Long-term follow-up after surgery for atrial fibrillation with concomitant open heart surgery. / Langtidsoppfølging etter atrieflimmeroperasjon og samtidig åpen hjertekirurgi.

BACKGROUND: Patients with atrial fibrillation and atrial flutter scheduled to undergo open heart surgery can receive ablation treatment of arrhythmogenic foci during the same intervention. Sinus rhythm is restored in the majority in the short term, but the long-term results are more uncertain. This study, which is part of the international CURE-AF trial, evaluates results after Cox-Maze IV surgery for atrial fibrillation in Norway at six-year follow-up. MATERIAL AND METHOD: Nineteen patients were included in this prospective cohort study. Atrial fibrillation had persisted for 40 months in the group with long-standing persistent atrial fibrillation (n = 12) and 6 months in the group with persistent atrial fibrillation (n = 7). Surgery for atrial fibrillation was performed according to the Cox-Maze IV procedure in the CURE-AF protocol. Follow-up in the first 12 months was strictly according to the CURE-AF protocol, thereafter conducted by the primary health service. RESULTS: Sinus rhythm was restored in 11 patients at the time of discharge and in 14 patients six months postoperatively. After 5-6 years of follow-up, all patients with long-standing persistent atrial fibrillation had experienced recurrence. Two achieved sinus rhythm after electroconversion. Six of the seven in the group with persistent atrial fibrillation had sinus rhythm after 5-6 years. INTERPRETATION: The results were good initially, with restoration of sinus rhythm in more than two thirds of the patients after 6-9 months. Five years later, a high recurrence rate was found in patients with long-standing persistent atrial fibrillation. Several recurrences had not been detected by the public health service or treatment had not been attempted.

Atrioventricular nodal ablation in patients with resynchronization therapy and atrial fibrillation - long term results.

OBJECTIVES: Atrioventricular nodal ablation (AVNA) is recommended for patients (pts) with cardiac resynchronization therapy (CRT) having atrial fibrillation (AF) and incomplete ventricular capture (Class IIa, level B). AVNA reduces mortality and improves the New York Heart Association (NYHA) functional class during intermediate term follow-up. The objectives were to study the long-term outcome regarding quality of life (QoL) and survival of our CRT pts after AVNA. DESIGN: 37 CRT-pts undergoing AVNA due to inadequate biventricular pacing were included in the study. Data were retrospectively obtained from clinical records and through telephone interviews. RESULTS: Twenty pts died during the follow-up period of average 30.6 ± 24 months. After AVNA the ventricular capture improved significantly from 68.4 ± 23% to 98.5 ± 2% (p < 0.001). A significant and sustained improvement of average 0.3 ± 0.5 (p = 0.001) in NYHA functional class was found. Additionally a large percentage of pts discontinued taking rate reducing drugs with potential severe side effects. CONCLUSION: AVNA in CRT pts was safe and effective. The treatment resulted in a sustained improvement in QoL, including long-term improvement in NYHA functional class.

Incidence and clinical predictors of subsequent atrial fibrillation requiring additional ablation after cavotricuspid isthmus ablation for typical atrial flutter.

OBJECTIVES: We sought to investigate the incidence of atrial fibrillation after catheter ablation for typical atrial flutter and to determine the predictors for symptomatic atrial fibrillation that required a further additional dedicated ablation procedure. DESIGN: 127 patients underwent elective cavotricuspid isthmus ablation with the indication of symptomatic, typical atrial flutter. The occurrence of atrial flutter, atrial fibrillation, cerebrovascular events and the need for additional ablation procedures for symptomatic atrial fibrillation was assessed during long-term follow-up. RESULTS: The majority of patients (70%) manifested atrial fibrillation during a follow-up period of 68 ± 24 months, and a significant proportion (42%) underwent one or multiple atrial fibrillation ablation procedures after an average of 26 months from the index procedure. Recurrence of typical atrial flutter was rare. Ten patients (8%) suffered cerebrovascular events. Earlier documentation of atrial fibrillation (OR 3.53), previous use of flecainide (OR 3.33) and left atrial diameter (OR 2.96) independently predicted occurrence of atrial fibrillation during the follow-up. A combination of pre- and intra-procedural documentation of atrial fibrillation (OR 3.81) and previous use of flecainide (OR 2.43) independently predicted additional atrial fibrillation ablation. DISCUSSION: Atrial fibrillation occurred in the majority of patients after ablation for typical atrial flutter and 42% of them required an additional dedicated ablation procedure. Pre- and intraprocedural documentation of atrial fibrillation together with previous use of flecainide independently predicted atrial fibrillation occurrence and a need for additional ablation. Anticoagulation treatment should be continued in high-risk patients in spite of clinical disappearance of atrial flutter.

