A recent, randomised, double-blind, placebo-controlled trial has demonstrated the effectiveness of palivizumab (Synagis®) for prophylaxis against infection by the respiratory syncytial virus in 1,287 young children with congenital cardiac disease. Guidelines for the use of palivizumab in these children considered to be at high risk were published by the American Academy of Pediatrics, followed by similar guidelines from the British Paediatric Cardiac Association, and recommendations from a number of other individual countries, including Canada, Germany, Spain, and France.

In May, 2004, further discussion was held between a group of 15 paediatric cardiologists at a European forum for clinical management held in Munich, Germany. The objective of this forum was to define optimal recommendations on prevention of infection by the respiratory syncytial virus in infants and young children with congenital cardiac disease, appropriate to the clinical needs and style of those practising in paediatrics in individual countries. Participants were invited because of their knowledge of the therapeutic area, and for their experience of using palivizumab for prophylaxis against the respiratory syncytial virus in children with congenitally malformed hearts. Measures to educate the carers of children with such congenital malformations on precautions against infection by the respiratory syncytial virus were discussed, along with the many different aspects of best practice for therapeutic prophylaxis with palivizumab. The most appropriate timing of prophylaxis, recommendations for which children are most likely to benefit from prophylaxis, and suggested protocols were among the issues covered. The recommendations resulting from the discussions are presented in this paper, as a step towards reaching consensus.

During the past decades, different variants of the Fontan circulation have become the primary therapeutic option for physiological correction of congenital cardiac malformations in which restoration to biventricular circulations is impossible. Subsequent to creation of the Fontan circulation, the pulmonary and systemic circulations are in series, with only one pumping chamber. Thus, the functionally single ventricle must provide energy for flow of blood to the lungs, as well as to the body. Generally, patients who have undergone these procedures have a good prognosis, although they have subnormal cardiac output at rest, while their central venous pressure is significantly elevated. Despite an adequate haemodynamic situation at rest, exercise performance is usually reduced. Thus far, this reduction has been attributed to cardiac factors, such as the absence of the morphologically right ventricle, or impaired function of the morphologically left ventricle. Due to the mechanical coupling between the heart and the peripheral circulation, however, the inadequate response to exercise in terms of cardiac output might also be dependant on insufficient peripheral vascular adjustments. In this review, we assess the existing experimental and clinical studies which provide detailed analysis of ventriculo-arterial mechanics in the setting of the Fontan circulation.

Introduction: We sought to establish a modern understanding of the safety and efficacy of trans-catheter pulmonary arterial angioplasty. Methods: A review of records in a sample of 104 dilations, out of a total of 711 procedures undertaken between January, 1996 and December, 2000, provided descriptive information regarding technique, adverse events, and changes achieved in luminal diameter. Because evidence during the review of angiograms suggested substantial differences according to whether the stenotic lesions were positioned proximally or distally within the pulmonary arterial tree, all analyses incorporated this classification. Results: We reviewed stenoses in 203 pulmonary arteries, 38% located proximally and 62% distally, with follow-up available concerning dilation in 92 vessels. Proximal dilations frequently involved a prior surgical site, and appeared more compliant and amenable to conventional angioplasty, as evidenced by more common elimination of the waist, but also more recoil, then requiring placement of stents. In contrast, distal lesions frequently required balloons capable of sustaining high pressures of inflation, and larger balloons relative to the size of the vessels. The proportional increase in diameter was greater for distal sites, at 90 plus or minus 77%, compared to proximal, at 64 plus or minus 70%, p equal to 0.002. Serious adverse events occurred in 3 of 104 procedures, giving a rate of serious adverse events of 2.9%. At follow-up, 9 of 92 vessels (10%), 95% confidence intervals from 5% to 18%, returned to their diameters prior to dilation, with no difference in the rate of restenosis according to the site of dilation. Conclusion: Our findings indicate the need to distinguish, and to consider, the important differences in technical issues and outcomes, when performing dilations at proximal as opposed to distal sites. Although angioplasty is effective therapy for pulmonary arterial stenosis, a subset of vessels, more often distal, remain resistant to conventional techniques.

