaxis among Scandinavian cardiac surgeons. Lack of confidence in the efficacy of these approaches is the main rationale for nonimplementation.

A core needle biopsy provides more malignancy-specific results than fine-needle aspiration biopsy in thyroid nodules suspicious for malignancy.

BACKGROUND AND AIMS: The most commonly used diagnostic method for the preoperative diagnosis of thyroid nodules is ultrasound-guided fine-needle aspiration biopsy (FNA), which often yields non-diagnostic or non-definitive results and seldom produces definite malignant diagnoses. To improve upon the malignancy-specific sensitivity, we tested core needle biopsies (CNBs) of thyroid lesions taken from surgical specimens. MATERIAL AND METHODS: 52 consecutive patients with malignant or malignant-suspicious thyroid nodules were referred to Tampere University Hospital between May 2010 and December 2011. Preoperative FNAs were categorised as follicular neoplasm (48%), suspicion for malignancy (46%) or malignancy (6%). Intraoperative FNA and CNB samples were acquired from surgical specimens removed during surgery. The results of the needle biopsies were compared with the final pathological diagnosis. RESULTS: CNBs had a high definitive sensitivity for malignancy (61%, CI 41% to 78%) whereas the definitive sensitivity for malignancy of FNAs was significantly lower (22%, CI 10% to 42%). CNB was not beneficial in the diagnosis of follicular thyroid lesions. When all suspected follicular tumours were excluded, the definitive sensitivity of CNB rose to 70% (CI 48% to 86%). CONCLUSIONS: CNB may be beneficial for the diagnosis of papillary thyroid carcinoma and other non-follicular thyroid lesions. CNB may be considered as an additional diagnostic procedure in cases with FNA suspicious for malignancy.

Intravenous metoprolol versus biatrial pacing in the prevention of atrial fibrillation after coronary artery bypass surgery: a prospective randomized open trial.

BACKGROUND AND AIMS: Atrial fibrillation (AF) is the most common arrhythmia after coronary artery bypass surgery (CABG). Intravenous metoprolol and biatrial pacing have been reported to be effective in AF prophylaxis after cardiac surgery. The purpose of this trial was to compare the efficacy of intravenous metoprolol versus biatrial pacing combined with oral metoprolol in the prevention of AF after CABG. METHODS: A single-centre prospective randomized open trial of 165 consecutive patients undergoing their first CABG. Patients were randomized to receive either intravenous metoprolol infusion 1-3 mg per hour or biatrial overdrive pacing and oral metoprolol (50-150 mg) daily for 72 hours after CABG starting immediately after the surgery. AAI pacing with a pacing rate of 10 beats/minute above the baseline heart rate was used. Patients had continuous ECG-monitoring. The primary end point was the first episode of AF. RESULTS: The incidence of postoperative AF in the intravenous metoprolol and biatrial pacing groups did not differ from each other (14% vs. 18% respectively, p=0.66). There was no difference in the time of AF onset between the groups (28.2 ± 16.2 h vs. 30.1 ± 21.2 h respectively, p = 0.8). Intravenous metoprolol infusion had to be temporarily interrupted for one hour in eleven patients because of hypotension or bradycardia. One case of bleeding from the left atria related to the pacemaker electrode wire was found. CONCLUSION: We found no difference in the incidence of AF between patients treated with intravenous metoprolol or the combination of biatrial pacing and oral metoprolol.

Rising incidence of small size papillary thyroid cancers with no change in disease-specific survival in Finnish thyroid cancer patients.

