Mechanical aortic and mitral valve replacement in infants and children.

BACKGROUND: The aim of this study was to evaluate early and late outcomes after mechanical systemic heart valve replacement in pediatric patients. METHODS: Between October 1981 and December 2003, 32 children (mean age 7.2 +/- 5.4 years; 4 months - 15.9 years) underwent mechanical mitral (MVR, n = 17), aortic (AVR, n = 13) or double valve replacement (DVR, n = 2) with St. Jude Medical valves. Twenty-two patients (69 %) had undergone previous cardiac surgery. Anticoagulation self-management was used since 1995. RESULTS: The operative mortality was 3.1 %. Perioperative complications were complete heart block (n = 5), ventricular fibrillation (n = 1) and myocardial infarction (n = 1) and were exclusively related to patients with MVR. Mean calculated valve size ratio (geometric prosthesis orifice area/normal valve size area) was 1.72 (1.07 - 2.85) for AVR and 1.4 (0.88 - 3.12) for MVR. Mean follow-up was 9.1 +/- 6.6 years (range 0.4 - 23.2 years, cumulative 283 patient-years). There were two late deaths in patients with MVR. Actuarial survival after 10 years was 93.8 %. Late complications were endocarditis (n = 2), minor hemorrhagic event (n = 1), and stroke (n = 1). Anticoagulation self-management is well accepted by all patients/parents. Overall 10-year freedom from any anticoagulation-related adverse event with phenprocoumon was 89.1 % (1.2 %/patient year). Nine patients required reoperations: redo-MVR (outgrowth of prostheses (n = 3), pannus overgrowth (n = 2), closure of paravalvular leak after AVR (n = 2), partial aortic valve thrombosis (n = 1) and redo-DVR (n = 1 for endocarditis). Freedom from reoperation after 10 years was 80.9 %. CONCLUSIONS: Mechanical valve prostheses are a valuable option for left-sided heart valve replacement in pediatric patients. Perioperative morbidity was exclusively related to patients with MVR. Oversizing was often possible to avoid early reoperation for outgrowth. The operative mortality and long-term morbidity are acceptable. Anticoagulation self-management is safe and well accepted.

First experience with an oral combination therapy using bosentan and sildenafil for pulmonary arterial hypertension.

BACKGROUND: New oral substances such as beraprost, bosentan and sildenafil have proven effective in different forms of pulmonary arterial hypertension (PAH), both alone and in combination with standard treatment such as intravenous and inhaled prostacyclins. However, there are few reports so far on the effect of a combination of exclusively oral substances. In this paper, we present our initial findings of treatment using a combination of these oral substances in a heterogeneous group of patients with different forms of PAH. MATERIALS AND METHODS: Eleven patients with a median age of 12.9 years (5.5-54.7 years) with both idiopathic PAH and forms associated with congenital cardiac defects (PAH-CHD) with a mean pulmonary arterial pressure > 25 mmHg were enrolled in an observational, open-label, prospective, single-centre study. Either combination treatment with bosentan and sildenafil was started initially, or an existing bosentan treatment was complemented with sildenafil given as an add-on therapy. Mean doses given were 2.3 +/- 0.6 mg kg(-1) for bosentan and 2.1 +/- 0.9 mg kg(-1) for sildenafil. Clinical status, exercise capacity, and haemodynamics were assessed at baseline and at the end of the observation period after a mean follow-up time of 1.1 years (0.5-2.5 years). RESULTS: No major side effects regarding liver function and blood pressure regulation were noted. One patient died of sudden death elsewhere. Most patients were in New York Heart Association (NYHA) functional class III. Clinical improvement was about one NYHA class (mean 2.8 +/- 0.4-1.6 +/- 0.8, P = 0.001), which was associated with an increase of transcutaneous oxygen saturation (89.9 +/- 9.9-92.3 +/- 7.1%; P = 0.037), maximum oxygen uptake (18.1 +/- 6.8-22.8 +/- 10.4 mL kg(-1) x min; P = 0.043), and 6-minute walking distance (351 +/- 58-451 +/- 119 m; P = 0.039). Mean pulmonary arterial pressure measured invasively decreased (62 +/- 12-46 +/- 18 mmHg; P = 0.041). CONCLUSIONS: In our patient group, a combination of oral bosentan and sildenafil proved to be safe and effective. Clearly, randomized, double-blind, placebo-controlled studies are warranted to define the role and type of combination therapies in PAH.