Background: Paediatric cardiovascular services are frequently absent or poorly developed in many countries around the world. Our foundation made 83 trips in support of cardiovascular services between April 1993 and March 2003 to help alleviate this problem. In this study, we present an analysis of our results over these period of 10 years. Methods: We performed a review of all available records relating to the trips, including patient databases, audited financial statements, donated product inventory lists, lists of team members, and follow-up data from the host sites concerning the state of the patients treated. Results: We made 83 trips to 14 countries, 40 of these being in Central Europe, 5 in Eastern Europe, 10 in Caribbean, and Central America, 18 in South America, 9 in Asia, and 1 in the Middle East. In the first 5 years, we made 23, as opposed to 60 in the second 5 years, this difference being significant (p less than 0.01). The total number of primary operations performed over 10 years was 1,580. The number of procedures performed yearly increased over the two intervals from 97.0 plus or minus 32.7 to 219.0 plus or minus 41.7, p less than 0.002. The probability of survival between the periods increased from 84.6 to 93.3 per cent, and this was also significantly different (p less than 0.001). Overall, the rate of survival for the period of 10 years was 90.5 per cent. Moreover, the value of services donated to support each trip also differed significantly, decreasing from 105,900 dollars plus or minus 14,581 dollars for the first period to 54,617 dollars plus or minus 11,425 dollars for the second period (p less than 0.001). Conclusions: Improving paediatric cardiac services in under-served countries requires significant financial and personnel commitments, but can produce reasonable outcomes.

Objectives: To determine whether the present system of reimbursement, based on diagnosis-related groups and regular financial budgeting, covers the costs incurred during hospitalisation of 7 children undergoing the three stages of the Norwood sequence for surgical treatment of hypoplastic left heart syndrome. Methods: Between January and September 2003, 7 patients underwent initial surgical palliation with the Norwood procedure at the Rikshospitalet University Hospital. A prospective methodology was developed by our group to measure the costs associated with each individual patient. The patients were closely observed, and the relevant data was collected during their stay in hospital. The stay was divided into four different periods of requirements of resources, defined as heavy intensive care, light intensive care, intermediate care, and ordinary care. At each stage, we recorded the number of staff involved and the duration of surgery and other major procedures, as well as the cost of pharmaceuticals and other consumables. Based on these data, we calculated the cost for each patient. These costs were compared with the corresponding revenue received by the hospital for each of the patients. Results: We found the total mean cost for the three stages of the Norwood sequence was 138,934 American dollars, while the corresponding revenue received by the hospital was 43,735 American dollars. During this period, one patient died during the first stage of the Norwood sequence. Conclusions: Our study shows that steps involved in the Norwood sequence are low-volume but high-cost procedures. The reimbursement received by our hospital for the procedures was less than one-third of the recorded costs.

Autonomic nervous control of the heart can be studied by analysing variability in heart rate. Although earlier studies have shown reduced variability in patients with the Fontan circulation, we are not aware of any previous study examining longitudinal changes in such children. We have examined 13 patients who had undergone total cavopulmonary connection, and 37 healthy controls matched for age and gender. The examinations included complete echocardiography, and 24-hour ambulatory electrocardiogram for analysis of the parameters for variability in heart rate. After the Fontan procedure, three follow-up examinations were performed at a mean of 4.4 years, 5.6 and 7.2 years. Reduced variability was found in those with the Fontan circulation. A significant difference was found between patients and their controls with respect to high-frequency power at the second, p equal to 0.05, and third, p equal to 0.03, examination. The ratio of low-to-high-frequency components progressively increased in those with the Fontan circulation, a phenomenon that led to a significant difference, p equal to 0.03, at the third examination. Our study shows that, in patients with the Fontan circulation, routine ambulatory electrocardiographic monitoring including analysis of variability in heart rate, detects over time a progressive sympatovagal imbalance.

The Fontan circuit is characterized by a pulmonary circulation dependent on central venous pressure in the absence of a subpulmonary ventricle. Patients with this circulation usually exhibit a low cardiac output. In addition to their abnormal cardiac state, recent studies have demonstrated impaired cardiac autonomic nervous activity, elevated neurohormonal factors, and impaired endothelial function, findings also encountered in adults with chronic heart failure. One major component of these impairments is the abnormal cardiorespiratory response during exercise. Despite some pathophysiologic similarities to adults with cardiac disease, those with the Fontan circulation usually have a congenitally malformed heart underscoring abnormal haemodynamics, with further compromise from multiple surgical procedures. It differs in many aspects from the situation in the adults with impaired systolic ventricular function in the setting of chronic cardiac failure. In this review, I will focus on the cardiorespiratory response during exercise, seeking to clarify the characteristics in these particular patients with the Fontan circulation.