BACKGROUND: The aim of this study was to investigate trends in the incidence, diagnostics, treatment and survival of thyroid cancer in Tampere University Hospital (TAUH) region in recent decades. MATERIAL AND METHODS: New thyroid cancer cases from 1981 to 2002 were ascertained from the Finnish Cancer Registry. Follow-up data was collected from medical records of TAUH. Differentiated thyroid cancer (DTC; consisting of papillary thyroid cancer (PTC) and follicular thyroid cancer (FTC)) patients' data was analyzed and divided into two equal time periods (1981-1991 and 1992-2002). RESULTS: The total amount of thyroid cancer cases was 553, of which 427 (77%) were papillary and 72 (13%) follicular. Thyroid cancer was four times more common in females than in males and the median age at the time of diagnosis was 52 years. The incidence of DTC was 4.5/100,000 in the earlier group and 6.0/100,000 in the later group (IRR 1.33, CI 1.11-1.60). The proportion of papillary thyroid cancer rose from 81% to 89% (p=0.02) in two study periods. Median tumour size became smaller, from 25 mm to 15 mm (p<0.001). Surgery became more radical as total thyroidectomies were performed almost exclusively on the later group (p<0.001). Median cumulative dose of radioiodine (I131) therapy was higher in the later group (p=0.04). There was no difference in number of cancer recurrences (p=0.54). The prognosis of DTC was good; 10-year disease-specific survival was 92% in the earlier group and 94% in the later group (p=0.43). CONCLUSIONS: The incidence of thyroid cancer has risen and proportion of papillary cancer has increased, however, median size of tumour has decreased. No difference was seen in either all-cause or disease-specific survival.

Impact of coronary artery bypass surgery on ischemic mitral regurgitation.

INTRODUCTION: To determine the course of ischemic mitral regurgitation (IMR) after coronary artery bypass grafting (CABG), and evaluate preoperative factors which predict the development of the severity of IMR after CABG. METHODS: Between 1992-2005, 1995 patients underwent CABG and 170 of them had IMR. Data of 131 patients were retrospectively analyzed and living patients (n = 112) had a clinical follow-up visit. The mean follow-up time was 6.5 years. RESULTS: At the time of CABG, 66% of the 131 cases analyzed had mild, 31% had moderate, and 3% had severe IMR. At the time of follow-up, 52% of patients had either no IMR or mild IMR, 27% had moderate IMR, 6% had severe IMR and 15% suffered from cardiac related death. During follow-up IMR grade reduced in 25% of study patients. None of the patient had re-operation due to the mitral regurgitation. Multivariate analysis showed that left ventricular ejection fraction (LVEF) was an independent predictor of good prognosis (O.R. 1.4, 95% C.I. 1.15-1.83/ 10% increase of LVEF, p = 0.02). CONCLUSION: Half of the patients, who have IMR at the time of CABG, have no IMR or only mild IMR postoperatively. Good LVEF adds to the probability that CABG only can reduce IMR.

Randomized clinical trial of tissue glue versus absorbable sutures for mesh fixation in local anaesthetic Lichtenstein hernia repair.

BACKGROUND: Chronic pain may be a long-term problem related to mesh fixation and operative trauma after Lichtenstein hernioplasty. The aim of this study was to compare the feasibility and safety of tissue cyanoacrylate glue versus absorbable sutures for mesh fixation in Lichtenstein hernioplasty. METHODS: Lichtenstein hernioplasty was performed under local anaesthesia as a day-case operation in one of three hospitals. The patients were randomized to receive either absorbable polyglycolic acid 3/0 sutures (Dexon(®); 151 hernias) or 1 ml butyl-2-cyanoacrylate tissue glue (Glubran(®); 151 hernias) for fixation of lightweight mesh (Optilene(®)). Wound complications, pain, discomfort and recurrence were identified at 1 and 7 days, 1 month and 1 year after surgery. RESULTS: A total of 302 patients were included in the study. The mean(s.d.) duration of operation was 34(12) min in the glue group and 36(13) min in the suture group (P = 0·113). The need for analgesics was similar during the first 24 h after surgery. Five wound infections (3·4 per cent) were detected in the glue group and two (1·4 per cent) in the suture group (P = 0·448). The recurrence rate at 1 year was 1·4 per cent in each group (P = 1·000). The rates of foreign body sensation, acute and chronic pain were similar in the two groups. Logistic regression analysis showed that the type of mesh fixation did not predict chronic pain 1 year after surgery. CONCLUSION: Mesh fixation without sutures in Lichtenstein hernioplasty was feasible without compromising postoperative outcome. REGISTRATION NUMBER: NCT00659542 (http://www.clinicaltrials.gov).

