Creation and enlargement of atrial defects in congenital heart disease.

Transcatheter creation and enlargement of interatrial defects (IAD) may improve hemodynamics; however, procedural outcomes have not been well defined. Hospital records were reviewed for children who underwent percutaneous procedures to create and enlarge an IAD and were grouped as follows: (1) right and (2) left heart obstructive lesions, (3) left atrial (LA) decompression during left heart assist, (4) failing Fontan circulation, and (5) miscellaneous. Forty-five children (mean age, 3.4 +/- 4.7 years; 30 (67%) male) were identified. In group 1 (n = 6), all achieved endpoints of right atrial (RA) decompression (n = 2), improved left ventricular filling (n = 3), or improved arterial saturations (n = 1). In group 2 (n = 18), mean LA pressure decreased (21 +/- 6 to 13 +/- 5 mmHg, p < 0.001) and arterial saturations increased (61 +/- 13% to 78 +/- 11%, p < 0.001). All except 2 patients achieved definitive repair, further palliation (n = 9), or heart transplantation (HTX) (n = 7). In group 3 (n = 5), the LA was decompressed (21 to 13 mmHg, p = 0.03) in all, and all except 1 patient survived to HTX (n = 2) or full recovery (n = 2). In group 4 (n = 11), of 7 patients with a low cardiac output syndrome after surgery, despite improved atrial shunting, 3 died and 1 required a HTX. In group 5 (n = 5), RA decompression (n = 1) or improved arterial saturation (n = 4) was achieved in all. Overall, 5-year HTX free survival was 75%. Mechanical ventilation before the procedure (p < 0.001), the need for a blade septostomy (p = 0.002), and higher LA pressures after the procedure (p = 0.04) independently predicted mortality or the requirement for HTX. Transcatheter optimization of an atrial communication can help optimize treatment strategies and has a low procedural risk.

[Long-term follow-up of patients with congenital heart defects]. / Langsiktig oppfølging av pasienter med medfødte hjertefeil.

There are about 500 new cases of congenital heart disease per year in Norway. Modern diagnostic skills, surgical techniques and follow-up programs have contributed to higher survival rates among patients. Based on international experience, 85-90 per cent of these children will survive into adulthood. Half will suffer from conditions which should be followed up by cardiologists. This article is based upon recommendations on long-term follow-up of patients with congenital heart disease.

Early age at repair prevents restrictive right ventricular (RV) physiology after surgery for tetralogy of Fallot (TOF): diastolic RV function after TOF repair in infancy.

OBJECTIVES: To assess diastolic right ventricular (RV) physiology after tetralogy of Fallot repair in infancy. BACKGROUND: Restrictive RV physiology after tetralogy of Fallot repair is related to type of repair, pulmonary regurgitation, and late arrhythmias. METHODS: Forty-seven patients were investigated, 27 and 20 patients in Lund and London, respectively. Median age at repair was 0.78 years (0.08-0.99) and median follow-up was 3.0 years (0.08-10.4). Restrictive RV physiology was assessed by Doppler echocardiography. RESULTS: Thirteen patients (28%) had restrictive RV physiology at follow-up, three of 19 patients (16%) with transatrial repair and 10 of 28 patients (32%) with transventricular repair, respectively (p=0.1). Ten percent of the patients repaired before 6 months of age were restrictive at follow-up, increasing to 38% with repair after 9 months. Transannular patch (TAP) repair was performed in 55% of the patients, including eight of 10 patients (80%) with repair before 6 months of age. Thirty-one percent of the patients with TAP repair were restrictive. These restrictive patients had more severe preoperative pulmonary stenosis (p < 0.05), were older at repair (p < 0.05), and had shorter duration of pulmonary regurgitation (p < 0.001) at follow-up. CONCLUSIONS: Restrictive RV physiology is inversely related to age at repair and independent of type of outflow tract repair. Since TAP repair is more common in early repair, and restriction seems to be less frequent, long-term follow-up to assess adverse effects of pulmonary regurgitation is mandatory.

Does restrictive right ventricular physiology in the early postoperative period predict subsequent right ventricular restriction after repair of tetralogy of Fallot?

