Diagnostic yield and cost analysis of electrocardiographic screening in Swiss paediatric athletes.

OBJECTIVES: Athletes performing sports on high level are at increased risk for sudden cardiac death. This includes paediatric athletes, even though data on screening strategies in this age group remain scarce. This study aimed to assess electrocardiogram interpretation criteria in paediatric athletes and to evaluate the cost of screening. METHODS: National, multicentre, retrospective, observational study on 891 athletes of paediatric age (<18 years) evaluated by history, physical examination and 12-lead electrocardiogram. The primary outcome measure was abnormal electrocardiogram findings according to the International Recommendations for Electrographic Interpretation in Athletes. The secondary outcome measure was cost of screening. RESULTS: 19 athletes (2.1%) presented abnormal electrocardiogram findings requiring further investigations, mainly abnormal T-wave inversion. These 19 athletes were predominantly males, performing endurance sports with a mean volume of 10 weekly hours for a mean duration of 6 years of training. Further investigations did not identify any relevant pathology. All athletes were cleared for competition with regular follow-up. Total costs of the screening were 108,860 USD (122 USD per athlete). CONCLUSIONS: Our study using the International Recommendations for Electrographic Interpretation in Athletes identified a low count of abnormal findings in paediatric athletes, yet raising substantially the cost of screening. Hence, the utility of electrocardiogram-inclusive screening of paediatric athletes remains to be elucidated by longitudinal data.

Probabilistic assessment of spatial heterogeneity of natural background concentrations in large-scale groundwater bodies through Functional Geostatistics.

We propose and exemplify a framework to assess Natural Background Levels (NBLs) of target chemical species in large-scale groundwater bodies based on the context of Object Oriented Spatial Statistics. The approach enables one to fully exploit the richness of the information content embedded in the probability density function (PDF) of the variables of interest, as estimated from historical records of chemical observations. As such, the population of the entire distribution functions of NBL concentrations monitored across a network of monitoring boreholes across a given aquifer is considered as the object of the spatial analysis. Our approach starkly differs from previous studies which are mainly focused on the estimation of NBLs on the basis of the median or selected quantiles of chemical concentrations, thus resulting in information loss and limitations related to the need to invoke parametric assumptions to obtain further summary statistics in addition to those considered for the spatial analysis. Our work enables one to (i) assess spatial dependencies among observed PDFs of natural background concentrations, (ii) provide spatially distributed kriging predictions of NBLs, as well as (iii) yield a robust quantification of the ensuing uncertainty and probability of exceeding given threshold concentration values via stochastic simulation. We illustrate the approach by considering the (probabilistic) characterization of spatially variable NBLs of ammonium and arsenic detected at a monitoring network across a large scale confined groundwater body in Northern Italy.

Inter-observer agreement in athletes ECG interpretation using the recent international recommendations for ECG interpretation in athletes among observers with different levels of expertise.

INTRODUCTION: International criteria for the interpretation of the athlete's electrocardiogram (ECG) have been proposed. We aimed to evaluate the inter-observer agreement among observers with different levels of expertise. METHODS: Consecutive ECGs of Swiss elite athletes (≥14 years), recorded during routine pre-participation screening between 2013 and 2016 at the Swiss Federal Institute of Sports were analysed. A medical student (A), a cardiology fellow (B) and an electrophysiologist (C) interpreted the ECG's independently according to the most recent criteria. The frequencies and percentages for each observer were calculated. An inter-observer reliability analysis using Cohen Kappa (κ) statistics was used to determine consistency among observers. RESULTS: A total of 287 ECGs (64.1% males) were analysed. Mean age of the athletes was 20.4±4.9 years. The prevalence of abnormal ECG findings was 1.4%. Both, normal and borderline findings in athletes showed moderate to good agreement between all observers. κ scores for abnormal findings resulted in excellent agreement (κ 0.855 in observer A vs C and B vs C to κ 1.000 in observer A vs B). Overall agreement ranged from moderate (κ 0.539; 0.419-0.685 95% CI) between observer B vs C to good agreement (κ 0.720; 0.681-0.821 95% CI) between observer A vs B. CONCLUSIONS: Our cohort of elite athletes had a low prevalence of abnormal ECGs. Agreement in abnormal ECG findings with the use of the recently published International recommendations for ECG interpretation in athletes among observers with different levels of expertise was excellent. ECG interpretation resulted in moderate to good overall agreement.

