Natural history of cornary artery disease studied by coronary arteriography. A seven-year study of 795 patients

Seven hundred and ninety-five consecutive patients with the diagnosis of angina pectoris were studied by coronary angiography and followed for 2-7 years. The prognosis is greatly determined by the extent of coronary artery involvement. Concomitant mitral insufficiency or ventricular aneurysm influence the prognosis adversely. There was no significant difference in prognosis between men and women. As regards patients with three-vessel disease and elevated left ventricular end-diastolic pressure, the prognosis was better in operated than in non-operated patients. The prognosis seems to have improved when angina pectoris materials collected in the 70s are compared with materials from the 60s.

Heat stroke in endurance exercise

Six athletes were examined immediately after collapsing from heat stroke during exercise, and then followed for several weeks. At the time of collapse most of the patients were sweating profusely, their rectal temperatures being more than 42 degrees C. All recovered within a few hours. The renal function was not disturbed more than expected during heavy exercise, serum levels of liver enzymes were, however, increased for several weeks. Electrolyte homeostasis was undisturbed but for a transient hypercalcemia that can not be fully explained. The marked increments in plasma levels of catecholamines, vasopressin and renin were as expected after heavy exercise. We conclude that as heat stroke presents as a continuum of clinical pictures, biochemical evidence of liver cell injury is a sensitive and important parameter for the diagnosis.

Response to changing plasma concentrations of isosorbide-bound NO2 during acute and sustained treatment with isosorbide dinitrate in patients with coronary artery disease

BACKGROUND

The mechanisms behind development of tolerance to nitrate effects during sustained, asymmetric isosorbide dinitrate (ISDN) therapy are not fully understood.

HYPOTHESIS

The study was undertaken to investigate the changes of the relationships between left ventricular (LV) function and plasma concentrations of ISDN and its vasoactive metabolites (2- and 5-ISMO) during acute and sustained, asymmetric ISDN therapy.

METHODS

Left ventricular function and plasma concentrations of ISDN, 2- and 5-isosorbide mononitrates (P-ISDN, P-2- and 5-ISMO) were measured at rest and at supine exercise before and for 4 h after peroral 30 mg ISDN in 15 patients with coronary artery disease, all with initial exercise pulmonary artery wedge pressure (PAWP) > 25 mmHg. Seven patients were untreated (acute group), while eight received 30 mg ISDN b.i.d. for 2 weeks before the invasive study. P-ISDN and the concentration of available isosorbide-bound nitrate (NO2) in plasma (P-ISDN.2 + P-2-ISMO + P-5-ISMO) (P-NO2) were used as measures of the nitric oxide (NO) offer to the tissues.

RESULTS

Throughout the study, after administration of medication, all plasma concentrations, in particular P-ISDN, were higher in the chronic than in the acute group. Peak P-ISDN was reached after 15 min in the chronic group and after 25 min in the acute group, while P-2- and 5-ISMO reached maximum only after 40 min in both groups. At rest, the full effect on PAWP was observed after 10 min in both groups, but at markedly higher levels of P-ISDN and P-NO2 in the chronic group. Afterward, no further changes in PAWP were observed. During exercise, 1 h after medication, PAWP and stroke index to PAWP ratio (SI/PAWP) were normal in both groups. Thereafter, at slowly declining P-NO2, PAWP rose and SI/PAWP declined toward the initial level in the chronic group, but remained unchanged in the acute group, in spite of higher P-NO2 and greater NO release in the former.

CONCLUSIONS

Patients receiving sustained, asymmetric 30 mg ISDN b.i.d. dosing had the same immediate beneficial effects on LV function during exercise after a morning dose as did untreated patients. However, in spite of higher P-NO2 and higher rate of NO release during sustained treatment, the effects deteriorated gradually 2 to 3 h after medication. The changes in metabolism and/or distribution of isosorbide-bound NO2 may possibly be part of the tolerance induced by long-term treatment, even with asymmetric dosing.