Objectives: To assess the volume and range of diagnosis in new patients referred to paediatric cardiac outpatient clinics. Methods: Data was collected prospectively, using a proforma completed at all outpatient clinics over a period of three months. Results: There were 526 new referrals, representing an increase of almost one-fifth compared to 5 years ago. Of the referrals, 78 percent came from hospital doctors, and 22 percent from general practitioners, with 221 of those referred being infants. A heart murmur was the most common reason for referral, representing almost two-thirds of cases. In 372 patients referred (71 percent), the heart was discovered to be structurally normal. The proportion of patients with normal hearts referred by general practitioners and hospital doctors were 81 percent, and 68 percent, respectively (p less than 0.004). There was considerable variation in the pattern of referral between doctors working in different hospitals. Conclusion: New referrals to centres dealing with congenital cardiac malformations are increasing alarmingly, with the majority of the children referred having normal hearts. This increase in demand for specialist services has important implications for resources and training.

Background: We sought to determine if the acute gains in pulmonary arterial diameter achieved by using Cutting Balloons to dilate stenoses in small arteries are maintained at follow-up. Methods: A search of our database identified all patients who underwent dilation with Cutting Balloons for pulmonary arterial stenosis between June 2001 and September 2003. We reviewed the procedural and angiographic data obtained at the initial and follow-up procedures. Results: Over the period of study, 29 patients with a median age of 3.7 years, and a range from 0.4 to 46.6, underwent treatment with Cutting Balloons at 41 procedures for one or more pulmonary arterial obstructions resistant to conventional angioplasty. At the initial procedure, we enlarged 79 vessels, with an initial minimal luminal diameter of 1.5 plus or minus 0.8 millimetres, to a diameter of 3.0 plus or minus 1.1 millimetres (p smaller than 0.001). Angiographic data indicated that 49% of the vessels showed evidence of vascular damage not requiring intervention, while stents were placed in 9 vessels. Follow-up angiography was available for 39 of the vessels, evaluated at a median of 6 months, with a range from 3 to 24 months, after the initial procedure. In these vessels, there was a mean loss of 10 plus or minus 25% in luminal diameter, p not significant. Of the 39 vessels, 8 had returned to a diameter within half of the initial diameter, giving a failure rate at follow-up of 21%, with 95% confidence intervals from 9% to 36%. All complications were identified within 24 hours of the catheterization procedure, and there were no late complications or deaths during the period of follow-up. Placement of stents produced both greater increases in diameter at the initial procedure (p smaller than 0.001), and greater losses at follow-up (p equal to 0.01). Conclusions: Despite the frequent identification of intravascular trauma, initial gains in luminal diameter after use of Cutting Balloons to dilate stenotic pulmonary arteries are maintained at follow-up.

Background: Objective assessment of the cardiopulmonary capacity in patients with complex congenital cardiac disease often remains difficult in clinical practice. The cardiopulmonary exercise test and determination of the levels of brain natriuretic peptide in the plasma are established tests, but expensive. The 6-minute walk test is also validated, but has not often been used in patients with heart failure due to congenital heart disease, nor compared with other tests. We sought to compare its value with the results of cardiopulmonary exercise testing and measuring the levels of brain natriuretic peptide in the plasma. Methods: We carried out a standardized 6-minute walk test in 31 patients with complex congenital cardiac disease on the same day that they underwent cardiopulmonary exercise testing and determination of levels of brain natriuretic peptide in the plasma. Of the patients, 7 had functionally univentricular hearts, 9 had transposition, 9 had tetralogy of Fallot, 3 had common arterial trunk, and 3 had pulmonary atresia with intact interventricular septum. Uptakes of oxygen at peak exercise, and at the anaerobic threshold, were determined using cardiopulmonary exercise testing, and classified as suggested by Weber. The 6-minute walk test was performed according to a standard protocol. Results: There was a significant correlation between brain natriuretic peptide, oxygen uptakes at peak exercise and 6-minute walk. The correlation between the 6-minute walk test and oxygen uptakes at the anaerobic threshold, however, was not significant. Conclusions: The 6-minute walk test can be performed easily, is inexpensive, widely available, and correlates well with measurements of brain natriuretic peptide and cardiopulmonary exercise testing, even in patients with corrected or palliated congenital cardiac malformations. A cut-off value of 450 metres in the 6-minute walk test allows a semi-quantitative classification in analogy to the classification suggested by Weber for cardiopulmonary exercise testing, and to a level of brain natriuretic peptide in the plasma of less or more than 100 picograms per millilitre.

