Non-invasive assessment of right and left ventricular volumes 11 to 24 years after corrective surgery on patients with tetralogy of Fallot

Effect of Balloon Pulmonary Valvuloplasty on Growth of Pulmonary Annulus in Infants with Tetralogy of Fallot

Percutaneous balloon pulmonary valvuloplasty (PBPV) is an alternative intervention in infants with Tetralogy of Fallot (TOF). It can not only improve hypoxia but also promote pulmonary annulus (PA) growth. In this study, we evaluated the effect of PBPV on PA growth in infants with TOF. To eliminate the effect of the systemic to pulmonary shunt (SPS) that may promote PA growth, we divided TOF infants into 2 groups: group A, patients who underwent PBPV with or without other SPS, and group B, patients who attempted SPS but without PBPV. Sixty patients were included, 28 patients in group A and 32 patients in group B. Age at the time of intervention in group A (range, 0.4-5.4; median 1.4 months) was lower than that in group B (range, 2.3-7.7; median 4.8 months), p-value 0.02. The body weight in group A (range, 3-5.5; median 3.7 kg) was also lower than that in group B (range 4.1-6.4; median 5.9 kg), p-value 0.02. Echocardiographic data at the mean follow-up period of 37.2 months (3-88 months) in group A and 39.6 months (6-95 months) in group B demonstrated an increase in mean PA diameter from 5.0 ± 1.3 mm to 10.2 ± 2.9 mm, p-value < 0.001 in group A; and from 6.2 ± 2 mm to 9.5 ± 2.9 mm, p-value < 0.001 in group B. The median PA z-score increased from - 3.4SD (- 3.9 to - 2.6SD) to - 1.8SD (- 2.5 to - 0.8SD), with the p-value of 0.002 in group A; and increased from - 2.9SD (- 4.5 to - 1.3SD) to - 2.7SD (- 3.6 to - 1.4SD), with the p-value of 0.73 in group B. By using the PA z-score as the absolute value, there was a statistically significant increase in the PA z-score during follow-up in group A, but not in group B. Balloon pulmonary valvuloplasty in infants with TOF can facilitate the growth of the pulmonic annulus even after eliminating the effect of the systemic to pulmonary shunt.

Usefulness of exercise-induced changes in plasma levels of brain natriuretic peptide in predicting right ventricular contractile reserve after repair of tetralogy of Fallot

Elevated levels of brain natriuretic peptide (BNP) have been associated with ventricular dysfunction, and exercise tests have been used for assessing cardiac contractile reserve. We examined the relation between BNP and right ventricular (RV) contractile reserve during exercise in patients after repair of tetralogy of Fallot (TOF). A total of 45 patients, 26 of whom underwent repair of TOF at 2 to 3 years of age and 19 age-matched healthy children, were studied. Plasma levels of BNP were measured at baseline and at maximal exercise. Echocardiography combined with tissue Doppler imaging (TDI) was performed at rest and during supine bicycle submaximal exercise. The peak value of the first derivation of RV pressure (peak dP/dt) was measured by the continuous-wave Doppler method. The severity of pulmonary regurgitation (PR) (mild, moderate, or severe) was based on color Doppler findings. Plasma BNP levels were significantly higher in patients with TOF than in controls (44 +/- 34 vs 6 +/- 4 pg/ml, p <0.01). Exercise was associated with increased plasma BNP levels in both groups. A larger increment in BNP was noted in patients with TOF than in normal subjects (15 +/- 12 vs 2 +/- 2 pg/ml, p <0.01). The peak systolic myocardial velocity (Sa) and peak dP/dt values increased significantly in both groups during exercise; however, the magnitude of increase in both of these values was significantly less in patients with TOF than in controls (36 +/- 19% vs 70 +/- 19% and 42 +/- 11% vs 81 +/- 12%, respectively; p <0.01). There were significant correlations between the increment in BNP and changes in Sa and peak dP/dt values (r = -0.67 and -0.53, p <0.01, respectively), and the severity of PR (r = 0.74, p <0.01). Thus, exercise increases plasma levels of BNP, and greater increases are associated with impaired RV contractile reserve in patients with TOF with various degrees of PR.