Relationship between exercise hyperpnea, hemodynamics, and blood gases before and during glyceryl trinitrate infusion in patients with exercise-induced elevation of pulmonary artery wedge pressure

BACKGROUND

The mechanisms underlying the excessive ventilatory response to exercise in patients with cardiac failure are still not fully understood.

HYPOTHESIS

This study was undertaken to investigate the mechanisms behind exercise hyperpnea in patients with exercise-induced left ventricular dysfunction.

METHODS

In 18 patients, aged 57-82 years, all with atherosclerotic lumbar aorta aneurysm and pulmonary artery wedge pressure (PAWP) > 25 mmHg during supine exercise, ventilation (V), central hemodynamics, and arterial and venous blood gases were examined during supine rest and exercise, before and during infusion of glyceryl trinitrate (GTN).

RESULTS

Before GTN, exercise PAWP was 32.2 +/- 6.1 mmHg and V/V O2 was 33.8 +/- 7.7 l/l (130% of predicted). With GTN, exercise PAWP was markedly reduced to 15.3 +/- 3.8 mmHg (p < 0.001), whereas V/V O2 was only marginally reduced to 32.3 +/- 3.0 l/l (124% of predicted) (p < 0.05). Exercise physiologic dead space (VD/VT) declined from 0.31 +/- 0.16 to 0.26 +/- 0.17 (p < 0.05), while PaCO2 was reduced from 5.20 +/- 0.31 to 5.10 +/- 0.24 kPa (p < 0.05). PvO2 and cardiac output (CO), however, were unchanged below normal.

CONCLUSION

The data show that exercise-induced hyperpnea was not substantially reduced by rapid normalization of PAWP and could not be related to preservation of normal PaCO2 in the presence of high VD/VT. The persistence of exercise hyperpnea and reduced PvO2 after GTN is consistent with augmented ventilatory stimuli from hypoxia-induced metabolic abnormalities in the skeletal muscles, or/and persistently reduced CO, due to changes in the integrated superior command of ventilation and circulation.

Effects of isosorbide dinitrate on electrocardiography, hemodynamics, and ventilation in patients with exercise-induced elevation of pulmonary artery wedge pressure

BACKGROUND

The mechanisms underlying exertional hyperpnea in patients with coronary artery disease and transient left ventricular dysfunction are still not fully understood.

HYPOTHESIS

The study was undertaken to investigate whether the ventilatory response to exercise reflects the effects of acute medical treatment of exercise-induced left ventricular dysfunction, and to evaluate mechanisms relevant to excessive exertional ventilation.

METHODS

In 11 male patients, aged 65.2 +/- 6.0 years, all with pulmonary artery wedge pressure (PAWP) > 25 mmHg and ST depression > 2 mm during moderate supine exercise, ventilation (V), oxygen uptake (VO2), hemodynamics, electrocardiogram (ECG), and arterial and mixed venous blood gases were examined during supine rest and exercise, before and at hourly intervals after peroral intake of 30 mg isosorbide dinitrate (ISDN). Six similar patients were examined with the same protocol without ISDN administration and comprised a control group.

RESULTS

Before administration of ISDN, exercise PAWP was 35.3 +/- 5.9 mmHg, ECG showed 2.77 +/- 1.06 mm ST depression, and V/VO2 was 31.8 +/- 4.8 l/l. One h after ISDN administration, exercise mean PAWP was 11.0 +/- 2.5 mmHg (p < 0.001), ST depression 0.59 +/- 0.8 mm (p < 0.001), whereas V/VO2 was unchanged, 30.1 +/- 5.3 l/l. Two h later, PAWP remained reduced and there were only minor ST depressions, while V/VO2 remained high. Exercise cardiac index (CI) and mixed venous oxygen tension (PvO2), initially 4.7 +/- 0.67 l/min/m2 and 3.54 +/- 0.35 kPa, respectively, remained at the same low level throughout the study. In the six nontreated patients, there were no significant changes in ST depression, exercise PAWP, or exertional ventilation.