Aims: To identify factors predisposing to abnormal left ventricular geometry and mechanics in 52 patients after successful repair of aortic coarctation. Methods and results: We evaluated left ventricular remodelling, systolic midwall mechanics, and isthmic gradient by echo-Doppler, systemic blood pressure at rest/exercise and by ambulatory blood pressure monitoring, and the aortic arch by magnetic resonance imaging. Echocardiographic findings were compared with those of 142 controls. The patients with aortic coarctation showed an increased indexed left ventricular end-diastolic volume, increased mass index, increased ratio of mass to volume and systolic chamber function. The contractility, estimated at midwall level, was increased in 21 percent of the patients. In 26 (50 percent) of the patients, we found abnormal left ventricular geometry, with 9 percent showing concentric remodelling, 33 percent eccentric hypertrophy, and 8 percent concentric hypertrophy. These patients were found to be older, underwent a later surgical repair, and to have higher systolic blood pressures at rest and exercise as well as during ambulatory monitoring. The relative mural thickness and mass index of the left ventricle showed a significant correlation with different variables on uni- and multivariate analysis. Age and diastolic blood pressure at rest are the only factors associated with abnormal left ventricular remodelling. Conclusions: Patients who have undergone a seemingly successful surgical repair of aortic coarctation may have persistently abnormal geometry with a hyperdynamic state of the left ventricle. This is more frequent in older patients, and in those with higher diastolic blood pressures.

Background: We have used the Amplatzer ductal occluder for transcatheter closure of large persistently patent arterial ducts, and used our experience to assess the safety and efficacy of the device in young children and infants. Methods and patients: We used the Amplatzer ductal occluder prospectively in 43 patients with large patent arterial ducts, reviewing our experience to identify any problems or complications. Results: The procedure proved successful in 42 of the patients. We achieved complete occlusion of the duct in 33 (78.5 per cent) of the patients on the day of insertion. In 6 additional patients, complete occlusion occurred 1 week to 6 months after the procedure. Trivial leaks persisted in 2 patients, while one had a significant residual leak. Problems were encountered in 7 patients. The procedure failed in one, a device was wasted in 2, pulled through in 3, while we experienced kinking of the long Mullins sheath, being unable to retrieve the device, in one patient. Minor complications occurred in 6 patients, finding flow at a peak velocity of 2.2 metres per second in the descending aorta in 2 patients, and at 2.5 metres per second in 2 further patients, and flow at 2.5 metres per second in the pulmonary arteries of two patients. One patient experienced a major complication due to excessive bleeding. Out of the 14 patients suffering adverse events, 13 weighed less than 10 kilograms. This rate of problems and complication in these patients weighing less than 10 kilograms was significantly higher than in the patients weighing more than 10 kilograms. Conclusion: Transcatheter occlusion of moderate to large patent arterial ducts with the Amplatzer ductal occluder device is safe and effective, with a high rate of complete occlusion. Problems and minor complications may be encountered in children weighing less than 10 kilograms. If the device is to be deployed completely in the ductal ampulla, and to avoid descending aortic obstruction, the size of the retention flanges of the occluder should not exceed the largest diameter of the patent arterial duct.

After repair of tetralogy of Fallot, many patients present in need of reoperative surgical reconstruction of the right ventricular outflow tract. The predominant physiologic lesion is pulmonary insufficiency, but there may also be varying degrees of obstruction of the right ventricular outflow tract. In the past, it has been felt that patients tolerate pulmonary insufficiency reasonably well. In some patients, however, the long-term effects of pulmonary insufficiency and subsequent right ventricular dilation and dysfunction are associated with poor exercise tolerance and increased incidence of arrhythmias and sudden death.1,2 Numerous studies support replacement of the pulmonary valve as treatment for pulmonary insufficiency in order to improve performance, optimize hemodynamics, and better control arrhythmias.3–10 The indications for reconstruction of the right ventricular outflow tract in this setting, nonetheless, as well as the operative strategy, continue to evolve. There are multiple surgical options for replacement of the pulmonary valve for these patients, including aortic and pulmonary homografts, stented and stentless porcine valves, porcine valved conduits, bovine jugular venous conduits, and even mechanical valves and mechanical valved conduits.11–32 It was a less than ideal experience with these currently available options that stimulated our interest into employing alternative materials and techniques. Favorable experimental and clinical experience with valves made of a polytetrafluoroethylene monoleaflet33–36 encouraged us to consider a new method of reconstruction with this material, using a bifoliate polytetrafluoroethylene valve. In this work, we review our indications for replacement of the pulmonary valve after repair of tetralogy of Fallot, the surgical options available, and our experience reconstructing the right ventricular outflow tract with a new surgically created bifoliate polytetrafluoroethylene valve.