10-year follow-up after radiofrequency ablation of idiopathic ventricular arrhythmias from right ventricular outflow tract.

BACKGROUND: The aim of this study was to examine the effect of radiofrequency ablation (RFA) of ventricular arrhythmias from right ventricular outflow tract (RVOT) during long-term follow-up. METHODS: A follow-up analysis was conducted using an in-house questionnaire, as well as a qualitative assessment of the patients' medical records. The study population of 34 patients had a previous diagnosis of idiopathic VT or frequent PVCs from the RVOT, and received RFA treatment between 2002 and 2005. RESULTS: The main symptoms prior to RFA were palpitations (82.4%) and dizziness (76.5%). A reduction in symptoms following RFA was reported by 91.2% of patients (p < 0.001). Furthermore, there was a reduced use of antiarrhythmic medication after RFA (p < 0.001). General health perception classified on a scale of 1 (poor) to 4 (excellent), improved from median class 1 to 3 (p < 0.001) during long-term follow-up. The fitness to work increased from median class 3 to class 5 (1 = incapacitated, 5 = full time employment, p = 0.038), while the rate of patients in full time employment increased from 26.5% to 55.9% after RFA (p = 0.02). CONCLUSIONS: A reduction of symptoms and use of antiarrhythmic medication, as well as an improvement in the general health perception and fitness to work after RFA of idiopathic ventricular arrhythmias can be demonstrated at ten-year follow-up.

Effects of ECT in treatment of depression: study protocol for a prospective neuroradiological study of acute and longitudinal effects on brain structure and function.

BACKGROUND: Major depression can be a serious and debilitating condition. For some patients in a treatment resistant depressive episode, electroconvulsive treatment (ECT) is the only treatment that is effective. Although ECT has shown efficacy in randomized controlled trials, the treatment is still controversial and stigmatized. This can in part be attributed to our lack of knowledge of the mechanisms of action. Some reports also suggest potential harmful effects of ECT treatment and memory related side effects have been documented. METHODS/DESIGN: The present study will apply state of the art radiology through advanced magnetic resonance imaging (MRI) techniques to investigate structural and functional brain effects of ECT. As a multi-disciplinary collaboration, imaging findings will be correlated to psychiatric response parameters, neuropsychological functioning as well as neurochemical and genetic biomarkers that can elucidate the underlying mechanisms. The aim is to document both treatment effects and potential harmful effects of ECT. SAMPLE: n = 40 patients in a major depressive episode (bipolar and major depressive disorder). Two control groups with n = 15 in each group: age and gender matched healthy volunteers not receiving ECT and patients undergoing electrical cardioversion (ECV) for atrial fibrillation (AF). Observation time: six months. DISCUSSION: The study will contribute to our understanding of the pathophysiology of major depression as well as mechanisms of action for the most effective treatment for the disorder; ECT.

Effect of flecainide on the extension and localization of complex fractionated electrogram during atrial fibrillation.

AIMS: Complex fractionated electrogram (CFE) ablation in addition to pulmonary vein isolation is an accepted strategy for the treatment of non-paroxysmal atrial fibrillation (AF). We sought to determine the effect of flecainide on the distribution and extension of CFE areas. METHODS: Twenty-three non-paroxysmal AF patients were enrolled in this prospective study. A first CFE map was obtained under baseline conditions by sampling 5 s of continuous recording from the distal electrodes of the ablation catheter. Intravenous flecainide (1 mg/kg) was administered over 10 min and followed by 30-min observation time. A second CFE map was obtained with the same modalities. CFE-mean values, CFE areas, and atrial electrogram amplitude were retrieved from the electro-anatomical mapping system (Ensite NavX). RESULTS: After flecainide administration, CFE-mean values increased (111.5 ± 55.3 vs. 132.3 ± 65.0 ms, p < 0.001) with a decrease of CFE area (32.9%) in all patients. Atrial electrogram amplitude decreased significantly (0.30 ± 0.31 vs. 0.25 ± 0.20 mV, p < 0.001). We observed 80.9% preservation of CFE areas. A CFE mean of 78 ms was the best cutoff for predicting stable CFE areas. CONCLUSIONS: Flecainide reduces the extension of CFE areas while preserving their spatial localization. A CFE-mean value <80 ms may be crucial to define and locate stable CFE areas.