OBJECTIVE: To assess the relation between immediate postoperative right ventricular (RV) diastolic physiology and subsequent diastolic function in patients after repair of tetralogy of Fallot. DESIGN: Serial prospective echocardiographic study early after surgical repair of tetralogy of Fallot and at mid-term follow up. SETTING: Tertiary referral centre. PATIENTS: 34 patients who had repair of tetralogy of Fallot between 1992 and 1995 were studied. MAIN OUTCOME MEASURES: Restrictive RV physiology defined as antegrade flow in the pulmonary artery in late diastole throughout the respiratory cycle. RESULTS: Sixteen of the 34 patients had early restrictive RV physiology. The need for transannular patch repair was an independent variable predictive of early restriction (odds ratio 4.3 (1.1-47), p < 0.05). Nine of 16 patients with early restriction also had restriction at follow up, while 15 of 16 patients without restrictive RV physiology continued without restriction. Early restriction was the only independent variable predictive of late restriction (odds ratio 6.0 (1.9-273), p = 0.01). CONCLUSIONS: Early and mid-term restrictive RV physiology after repair of tetralogy of Fallot is related to the repair type. Although evidence for this physiology tends to resolve in the first few days after operation, it is highly predictive of subsequent abnormalities of RV diastolic function. Similarly, normal RV diastolic physiology without restriction in the immediate postoperative period persists in the mid-term and may be associated with the long term problems of progressive RV dilatation.

Biventricular long axis function after repair of tetralogy of Fallot.

Right ventricular restrictive physiology is common after repair of tetralogy of Fallot and relates to exercise performance and symptomatic arrhythmias. In this study, we examined biventricular long axis function in an attempt to clarify further the mechanical substrate of this phenomenon. We studied prospectively 95 patients with tetralogy of Fallot (age range 1-44.3 years) at a median of 4.3 years after repair with Doppler and M-mode echocardiography. Pulmonary arterial, tricuspid, and mitral Doppler spectrals and 2-D guided M-mode recordings of ventricular minor and long axes were obtained with simultaneous phonocardiogram and respirometer recordings. Right ventricular restriction was defined by the presence of antegrade pulmonary arterial flow during atrial systole throughout the respiratory cycle. Restrictive right ventricular physiology was demonstrated in 36 (39%) [group 1] of the 92 patients in whom the data were analyzed. Left ventricular function (FS, isovolumic relaxation time and transmitral E wave deceleration time) was not different in the two groups (p < 0.1, p < 0.6, and p < 0.8, respectively). The presence of antegrade diastolic flow shortened the pulmonary regurgitation in the restrictive group (PR duration/square root of RR 10.7 +/- 2.1 vs 12.1 +/- 2.1, p < 0.01). There was delayed onset of shortening (97.4 +/- 24 vs 88.8 +/- 24 ms, p = 0.01), and the amplitude of right atrioventricular ring excursion, corrected for body surface area, was significantly lower during atrial systole in the restrictive group (0.43 +/- 0.15 vs 0.54 +/- 0.2 cm/m2, p < 0.01). There was also a tendency toward a smaller ratio of right to left total atrioventricular ring excursion in the same group (1.14 +/- 0.19 vs 1.22 +/- 0.23, p = 0.1). Impaired long axis function in patients with restrictive right ventricular physiology following repair of tetralogy of Fallot is associated with abnormal diastolic filling and may contribute to the long-term cardioprotective effect of restrictive physiology by limiting the degree of right ventricular dilatation.

[Coil embolization of persistent ductus arteriosus]. / Coillukking av persisterende ductus arteriosus.

From September 1994 to January 1996, 57 patients were admitted to Brompton Hospital for catheter closure of persistent ductus arteriosus. Umbrella closure was attempted in 22 patients and coil closure in 35. The duct was closed by a device in 55 of 57 patients (96.4%). Two patients were referred for surgical closure, one after failure of the umbrella closure and one after coil embolization to a branch of the pulmonary artery. Two additional coils embolized to pulmonary artery branches. Both coils were successfully retrieved by a snare, and the procedure then finished successfully. We recommend the use of coils for closure of small ducts, and for residual leak after previous umbrella closure. This is also a promising method for closure of larger ducts.

Relationship between type of outflow tract repair and postoperative right ventricular diastolic physiology in tetralogy of Fallot. Implications for long-term outcome.