Objective: To examine the current subjective state of health, and the longitudinal course of psychological well-being, in adult patients with congenital cardiac malformations. Methods: Our study concerns the second follow-up of a cohort of patients with congenital cardiac malformations. We examined 362 consecutive patients, aged from 20 to 46 years, who underwent surgical procedures for treatment of congenital cardiac disease between 1968 and 1980, specifically for treatment of atrial and ventricular septal defects, tetralogy of Fallot, transposition, and pulmonary stenosis. The patients were submitted to extensive medical and psychological examination. During psychological examination, in which all patients were seen by the same psychologist (EvR), patients filled in questionnaires concerning their current subjective state of health, using the 36-item Short Form Health Survey (SF-36), and psychological well-being, answering the Heart Patients Psychological Questionnaire. The data we acquired at their first follow-up was used to measure the longitudinal course of psychological well-being over the intervening period of 10 years. Results: When compared to a reference group, the patients assessed their state of health less favourably concerning physical functioning, but more favourable with regard to social functioning, bodily pain, and limitations of role due to emotional problems. Younger female patients reported more limitations of role due to physical functioning than did the female patients who were older. Patients with transposition showed a negative trend for their subjective state of health, but reported the least bodily pain. Within the overall group of patients, displeasure had increased, while social inhibition had decreased, over the intervening period of 10 years. Conclusion: Extra attention should be paid to the subjective experiences of young female patients with congenital cardiac disease. The patients with transposed arterial trunks seem overall to experience poorer physical health.

The ultra-fast, thin-cut computerised tomographic angiogram is an efficient method to diagnose extracardiac lesions associated with congenital cardiac disease. For the purposes of this review, we evaluated various facets of the technique as used in 30 patients who were referred for diagnosis of congenital cardiac disease. The technique had high diagnostic accuracy, with a sensitivity of 93 percent in 15 of these patients referred for either interventional catheterisation or surgery. There were no immediate side-effects associated with the scanning procedure. The scan was also found to be more cost-effective as compared to an alternative noninvasive modality for imaging modality, namely magnetic resonance imaging. The angiographic technique, however, does expose the child to between 2 and 2.5 rems of radiation, despite the short period of scanning, of 10 plus or minus 2 seconds.

Endothelial dysfunction has been reported in hypoxaemic patients with the Eisenmenger syndrome, but a direct correlation between levels of endothelial markers and the severity of hypoxaemia has not been explored. With this in mind, we compared the levels in the plasma of tissue-type plasminogen activator, thrombomodulin, and von Willebrand factor in 25 patients with the Eisenmenger syndrome. They had a median age of 31 years, and were divided into 2 groups according to their recent clinical history. Thus, 18 patients were stable, being in functional class II or III, seen as outpatients, and having peripheral saturations of oxygen of 89 plus or minus 5 percent. In contrast, 7 patients were unstable, showing episodes of symptoms placing them in functional class IV, requiring care in hospital, and manifesting saturations of oxygen of 77 plus or minus 5 percent. We were able to follow 12 patients, 8 who were stable and 4 unstable, for 24 months. At baseline, levels of von Willebrand factor were higher in the unstable patients when compared to those who were stable, at 142 plus or minus 29 and 110 plus or minus 25 units per decilitre, respectively (p equal to 0.013). This correlated positively with oxygen desaturation (p less than 0.020). The structural abnormalities also correlated positively with the magnitude of hypoxaemia (p less than 0.020). Levels remained higher in the unstable patients throughout the period of follow-up (p equal to 0.006). Tissue-type plasminogen activator was also increased, at 14.3 plus or minus 8.4 versus 6.5 plus or minus 2.7 nanograms per millilitre in controls (p less than 0.001), whereas thrombomodulin was decreased, with values of 14.4 versus 34.6 nanograms per millilitre in controls (p for median values of less than 0.001). There was no correlation with saturations of oxygen. We conclude that measurement of von Willebrand factor, as compared with tissue-type plasminogen activator and thrombomodulin, will prove a better marker of endothelial response to hypoxaemia in patients with the Eisenmenger syndrome.