CONCLUSION

Isosorbide dinitrate treatment markedly improved exercise-induced left heart dysfunction, whereas excessive ventilatory response was unaffected, even after 3 h. Thus, measurements of the exercise hyperpnea did not properly reflect effective reduction of myocardial ischemia.

Declining aerobic capacity of patients with arterial and atrial switch procedures

BACKGROUND

Patients with transposition of the great arteries corrected by an atrial switch procedure are believed to have a worse physical outcome than patients with an arterial switch procedure correction. This study aimed to compare exercise data for patients with the two surgical methods.

METHODS

This study retrospectively analyzed exercise treadmill test results for 7- to 17-year-old patients who underwent either an atrial switch procedure (n=45) or an arterial switch procedure (n=44). The results were compared with reference material.

RESULTS

Both groups showed significantly less aerobic capacity than healthy subjects. The atrial switch patients achieved 69% of reference status, and the arterial switch patients achieved 82%. A gradual decline in exercise capacity with increasing age was shown for patients with atrial switch circulation (p<0.0001). No significant difference was found for the arterial switch group (p=0.319).

CONCLUSIONS

Significantly less aerobic capacity was found in atrial and arterial switch patients than in healthy subjects. A decline in aerobic capacity with increasing age was found in the atrial switch patients. However, the small number of teenagers in the arterial switch group limits the ability to be conclusive. The results indicate that chronotropic incompetence may be one of the reasons for diminishing capacity. The decline in exercise performance leads the authors to recommend regular follow-up exercise testing.

Differing lung function development in infants with univentricular hearts compared with healthy infants

AIM

To compare the difference in lung function development of healthy controls and patients with univentricular hearts from birth prior to surgery and during the first year of life when cardiac shunt procedures and the cavopulmonary connection are required.

METHODS

Tidal flow-volume measurements and single-occlusion tests were performed from birth serially up to 18 months of age on 28 unsedated spontaneously breathing infants with univentricular hearts and 58 healthy control infants.

RESULTS

Infants with univentricular heart physiology had low tidal volumes, low compliance of the respiratory system and high respiratory rate at birth, which over time normalized, whereas the peak expiratory flow increased during the study period. The lung function measured at birth was predictive of later lung function measurements.

CONCLUSION

The pattern of lung function development is different in the patients with univentricular hearts compared to healthy controls. Lung function measured at birth is predictive of later lung function.

Autonomic heart rate control at rest and during unloading of the right ventricle in repaired tetralogy of Fallot in adolescents

Arrhythmias in patients with repaired tetralogy of Fallot (ToF) might be due in part to altered autonomic heart rate control caused by altered right ventricle hemodynamics. This study investigated autonomic heart rate control in adolescents with ToF at rest and during unloading of the right ventricle. A total of 17 patients with ToF and 56 healthy controls aged 12 to 18 years underwent orthostatic stress with lower body negative pressure of -20 mm Hg. Heart rate, blood pressure, and stroke volume were recorded noninvasively. Indices of heart rate variability were computed in time and frequency domains. All patients with ToF also underwent cardiac magnetic resonance imaging, demonstrating pulmonary regurgitation and right ventricular dilation. At rest, heart rate variability indices of vagal heart rate control were nonsignificantly lower in the patients with ToF compared with controls. During lower body negative pressure, heart rate increased more in controls than patients with ToF (p <or=0.001). Further, most heart rate variability indices decreased in controls, but increased in patients with ToF (p <or=0.01 or p <or=0.001 for all variables), suggesting vagal activation in the patients with ToF. In conclusion, adolescents after ToF repair have fairly normal heart rate control at rest despite altered right ventricular hemodynamics. During unloading of the right ventricle, however, vagal heart rate control increases in the patients with ToF and decreases in the controls.