Prospective European survey on atrial fibrillation ablation: clinical characteristics of patients and ablation strategies used in different countries.

BACKGROUND: Atrial fibrillation (AF) ablation is widely adopted. Our aim was to conduct a prospective multicenter survey to verify patients' characteristics, approaches, and technologies adopted across Europe. METHODS AND RESULTS: A total of 35 centers in 12 countries actively participated in the study and 940 patients (median age 60 years) were enrolled. AF was paroxysmal, persistent, and long-lasting persistent in 52.4%, 36%, and 11.6% of patients, respectively; 95.5% of patients were symptomatic and 91.4% were refractory to antiarrhythmic therapy. Redo procedures were performed in 20.9%. Pulmonary vein isolation (PVI) emerged as the cornerstone of ablative therapy and has been performed in 98.7% of procedures, with confirmation of PVI in 92.9% of cases. The ablation of nonparoxysmal AF was not generally limited to isolating the PVs and several adjunctive approaches are adopted, particularly in the case of long-lasting persistent AF. Linear lesions or elimination of complex fractionated atrial electrograms were more frequently added. Circular mapping catheters and imaging techniques were seen to be used in about two-thirds of cases. Radiofrequency energy was delivered through open irrigated catheters in 68% of cases. CONCLUSIONS: European centers are largely following the recommendations of the guidelines and the expert consensus documents for AF ablation. AF ablation is mainly performed in relatively young patients with symptomatic drug refractory AF and no or minimal heart disease. Patients with paroxysmal AF are the most frequently treated with a quite uniform ablative approach across Europe. A less standardized approach was observed in nonparoxysmal AF patients.

Ablation effect indicated by impedance fall is correlated with contact force level during ablation for atrial fibrillation.

INTRODUCTION: Previous studies have validated the use of impedance fall as a measure of the effects of ablation. We investigated whether catheter-to-tissue contact force correlated with impedance fall during atrial fibrillation ablation. METHODS AND RESULTS: A total of 394 ablation points from 35 patients who underwent atrial fibrillation ablation were selected and analyzed in terms of the presence of stable catheter contact in non-ablated areas in the left atrium. A fixed power output (30 W) was applied for 60 seconds. Contact force, impedance fall, and force-direction angle were retrieved and exported for off-line analysis. Qualified points were divided into 5 groups according to the level of contact force (1-5 g, 6-10 g, 11-15 g, 16-20 g, and >20 g). An acute impedance fall was observed in the first 10 seconds followed by a plateau in group I and by a further fall in the other groups. Group V showed a rise in impedance during the last 20 seconds of ablation. Levels of impedance fall at each time point were significantly different among all the groups (P<0.001) except between groups III and IV. There was a significant correlation between contact force and maximum impedance fall (rho = 0.54, P<0.01). Lesions with a force-direction angle of 0-30° had significantly lower contact force and maximum impedance fall than those with angles of 30-60° and 60-135° (P<0.01). CONCLUSIONS: Under stable catheter conditions, contact force correlates with impedance fall during 60 seconds of ablation. Contact force exceeding 5 g produces greater impedance fall, which probably indicates adequate lesion formation. A contact force greater than 20 g may lead to late tissue overheating.

Ventricular arrhythmias originating from the aortomitral continuity: an uncommon variant of left ventricular outflow tract tachycardia.

AIMS: Ventricular arrhythmias arising from the fibrous rings have been demonstrated, but knowledge about the aortomitral continuity (AMC) as a source of the arrhytmias is still limited. The objective is to describe the characteristics of ventricular arrhythmias originating from the AMC in patients without structural heart disease. METHODS AND RESULTS: Ten patients with ventricular tachycardia (VT) and/or premature ventricular contractions, who had been successfully treated by catheter ablation at the AMC beneath the aortic valve, were enrolled. Clinical data and electrocardiographic characteristics were analysed. Three of the 10 patients had previously registered episodes of supraventricular tachycardia and had undergone catheter ablation of atrioventricular nodal reentrant tachycardia (AVNRT). In four patients with anterior AMC location, early R/S wave transition was found in the precordial leads, with equal R and S amplitudes in V2, rS in V1, and R in V3. In six patients whose VT arose from the middle part of the AMC, we demonstrated a special ('rebound') transition pattern, with which equal R and S amplitudes occurred in V2, and high R waves in V1 and V3. In the anterior AMC location, the S/R ratios in leads V1 and V2 were >1 and statistically significantly higher than those located in the middle (V1: 1.59 vs. 0.23, P< 0.001; V2: 1.52 vs. 0.41, P< 0.01). CONCLUSIONS: We report a series of ventricular arrhythmias arising from the AMC with different R/S wave transition patterns in the precordial leads on the electrocardiogram. There may be a relationship between ventricular arrhythmias from AMC and AVNRT.

