Cardiomyopathy of glycogen storage disease type III

To identify the severity of cardiac involvement in glycogen storage disease type III (GSDIII), and its relation to skeletal muscle involvement and age, 23 patients were studied. The median age was 10 years. Echocardiography, electrocardiography, and creatine phosphokinase (CK) levels were used to assess cardiac and skeletal muscle involvement. Septal and left ventricular posterior wall measurements were compared with normal data. Shortening fraction was derived from left ventricular cavity dimensions. In some patients the echocardiogram resembled that of hypertrophic cardiomyopathy. Thirteen of 20 electrocardiograms (ECG) were abnormal. Eleven patients had septal and/or posterior wall thickness > 95% confidence limits (CL). Despite this, cardiac symptoms were uncommon. The CK levels were not directly associated with cardiac abnormalities. Older patients (> 20 years) had more abnormal measurements of posterior wall thickness than did younger ones (< 20 years). This finding, albeit in a cross-sectional series, suggests progressive myocardial involvement with age despite the absence of symptoms.

Angiographic diagnosis of anomalous coronary artery in tetralogy of Fallot

OBJECTIVE

To obtain angiographic views in tetralogy of Fallot that can show whether or not an anomalous coronary artery passes anterior to the right ventricular outflow tract.

DESIGN

(a) A 10 year retrospective review of all patients who underwent repair of tetralogy of Fallot up to December 1990; (b) a prospective study of 30 children undergoing routine cardiac catheterisation.

PATIENTS AND METHODS

295 cases in whom standard angiographic views had been used were reviewed retrospectively. Thirty non-consecutive children with tetralogy of Fallot were studied prospectively, including one child previously studied in whom diagnosis of an unsuspected anomalous coronary artery was made only at operation. The aortogram was performed with > or = 45 degrees caudocranial and 20 degrees-30 degrees left anterior oblique angles.

SETTING

Tertiary referral centre.

RESULTS

Ten of the 295 cases reviewed were shown to have a coronary vessel traversing the right ventricular outflow tract. In one case the diagnosis was suspected before operation but it was missed in the others. Even in retrospect we could not be certain of the precise anatomy with the use of standard angiographic views. In the prospective study the caudocranial aortogram showed the aortic valve face on in all the patients. The right ventricular outflow tract lay in a left and anterior (seen as superior) position in relation to the aortic root. Thus any vessel crossing the outflow tract could be identified. Identification of the aortic cusps allowed precise definition of the origin of the coronary arteries. All but four had normal origin and course of the coronary arteries. Four had paired left anterior descending arteries (including the restudied patient), in all cases with a large vessel originating from the right coronary artery passing across the right ventricular outflow tract.

CONCLUSIONS

Important anomalies of the coronary arteries in tetralogy of Fallot may remain undiagnosed if standard angiographic projections are used. Aortography with > or = 45 degrees caudocranial and 20 degrees-30 degrees left anterior oblique angles allows precise definition of the anatomy and certainty as to whether any major vessel crosses the right ventricular outflow tract. Interpretation, however, can only be correct if the projection is technically adequate with a view of the aortic valve face on. Furthermore, a normal bifurcation of the left main stem does not exclude a second left anterior descending artery crossing the pulmonary outflow tract.

Exercise capacity after complete repair of tetralogy of Fallot: deleterious effects of residual pulmonary regurgitation

OBJECTIVE

To determine the effects of residual pulmonary regurgitation on exercise tolerance after complete repair of tetralogy of Fallot.

DESIGN

Prospective study of symptom free patients more than five years after complete repair. Graded exercise performance was measured with standard Bruce protocol. Maximal oxygen uptake and ventilatory anaerobic threshold were measured by respiratory mass spectrometry. Measurement of pulmonary regurgitant fraction was from pressure-volume loops constructed from measurements of right ventricular volume obtained from biplane angiograms and simultaneous pressures measured with a micromanometer.

SETTING

Tertiary referral centre.

PATIENTS

16 patients were studied. Two patients had been excluded because of residual cardiac lesions or inadequate data from cardiac catheterisation. Four were later excluded because they failed to reach a respiratory quotient of greater than 1.0 during graded exercise.