Impaired weight gain predicts risk of late death after surgery for congenital heart defects

OBJECTIVES

To describe long-term somatic growth in terms of weight for age in children operated on for congenital heart defects who die late (after the first 30 postoperative days) and to study the relationship between postoperative weight gain and survival after surgery for congenital heart defects.

METHODS

This was a nested case-control study of 80 children born in 1990-2002 who died late after surgery for congenital heart defects at Rikshospitalet, Norway. Weight data were obtained for 74 children, of whom 31 with no extra-cardiac anomalies were defined as cases and 31 surviving children with similar surgical complexity were defined as controls.

RESULTS

In the 74 children who died late, mean weight for age converted to z scores at birth, at last operation and at last recorded weight were 0.12, -1.31 and -2.09. In the 31 children defined as cases, the same weight z scores were 0.07, -1.21 and -2.01 compared with 0.05, -1.10 and -0.99 in the 31 matched controls. The odds ratio (OR) for death was 13.5 (95% CI 3.6 to 51.0) if there was a decrease in weight z score of >0.67 after the last operation. Median follow-up time after operation was 5.7 months.

CONCLUSIONS

A decrease in weight for age during the first months after surgery for congenital heart defects of more than 0.67 z scores, corresponding to a downward percentile crossing through at least one of the displayed percentile lines on standard growth charts, is strongly related to late mortality in children operated on for congenital heart defects.

Enhanced vagal withdrawal during mild orthostatic stress in adolescents with chronic fatigue

BACKGROUND

Hemodynamic abnormalities have been documented in the chronic fatigue syndrome (CFS), indicating functional disturbances of the autonomic nervous system responsible for cardiovascular regulation. The aim of this study was to investigate autonomic heart rate control during mild orthostatic stress in adolescents with CFS.

METHODS

A total of 14 CFS patients and 56 healthy controls having equal distribution of age and gender underwent lower body negative pressure (LBNP) of horizontal line 20 mmHg. The RR interval (RRI) was recorded continuously, and spectral power densities were computed in the low-frequency (LF) band (0.04-0.15 Hz) and the high-frequency (HF) band (0.15-0.50 Hz) from segments of 120-second length, using an autoregressive algorithm. In addition, the time-domain indices SDNN, pNN50, and r-MSSD were computed.

RESULTS

At rest, CFS had lower RRI than controls (P < 0.05), but indices of variability were similar in the two groups. During LBNP, compared to controls, CFS patients had lower normalized and absolute HF power and r-MSSD (P < 0.05), and higher RRI (P < 0.001), normalized LF power and LF/HF (P < 0.05).

CONCLUSIONS

During mild orthostatic stress, adolescents with CFS appear to have enhanced vagal withdrawal, leading to a sympathetic predominance of heart rate control compared to controls. Possible underlying mechanisms include hypovolemia and abnormalities of reflex mechanisms.

Antioxidant activity in the newborn brain: a luciferase mouse model

INTRODUCTION

Oxidative stress in the newborn period may cause cell injury and inflammation if the antioxidant capacity is insufficient. To monitor antioxidant and inflammatory activity we examined by in vivo imaging various strains of luciferase reporter mice whose light-emitting properties were regulated by response elements or complete promoters related to oxidative stress and/or inflammation. The aim of this study is to present a model that can monitor genetic activity in vivo during pregnancy and the first 10 days of life.

METHODS

One mouse strain reports the activity of nuclear factor-kappaB (NF-kappaB) activity, a transcription factor essential for modulating inflammation, apoptosis, differentiation and cell growth. A second mouse strain reports on superoxide dismutase 1-promoter activity. A third strain reports the promoter activity of gamma-glutamylcysteine synthetase, the rate limiting enzyme in glutathione production, and the last strain reports on antioxidant responsive element (ARE)/electrophil responsive element. Wild-type female mice mated with NF-kappaB mice were imaged through pregnancy to monitor intrauterine NF-kappaB activation.