[Magnetic navigation for ablation of cardiac arrhythmias]. / Magnetstyrt ablasjonsbehandling av hjerterytmeforstyrrelser.

BACKGROUND: The first use of magnetic navigation for radiofrequency ablation of supraventricular tachycardias, was published in 2004. Subsequently, the method has been used for treatment of most types of tachyarrhythmias. This paper provides an overview of the method, with special emphasis on usefulness of a new remote-controlled magnetic navigation system. MATERIAL AND METHODS: The paper is based on our own scientific experience and literature identified through a non-systematic search in PubMed. RESULTS: The magnetic navigation system consists of two external electromagnets (to be placed on opposite sides of the patient), which guide an ablation catheter (with a small magnet at the tip of the catheter) to the target area in the heart. The accuracy of this procedure is higher than that with manual navigation. Personnel can be quickly trained to use remote magnetic navigation, but the procedure itself is time-consuming, particularly for patients with atrial fibrillation. The major advantage is a considerably lower radiation burden to both patient and operator, in some studies more than 50 %, and a corresponding reduction in physical strain on the operator. The incidence of procedure-related complications seems to be lower than that observed with use of manually operated ablation catheters. Work is ongoing to improve magnetic ablation catheters and methods that can simplify mapping procedures and improve efficacy of arrhythmia ablation. The basic cost for installing a complete magnetic navigation laboratory may be three times that of a conventional electrophysiological laboratory. INTERPRETATION: The new magnetic navigation system has proved to be applicable during ablation for a variety of tachyarrhythmias, but is still under development.

Long-term assessment of electrocardiographic and echocardiographic findings in Norwegian elite endurance athletes.

OBJECTIVES: The long-term outcome and clinical significance of athlete's heart has been debated and more longitudinal data are needed. We present a prospective 15 years' follow-up study of ECG and echo findings in elite endurance athletes following the end of their competitive career. METHODS: Clinical evaluation, ECG, ambulatory Holter recording and echocardiography were performed in 30 top-level endurance athletes with a mean age of 24 years with follow-up 15 years later. All had then ended their competitive career, but still performed recreational sports activities. RESULTS: No clinical events were reported. Average resting heart rate was unchanged (53.5 +/- 10 at baseline and 55.4 +/- 11 at follow-up, p = n.s.), complex ventricular arrhythmias did not occur and the number of ventricular premature beats (VPBs) were 0.4 +/- 0.8/h at baseline and 3.8 +/- 10/h at follow-up (p = n.s.). In a subgroup of 4 subjects with >100 VPBs per hour at follow-up left ventricular mass was increased compared to the others (p < 0.03). Furthermore, regression of sino-atrial (SA) and atrioventricular (AV) blocks was shown. There were no cases of atrial flutter or fibrillation. There was a slight reduction in mean left ventricular wall thickness (9.9 +/- 1.2 vs. 9.5 +/- 1.4 mm, p < 0.05) and a highly significant reduction of relative wall thickness (0.38 vs. 0.35, p < 0.001). Left ventricular end-diastolic volume (68 +/- 6 vs. 70 +/- 7 ml ml/m(2), p = n.s.) and left ventricular mass (109 +/- 19 vs. 107 +/- 19 g/m(2), p = n.s.) were unchanged when corrected for body surface area and ejection fraction (EF) increased (60 +/- 7 vs. 67 +/- 6%, p < 0.01). Parameters of left ventricular diastolic function were normal both at baseline and follow-up. CONCLUSIONS: There was no evidence of deleterious cardiac effects of previous top-level endurance athletic activity at 15 years' follow-up.

Spatial relationships between the pulmonary veins and sites of complex fractionated atrial electrograms during atrial fibrillation.