Surgical wound infections after vascular surgery: prospective multicenter observational study.

BACKGROUND AND AIMS: this multicenter prospective observational study defined the incidence and risk factors of surgical wound infections (SWI) after infrarenal aortic and lower limb vascular surgery procedures and evaluated the severity and costs of these infections. METHODS: the study cohort comprised of 184 consecutive patients. Postoperative complications were recorded. The additional costs attributable to SWI were calculated. RESULTS: Eighty-four (46%) patients had critical ischaemia, 81 (45%) patients underwent infrainguinal bypass surgery and 64 (35%) received vascular prosthesis or prosthetic patch. Forty-nine (27%) patients developed SWI. Staphylococcus aureus was the leading pathogen cultured from the wound. Forty-seven of the 49 infected wounds responded to and healed with the treatment. SWI was the cause of one major amputation. Independent predictors for SWI were infrainguinal surgery (OR 7.2, 95% Cl 2.92-17.65, p < 0.001), obesity (OR 6.1, 95% Cl 2.44-15.16, p < 0.001) and arteriography injection site within the operative area (OR 2.5, 95% Cl 1.13-5.48, p = 0.02). The average cost attributable to SWI was 3320 Ä. CONCLUSION: the incidence of SWI after vascular surgery is high. The risk factors for SWI are infrainguinal surgery, obesity and arteriography injection site within the operative area. SWI increases morbidity and costs of operative treatment.

Long-term follow-up of a randomized clinical trial of open versus laparoscopic appendicectomy.

BACKGROUND: The aim of this study was to assess long-term outcome following open versus laparoscopic appendicectomy. METHODS: A total of 105 patients with suspected acute appendicitis were randomized to LA (51) or OA (54) between 1997 and 1999 at one hospital. Perioperative factors and follow-up data from the outpatient clinic were recorded. Information about symptoms and overall satisfaction was obtained by telephone interview. In addition, appendicectomy data for 2008 were analysed retrospectively for comparison in a contemporary setting. RESULTS: Data from 52 patients who had OA and 47 who had LA were analysed. OA was performed mostly by trainees, but LA was more likely to be undertaken by a consultant. The open procedure was quicker than the laparoscopic operation in the trial period (median 38 versus 65 min respectively; P < 0.001), but the difference was only 10 min in 2008. The OA group returned to work later than the LA group (median 13 versus 8 days; P = 0.013) and had more complications (22 versus 6; P = 0.014). Only one patient (OA) had a reoperation, owing to abdominal adhesions. Among 76 patients available for telephone interview, satisfaction scores were marginally higher for LA than OA. CONCLUSION: LA has some advantages compared with an open approach. REGISTRATION NUMBER: NCT00908804 (http://www.clinicaltrials.gov).

Vacuum Rabi splitting and strong-coupling dynamics for surface-plasmon polaritons and rhodamine 6G molecules.

We report on strong coupling between surface-plasmon polaritons (SPP) and Rhodamine 6G (R6G) molecules, with double vacuum Rabi splitting energies up to 230 and 110 meV. In addition, we demonstrate the emission of all three energy branches of the strongly coupled SPP-exciton hybrid system, revealing features of system dynamics that are not visible in conventional reflectometry. Finally, in analogy to tunable-Q microcavities, we show that the Rabi splitting can be controlled by adjusting the interaction time between waveguided SPPs and R6G deposited on top of the waveguide. The interaction time can be controlled with sub-fs precision by adjusting the length of the R6G area with standard lithography methods.

Antegrade flow and peripheral resistance determine the level of endogenous arteriogenesis in patients with superficial femoral artery occlusion.