RESULTS

Intrauterine NF-kappaB activity increased dramatically from day 17 towards labor. During the first 4 days of life luminescence measured was intense in all mice with distinct strain differences. All strains had high luminescence levels at day 1 and a considerably lower level at day 10.

CONCLUSION

This model allows investigation of the transcriptional regulation of key proteins related to oxidative stress and inflammation in pregnancy and the first days of life. With very little stress to the newborn animals genetic activity can be monitored day by day.

Sympathetic cardiovascular control during orthostatic stress and isometric exercise in adolescent chronic fatigue syndrome

The chronic fatigue syndrome (CFS) has been shown to be associated with orthostatic intolerance and cardiovascular dysregulation. We investigated the cardiovascular responses to combined orthostatic stress and isometric exercise in adolescents with CFS. We included a consecutive sample of 15 adolescents 12-18 years old with CFS diagnosed according to a thorough and standardized set of investigations, and a volunteer sample of 56 healthy control subjects of equal sex and age distribution. Heart rate, systolic, mean and diastolic blood pressure, stroke index, and total peripheral resistance index were non-invasively recorded during lower body negative pressure (LBNP) combined with two consecutive periods of handgrip. In addition, we measured baseline plasma catecholamines, and recorded symptoms. At rest, CFS patients had higher heart rate, diastolic blood pressure, plasma norepinephrine (P < 0.01), mean blood pressure and plasma epinephrine (P < 0.05) than controls. During LBNP, CFS patients had a greater increase in heart rate, diastolic blood pressure, mean blood pressure (P < 0.05) and total peripheral resistance index (n.s.) than controls. During handgrip, CFS patients had a smaller increase in heart rate, diastolic blood pressure (P < 0.05), mean blood pressure and total peripheral resistance index (n.s.) than controls. Our results indicate that adolescents with CFS have increased sympathetic activity at rest with exaggerated cardiovascular response to orthostatic stress, but attenuated cardiovascular response when performing isometric exercise during orthostatic stress. This suggests that CFS might be causally related to sympathetic dysfunction.

Sympathetic cardiovascular control during orthostatic stress and isometric exercise in adolescent chronic fatigue syndrome

The chronic fatigue syndrome (CFS) has been shown to be associated with orthostatic intolerance and cardiovascular dysregulation. We investigated the cardiovascular responses to combined orthostatic stress and isometric exercise in adolescents with CFS. We included a consecutive sample of 15 adolescents 12-18 years old with CFS diagnosed according to a thorough and standardized set of investigations, and a volunteer sample of 56 healthy control subjects of equal sex and age distribution. Heart rate, systolic, mean and diastolic blood pressure, stroke index, and total peripheral resistance index were non-invasively recorded during lower body negative pressure (LBNP) combined with two consecutive periods of handgrip. In addition, we measured baseline plasma catecholamines, and recorded symptoms. At rest, CFS patients had higher heart rate, diastolic blood pressure, plasma norepinephrine (P < 0.01), mean blood pressure and plasma epinephrine (P < 0.05) than controls. During LBNP, CFS patients had a greater increase in heart rate, diastolic blood pressure, mean blood pressure (P < 0.05) and total peripheral resistance index (n.s.) than controls. During handgrip, CFS patients had a smaller increase in heart rate, diastolic blood pressure (P < 0.05), mean blood pressure and total peripheral resistance index (n.s.) than controls. Our results indicate that adolescents with CFS have increased sympathetic activity at rest with exaggerated cardiovascular response to orthostatic stress, but attenuated cardiovascular response when performing isometric exercise during orthostatic stress. This suggests that CFS might be causally related to sympathetic dysfunction.

