Mitral and aortic regurgitation in 84 patients with mucopolysaccharidoses.

UNLABELLED: In echocardiographic and necropsy studies nodular thickening of the mitral valve and, less frequently, of the aortic valve has been found in 60%-90% of patients with mucopolysaccharidoses (MPS). Little is known about the haemodynamic consequences of these morphological changes. In this study 84 unselected patients with different enzymatically proven MPS and 84 age and sex matched, healthy persons were studied prospectively by colour Doppler flow mapping. The patients' age ranged from 1 to 47 years (median 8.1 years). Mitral and aortic regurgitation were defined as a holosystolic or holodiastolic jet originating from the valve into the left atrium or the left ventricular outflow tract, respectively, with peak velocities exceeding 2.5 m/s. Of the 84 patients with satisfactory studies, mitral regurgitation was detected in 64.3% and aortic regurgitation in 40.5%, respectively. Regurgitation was severe in 4.8% of mitral valves and 8.3% of aortic valves. The frequency of aortic and/or mitral regurgitation was 75% in all patients, 89% in MPS I, 94% in MPS II, 66% in MPS III, 33% in MPS IV, and 100% in MPS VI. Combined mitral and aortic regurgitation was present in 29% of our patients. None of the control persons showed mitral or aortic regurgitation. CONCLUSION: Aortic and mitral regurgitation are more frequent in patients with MPS than previously thought and that therefore these patients should have regular colour Doppler flow mapping and antibiotic prophylaxis when required.

Effects of tolazoline and prostacyclin on pulmonary hypertension in infants after cardiac surgery.

OBJECTIVE: To evaluate the hemodynamic effects of tolazoline and prostacyclin in infants with pulmonary vasospasm after cardiac surgery. DESIGN: Prospective cohort study. SETTING: Pediatric ICU. PATIENTS: The cohort consisted of 42 infants and children with congenital heart disease and pulmonary hypertension who underwent corrective surgery and were monitored postoperatively using pulmonary artery catheters. Fourteen infants (2 to 12 months old) in this group required postoperative treatment with tolazoline or prostacyclin. INTERVENTIONS: Tolazoline was administered as a bolus of 0.5 mg/kg for treatment of persistent pulmonary hypertension or acute pulmonary hypertensive crisis. If its effectiveness was proved after 30 mins by hemodynamic measurements, a continuous iv infusion of 0.5 mg/kg/hr was established. Higher doses of tolazoline were avoided. If tolazoline treatment did not fulfill the criteria for pulmonary vasodilation, prostacyclin was given by continuous iv infusion at a starting rate of 5 ng/kg/min, followed by 10 ng/kg/min. In three patients, the infusion rate was increased to 15 ng/kg/min. RESULTS: Bolus administration of tolazoline resulted in a distinct pulmonary vasodilation in seven infants: mean pulmonary artery pressure and pulmonary vascular resistance decreased by an average of 35% and 45%, respectively. In these patients, tolazoline was infused over the following 12 to 72 hrs. One infant who received tolazoline for 72 hrs developed a clinically important gastrointestinal hemorrhage. In seven nonresponders to tolazoline, prostacyclin (PGI2) at an infusion rate of 5 ng/kg/min led to pulmonary vasodilation in five patients, at an iv infusion rate of 10 ng/kg/min in all seven infants studied. The latter dose of PGI2 reduced the mean pulmonary artery pressure by an average of 37%, and pulmonary vascular resistance by 43%. Transient withdrawal of prostacyclin in five infants demonstrated its short half-life and clinical effectiveness. Apart from a facial flush, no side-effects were encountered using PGI2 as an infusion over durations ranging from 12 to 504 hrs. CONCLUSIONS: These data suggest that, if tolazoline in a relatively low dose proves to be inefficient, prostacyclin can still be used as a safe and effective drug for treatment of pulmonary vasospasm. Prostacyclin offers more than a pharmacologic alternative to increased tolazoline dosages.

Determination of cardiac output by an angle and diameter independent dual beam Doppler technique in critically ill infants.