Telemedicine for cardiac surgery candidates.

BACKGROUND: Cardiac surgery is generally well or over-represented in many Western countries. Since the southern part of Switzerland relies on 300 km distance centers for cardiac surgery, we started a project of telemedicine for the distant evaluation of cardiac surgery candidates. We report our experience of the results of the diagnosis made by telemedicine and by direct scrutiny of coronary angiograms. METHODS: Coronary angiography was performed at the distant hospital by an invasive cardiology team. Teletransmission of images was performed using three Integrated Service Digital Network (ISDN) lines by direct transmission of recent recording. A total of 98 cases were reviewed (87 aorto-coronary bypass candidates, seven valvular and four congenital heart disease). We further performed a prospective blinded comparison of 47 consecutive cases with severe coronary artery disease (CAD) with respect to localization and number of significant coronary lesions, obtained by direct scrutiny of the original angiograms and the evaluation obtained with the teletransmitted images. RESULTS: In 89 cases of the 98 analyzed (91%) correct diagnosis and surgical approach could be established by distant transmission. In nine cases (9%, all aortocoronary bypass candidates) definitive diagnosis and treatment was feasible only by direct scrutiny of the original angiograms. Five critically ill patients were urgently referred to the surgical care center based on the correct distant diagnosis. The blinded comparison of distant diagnosis and direct scrutiny of angiograms in defining 1-2-3 vessel CAD was good: r=0.87, P<0.01. CONCLUSION: Initial experience using non-sophisticated telemedical transmission of angiograms of cardiac surgery candidates seems to be a promising facility for distantly located centers.

The high-dose sequential (Milan) chemotherapy/PBSC transplantation regimen for patients with lymphoma is not cardiotoxic.

BACKGROUND: The high-dose sequential (HDS) regimen developed in Milan for high-grade lymphomas is very active, but its toxicities are still partly unknown. We evaluated prospectively by doppler-echocardiography the cardiotoxicity of this treatment. PATIENTS AND METHODS: Over seven weeks, 20 patients received a sequence of cyclophosphamide, methotrexate, etoposide, mitoxantrone and melphalan, each at its maximum tolerable dose, and the latter in conjunction with autologous peripheral stem-cell transplantation. Echocardiography was performed at baseline, before administration of mitoxantrone and 2, 6 and 12 months after transplantation. The following parameters of the left ventricular systolic and diastolic functions were determined: end diastolic (LVD) and end systolic (LVS) dimensions, the ejection fraction (EF), and the Doppler derived diastolic parameters: peak velocity of the early (E) and late (A) transmitral flow, the E:A ratio, deceleration time of the E wave (DT) and isovolumetric relaxation time (IVRT). A group of 20 normal volunteers served as control. RESULTS: At baseline, in comparison to controls, the patients had altered diastolic function (diminished E:A ratio) and, although still within the normal range, a slightly reduced systolic function (EF). During treatment or in the course of follow-up none of the patients showed clinical signs or symptoms of cardiac failure, nor significant changes of systolic or diastolic parameters, apart from a transient increase in the E:A ratio after the first three chemotherapy cycles (from 1.14 to 1.37, P < 0.05). The EF remained constant during, and up to six months after, transplantation, decreasing only slightly after one year (from 62% to 59%, P < 0.05). Using analysis of covariance we showed that the major determinants of baseline cardiac function and of its evolution over time were patient age and gender, with previous treatment with anthracyclines having a minor role. CONCLUSIONS: The HDS chemotherapy regimen produced no significant sign of cardiotoxicity up to one year after transplantation in patients with normal baseline cardiac function and no history of cardiac disease, pretreated with up to 550 mg/m2 of doxorubicin.

Serious interaction between mibefradil and tacrolimus.

BACKGROUND/AIMS: Tacrolimus is metabolized by cytochrome P450 3A4 and 2D6 and has a narrow therapeutic range. We report a serious kinetic interaction between tacrolimus and mibefradil, a potent cytochrome P450 inhibitor. CASE REPORT: A 62-year-old women who had undergone liver transplantation was treated with tacrolimus for immunosuppression. For control of blood pressure, the patient was treated with nifedipine. She developed ankle edema, and nifedipine was replaced by mibefradil. Four days later, she presented with mental confusion, renal failure, and hyperglycemia, compatible with tacrolimus toxicity. In agreement with this assumption, the tacrolimus blood concentration was 100 ng/ml. Mibefradil and tacrolimus were both stopped, and the patient recovered within 1 week. Eight days after stopping mibefradil, tacrolimus was restarted at the same dosage and the subsequent plasma concentrations remained in the therapeutic range. CONCLUSIONS: Mibefradil increases the tacrolimus blood concentration by inhibiting its metabolism and should, therefore, not be used in patients treated with tacrolimus.