Sympathetic predominance of cardiovascular regulation during mild orthostatic stress in adolescents with chronic fatigue

Haemodynamic abnormalities have been documented in the chronic fatigue syndrome (CFS), indicating functional disturbances of the autonomic nervous system responsible for cardiovascular control. This study was designed to explore the pathophysiology in adolescent CFS-patients by analysing RR-interval (RRI) variability and diastolic blood pressure (DBP) variability during mild orthostatic stress, using an algorithm which accounts for non-stationary biosignals. A total of 27 adolescents with CFS and 33 healthy control subjects having equal age- and sex distribution underwent 15 min of 20 degrees head-up tilt (HUT). The spectral power densities of RRI and DBP were computed in the low-frequency (LF) band (0.04-0.15 Hz) and the high-frequency (HF) band (0.15-0.4 Hz) using an adaptive autoregressive algorithm to obtain a time-varying spectrum. RMSSD, a time domain index of RRI variability, was also computed. At rest, all indices of variability were similar in the two groups. During tilt, CFS patients had a larger increase in the LF/HF ratio (P<or=0.001) and normalized LF power of RRI (P<or=0.01), and a larger decrease in normalized HF power (P<or=0.01) of RRI than controls. CFS patients also had trends towards a larger decrease in absolute HF power of RRI and a larger increase in normalized LF power of DBP. These findings suggest that adolescents with CFS have sympathetic predominance of cardiovascular regulation during very mild orthostatic stress. Possible underlying mechanisms are moderate hypovolemia, abnormalities of reflex control or physical de-conditioning.

Congenital heart defects--chromosomal anomalies, syndromes and extracardiac malformations

AIM

To register chromosomal anomalies, syndromes and extracardiac malformations in patients with Congenital heart defects (CHDs).

METHOD

Population-based prospective observational study.

RESULTS

Of 57 027 live births during 1982-2005, CHDs were detected in 662 (11.6 per 1000), of whom 146 (22%) had associated anomalies. Of these 52 (36%) had chromosomal anomalies (exclusive microdeletions), 26 (18%) genetic syndromes/microdeletions, 1 (0.7%) a teratogenous syndrome and 67 (46%) extracardiac malformations. In perimembraneous ventricular septal defects (VSDs), associated anomalies occurred in 22 of 70 (31%) compared to 27 of 298 (9%) in VSDs located in the muscular part of the septum (p < 0.0001). The prevalence of CHDs with associated disorders increased significantly from the cohort born during 1982-1993 to those born during 1994-2005 (2.0 vs. 3.1 per 1000, respectively; p < 0.0001), mainly caused by an increase of chromosomal trisomies (0.5 vs. 1.1 per 1000; p = 0.026). The percentage of women giving live birth at 35 years of age or more was 7.6% for the period 1982-1993 compared to 13.4% for 1994-2005 (p = 0.001).

CONCLUSIONS

Chromosomal anomalies, syndromes and extracardiac malformations occurred in nearly one-fourth of CHD cases. Muscular VSDs had a low prevalence of such conditions. The prevalence of CHDs with chromosomal trisomies increased, and was probably related to an increasing age of women giving birth.

A population-based study relevant to seasonal variations in causes of death in children undergoing surgery for congenital cardiac malformations

AIMS

Our objectives were, first, to study seasonal distribution of perioperative deaths within 30 days after surgery, and late death, in children undergoing surgery for congenitally malformed hearts, and second, to study the causes of late death.

METHODS

We analysed a retrospective cohort of 1,753 children with congenital cardiac malformations born and undergoing surgery in the period from 1990 through 2002 with a special focus on the causes of late death. The data was obtained from the registry of congenital cardiac malformations at Rikshospitalet, Oslo, and the Norwegian Medical Birth Registry. The mean follow-up from birth was 8.1 years, with a range from zero to 15.2 years.

RESULTS

During the period of follow-up, 204 (11.6%) of the children died having undergone previous surgery. Of these 124 (7.1%) died in the perioperative period, and 80 (4.5%) were late deaths. There were 56 late deaths during the 6 coldest months, compared with 24 during the 6 warmest months (p < 0.01). There was no significant seasonal variation in perioperative deaths. Respiratory infection was the most common cause of late death, and occurred in 25 children, of whom 24 died during the 6 coldest months. Of the 8 sudden late deaths, 7 occurred during the 6 coldest months. There was no seasonal variation for the other causes of death.