OBJECTIVE: To compare cardiac output measurements in critically ill infants by the dual beam Doppler and thermodilution techniques. DESIGN: Prospective direct comparison of the two techniques. For statistical evaluation one randomly assigned paired measurement of every patient was used. SETTING: Paediatric intensive care unit in a university hospital. PATIENTS: 18 infants after open heart surgery aged 4-25 months (weight 4-10 kg). INTERVENTIONS: Cardiac output measurements by dual beam Doppler and thermodilution techniques were performed within 10 minutes of each other and without knowledge of the results of the other methods. Multiple measurements were performed on some patients with a pharmacological or electrophysiological intervention or with a minimum of six hours between each pair of measurements. MEASUREMENTS AND MAIN RESULTS: Three patients were excluded because of an inadequate Doppler signal or a significant residual shunt. Cardiac output measurements ranged from 0.4 to 2.2 l/min for the thermodilution technique and from 0.5 to 2.1 l/min for the dual beam Doppler technique. Agreement between both methods was acceptable. The mean difference between the two methods was 0.026 l/min with two standard deviations ranging from -0.20 to 0.26 l/min. CONCLUSION: The dual beam Doppler technique was shown to have promise for the non-invasive determination of cardiac output in critically ill infants.

Evaluation of the valve area underestimation by the continuity equation.

During the last years, noninvasive determination of the aortic valve area by Doppler echocardiography using the continuity equation became popular. However, a systematic valve area underestimation of about 15% compared to invasive measurements using the Gorlin formula has been reported. The cause therefore is unknown. The purpose of this study was to evaluate whether the valve area underestimation by the Doppler method might be due to differences in the hydrodynamic background of both methods. This comparison is facilitated by the fact that the Gorlin formula is based on the continuity equation. Compared to the continuity equation, there are four changes within the Gorlin formula: (1) the additional use of a discharge coefficient, which leads to valve area overestimation by the factor 1.17; (2) neglect of the pre-stenotic velocity, causing further overestimation by the factor 1.036 (in mild stenosis this factor may be 1.18 and more); (3) the wrong calculation of the mean pressure drop, which leads to a mean change by the factor 0.95, and (4) the incorrect substitution of the height by the pressure drop in the derivation of the Gorlin formula causes underestimation by the factor 0.97. Combining these four factors results in valve area overestimation of the Gorlin formula compared to the continuity equation by the factor 1.12. This explains to a large extent the valve area underestimation by the continuity equation.

Congenital mitral regurgitation caused by a perforation in the anterior leaflet: perioperative evaluation by color-coded Doppler echocardiography.

Color-coded two-dimensional (2D) echocardiography confirmed the presence of severe congenital mitral regurgitation in an 8-month-old infant. Intraoperative inspection revealed an isolated perforation in the anterior leaflet.

Acute hemodynamic response to intravenous enoximone: an animal study and preliminary report in infants after cardiac surgery.

In light of previous studies in adults, we considered that enoximone could be useful in treating children with therapy-resistant cardiovascular insufficiency. Prior to clinical administration, we investigated the cardiovascular properties of enoximone in anesthetized and ventilated piglets characterized by small stroke volume and high heart rate. Enoximone was administered intravenously in increasing doses (0.25, 0.5, and 1 mg/kg). The animals were monitored with heart rate, systemic and pulmonary arterial pressures, and continuous electromagnetic flow. Enoximone induced a dose-dependent flow increase, whereby heart rate and systemic arterial pressure changed only slightly. With regard to persistent pulmonary hypertension in newborns, enoximone was also used in piglets to investigate the effects on endotoxin-induced, dopamine-resistant pulmonary hypertension. Enoximone (1 mg/kg i.v.) was given immediately after E. coli endotoxin (1.5 micrograms/kg i.v.) and inhibited the endotoxin-induced, eicosanoid-mediated pulmonary hypertension, whereas during infusion of dopamine (2 mg/kg/h), no drop in systemic blood pressure could be observed. In the clinical study, six infants with post-cardiac surgery low output syndrome despite maximal catecholamine inotropic support were given enoximone (i.v. bolus of 0.2, 0.5, or 1 mg/kg followed by continuous infusion of 7.5-10 micrograms/kg/min). Continuously measured mixed-venous oxygen saturation increased in a dose-related manner. Cardiac output increased significantly by 28%, accompanied by a decrease of arteriovenous oxygen content difference and O2 utilization ratio. The preliminary results show that intravenous enoximone produces acute useful hemodynamic effects in infants, in particular allowing a weaning of vasoactive amines.

Continuous monitoring of mixed venous oxygen saturation in infants after cardiac surgery.