[Levosimendan-long-term inodilation in an infant with myocardial infarction]. / Säugling mit therapie-refraktärer suprasystemischer pulmonaler Hypertonie nach MyokardinfarktIntermittierende Stabilisierung mit Levosimendan, einem neuartigen Langzeit-Inodilatator.

An infant with myocardial infarction due to congenital stenosis of the left coronary artery with consecutive left ventricular dysfunction and mitral regurgitation developed refractory pulmonary hypertension (PHT) and recurrent PHT crises. Catecholamines to support cardiac function, or pulmonary vasodilators like inhaled nitric oxide showed no effect. Treatment with Levosimendan (Simdax), a new inodilator, combining both inotropic and pulmonary vasodilating effects, improved left ventricular dysfunction, increased cardiac index, decreased pulmonary vascular resistance and reduced frequency and extent of the PHT crises. This case may suggest the use of Levosimendan as a long-term inotropic agent and pulmonary vasodilator in children with depressed cardiac function.

Proximal left coronary artery occlusion in a 15-year-old boy with noonan syndrome and hypertrophic cardiomyopathy.

Whereas intra- and extramural coronary artery narrowing have been found in patients with hypertrophic cardiomyopathy, occlusion of extramural coronary arteries has not been reported. Also, only three cases with Noonan syndrome and congenital coronary artery anomalies have been described. We report a patient with Noonan syndrome, hypertrophic cardiomyopathy, and complete occlusion of the proximal left coronary artery.

Fate of intramural coronary arteries after arterial switch operation.

BACKGROUND: To evaluate the impact of intramural coronary arteries for the peri-, postoperative and long-term course after arterial switch operation (ASO). METHODS: ASO was performed in 351 patients between 1981 and 2000 with dextrotransposition of the great arteries (d-TGA). Five patients (1.4 %) had an intramural coronary artery. Coronary transfer was performed with a collar under dissection of the commissure without longitudinal splitting of the intramural section. RESULTS: None of these patients died; the intraoperative course was uneventful, and no myocardial ischemic changes were observed. In three patients, follow-up cardiac catheterization after 5, 16 and 53 months revealed an occlusion of the intramural coronary ostium. Exercise electrocardiography and myocardial scintiscan showed myocardial ischemia. Two of these patients underwent a successful internal mammary artery bypass. CONCLUSIONS: The intramural course of coronary arteries in patients with d-TGA is rare and does not cause increased mortality or myocardial infarction rates. However, the risk of coronary occlusion over time seems to be high. Therefore, patients with this condition require selective coronary angiography and frequent exercise investigations. Revascularization with an internal mammary artery bypass may be indicated.

Long term complications of inferior vena cava thrombosis.

AIM: To evaluate the long term outcome after paediatric inferior vena cava (IVC) thrombosis. METHODS: A combined retrospective and prospective study on infants and children with IVC thrombosis treated at Aachen and Maastricht University Hospitals between 1980 and 1999. RESULTS: Forty patients were enrolled, including four with preceding cardiac catheterisation, 18 with central venous saphenous lines, and an additional eight with umbilical venous catheters. Six patients died within three months of diagnosis; one patient was lost to follow up. Twelve of the remaining 33 patients had suffered from limited IVC thrombosis; during follow up (for up to nine years) none showed persisting caval obstruction (successful thrombolysis, n = 2; spontaneous recanalisation, n = 10). The remaining 21 patients presented with extensive IVC thrombosis. During follow up (for up to 18 years) complete restitution was found in only four cases (one thrombolysis, two surgery, one spontaneous recanalisation). Persisting iliac and/or caval venous obstruction occurred in 17 patients, including six with thrombolysis. Varicose veins were found in 12, and post-thrombotic syndrome in seven of these cases. According to Kaplan-Meier analysis, 30% of patients with persisting venous disease will develop post-thrombotic syndrome within 10 years of the thrombotic event. CONCLUSIONS: Infants and children with extensive IVC thrombosis are at high risk for persisting venous disease and serious long term complications. Prospective trials are urgently needed to establish effective treatment strategies and to improve long term prognosis. Central venous catheters, contributing to IVC thrombosis in the majority of cases reported here, should be inserted only if essential.