CONCLUSIONS

In children undergoing surgery for congenital cardiac malformations in Norway, there is a seasonal variation in late death, with a higher proportion occurring in the coldest months. Death related to respiratory infections predominantly occurs in the winter season, and is the overall most common cause of late death.

Abnormal thermoregulatory responses in adolescents with chronic fatigue syndrome: relation to clinical symptoms

OBJECTIVES

Chronic fatigue syndrome is a common and disabling disease of unknown etiology. Accumulating evidence indicates dysfunction of the autonomic nervous system. To further explore the pathophysiology of chronic fatigue syndrome, we investigated thermoregulatory responses dependent on catecholaminergic effector systems in adolescent patients with chronic fatigue syndrome.

PATIENTS AND METHODS

A consecutive sample of 15 patients with chronic fatigue syndrome aged 12 to 18 years and a volunteer sample of 57 healthy control subjects of equal gender and age distribution were included. Plasma catecholamines and metanephrines were measured before and after strong cooling of 1 hand. Acral skin blood flow, tympanic temperature, heart rate, and mean blood pressure were measured during moderate cooling of 1 hand. In addition, clinical symptoms indicative of thermoregulatory disturbances were recorded.

RESULTS

Patients with chronic fatigue syndrome reported significantly more shivering, sweating, sudden change of skin color, and feeling unusually warm. At baseline, patients with chronic fatigue syndrome had higher levels of norepinephrine, heart rate, epinephrine, and tympanic temperature than control subjects. During cooling of 1 hand, acral skin blood flow was less reduced, vasoconstrictor events occurred at lower temperatures, and tympanic temperature decreased more in patients with chronic fatigue syndrome compared with control subjects. Catecholamines increased and metanephrines decreased similarly in the 2 groups.

CONCLUSIONS

Adolescent patients with chronic fatigue syndrome have abnormal catecholaminergic-dependent thermoregulatory responses both at rest and during local skin cooling, supporting a hypothesis of sympathetic dysfunction and possibly explaining important clinical symptoms.

Treatment of chronic fatigue and orthostatic intolerance with propranolol

We describe the effect of propranolol in an adolescent with chronic fatigue syndrome and orthostatic intolerance. Our observations suggest that the head-up tilt-test and beta-blocker treatment might be considered in patients with chronic fatigue syndrome and that enhanced sympathetic nervous activity might be part of the underlying pathophysiology.

Treatment of patients with Eisenmenger's syndrome with Bosentan

We treated prospectively 14 patients with Eisenmenger's syndrome, with a mean age of 10 years, ranging from 3 to 18 years. Treatment continued for 12 months, and demonstrated a lasting symptomatic improvement, but no improvement in terms of mean saturation of oxygen over 24 hours. Exercise capacity, as judged by peak uptake of oxygen, worsened in the six patients able to perform a treadmill test. The symptomatic benefit from dual blockage of endothelin receptors in these patients may be due to mechanisms other than selective pulmonary vasodilatation alone.

Usefulness of an abnormal cardiovascular response during low-grade head-up tilt-test for discriminating adolescents with chronic fatigue from healthy controls

Hemodynamic dysfunction is documented in chronic fatigue syndrome (CFS). This study was conducted to investigate cardiovascular responses to orthostatic stress in adolescents with CFS, using a novel procedure for tilt-table testing. A total of 27 adolescents with CFS and 33 healthy control subjects with equal age and gender distribution underwent 15 minutes of 20 degrees head-up tilt testing. Heart rate, systolic blood pressure (BP), mean BP, diastolic BP, stroke index, total peripheral resistance index, end-diastolic volume index, and acceleration index were continuously and noninvasively recorded. At rest, patients with CFS had higher total peripheral resistance index values (p<0.01) and lower stroke index and end-diastolic volume index values (p<0.05) than controls. During 20 degrees head-up tilt testing, patients with CFS had greater increases in heart rate, diastolic BP (p<0.001), mean BP (p<0.01), and total peripheral resistance index (p<0.05) than controls and greater decreases in stroke index (p<0.05). Syncope or near syncope was not observed. In conclusion, this study found that adolescents with CFS have significant abnormalities of cardiovascular regulation in response to mild orthostatic stress, differentiating them from healthy controls.