Continuous mixed venous oxygen saturation (SvO2c) was measured in 16 infants immediately after cardiac surgery. A polyurethane 4F, dual channel catheter (Opticath, Modell U440, Oximetrix) with fiberoptic filaments was introduced into the pulmonary artery during cardiothoracic surgery. The catheters were left in place for an average of 67.5 h (range 27 h -125 h) and there were no catheter-related complications. Correlation between continuous in vivo SvO2 values and in vitro values was satisfactory (r = 0.85), whereas a correlation between SvO2c and arterial oxygen saturation (SaO2) was not found (r = 0.07). The sampled arterial lactate values were inversely correlated to the simultaneously measured SvO2c, but the correlation coefficient was only r = -0.4. There was an inverse correlation between SvO2c and arteriovenous oxygen content difference (Ca-vDO2) (r = -0.82), and a marked inverse correlation to the calculated oxygen utilization ratio (r = -0.97). Therefore SvO2c continuously reflects the overall balance between oxygen consumption and delivery, but the use of SvO2 as a predictor of blood lactate levels is unreliable. A further purpose of the present study was to demonstrate the clinical applications and to show the usefulness of SvO2c-monitoring; particularly as a surveillance and early warning system, as a guide for assessing therapy and its relevance in interpreting other monitored parameters. In our opinion continuous SvO2 measurement is a reliable and valuable indicator of cardiopulmonary function in the immediate post-operative period, even in infants with complicated repair of cardiac malformations.

[Supravalvular pulmonary stenosis following anatomic correction of transposition of great vessels: report of a successful balloon dilatation]. / Supravalvuläre Pulmonalstenose nach anatomischer Korrektur bei Transposition der grossen Gefässe: Bericht über eine erfolgreiche Ballondilatation.

Primary anatomical repair of TGA has several theoretical advantages over conventional atrial baffle techniques. However, one of the most common postoperative complications of the new technique is the development of an obstruction at the arterial anastomosis to the pulmonary artery (PA). A supravalvular pulmonary stenosis developed progressively over the first months after an arterial switch operation of a simple TGA in a newborn infant. The diagnosis was easily performed by Doppler-echocardiographic follow-up studies. Hemodynamic assessment by cardiac catheterization performed when the patient was five months old revealed a systolic gradient of 76 mm Hg at the arterial anastomosis. Percutaneous balloon angioplasty was successfully performed.

[Congestive heart failure in a newborn infant with arteriovenous malformation of the vein of Galen: diagnosis using color-coded Doppler image echography]. / Kongestive Herzinsuffizienz bei einem Neugeborenen mit arteriovenöser Malformation der Vena Galeni: Diagnose mittels farbkodierter Doppler-Bild-Echographie.

Arteriovenous malformations of the vein of Galen are rare disorders that may appear in the newborn period with severe congestive heart failure mimicking many intrinsic cardiac defects. Using combined two-dimensional ultrasound and color-coded blood flow mapping arterio-venous aneurysm of the vein of Galen and congenital atrial septal defect could be diagnosed in an newborn with congestive heart failure. In addition to the presented clinical value of the new two-dimensional color Doppler echography physiological aspects of intracranial arteriovenous fistula in infancy discussed.

The effect of nifedipine alone or combined with low dose acetylsalicyclic acid on endotoxin-induced pulmonary hypertension in the piglet.

Cardiovascular responses to the calcium antagonist nifedipine, alone and combined with low dose acetylsalicyclic acid (ASA), were evaluated in a piglet model of endotoxin-induced pulmonary hypertension. All animals were anesthetized, paralyzed and mechanically ventilated. Cardiac output (CO), pulmonary artery pressure (PAP), aortic blood pressure (SAP), pulmonary capillary wedge pressure (PCWP), right atrial pressure (RAPM) and arterial blood gases were measured before and after induction of pulmonary hypertension by E. coli endotoxin and after treatment. Results of treated groups were compared to a control group of piglets subjected to the same dose (0.15 micrograms/kg i.v.) of endotoxin. Control animals responded to a bolus injection of endotoxin within 15 min with an increase in mean PAP by 110%. Pulmonary vascular resistance (PVR) increased by 144%. Mean arterial pressure did not change significantly from baseline values. In animals treated with a single dose of 1 mg/kg ASA prior to endotoxin, the initial pulmonary response was not quantitatively different from control values, whereas ASA 20 mg/kg abolished the pulmonary vascular reaction. The increase of systemic vascular resistance (SVR) produced by endotoxin was aggravated by high dose ASA. In piglets treated with nifedipine (4 micrograms/kg/min) over 30 min after the application of endotoxin with and without additional infusion of nifedipine 60 min prior to endotoxin the PVR could be attenuated. The combination of nifedipine and low dose ASA showed synergistic effects compared to control. The increase of mean PAP was significantly reduced, the PVR remained in baseline range due to a marked elevation of cardiac output.