Those patients with functionally univentricular hearts are the ones in which surgical repair so as to produce biventricular circulations is deemed impossible, despite the fact that in most instances there are two ventricles within the ventricular mass. Before the era of the Fontan procedure, the typical course of patients with such functionally univentricular arrangements consisted of cardiac failure and death within the first year of life. Despite the advent of effective palliative therapy, ventricular dysfunction remains a significant clinical problem for these patients.

Background: Congenital cardiac disease is the greatest cause of death in patients with Down's syndrome during the first two years of life, with from two-fifths to two-thirds of those with Down's syndrome also having congenital cardiac malformations. The lesions within the heart can be single or multiple. Our objective was to evaluate the frequency and type of such congenital cardiac malformations in patients born with Down's in Guatemala, and to provide baseline information for further research. Methods: We reviewed all patients with Down's syndrome who underwent a cardiologic screening examination between January, 1997, and December, 2003, in the only department dealing with Paediatric Cardiology in Guatemala. Results: Of the 349 patients reviewed, 189 (54.1 per cent) also had an associated congenital cardiac malformation. The median age at diagnosis was 6 months, with a range from 2 to 13 months. In 152 patients (80.4 per cent), the cardiac lesion was isolated, while 37 patients (19.6 per cent) had multiple defects. The most common single defect was patency of the arterial duct, found in 54 of the 189 patients (28.6 per cent), followed by ventricular septal defect in 27.5 per cent, atrial septal defect in 12.7 per cent, and atrioventricular septal defect with common atrioventricular junction in 9.5 per cent. The most frequent concomitant malformation found co-existing with other congenital cardiac lesions was patency of the arterial duct, found in 17.5 per cent. Conclusions: As far as we are aware, ours is the first epidemiologic study concerning the frequency and type of congenital cardiac disease found in Guatemalan children with Down's syndrome. The high frequency of patency of the arterial duct, and the differential distribution of the cardiac malformations associated with Down's syndrome among Guatemalan children, differ from what has been reported in the United States of America, Europe, and Asia. This difference warrants further research.

My role in the debate between myself and Bill Gaynor is to substantiate the notion that severe pulmonary valvar insufficiency should be treated in aggressive fashion. This gives me few problems. At Children's Memorial Hospital in Chicago, we have a long tradition of favouring early insertion of new pulmonary valves in patients with significant pulmonary valvar insufficiency following repair of tetralogy of Fallot. Our results with this strategy in the current era were first presented in 1986 at the Western Thoracic Surgical Association.1 At that time, we had inserted pulmonary valves late following repair of tetralogy of Fallot in 42 patients. We postulated that early control of pulmonary insufficiency may prevent long-term deterioration in right ventricular function. The fact that this is a controversial issue became immediately apparent during the discussion of our presentation. Dr. Frank Spencer, from New York, stated “I would completely disagree with the concept of electively inserting a porcine valve in a child on the basis of haemodynamic data. I fear that the approach recommended in this presentation is probably treating one disease by creating a worse one.”

We describe the electrophysiological studies undertaken in four patients with atrioventricular nodal reentry tachycardia in the setting of concordant atrioventricular and discordant ventriculo-arterial connections (transposition). Radiofrequency ablation was attempted in three, all with success. Clear evidence of dual antegrade pathways through the atrioventricular node was present in only one of the four, but other characteristics of discrete fast and slow pathways into the atrioventricular node were present in all. Atrioventricular nodal reentry tachycardia was inducible in all. In the three patients in whom ablation was attempted, the application of radiofrequency energy to the low medial regions of the systemic venous atrium (morphologically left) consistently caused junctional accelerated rhythm, but these lesions were not successful in eliminating the tachycardia. Successful radiofrequency ablation required a retrograde approach to the region of the slow pathway in the pulmonary venous atrium (morphologically right).