RESULTS

There was a significant negative correlation between the degree of residual regurgitation and both total duration of exercise and maximal heart rate achieved. Maximal heart rate and total duration of exercise were significantly lower in the patients than in normal controls. Patients with an abnormal maximal oxygen uptake (less than 85% of the predicted normal value) had significantly greater residual pulmonary regurgitation than those in whom oxygen uptake was normal.

CONCLUSIONS

Impaired exercise capacity after complete repair of tetralogy of Fallot is directly related to the degree of residual pulmonary regurgitation. These data should be taken into account when deciding the optimal timing and nature of corrective surgery.

Analysis of left ventricular wall movement before and after reimplantation of anomalous left coronary artery in infancy

Five infants who underwent direct reimplantation or redirection of an anomalous left coronary artery from the pulmonary artery to the aorta were studied. There were no deaths from the procedure. Anastomoses were patent at a mean follow up of 33 months. Left ventricular angiograms before and after operation were digitised frame by frame. Analysis of wall motion showed considerable generalised hypokinesia with no change in cavity shape before operation. After reimplantation there was a significant improvement of global ventricular function as assessed by ejection fraction and end diastolic shape index. There was also a tendency for the shape index change to increase; this was compatible with better global systolic function. Three of the four patients who were restudied showed normal isometric and contour wall motion plots. One child, the oldest at the time of operation, still showed asynchronous onset of contraction and isovolumic relaxation. The procedure offers a low risk of mortality and a high rate of patency of the anastomosis. Improvement of ventricular function can be remarkable and its extent cannot be assessed simply by ejection fraction measurements.

Hepatic venous connection to a persistent inferior caval vein in left isomerism

In 22 cases of left atrial isomerism studied at the Brompton Hospital, four cases were found to have an unusual arrangement of the abdominal vessels. There was persistence of an inferior caval vein, partially anomalous hepatic venous connection and additional continuation of part of the venous return from the lower body through the azygos venous system. This venous pattern had surgical implications in our index case, since redirection of the inferior caval venous return was necessary.

Continuous wave Doppler echocardiography and coarctation of the aorta: gradients and flow patterns in the assessment of severity

Indices of the severity of coarctation derived from non-invasive Doppler echocardiography were compared with measurements derived from cardiac catheterisation and angiography. In 24 Doppler studies from 17 children instantaneous peak systolic and diastolic gradients and time to half peak systolic and diastolic velocities were compared with the ratio of the coarctation diameter to the diameter of descending aorta at the level of diaphragm obtained from angiographic systolic frames of the aorta. A high peak systolic gradient (greater than 40 mm Hg) or long time to half peak diastolic velocity (greater than 100 ms) (that is, maintenance of flow in diastole) were both highly specific (100%) in detecting coarctation of the aorta where the angiographic ratio was less than or equal to 0.5. Diastolic measurements, however, were more sensitive (79% both for peak diastolic gradient and for time to half peak diastolic velocity) than systolic (57% for peak systolic gradient and 64% for time to half peak systolic velocity). Even higher sensitivity (93%) was obtained when the peak systolic gradient was greater than 40 mm Hg or the time to half peak diastolic velocity was greater than 100 ms. Examination by continuous wave Doppler echocardiography is an effective non-invasive method of assessing the severity of coarctation of the aorta, particularly when systolic and diastolic events are considered together. This approach overcomes the relatively low sensitivity of peak systolic gradient alone.

Early diastolic clicks after the Fontan procedure for double inlet left ventricle: anatomical and physiological correlates

M mode echocardiograms and simultaneous phonocardiograms were recorded in four patients with early diastolic clicks on auscultation. All had double inlet left ventricle and had undergone the Fontan procedure with closure of the right atrioventricular valve orifice by an artificial patch. The phonocardiogram confirmed a high frequency sound occurring 60-90 ms after aortic valve closure and coinciding with the time of maximal excursion of the atrioventricular valve patch towards the ventricular mass. One patient had coexisting congenital complete heart block. The M mode echocardiogram showed "reversed" motion of the patch towards the right atrium during atrial contraction. Doppler flow studies showed that coincident with this motion there was forward flow in the pulmonary artery with augmentation when atrial contraction coincided with ventricular systole. The early diastolic click in these patients was explained by abrupt cessation of the motion of the atrioventricular valve patch towards the ventricular mass in early diastole. In one patient atrial contraction led to a reversal of this motion and was associated with forward flow in the pulmonary artery.