[Color-coded Doppler echocardiography in an infant with an aortopulmonary window. A pre- and postoperative study]. / Farbkodierte Doppler-Echokardiographie bei einem Säugling mit aortopulmonalem Fenster. Eine prä- und postoperative Untersuchung.

The clinical value of the new two-dimensional color Doppler echocardiography (2D-color Doppler) for the non-invasive visualization of shunting across the aorticopulmonary window (APW) in a 5-month-old infant is described. The quality of the color-coded bloodflow mapping may be equal to that of angiography. The sensitivity of the method is demonstrable by the minimal diastolic shunt across the operated APW. The 2D-color Doppler may enhance the diagnostic impact of 2D-echocardiography, especially by improving diagnostic accuracy non-invasively in critically ill infants.

Effects of dobutamine on left ventricular performance in newborns as determined by systolic time intervals.

To evaluate the effects of dobutamine on myocardial function in newborns, left ventricular systolic time intervals (STI) - normalized pre-ejection period (PEPI), normalized left ventricular ejection time (LVETI) and pre-ejection period to left ventricular ejection time ratio (PEP/LVET) - were assessed by echocardiography in 18 newborns treated with dobutamine for clinically diagnosed heart failure. Examinations were performed prior to and 30 min after starting dobutamine infusion (7.5 or 10 micrograms/kg per min). Patients were assigned to two groups according to their PEP/LVET prior to dobutamine administration: group I (n = 9) with pre-treatment PEP/LVET less than or equal to 0.35 and group II (n = 9) with pre-treatment PEP/LVET greater than 0.35. While there was no change of STI in group I, dobutamine infusion resulted in a significant decrease in PEPI (from 102 +/- 4.8 to 87.8 +/- 4.2; mean +/- SEM; P less than 0.01) and of PEP/LVET (from 0.56 +/- 0.05 to 0.45 +/- 0.05; mean +/- SEM; P less than 0.01) and in a significant increase of LVETI (from 237.6 +/- 5.6 to 253.3 +/- 5.2; mean +/- SEM; P less than 0.01) in group II. Heart rate increased significantly in both groups. Left ventricular end-diastolic dimension, also assessed by echocardiography, did not change in the eight studies performed. An increase in mean arterial pressure was found in three out of five newborns of group II and in one out of four patients in group I. It is concluded that dobutamine can improve cardiac performance in newborns with impaired left ventricular function. This effect is probably due to an improvement in myocardial contractility.

[Experiences with nifedipine in the treatment of acute hypertension in childhood]. / Erfahrungen mit Nifedipin bei der Behandlung akuter Hypertonien im Kindesalter.

The efficacy of Nifedipine (N) as an antihypertensive drug was assessed in 4 children aged 6-12 years with acute severe hypertension. In one child with a hypertensive encephalopathy N 10 mg administered sublingually in addition to other antihypertensive drugs caused a prompt fall in blood pressure followed by a rapid clinical improvement. In the other 3 children N 10 mg reduced systolic and diastolic blood pressure by 13.7% and 16.4% respectively. This antihypertensive action lasted for about 3-4 hours and was associated with an increase in heart rate by 11.5%. The antihypertensive effects of N are positively related to pretreatment blood pressure. These results provide support that N is a safe and effective drug for controlling blood pressure also in hypertensive emergencies of children.

[The treatment of arrhythmias in infants and children using propafenone]. / Die Behandlung von Herzrhythmusstörungen mit Propafenon bei Säuglingen und Kindern.

Antiarrhythmic treatment was required in 35 patients aged one day to 11 8/12 years (average 5 7/12 years) for one or several of the following arrhythmias: paroxysmal supraventricular tachycardia (17), ventricular extrasystole (16), ventricular tachycardia (17), ventricular extrasystole (16), ventricular tachycardia (4), junctional tachycardia (4), and atrial flutter (3). 300 mg/m2/day oral propafenone was administered in 3 to 4 divided doses. The arrhythmia in 21 of the 35 patients had been unsuccessfully treated by digoxin (6), verapamil (5), ajmalin (4), propranolol (3), spartein (1), phenytoin (1), and lidocain (1) prior to the propafenone therapy. However, the arrhythmias could be abolished or reduced in 30 patients (85.7%) by Propafenone. In 5 patients with supraventricular tachycardia (2), junctional tachycardia (2), or ventricular extrasystole (1), propafenone therapy had no effect. In two other patients propafenone led to atrioventricular conduction disturbances and had to be discontinued. Propafenone is an effective well tolerated antiarrhythmic drug without major side effects in pediatric patients.