Assessment of right ventricular function during exercise with quantitative Doppler tissue imaging in children late after repair of tetralogy of Fallot

Doppler tissue imaging (DTI) has been developed to assess ventricular wall-motion velocity quantitatively for patients with various types of heart disease. This technique has a possibility of assessing right ventricular (RV) function reserve during exercise. To investigate RV function during exercise using DTI, 21 patients (9.3 +/- 3.3 years) who had undergone operation for tetralogy of Fallot at 1 to 3 years of age and 19 age-matched healthy children were studied. Echocardiography combined with DTI was performed at rest and during supine bicycle submaximal exercise. DTI of tricuspid annulus movement during systole (Sa) was obtained from a 4-chamber view. RV pressure was estimated by maximal tricuspid regurgitation (TR) velocity. The peak value of the first derivation of RV pressure (peak dP/dt) was measured from the continuous wave Doppler-derived TR profile. Adequate spectral Doppler recordings of TR were obtained in all participants. However, 9 healthy children and 2 patients with tetralogy of Fallot were excluded from the study because of an inability to determine the entire spectral TR velocity envelope during exercise. Therefore, data were analyzed in 29 participants. At rest, the mean RV pressure for patients was higher than that in control subjects (27 +/- 4 vs 18 +/- 3 mm Hg, P <.01). The mean Sa and RV peak dP/dt for patients were lower than those in control subjects (6.7 +/- 1.6 vs 8.8 +/- 1.7 cm/s and 464 +/- 77 vs 550 +/- 80 mm Hg/s, P <.01, respectively). Sa and RV peak dP/dt in the two groups increased significantly during exercise. However, the magnitude of increases in Sa and peak dP/dt was significantly less for patients than in control subjects (37 +/- 16 vs 66 +/- 19% and 42 +/- 10 vs 80 +/- 13%, P <.01, respectively). The magnitude of increase in Sa correlated with that in RV peak dP/dt (r = 0.84, P <.01). Results of DTI show high correlation with RV peak dP/dt during exercise. This technique has a potential as a useful indicator of the effect of exercise on RV systolic function. An insufficient increase in Sa suggests impaired response to exercise of RV in patients with tetralogy of Fallot.

Exercise MR imaging in the assessment of pulmonary regurgitation and biventricular function in patients after tetralogy of fallot repair

PURPOSE

To assess the responses of pulmonary regurgitation (PR) and biventricular function to submaximal exercise by using a magnetic resonance (MR) imaging exercise protocol with young adult patients who underwent tetralogy of Fallot repair at a young age.

MATERIALS AND METHODS

Fifteen patients with corrected tetralogy of Fallot (mean age, 17.5 years +/- 2.5 [SD]) underwent MR imaging at rest and during exercise for the evaluation of PR and biventricular function. Results were compared with findings from 16 control subjects (mean age, 17.5 years +/- 2.3). Mean age at tetralogy of Fallot repair was 2.1 years +/- 1.6, and mean follow-up time after repair was 15.4 years +/- 2.6. Exercise level at MR imaging was calculated individually and corresponded to 60% of peak oxygen uptake. The parameters of cardiac function obtained at rest and during exercise were compared by using a paired t test. An unpaired t test was used to compare parameters of cardiac function between patients and control subjects.

RESULTS

PR decreased during exercise (from 27 mL/m(2) +/- 17 to 23 mL/m(2) +/- 15; P =.012). At rest, right ventricular (RV) ejection fraction was normal (>47%) in 80% of patients. RV response to exercise in the patient group was abnormal compared with response in the control group, as demonstrated by an increase in RV end-diastolic volume index (132 mL/m(2) +/- 36 to 137 mL/m(2) +/- 38; P =.041) and no significant change in end-systolic volume index or ejection fraction. In only one patient, RV ejection fraction increased by more than 5%. Left ventricular response was not different between patients and control subjects.