Preoperative lung function in newborn infants with univentricular hearts compared with healthy controls

AIM

To measure the difference in lung function between newborns with univentricular hearts and healthy controls and study associations between lung function and pulmonary blood flow and pulmonary vasculature markings.

METHOD

Tidal flow-volume measurements and single occlusion tests were performed before surgery on 25 unsedated spontaneously breathing newborns with univentricular hearts recruited over a 3-year period. Seventy-five healthy control infants were measured. Pulmonary blood flow was graded according to the haemodynamic effect of the echocardiographically defined anatomy of the heart defect. Pulmonary vasculature was graded according to radiological markings.

RESULTS

The infants with univentricular hearts had a lower mean tidal volume of 4.7 ml (CI 2.3, 7.2, p < 0.001) (n = 24) and a lower mean compliance of the respiratory system of 12.7 ml/kPa (CI 4.6, 20.8, p = 0.004) (n = 14). Pulmonary blood flow grading was associated with respiratory rate (r = 0.53, p < 0.001), tidal volume (r =-0.48, p < 0.001), compliance (r =-0.55, p < 0.001) and resistance (r =-0.31, p = 0.043). Pulmonary vasculature grading was associated with compliance (r =-0.68, p = 0.006), resistance (r =-0.69, p = 0.007) and the time constant (r =-0.62, p = 0.042).

CONCLUSION

Newborns with univentricular hearts have reduced tidal volumes and reduced compliance of the respiratory system. The lung function abnormalities are associated with the degree of pulmonary blood flow and pulmonary vasculature markings.

Pulmonary arterial hypertension in adults born with a heart septal defect: the Euro Heart Survey on adult congenital heart disease

AIM

To investigate the role of pulmonary arterial hypertension (PAH) in adult patients born with a cardiac septal defect, by assessing its prevalence and its relation with patient characteristics and outcome.

METHODS AND RESULTS

From the database of the Euro Heart Survey on adult congenital heart disease (a retrospective cohort study with a 5-year follow-up), the relevant data on all 1877 patients with an atrial septal defect (ASD), a ventricular septal defect (VSD), or a cyanotic defect were analysed. Most patients (83%) attended a specialised centre. There were 896 patients with an ASD (377 closed, 504 open without and 15 with Eisenmenger's syndrome), 710 with a VSD (275, 352 and 83, respectively), 133 with Eisenmenger's syndrome owing to another defect and 138 remaining patients with cyanosis. PAH was present in 531 (28%) patients, or in 34% of patients with an open ASD and 28% of patients with an open VSD, and 12% and 13% of patients with a closed defect, respectively. Mortality was highest in patients with Eisenmenger's syndrome (20.6%). In case of an open defect, PAH entailed an eightfold increased probability of functional limitations (New York Heart Association class >1), with a further sixfold increase when Eisenmenger's syndrome was present. Also, in patients with persisting PAH despite defect closure, functional limitations were more common. In patients with ASD, the prevalence of right ventricular dysfunction increased with systolic pulmonary artery pressure (OR = 1.073 per mm Hg; p<0.001). Major bleeding events were more prevalent in patients with cyanosis with than without Eisenmenger's syndrome (17% vs 3%; p<0.001).

CONCLUSION

In this selected population of adults with congenital heart disease, PAH was common and predisposed to more symptoms and further clinical deterioration, even among patients with previous defect closure and patients who had not developed Eisenmenger's physiology.