BACKGROUND: Restrictive right ventricular (RV) physiology can be present early and late after tetralogy of Fallot repair. It is associated with a complicated early postoperative course but is favorable late after repair because it is associated with less pulmonary regurgitation, better exercise tolerance, and less QRS prolongation and symptomatic ventricular arrhythmias. It is not known, however, whether in the current surgical era, this physiology is present in tetralogy of Fallot patients at mid-term follow-up and whether it is related to the type of RV outflow tract repair. Finally, the impact of this physiology on the early evolution of QRS prolongation has not been examined previously. In this study we attempted to address these issues in a cohort of recently operated patients. METHODS AND RESULTS: Ninety-five patients were studied 4.3 years after repair by Doppler echocardiography, serial electrocardiograms, and chest radiographs. Restrictive RV physiology defined by the presence of antegrade pulmonary artery flow in late diastole was present in 38% of the patients. It was more common in patients with transannular patch (TAP) repair compared with non-TAP repair (50% versus 21%, P < .05). QRS duration at follow-up was 121.2 +/- 17.6 and 132.6 +/- 11.8 ms in restrictive and nonrestrictive patients with TAP repair, respectively (P < .02). CONCLUSIONS: Restrictive RV physiology has been identified at mid-term follow-up in a contemporary surgical series. It is associated with less QRS prolongation, regardless of the technique used for outflow tract repair, and may be associated with fewer long-term complications. Nonrestrictive physiology is associated with the most marked QRS prolongation. This subgroup is most at risk from the late deleterious consequences of chronic pulmonary regurgitation.

[Treatment of supraventricular tachycardia in children]. / Behandling av supraventrikulaer takykardi hos barn.

Although young infants may have severe symptoms from supraventricular tachycardia the majority responds to treatment. In 60-90% of the infants the arrhythmias disappear within 6-12 months, whereas in older children the supraventricular tachycardia tends to reoccur. Our recommended acute treatment in infants less than six months of age is to emmerse the face in cold water, but adenosine should be used for pharmacological termination of supraventricular tachycardia in all age groups. If this fails, direct current cardioversion should be applied without delay. Intravenous verapamil should not be used, however, in infants for termination of supraventricular tachycardia. Flecainide can be used for acute and prophylactic treatment.

Right ventricular size and function as assessed by echocardiography and angiography in patients with different volume load.

A comparative study of right ventricular (RV) function, assessed by echocardiography and angiography, undertaken in 20 patients, 10 of whom had atrial septal defects (ASDs) and 10 had various other heart diseases. All of the measured echocardiographic variables of RV size, apart from RV length, were larger in the patients with ASD. When assessed by multiple regression analysis, the RV M-mode dimension was an independent variable of RV angiographic end-diastolic volume (EDV) in patients without RV volume load (R = 0.92, R2 = 0.85, p < 0.001). In the patients with ASD, echocardiographic RV end-diastolic area was an independent variable of angiographic RVEDV (R = 0.75, R2 = 0.55, p < 0.05), whereas M-mode dimension had a weaker correlation (r = 0.29). The agreement between RV ejection fraction (RVEF) obtained by echocardiography and angiography was moderate in both patient groups. However, fractional area change and fractional length change could not estimate RVEF better. Thus care should be taken to use single measurements and derivatives as the only parameters of RV size and function.

Variability of digitized left ventricular M-mode echocardiography: a study in healthy subjects and patients with repaired tetralogy of Fallot.

To assess possible factors affecting the variability of digitized left ventricular M-mode echocardiograms, the influence of respiration and the variability due to different beats and observers were analysed in 11 healthy subjects and 11 patients with repaired tetralogy of Fallot. Left ventricular end-diastolic dimension (LVEDD) decreased from end-expiration to end-inspiration in the healthy subjects, but not in the patients. The maximal rate of dimension change decreased in both healthy subjects and patients from end-expiration to end-inspiration. The beat-to-beat variability assessed by the coefficient of variation (CV,%) between measurements of one cardiac cycle was twice the CV for three cycles, whereas the CV for three and five cardiac cycles was not different. The CV for intraobserver variability was less than 5.0% for dimensions and less than 13.0% for the rates of dimension change, whereas the interobserver variability had CV of 17.1% for rates of dimension changes. The influence of respiration and different observers on the variability of LV end-systolic dimension and shortening fraction was larger in the patients than in the healthy subjects. Thus, to obtain optimal technique for analysis of digitized LV M-mode echocardiograms in serial patient studies, the number of observers should be kept at a minimum and at least 3 beats at end-expiration should be used.