Preoperative measurement of pulmonary vascular resistance in complete transposition of the great arteries

Transposition of the great arteries is frequently complicated by the early onset of pulmonary vascular disease. It is difficult to measure pulmonary blood flow by the Fick principle because the pulmonary arteriovenous oxygen content difference is small and bronchial blood flow is increased in this condition. In eight patients (mean age 7.7 years, range 3 months to 29 years) with transposition of the great arteries mass spectrometry was used to measure oxygen uptake and predict pulmonary end capillary blood oxygen content. The effects of the bronchial circulation were studied by computer modelling. There was close agreement between pulmonary end capillary and pulmonary vein blood oxygen contents but the resultant percentage difference in arteriovenous content difference was significant (mean (SE of difference)) (14.5(3.8)%). The effect of the bronchial circulation was to give spuriously high estimates of pulmonary blood flow. The error was greatest when oxygen consumption was low and aortic blood was very desaturated.

Do asymptomatic school children have normal haemodynamics 6-13 years after Mustard's operation?

Twenty asymptomatic school children who had undergone Mustard's operation for simple complete transposition (concordant atrioventricular and discordant ventriculo-arterial connexions) were catheterised electively 6-13 years later. The studies were carried out under general anaesthesia in air and in 100% O2. Oxygen consumption was measured and end-tidal gases were monitored using respiratory mass spectrometry. There was significant left ventricular outflow tract obstruction in 2 patients. Cardiac output in air was normal in 15 and decreased in 5 patients. The pulmonary vascular resistance was normal in 18 of 19 cases, but grossly elevated in one patient. Baffle dysfunction was present in 11 patients: 10 with important gradients between the venous pathways and the systemic venous atrium, and 5 with a leak identified either by a left-to-right shunt or by the course of the catheter. Balloon dilatation was attempted in the inferior caval venous channel in 6 and in the superior caval venous channel in 2. Mean gradient before the dilatation fell after the procedure. No pulmonary venous obstruction was identified. Even in this group of children selected as asymptomatic, approximately half had a detectable haemodynamic abnormality.

Treatment of visceral leishmaniasis with pentavalent antimony and interferon gamma

Acute visceral leishmaniasis is associated with an antigen-specific immunosuppression of mononuclear cells as evidenced by defective in vitro production of interferon gamma. We evaluated treatment with recombinant human interferon gamma in combination with conventional pentavalent antimony therapy in patients with visceral leishmaniasis. Six of eight patients with visceral leishmaniasis (mean duration, 17 months) that had been unresponsive to multiple courses of pentavalent antimony responded to treatment with recombinant human interferon gamma (100 to 400 micrograms per square meter of body-surface area per day) in addition to pentavalent antimony (20 mg per kilogram of body weight per day) for 10 to 40 days. The other two patients improved initially but then relapsed and required treatment with amphotericin B. Eight of nine additional patients with previously untreated severe visceral leishmaniasis were also successfully treated with the combination of interferon gamma and pentavalent antimony. The 14 patients who responded to this regimen had marked improvement in symptoms and in measures of anemia and leukopenia, as well as weight gain, a decrease in spleen size, and an absence or reduction of leishmanias in splenic aspirates. These patients had no recurrence of illness after a mean (+/- SE) follow-up of 8 +/- 1 months. Fever was the only major side effect of interferon gamma. We conclude that the combination of interferon gamma and pentavalent antimony is effective in treating seriously ill patients with refractory or previously untreated visceral leishmaniasis.