Twenty years experience with pediatric pacing: epicardial and transvenous stimulation.

OBJECTIVE: Permanent cardiac pacing in children and adolescents is rare and often occurs by means of epicardial pacing. Based on two decades of experience, operative and postoperative data of patients with epicardial and transvenous pacing were analyzed retrospectively. METHODS: Between October 1979 and December 1998, 71 patients (mean age, 5.3+/-4.2, range, 1 day-16.2 years; mean body weight, 18+/-12; range, 8-56 kg) underwent permanent pacemaker implantation. Indications were sinus node dysfunction and atrio-ventricular block following surgery for congenital heart disease (69%), or congenital atrioventricular block (31%). Pacing was purely atrial (1.4%), purely ventricular (73%), ventricular with atrial synchronization (5. 6%), or atrioventricular synchronized (20%). Epicardial pacing was established in 49 (69%), transvenous in 22 (31%) patients. Follow-up was 3.4+/-3.8 years (epicardial) and 3.0+/-4.0 years (transvenous). RESULTS: Epicardial leads were implanted in younger patients (mean age: 4.5 vs. 7.0 years, P<0.05) and preferably after surgery induced atrioventricular block (78 vs. 46%, P<0.05). The youngest patient with transvenous pacing was 1.3 years old (weight, 8.5 kg). At implantation epicardial ventricular stimulation threshold at 1.0 ms was 1.07+/-0.46 vs. 0.53+/-0.31 V (transvenous) (P<0.05). The age-adjusted rate of lead-related reoperations was significantly higher in patients with epicardial leads (P<0.05), mainly due to increasing chronic stimulation thresholds resulting in early battery depletion. In three patients who received steroid-eluting epicardial leads initial low thresholds persisted after five month to one years. In two patients with recurrent epicardial threshold increase, steroid-eluting epicardial leads led to good acute and chronic thresholds after nine to 15 month. Two post-operative death (2.8%) were probably due to a dysfunction of the (epicardial) pacing system. CONCLUSIONS: Transvenous pacing in the pediatric population is associated with a lower acute stimulation threshold and a lower rate of lead-related complications. If epicardial pacing is necessary (e. g. small body weight, special intracardiac anatomy (e.g. Fontan), impossible access to superior caval vein), steroid-eluting leads may be considered.

Pericardial effusions in infants and children: injection of echo contrast medium enhances the safety of echocardiographically-guided pericardiocentesis.

Pericardiocentesis is usually an easy and uncomplicated procedure when guided by cross-sectional echocardiography, but an abnormal intracardiac or extrapericardial position of the puncture system can occur, especially in children. Injection of echo contrast medium through the puncture needle is a very sensitive, quick, easy and harmless procedure which can be performed at the bedside in all cases in which doubt remains concerning the location of the needle. Prompt enhancement of signal intensity of the pericardial fluid validates the correct intrapericardial position, and permits visualization of the tip of the needle. Absence of echodense formations excludes an intrapericardial position. We recommend the use of echo contrast medium during pericardiocentesis whenever blood is aspirated through the needle, or if there is any doubt concerning its location.

Detection of abnormal aortic elastic properties in asymptomatic patients with Marfan syndrome by combined transoesophageal echocardiography and acoustic quantification.