BACKGROUND: Pulmonary vein (PV) isolation is used for the treatment of atrial fibrillation (AF). Complex fractionated atrial electrogram (CFAE) mapping has been introduced to guide AF ablation. However, the spatial relationship between PV and CFAE is not well defined. METHODS AND RESULTS: The study included 21 patients (mean age 57 +/- 11 years, 17 men, 14 paroxysmal, two persistent, and five long-standing persistent AF) referred for PV isolation. Electrograms were sampled for 8 seconds at each site during stable AF (13 induced). High-frequency was defined as <80 ms of CFAE value. The distance between CFAE and the nearest PV ostium was measured. The PV ostia and antra were demarcated by fluoroscopy guidance and endocardial reconstruction. Among 82 PV mapped (left common four, superior 17, inferior 17; right superior 21, inferior 21, middle 2), 52.4% and 25.6% of high-frequency CFAE were located on the anterior and posterior walls, respectively, inside the PV or at the ostium. No high-frequency CFAE was observed in two out of 60 and one out of 20 PV anteriorly, versus seven out of 60 and 11 out of 20 PV (P < 0.001) posteriorly, in paroxysmal and persistent AF, respectively. In the PV with high-frequency CFAE, the mean shortest distances to the PV ostia in paroxysmal versus persistent AF were 2.7 +/- 5.1 versus 7.4 +/- 5.4 mm anteriorly (P < 0.01), and 6.5 +/- 6.4 versus 9.4 +/- 8.4 mm posteriorly (ns). CONCLUSIONS: During PV isolation, extending the ablation lesions by up to 10 mm from the PV ostia might cover most high-frequency CFAE around the PV antra. High-frequency CFAE were more often located in the PV ostia in paroxysmal than in persistent AF.

[Catheter ablation of tachyarrhythmias in children and adolescents]. / Ablasjonsbehandling av takyarytmier hos barn og unge.

BACKGROUND: Catheter ablation has been increasingly applied in children and adolescents with tachyarrhythmias. The aim of this article is to assess the results of ablation therapy of tachycardias in patients below 18 years of age at Haukeland University Hospital. MATERIAL AND METHODS: 141 patients (70 boys and 71 girls, aged 5-17 (13.5 +/- 3.5 ) years with tachyarrhythmias underwent an electrophysiologic study and catheter ablation in the period 1992-2007. RESULTS: Ablation was successfully performed in 138/141 (98%) patients., The procedure was repeated (3 patients twice) until the arrhythmia substrate disappeared in 16 of 138 patients. 81/141 (57%) patients had accessory pathways; 52 (37%) had double atrioventricular nodal pathways, 48 had concealed and 33 patients had overt (classical Wolff-Parkinson-White-syndrome) atrioventricular pathways. 8 (6%) patients had other atrial or ventricular tachyarrhythmias and 4 (3%) had organic heart disease. Use of a 3D mapping system was decisive for success for ablation in patients with complex cardiac diseases. Procedure-related complications were observed in 2/141 (1.4%) patients of whom one had a temporary third degree and one had a permanent first-degree atrioventricular block which did not entail further treatment. CONCLUSION: Catheter ablation of tachycardia in children and adolescents is a safe treatment method with a high success rate and few complications and should be preferred before drug therapy.

Treatment of atrial fibrillation by silencing electrical activity in the posterior inter-pulmonary-vein atrium.

AIMS: The recurrence of atrial fibrillation (AF) after pulmonary vein (PV) isolation is still a challenge. We investigated a new approach to treating AF patients by silencing electrical activity in the posterior inter-pulmonary-vein atrium (PIA). METHODS AND RESULTS: Three ablation steps are required to obtain PIA electrical silence: electrical PV isolation, the creation of two lines of lesions between the two superior and inferior PVs and the abolition of residual electrical signals within the PIA. The endpoint was the electrical silence and the inability to pace in the PIA. The posterior inter-pulmonary-vein atrium silence was obtained in 42 AF patients (56 +/- 9 years, four women). Recurrence of AF and atrial flutter was observed in 14 (33.3%) patients after the first procedure. Freedom from atrial arrhythmias after the second procedure was displayed by 94.4, 85.7, and 60.0% of patients with paroxysmal, persistent, and permanent AF, respectively. The left atrium (LA) volume was larger, and the percentages of the silent area of the LA surface and voltages were lower in patients with AF recurrence than in recurrence-free patients. CONCLUSION: Posterior inter-pulmonary-vein atrium electrical silence can greatly decrease the AF recurrence. The clinical AF recurrence may be related to an enlarged LA, a low percentage of electrically silent area, and low voltage in the LA.

Entrapment and retrieval of a diagnostic electrophysiological catheter in the Chiari network.