CONCLUSION

MR imaging is well suited to assess cardiac response to exercise, and findings revealed a decrease in PR and an abnormal RV response to exercise in patients with corrected tetralogy of Fallot.

Oxygen uptake versus exercise intensity: a new concept in assessing cardiovascular exercise function in patients with congenital heart disease

OBJECTIVE

To assess the relation between exercise intensity and oxygen uptake during graded exercise in paediatric patients who underwent surgical repair of congenital heart disease, and to compare it with conventional measures of aerobic exercise function.

DESIGN

Cross sectional study. Exercise testing was performed on a treadmill and gas exchange was measured on a breath by breath basis.

PATIENTS

29 patients who underwent an atrial switch operation for transposition of the great arteries (TGA) (mean (SD) age at testing 10.3 (2.5) years) and 30 patients who underwent total repair of tetralogy of Fallot (TF) (age 12.1 (3.3) years) performed graded exercise testing. Exercise responses were compared with data obtained in 24 normal controls (age 11.4 (2.6) years).

RESULTS

The slope of oxygen uptake versus exercise intensity averaged 1.50 (0. 64) ml O(2)/min(2)/kg in the patients with TGA and 1.68 (0.75) ml O(2)/min(2)/kg after TF repair, both lower (p < 0.005) than in normal controls (2.42 (0.68) ml O(2)/min(2)/kg). The lower slope of oxygen uptake was correlated with a subnormal value for ventilatory anaerobic threshold, which averaged 78.0 (13.3)% of normal in TGA and 85.1 (10.6)% in TF. This was associated with a steeper slope (p = 0.001) of carbon dioxide output versus oxygen uptake above the ventilatory anaerobic threshold in TGA (1.26 (0.20)) and TF (1.20 (0. 18)) compared with the normal controls (1.05 (0.13)), and also a steeper slope of ventilation versus carbon dioxide in TGA (47.0 (15. 4)) and TF (41.5 (13.7)) than in the controls (30.3 (8.5)).

CONCLUSIONS

Calculation of the steepness of the slope of oxygen uptake versus exercise intensity is a valid measurement of oxygen flow to the exercising tissues, which may be limited in congenital heart disease.

Twenty-to-thirty-seven-year follow-up after repair for Tetralogy of Fallot

OBJECTIVE

To describe the long-term prognosis after repair of Tetralogy of Fallot with pulmonary stenosis beyond 20 years.

METHODS

One hundred and eighty five patients underwent corrective repair of Tetralogy of Fallot at Rigshospitalet in Copenhagen between January 1960 and July 1977. Ninety seven patients had undergone a palliative operation prior to Tetralogy of Fallot repair. All the 125 patients who were discharged from the hospital were traced through the population register and the patients alive July 1997 were contacted by mail and/or telephone and questioned about use of medicine, professional status, family status and ability to perform sport activities.

RESULTS

Sixty patients died in hospital and 125 patients, 78 males and 47 females, were discharged alive. Among operative survivors, median age at operation was 12.8 years (range 0.4-41 years). Thirteen patients required a reoperation, the main indication was failed VSD closure. There were 16 late cardiac deaths, out of which seven were sudden and unexpected and three were in immediate relation to reoperations. One hundred and nine patients were alive at follow-up. The mean follow-up time was 25.5 years (range 20-38 years). Sixteen percent used cardiac drugs, 89% were, or had been, working normally (all professions from academics to hard manual labors were represented), 53% (64% of women) had given birth after the repair and 51% performed sport activities regularly. No patients were lost to follow-up.