OBJECTIVES: Occlusion in a limb artery leads to impaired blood supply and ischaemia. Collateral artery growth (arteriogenesis) is one of the most effective natural response mechanisms to compensate this pathologic situation. However, it is unknown if clinically important features, like poor run-off, have an impact on compensatory vessel growth. METHODS: Study population of this retrospective study consisted of 70 patients who suffered from lower limb ischaemia and underwent bypass surgery because of an occlusion of the superficial femoral artery. Clinical data were collected and pre- and postoperative angiograms were reviewed. Number of collateral vessels bypassing the occluded segment was counted. Features of inflow and outflow vessels were recorded. RESULTS: The mean number of collaterals was 13 + or - 0.5 per patient. In univariate analysis, short daily walking distance, chronic critical leg ischaemia, low ankle brachial index, low number of patent calf arteries and stenosed inflow arteries predicted low number of collateral arteries. In the multivariate analysis, only the quality of inflow and the number of patent calf vessels demonstrated an independent association (P < 0.05) with the number of collaterals. CONCLUSIONS: Ankle-brachial index, grade of symptoms and daily walking capacity could be used to predict collateral density. Importantly, a good antegrade flow and peripheral runoff seem to have a significant effect on collateral density, implying an impact on the activation of arteriogenesis.

Analysis of multiple casualty incidents - a prospective cohort study.

BACKGROUND: Our aim was to report the rate and causes for multiple casualty incidents (MCI) to analyse the prehospital part of responding to MCIs, report mortality and find areas for improvement. METHODS: A prospective cohort study conducted in an urban emergency medical service (EMS) between 1.3.1998 and 28.2.2004. RESULTS: Fifty-nine MCIs involving 263 patients (167 walking, 96 non-walking) occurred. The incidence of MCIs was 1.8/100,000 inhabitants year(-1). Traffic accidents were the most common cause followed by residential fires, intoxications and stabbings or shootings. Early MCI alarm by the dispatching centre was performed in 18 MCIs. Deviations from standard emergency medical care occurred in 12% of patients. Lack of immobilization of the neck or back in trauma patients and lack of administration of 100% oxygen in suspected carbon monoxide intoxication were the most common deviations. Deviations were related to the lack of presence of on-scene medical command (P = 0.0013) and inadequate resources (P = 0.0342). One hundred and ninety-two patients were transported to emergency departments. Mortality during the prehospital phase was 4.9% (13/263) and during the next 28 days 2.3% (6/263). Adequate resources for safe and effective management of a MCI were related to an early MCI alarm by the dispatching centre (P = 0,022) and to the presence of on-scene medical command (P < 0,001). CONCLUSIONS: Traffic accidents, residential fires and intoxications were the leading causes for MCIs. Emergency medical service could respond to most MCIs efficiently and safely. Majority of deviations from standard medical care seemed potentially preventable. Several areas for improvement were identified. From prehospital links, the dispatching centre and on-scene medical command had a vital role in the successful management of MCIs.

Prediction of atrial fibrillation after coronary artery bypass grafting by measuring atrial peptide levels and preoperative atrial dimensions.

OBJECTIVE: We prospectively tested the hypothesis that atrial enlargement and increased level of atrial natriuretic peptide, N-terminal atrial natriuretic peptide and brain natriuretic peptide would predict atrial fibrillation after coronary artery bypass grafting. METHODS: Eighty-eight elective coronary artery bypass grafting patients had preoperative echocardiographic assessment. The level of atrial natriuretic peptide, N-terminal atrial natriuretic peptide and brain natriuretic peptide were measured preoperatively. Patients were ECG- monitored during the whole hospital stay. RESULTS: Thirty one (35.2%) patients had postoperative atrial fibrillation. In univariate analysis increased age (P=0.003), enlargement of left and right atria (P=0.002 and P=0.004, respectively) and increased level of preoperative atrial natriuretic peptide and N-terminal atrial natriuretic peptide (P=0.016 and P=0.03, respectively) were associated with postoperative atrial fibrillation. There was correlation between the age and level of N-terminal atrial natriuretic peptide (r=0.45 and P<0.001). In multivariate analysis only age and the left atrial enlargement were independent predictors of postoperative atrial fibrillation (P=0.02 and P=0.01). CONCLUSION: Left atrial enlargement was independent predictor for postoperative atrial fibrillation. However, atrial peptides were associated with age and did not independently predict postoperative atrial fibrillation. In addition, the wide variation of the peptide levels renders the implementation of this measure in clinical practice superfluous.