OBJECTIVE: To evaluate the potential value of transoesophageal echocardiography combined with automated border detection and acoustic quantification for the assessment of elastic properties of the thoracic aorta in patients with Marfan syndrome. SUBJECTS: 16 patients with Marfan syndrome and 12 age matched normal controls. METHODS: Transoesophageal echocardiography was performed in all subjects. Minimum and maximum diameters of the descending thoracic aorta were obtained from M mode images and acoustic quantification was used for the on-line evaluation of cross sectional aortic area and peak positive area changes over time. Compliance, distensibility, and stiffness index were calculated using M mode data and non-invasively measured blood pressure and were compared with the indices derived from acoustic quantification. RESULTS: Aortic dimensions normalised for body surface area were not statistically different between patients and normal controls, but there were significant differences for all elasticity indices except compliance. Marfan patients had a lower distensibility [4.2 (SD 1.8) v 5.8 (2.1) cm2/dyn, P < 0.05] and a higher stiffness index [9.7 (3.0) v 7.1 (1.8), P < 0.05]. The dynamic indices derived from the acoustic quantification were significantly smaller in Marfan patients [peak positive area change: 5.1 (1.0) v 7.7 (1.7) cm2/s; P < 0.001; and normalised peak positive area change: 2.5 (1.2) v 4.0 (0.8) cm2/s respectively, P < 0.001] and were suitable to discriminate between normal and abnormal elastic properties. CONCLUSIONS: In Marfan syndrome elastic properties of the descending aorta are significantly different from normal controls, even in the absence of vessel dilatation. In addition to established static indices, indices derived from acoustic quantification reflect dynamic changes of the cross sectional area for the evaluation of regional vessel mechanics. The on-line assessment of peak positive area change allows differentiation from normal individuals and may be more accurate than standard M mode measurements.

[The management of adolescents and adults with congenital heart defects: 3 years experiences with interdisciplinary consultation]. / Die Betreuung von Adoleszenten und Erwachsenen mit angeborenem Herzfehler: 3 Jahre Erfahrungen mit einer interdisziplinären Sprechstunde.

UNLABELLED: Since September 1991, 204 patients (pts), 109 male and 95 female, mean age 27.3 +/- 10.6 years, were followed in a newly established interdisciplinary outpatient clinic combining both adult and pediatric cardiologists. 61 pts predominantly presented with left-to-right shunt congenital heart disease (CHD), 32 with valvar CHD, 20 with aortic coarctation, 23 with complex acyanotic, and 49 with cyanotic CHD. The population included 19 pts with Marfan syndrome. 106 pts had had previous cardiac surgery, 32 of them with up to three reoperations. Deficits and needs in medical and social care were analyzed in 100 pts using a standardized questionnaire at the time of first examination: One-third of pts were not or only incompletely informed about their CHD, previous surgical procedures and need for antibiotic prophylaxis of endocarditis. Only a minority of pts had had vocational advice (34%) or counseling concerning contraception (40%) or pregnancy (30%). Cardiac catheterization was performed in 37 pts (18%) after being first seen in our outpatient clinic, followed by a primary surgical intervention in 19 and reoperation in eight cases. Overall, 30 pts (15%) underwent surgery (28) or interventional procedures (one closure of the arterial duct, one AV node ablation after Mustard-operation) as a consequence of admission to our unit. Successful late Fontan operations were performed in four adults aged 21 to 35 years. There was 1/30 postoperative death (M. Ebstein, thrombosis of the mechanical prosthesis). The population includes five pts with severe pulmonary vascular disease (one waiting for lung transplantation) and two pts with pulmonary artery arborisation malformations not amenable to surgery. CONCLUSION: In a population of 204 adolescents and adults with CHD, we clearly found deficits in medical and social care and, in addition, an unexpected high percentage of necessary invasive investigations (18%) and surgical or interventional procedures (15%). Interdisciplinary management of these patients is mandatory combining the special facilities of adult and pediatric cardiologists.

Cardiac involvement in tuberous sclerosis.

OBJECTIVE: To assess the incidence, importance, and history of cardiac involvement in infants and children with tuberous sclerosis. DESIGN: Prospective study; clinical examination, sector and Doppler echocardiography, standard and ambulatory electrocardiography. SETTING: A tertiary referral centre. PATIENTS: 21 patients with tuberous sclerosis aged 1 day to 16 years (mean 6.3 years); follow up investigations were available in 14 cases (10 retrospective, 4 prospective; mean follow up 4.3 years). RESULTS: Multiple cardiac rhabdomyomas in the right ventricle (11) and left ventricle (14) as well as in the right atrium (1) were present in 14/21 patients. Two of them had obstruction of the left ventricular inflow and outflow tract related to a tumour. In the remaining 7 patients, echocardiography was normal in 4 and equivocal in 3 cases. The standard electrocardiogram (n = 20) showed ventricular hypertrophy (2), ventricular pre-excitation (1), arrhythmias (2), and repolarisation disturbances (4) in 7/13 patients with rhabdomyomas but was normal in all patients with a normal or equivocal echocardiogram. The ambulatory electrocardiogram (n = 19) showed frequent premature atrial (2) and polymorphous ventricular (2) contractions. The polymorphous ventricular contractions coexisted with rhabdomyomas. No arrhythmias that needed medical treatment were found. Follow up investigations showed return to a normal standard electrocardiogram in 3 patients. Definite regression or complete disappearance of the tumour occurred in 6 infants. CONCLUSIONS: Cardiac rhabdomyomas, although often present in these patients with tuberous sclerosis, caused neither major arrhythmias nor haemodynamic obstruction except in the neonatal period. The indication for operation is limited to cases with life threatening obstruction or arrhythmias refractory to medical treatment.