The Chiari networks are reticulated fibers of embryological remnant venous valves in the right atrium. In patients with this congenital variation, manipulation of diagnostic catheters can be difficult, and there is a substantial risk of entrapment during electrophysiological studies. We report a case of successful retraction of a diagnostic catheter entangled in the Chiari network with the use of a lead extraction tool during a scheduled atrial fibrillation ablation. Rescheduled cryoablation was performed without complication and provided a good outcome.

Long-term follow-up in patients treated by stent implantation for post-ablation pulmonary vein stenosis.

PURPOSE: Symptomatic severe pulmonary vein stenosis (PVS) after catheter ablation of atrial fibrillation (AF) is a rare but well-recognized complication. Treatment options include pulmonary vein angioplasty with or without drug eluting balloons or angioplasty with stent implantation. The treatment of choice is unclear. In our center, pulmonary vein stenting is the treatment of choice for significantly stenotic veins. We present the long-term clinical outcome of 9 patients treated with stent implantation. METHODS: Between 2001 and 2015, 3048 patients with AF were treated with catheter ablation at our institution, of which 9 developed symptomatic PVS. A total of 11 PVS were treated. Pre-procedural imaging (CT, MR, transesophageal echocardiography, angiography) was performed in all patients. RESULTS: Mean time from ablation to stenting was 18 months. Three patients had recurrent pneumonia and the remaining reduced functional capacity (NYHA 2). All patients were in functional capacity NYHA 1 (p < 0.05) after a mean follow-up of 64 (18-132) months. Three patients still had paroxysmal AF, of which two have undergone repeated ablation. CONCLUSIONS: Symptomatic PVS after AF ablation can be successfully treated by stent implantation with durable results and good clinical outcome. AF ablation is still a feasible option after stent deployment.

[Risk factors for sudden cardiac death related to the long QT syndrome]. / Risikofaktor for brå hjertedød ved lang QT-syndrom.

BACKGROUND: Long QT syndrome is a rare condition. The syndrome is characterised by a prolonged QT-interval corrected for heart rate (QTc). The typical clinical presentation is the occurrence of syncope or cardiac arrest in young and otherwise healthy individuals. Cardiac events can be precipitated by environmental factors and use of certain drugs. The purpose of the present study is to provide guidelines regarding risk factors that may worsen the syndrome, based on available literature. MATERIAL AND METHODS: PubMed was searched for all literature in English from 1966 through 2004 on the Long QT syndrome. The articles and their literature references were examined. Additional information was achieved from experienced colleagues and from some key sites on the internet. RESULTS: The symptoms of the Long QT syndrome are tachycardia, syncope or cardiac arrest, often related to psychological or physical stress in young, usually healthy individuals. The syndrome can be inherited or acquired and is commonly caused by mutations in the potassium channel or by lack of inactivation of the sodium channels. The most common causes of acquired conditions are electrolyte abnormalities, intracranial disease, dietary deficiencies, myocardial infarction, dilated cardiomyopathy, mitral valve prolapse, bradycardia, severe malnutrition among anorexic patients and the use of medication. INTERPRETATION: It is important to have knowledge about the Long QT Syndrome. The treatment is primarily to remove potential risk factors and medically to give beta-blockers or insert pacemakers or cardiac defibrillators.

[Atrioventricular nodal reentry tachycardia in children]. / Atrioventrikulaer nodal takykardi hos barn.

BACKGROUND: Atrioventricular nodal reentry tachycardia is a supraventricular tachycardia with a double nodal pathway between the atria and the ventricles located in the normal AV-node. It may cause a reentry circuit. Atrioventricular nodal reentry tachycardia is one of the most common supraventricular tachycardias in adulthood, but is seldom diagnosed in children--perhaps because of difficulties with diagnosing them. We have studied diagnostic criteria, clinical presentation, incidence, prognosis and treatment in children and adolescents. METHODS: The article is based on the literature found in the databases PubMed and Medline. We used the search words atrioventricular nodal reentry tachycardia, AVNRT, permanent junctional reentry tachycardia, PJRT, supraventricular tachycardia, neonates, infants and children. Articles were also identified by examining the references. RESULTS: Atrioventricular nodal reentry tachycardia is rare during the first years of life, but becomes more frequent with age. There are few studies of this rhythm disturbance in children and reliable data on incidence, prognosis and prognostic variables are limited, especially for untreated cases. There are three main treatment regimens, acute and prophylactic medication and curative treatment with radiofrequency catheter ablation.