Randomised comparison of Micro Stent I with Palmaz-Schatz stent placement for the elective treatment of short coronary stenoses.

This randomised trial compared the Micro Stent I and the Palmaz-Schatz stent for the elective treatment of short (<8 mm long), new-onset coronary stenoses. The primary endpoints were restenosis rate and minimal luminal diameter at 6 mo angiographic follow-up. The secondary endpoints were angiographic and procedural success of stenting and a composite clinical endpoint at 6 mo (death, myocardial infarction, and target site revascularisation). A total of 93 patients were randomised. Clinical and angiographic characteristics of the two groups were comparable. Angiographic success of stenting was 96% in both groups, and there were no complications so that the procedural success was also 96% in both groups. The restenosis rate was 29% for Micro Stent I and 27% for the Palmaz-Schatz stent (P = NS). The minimal luminal diameter at 6 mo was 1.75 +/- 0.72 mm in the Micro Stent I group and 1.84 +/- 0.59 in the Palmaz-Schatz group (P = NS). At 6 mo, a clinical endpoint was reached by 21% of the patients in the Micro Stent I group and by 11% in the Palmaz-Schatz group (P = NS). In conclusion, the elective treatment of short coronary stenosis with the Micro Stent I or the Palmaz-Schatz stent resulted in similar early and late outcomes. In particular, the late angiographic results were very similar.

[Immediate and mid-term clinical and angiographic results after implantation of AVE intracoronary micro-stents in 140 consecutive cases. An experience in Lausanne]. / Résultats cliniques et angiographiques immédiats et à moyen terme après l'implantation de microprothèses endocoronaires AVE chez 140 patients consécutifs. Expérience lausannoise.

Two hundred AVE (Arterial Vascular Engineering) microstents measuring 4 to 30 mm were implanted in 140 patients aged 62 +/- 10 years with Class II to IV angina of the Canadian Cardiovascular Society Classification. The indications were: de novo lesions (30%), suboptimal angioplasty results (54%), acute occlusion (8%) or restenosis (8%). The stents of 3.0 to 4.0 mm diameter were implanted in the left main coronary artery (1%) the left anterior descending artery (20%), the left circumflex artery (19%), the right coronary artery (44%) or a venous bypass graft (7%) after intravenous injection of 15,000 IU of heparin. Daily treatment with aspirin 100 mg and ticlopidine 500 mg was instituted from the day of the procedure. The success rate was 98.5% with only 3 technical failures. The minimal luminal diameter and percentage stenosis ranged from 0.80 +/- 0.2 mm and 74 +/- 13% before to 2.66 +/- 0.38 mm and 15 +/- 7% after the procedure in vessels with an average reference diameter of 3.05 +/- 0.35 mm. There were 3% of stent-related immediate clinical complications. In February 1996, 97 patients had survived 6 months. With a 97% follow-up rate, the clinical event rate was 18%. The angiographic follow-up rate was 70% and the restenosis rate was 27%. The authors conclude that the AVE microstents are easy to implant and provide excellent immediate angiographic results with a low complication rate.

[Lausanne experience in radiofrequency percutaneous ablation of the slow pathway in nodal tachycardia]. / Expérience lausannoise de l'ablation percutanée par radiofréquence de la voie lente de la tachycardie nodale.