Arrhythmias in infants and children with primary cardiac tumours.

Twenty-one patients, aged from 1 day to 16 years (median 8 months), with primary cardiac tumours, were studied with regard to the occurrence of arrhythmias. Standard electrocardiogram (ECG) was available in 20 cases and 24 h ambulatory ECG in 19; nine patients had prospective follow-up investigations (mean follow-up time 3.0 years). Standard ECG revealed preexcitation in two and arrhythmias in six patients. Ambulatory ECG disclosed seven patients with significant rhythm disturbances and in four of these, the arrhythmia was the symptom leading to the diagnosis of a cardiac tumour. Three patients were symptomatic from arrhythmia and two of them were successfully treated with antiarrhythmic agents. The remaining patient with recurrent life-threatening ventricular tachycardia underwent partial resection of a large left ventricular fibroma; no further episodes of ventricular tachycardia were observed postoperatively. Only one of the 15 patients with cardiac rhabdomyomas required antiarrhythmic therapy. None of the nine patients prospectively followed developed arrhythmias requiring therapy. The present data underline the fact that infants and children with cardiac tumours rarely need surgery because of arrhythmia resistant to medical treatment. As far as possible, conservative management is indicated in infants with suspected rhabdomyomas.

Evaluation of aortic coarctation after surgical repair: role of magnetic resonance imaging and Doppler ultrasound.

OBJECTIVE: To compare the usefulness of magnetic resonance imaging (MRI) and Doppler ultrasound with that of cross sectional echocardiography and oscillometric blood pressure measurement for the evaluation of aortic coarctation after surgical repair. DESIGN: Prospective study. Aortic diameters measured by cross sectional echocardiography, MRI, and angiography (selected cases) and functional data determined by physical examination, oscillometric blood pressure measurement, and continuous wave Doppler. SETTING: Tertiary referral centre. PATIENTS: 40 patients aged 2-28 years (mean 10.6 years) who had had surgical correction of aortic coarctation (mean follow up 5.7 years). RESULTS: In all patients MRI gave diameter measurements of the aortic arch and the thoracic aorta whereas in half of them cross sectional echocardiographic measurement of the isthmic region failed. The correlation coefficient for aortic diameters measured by MRI and angiography was 0.97 and that between MRI and echocardiography was 0.89. Peak velocities in the descending aorta correlated better with residual narrowing of the aortic isthmus or distal aortic arch or both than systolic blood pressure gradients between the upper and lower limbs. A peak velocity of < 2 m/s in the descending aorta during systole excluded important restenosis. Prolongation of anterograde blood flow during diastole always indicated a morphological abnormality--either important restenosis or aneurysmal dilatation. CONCLUSIONS: MRI was better than cross sectional echocardiography for imaging the aortic arch after coarctation repair and measuring its diameter. Peak velocity in the descending aorta correlated better with residual stenosis than did the systolic blood pressure gradient between the upper and lower limbs and this index could be used to indicate a need for MRI.

Detection of sinus venosus atrial septal defect by two-dimensional echocardiography.

In a 4-year period, 10 patients (mean age, 3.6 years) with a superior type sinus venosus atrial septal defect were investigated by two-dimensional echocardiography. The defects were easily visualized in all patients using a long axis vena cava superior-inferior plane with a subcostal approach, while the atrial septum seemed to be intact in the coronal plane conventionally used for atrial septal defects of the primum or secundum type. Additional colour flow mapping, performed in two patients, demonstrated shunting across the depicted defect. In our experience, the modified plane is of great diagnostic value in cases with a sinus venosus defect.