CONCLUSIONS

The vast majority of the patients seemed to live normal lives 20-37 years after Tetralogy of Fallot repair. Late deaths were cardiac in origin, including sudden death from arrhythmias. The number of late reoperation has been low. Considering the natural history of the disease, Fallot repair has proven to be a beneficial procedure even including the very early experience short after introduction of open heart surgery.

Role of right ventricular and pulmonary functional abnormalities in limiting exercise capacity in adults with congenital heart disease

This study evaluates right ventricular (RV) and pulmonary function during exercise in adults with congenital heart disease (CHD). Thirty-one patients with CHD involving the right side of the heart underwent symptom-limited bicycle exercise testing with simultaneous expired gas analysis and measurement of RV ejection fraction (EF). Twenty-one age-matched normal controls underwent the identical exercise protocol. Maximal oxygen consumption was lower in the CHD than in normal controls (19.5 +/- 6.4 vs 30.5 +/- 0.8 ml/kg/min, p = 0.0001 patients vs controls). Both heart rate (156 +/- 25 vs 171 +/- 13 beats/min, p = 0.01) and oxygen pulse (9.3 +/- 3.7 vs 12.3 +/- 3.7 ml/beat, p = 0.01), an indirect measure of stroke volume, were found to be lower in the CHD group at peak exercise. Pulmonary dysfunction was evidenced in the CHD group by decreased forced expiratory volume, forced vital capacity and maximum voluntary ventilation, and by a higher ventilation/expired carbon dioxide ratio at peak exercise (37.2 +/- 6.9 vs 33.0 +/- 5.4, p = 0.02), suggesting an increase in dead space ventilation. Maximal oxygen consumption was lower in patients whose RVEF decreased with exercise (17.6 +/- 5.4 vs 22.8 +/- 6.4 ml/kg/min, p = 0.03 "decrease RVEF" group vs "increase RVEF" group). Maximal oxygen consumption correlated with the change in RVEF only in the group whose RVEF decreased with exercise (r = 0.5, p = 0.03). In the group that had increased RVEF with exercise, maximal oxygen consumption correlated with forced expiratory volume (r = 0.7, p = 0.02). Thus, adults with CHD have a reduced functional capacity compared with normal controls. This phenomenon appears to be associated with both RV and pulmonary abnormalities.

Work capacity and central hemodynamics thirteen to twenty-six years after repair of tetralogy of Fallot

Exercise tests and cardiac catheterization were performed in 53 patients, 13 to 26 years after intracardiac repair of tetralogy of Fallot. At the time of repair, the median age was 7 years, and 60% of patients with cyanosis had had a previous palliative procedure. The right ventriculotomy was closed without a patch in 21 patients (40%), a patch restricted to the right ventricle was inserted in 18 patients (34%), and in 14 (26%) the patch extended across the pulmonary anulus. At follow-up, 94% of the patients were free of symptoms. Symptom-limited work capacity was 87% of the predicted value (95% confidence limits, 82% to 94%). Work capacity was inversely related to age at follow-up, to right ventricular systolic pressure at rest, and to presence of moderate or severe pulmonary valve regurgitation. Cardiac output in relation to oxygen uptake was reduced in 74% of patients during exercise. In 12 patients (23%), systolic pressure at rest in the right ventricle was 50 mm Hg or higher. Systolic pressure during exercise in the right ventricle was lower in patients without a patch than in those with a patch and was abnormally high in all groups compared with healthy subjects. The ratio of right to left ventricular pressure was significantly lower than measurements taken immediately after repair. An intracardiac left-to-right shunt was present in 6 patients (11%). Three patients required invasive treatment as a result of our follow-up. We conclude that work capacity was moderately reduced 13 to 26 years after repair of tetralogy of Fallot and was adversely influenced by right ventricular hypertension and pulmonary valve regurgitation. Intermittent lifelong surveillance is advocated, because patients without symptoms may have hemodynamic abnormalities that necessitate intervention.

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.