[Diagnostic value of CK-MB isoenzyme determinations in children with craniocerebral injuries and polytrauma]. / Diagnostischer Wert von CK-MB-Isoenzym-Bestimmungen bei Kindern mit Schädelhirntrauma und Polytrauma.

Total creatine kinase (CK) and its myocardial isoenzyme (CK-MB) were determined in 71 children with isolated acute head injury (N = 30), with head injury and polytrauma but without chesttrauma (N = 11) and with head injury and polytrauma including chest trauma (N = 30) on the second and third day after injury. Electrocardiograms were recorded in 56/71 children on each of the first three days in hospital. Elevations of CK-MB isoenzyme over 6% respectively over 10% of total CK are found as frequently in children with head injury without chest trauma as in children with head trauma and chest trauma. In addition there is no significant correlation between the level of the CK-MB and the incidence of ECG features characteristically associated with heart contusion. This study shows that the determination of CK-MB cannot be used as a criterion for diagnosing heart contusion in children with head injury. The finding of CK-MB in the serum of 53% children with isolated head injury exceeding 6% of total CK, and in the serum of 33% children exceeding 10% of total CK strongly suggests myocardial damage to be a frequent complication of cerebral damage with consecutive extreme sympathetic stimulation.

[Drowning accidents in childhood]. / Ertrinkungsunfall im Kindesalter.

This paper reviews the pathophysiology and therapy of the multiorgan failure which occurs with submersion injury of children. First, the influence of hypothermia, the pulmonary, cardiovascular, neurologic and renal changes and the blood gas, acid-base and bloodvolume and serum electrolyte disturbances are discussed in detail. The therapeutic procedures are separated in the cardiopulmonary resuscitation at the scene of the accident and in the management of the children within the hospital where all near-drowned children should be taken. The intensity of the treatment at the hospital depends on the level of consciousness and on the respiratory and cardiovascular problems of the near-drowned child. For the treatment of comatose children with abnormal patterns of respiration and cardiovascular derangements the routine management and a more aggressive approach to therapy are presented. The rational for the aggressive therapy is to improve cerebral salvage. The urgency for an extensive monitoring system is underlined.

[Standardized morphometric studies of the right pulmonary artery in the suprasternal M-mode echocardiogram in childhood]. / Standardisierte morphometrische Untersuchung der rechten Pulmonalarterie im suprasternalen M-Mode-Echokardiogramm im Kindesalter.

236 children of all age-groups, without any evidence of cardiopulmonary disease, underwent measurement of the diameters of the right pulmonary artery (RPA) in the suprasternal M-mode echocardiogram with respect to the characteristic motion pattern of the RPA. Since a high correlation was found between these diameters and height (r = 0.94; y = 1.66 square root X - 6.19), the children were divided into 9 sub-groups according to height, and mean values were calculated for all parameters in each sub-group. The systolic expansion of the RPA ranged from 18% to 30% within groups and correlated only weakly to height (r = 0.28). Suprasternal echocardiographic standards for measurement of the RPA may enhance the usefulness of this echocardiographic approach in pediatrics.

[Dobutamine in childhood]. / Dobutamin im Kindesalter.

The synthetic catecholamine Dobutamine has potent inotropic effects. It is frequently used in the management of adult patients with low cardiac output and elevated left ventricular enddiastolic pressure not yet associated with systemic hypotension. The few available informations on hemodynamic effects of Dobutamine in children emphasize the effectiveness of this sympathomimetic amine also in the treatment of children especially older than 12 months with acute low cardiac output states. Neonates and infants appear to respond to Dobutamine as well, but possible changes in cardiovascular structure and function accompanying growth which are discussed and which could cause a considerable variance in individual patient response, require an exceptionally close monitoring of the hemodynamic effects of Dobutamine in this age-group.

[Patterns of blood pressure and pulse frequency in infants during Vojta therapy]. / Zum Verhalten von Blutdruck und Puls bei Vojta-Therapie im Säuglingsalter.

In twenty infants aged seven weeks on average blood pressure and pulse frequency were measured during physiotherapy according to Vojta. At one of the exercises ("reflex reversion") blood pressure increased at an average of 60 mm Hg compared with the basic value under rest conditions. At another exercise ("reflex supporting") blood pressure reached about 52 mm Hg higher values as under rest conditions. The pulse frequency, however, showed a less impressive increase: it corresponded approximately to the value measured during crying. As probable causes for the increase of blood pressure are discussed: sustained muscle contractions, varied intrathoracal pressure conditions, and the emotional irritations of the infants. In infants with cardiovascular disease the increased strain during physiotherapy according to Vojta should be taken into account as an additional risk.