Hemodynamic status in repaired tetralogy of Fallot assessed by Doppler echocardiography and cardiac catheterization. Comparisons with healthy subjects and elucidation of factors associated with cardiorespiratory function.

Thirty-four patients were studied after corrective surgery for tetralogy of Fallot (mean follow-up 10 years) and compared with healthy matched controls. All underwent Doppler echocardiography, spirometry and treadmill exercise test. Post-operative cardiac catheterization had been performed on 26 (76%) of the patients and showed poor hemodynamic results in four (15%). Significant correlations of pressure gradients obtained from catheterization and estimated by Doppler echocardiography were right ventricular to right atrial (r = 0.77), pulmonary outflow (r = 0.75), pure valvular pulmonary outflow (r = 0.94) and diastolic pulmonary pressure gradients (r = 0.53). Pulmonary outflow gradients and right ventricular to right atrial pressure gradients estimated from tricuspid regurgitation jets were significantly increased in the patients. Diastolic pulmonary artery pressure, vital capacity and ventilatory anaerobic threshold were independent factors of maximal oxygen consumption. It is suggested that Doppler-derived diastolic pulmonary artery pressure, lung function studies and exercise testing with assessment of the ventilatory anaerobic threshold should be included in follow-up after repair of Fallot's tetralogy.

Effects of impaired lung function and pulmonary regurgitation on maximal exercise capacity in patients with repaired tetralogy of Fallot.

Long-term haemodynamic results and exercise capacity were studied in 34 patients with tetralogy of Fallot (24 men and 10 women) repaired 10.0 +/- 4.9 (mean +/- SD) years previously and compared to 34 healthy matched controls. All subjects were studied by resting spirometry, echocardiography and a symptom limited treadmill exercise test (modified Bruce protocol). The maximal oxygen consumption was 38.2 +/- 8.0 ml.kg-1.min-1 in patients and 48.1 +/- 8.1 ml.kg-1.min-1 in the control group (P < 0.001). Reduced maximal oxygen consumption was found in patients with low vital capacity (VC) and pulmonary regurgitation (PR). The ventilatory anaerobic threshold (VAT) was 23.8 +/- 0.6 ml.kg-1.min-1 and 29.9 +/- 0.6 ml.kg-1.min-1 in patients and controls, respectively (P < 0.001). VC was 3.4 +/- 1.21 in patients and 4.0 +/- 1.31 in controls (P < 0.02). In the patients, maximal ventilation was reduced and at submaximal exercise, the breathing frequency increased. Heart rates during exercise were similar in patients and controls. Tricuspid regurgitation (TR) was detected in 20 patients (58.8%); however, the exercise capacity was not reduced. Thus, impaired exercise capacity in tetralogy of Fallot is partly due to reduced resting lung function, pulmonary regurgitation and low ventilatory anaerobic threshold.

Effects of respiration on right ventricular size and function: an echocardiographic study.

The effects of quiet respiration and body position on right ventricular (RV) size and function were assessed by two-dimensional (2DE) and M-mode echocardiography in 15 healthy children. All end-diastolic echocardiographic dimensions, areas, and volumes increased slightly but significantly with inspiration. At end-systole similar changes were found. RV ejection fractions were significantly higher during inspiration, as were stroke volume indices. RV dimensions also increased from supine to left lateral decubitus position. Thus, our results indicate a need for standardization of 2DE and M-mode measurements not only for body position, but also for respiratory phase when used to assess RV size and function.

Assessment of the thiamine nutritional status. An evaluation of erythrocyte transketolase activity, the stimulated erythrocyte transketolase activity, and the thiamine pyrophosphate effect.

The most widely accepted approach to estimation of thiamine nutrition has been the measurement of the erythrocyte transketolase activity (ETKA), the ETKA stimulated in vitro with thiamine pyrophosphate (TPP) (which is suggested to be designated ETKAS) and the percentage increase of ETKA after stimulation with TPP in vitro, called the thiamine pyrophosphate effect (TPPE). In spite of 30 years of experience in the determination of these variables doubtfulness still exists of how to assess them. On the basis of a study of a group of alcoholics and a group of non-alcoholics a system of evaluation of ETKA, ETKAS and TPPE is proposed.