Atrioventricular nodal reentrant tachycardia (AVNRT) is the most frequent paroxysmal supraventricular tachycardia and results from reentry in the atrioventricular nodal region via slow and fast pathways. The curative treatment of choice consists of selective radio-frequency catheter ablation of the slow pathway. In this retrospective study we report our experience of 73 consecutive patients suffering from AVNRT treated by selective slow pathway ablation and also review some features of AVNRT. AVNRT appeared for the first time at the age of 29 +/- 15 years and lasted for 17 +/- 13 years. In 37% of the patients AVNRT recurred at least weekly, 10% presented with syncope and 15% were admitted to hospital more than 5 times. On average, 2.5+/-1.6 drugs were prescribed to 66 of the 73 patients and 83% of them were drug-refractory. Selective slow pathway ablation was successfully performed in 65 patients (89%). The procedure, although effective, was complicated by atrioventricular block in 2 patients (2.7%) and failed in 6 patients. In 5 of them, fast pathway ablation was attempted and was successful in 2 cases, resulted in atrioventricular block in one case and failed in 2 cases. The complications, apart from atrioventricular block necessitating a pacemaker in all cases, were one pulmonary embolism and 2 pneumothorax. The mean follow-up for the 70 patients for whom ablation was effective (with or without atrioventricular block) is 12.7+/-7.3 months. AVNRT relapsed in 5 patients (7%); all of them underwent a second ablation with 4 successes (slow pathway) and one atrioventricular block (fast pathway after failed slow pathway ablation). 11 patients (16%) developed palpitations: in one case they were due to atrial fibrillation and in 10 cases they remained of unknown origin. The palpitations were of short duration and well tolerated, and these patients nevertheless felt an improvement after the ablation. Therefore, at medium term, 62 patients (85%) remained free from symptoms or only slightly symptomatic and without a pacemaker, and 51 of them (70%) remained completely asymptomatic and without a pacemaker. AVNRT can result in considerable morbidity and antiarrhythmic drugs are frequently ineffective. Slow pathway ablation is a safe and effective treatment for AVNRT. In our opinion, if AVNRT or medical treatment diminish the quality of life, ablation is indicated. When AVNRT presents with hemodynamic collapse, ablation is mandatory. Fast pathway ablation after failed slow pathway ablation is associated with a high incidence of atrioventricular block and is targeted only at very symptomatic patients who accept the possibility of definitive pacemaker implantation.

[Permanent junctional reciprocating tachycardia: a little-known clinical entity curable with radiofrequency ablation]. / La tachycardie jonctionnelle réciproque permanente: une entité clinique méconnue, curable par l'ablation par radiofréquence.

We report our experience of 5 patients with the permanent form of junctional reciprocating tachycardia (PJRT), a rare form of supraventricular arrhythmia. PJRT was discovered at a mean age of 31 years (8-60 years) and the mean duration of tachycardia was 13 years (1-40 years). 4 patients had nearly incessant tachycardia and one had paroxysmal attacks. Heart rate varied between 100 and 190 beats/minute and the minimal heart rate was on average 114 beats/minute. Four patients had palpitations, 2 developed tachycardia-induced cardiomyopathy, reversible after control of the arrhythmia, and 4 had asymptomatic episodes of PJRT. ECG showed in all cases a narrow-complex tachycardia with inverted P waves in inferior leads and RP interval greater than PR. All patients presented a posteroseptal accessory pathway. 4 patients received different antiarrhythmic drugs with only partially effective results. Radiofrequency catheter ablation of the accessory pathway was performed in all patients and was successful in 4, who remained free of recurrence after a mean follow-up of 26.5 months (4-37 months). The procedure was partially successful in the 5th patient, who is now asymptomatic under sotalol. Radiofrequency catheter ablation is therefore the treatment of choice of PJRT, a rare arrhythmia which should nevertheless be known in order to treat the patient correctly and avoid progression to cardiac failure, which is not always completely reversible.

[Infectious complications in cardiac transplantation: Lausanne experience]. / Complications infectieuses du transplanté cardiaque: expérience lausannoise.

Infectious complications, a major cause of morbidity and mortality after heart transplantation, were reviewed in 49 heart transplant patients at Lausanne. The follow-up lasted 32 months on average. 43 patients (88%) presented 108 infections (2.20 episodes of infection/patient). 38 severe infections (0.78 episodes/patient) were diagnosed in 27 patients (55%). 2 of the 9 deaths which occurred were due to infection. The viruses, principally of the herpes group, were responsible for 37% of all the infections, and bacteria for 28%. About a third of the viral and bacterial infections were severe. The other documented infections were caused by fungi (13%), which were most often responsible for superficial infections, and rarely by protozoa (5%). Finally, in 17% of infectious episodes, the pathogen could not be identified. Cytomegalovirus was the pathogen the most frequently responsible in severe infections. The highest incidence of infections occurred during the first 2-3 months after transplantation and was reduced considerably after the 6th month. The distribution of different pathogens was related to specific periods after the transplant. Our results confirm that infection is a major complication of heart transplantation. Clinical and prophylactic aspects of some infections are reviewed.