Open valvotomy for critical aortic stenosis in infancy

Over a 5 year period open valvotomy was performed on 13 patients under the age of one year with critical aortic stenosis. All 13 survived operation. There were two late deaths--one 38 days after operation, associated with an unrelated neurosurgical procedure and the other 2 years 6 months after when aortic root enlargement and replacement of the aortic valve were performed. During this period two other infants presented with aortic stenosis. One, who was very ill before transfer, died before operation could be performed. The second patient had a hypoplastic left ventricle with a small mitral valve ring and was, therefore, considered to be part of a different subgroup. All the surviving children have been followed up (median length of follow up 2 years and 11 months, range 7 months-5 years). Left ventricular function, in terms of percentage systolic wall thickening, was shown to be significantly impaired in all age groups. Peak diastolic thinning was abnormal in those children aged from 3 to 5. The aortic valve gradient, as assessed by peak instantaneous continuous wave Doppler, was less than 40 mm Hg in five patients and between 40 and 70 mm Hg in seven patients. One patient, with appreciable restenosis, has undergone successful percutaneous balloon dilatation of the aortic valve.

Heterologous serum albumin as tracer for plasma volume measurements evaluated in conscious nondehydrated and 48-hour water-deprived rats

The feasibility of using nonradioactive heterologous serum albumin measured by rocket immunoelectrophoresis as tracer for plasma volume measurements was evaluated by comparing simultaneous distribution volumes and plasma half-lives (t1/2) of human serum albumin (HSA) and Evans blue dye (T1824) in a group of conscious rats. The animals were studied under normal water intake and after a 48-h period of water deprivation. The kinetic behavior in plasma was qualitatively similar for both tracers, but T1824 distributed beyond the HSA space and had half-lives in plasma lower than those of HSA. Water deprivation induced a 14% decrease in the HSA space, from 2.7 +/- 0.1 to 2.4 +/- 0.2 ml/100 g body weight. We conclude that serum albumin spaces measured immunoelectrophoretically are a better reflection of true plasma volume than T1824 spaces and can be used advantageously in determinations of plasma volume.

Does digoxin have a place in the treatment of the child with congenital heart disease?

The place of digoxin in the pediatric cardiologist's armamentarium remains uncertain. As an antiarrhythmic, its use in the Wolff-Parkinson-White syndrome is obsolete, but it remains useful in the treatment of the chronic atrial fibrillation seen in some patients postoperatively and in children with dilated cardiomyopathy. The efficacy of digoxin in heart failure is unproven. There is some evidence of improvement in non invasive left ventricular contractile indices in neonates and infants, but it is unclear whether this is associated with sustained clinical improvement. There is even less evidence of its effectiveness in the older child. Whilst the measurement of any effect will undoubtedly be difficult, the time has come for double-blind, placebo-controlled trials in selected groups of patients. These should be designed not only to test the notion that digoxin does not improve ventricular function, but also to embrace the possibility that its administration may result in clinical improvement over and above that following diuretics alone. An absence of proof of efficacy must be distinguished from no efficacy--more data are needed.

Cross sectional echocardiography for recognition of ventricular topology in atrioventricular septal defect

The cross sectional echocardiograms of 150 children with atrioventricular septal defects were reviewed to determine the spatial orientation of the ventricles. In 125 cases with usual atrial arrangement (situs solitus), ventricular topology showed the right hand pattern. Of the 25 patients with atrial isomerism, 13 had similar right hand topology but 12 (48%) had the left hand pattern. This finding was more common in hearts in the right side of the chest (dextrocardia), but there was no significant correlation between ventricular topology and number of atrioventricular valves or the ventriculoarterial connection. In part because of inferences for disposition of the conducting tissue, knowledge of ventricular topology is important when operation for atrioventricular septal defects is considered. Ventricular topology can be promptly recognised by cross sectional echocardiography.

Infection of modified Blalock shunts

A left-sided interposition graft (modified Blalock-Taussig anastomosis) was constructed with polytetrafluoroethylene in a three month old child with tetralogy of Fallot. This shunt thrombosed and a replacement shunt became the site of chronic Pseudomonas infection. The second anastomosis was excised and a third interposition graft was inserted on the right side because the anatomy was unsuitable for a classical Blalock-Taussig shunt. The patient died when he was 12 months old, after signs of infection and shunt occlusion had developed. At necropsy the acutely thrombosed right sided shunt was found to be the site of Candida albicans infection. Gallium and labelled white cell scans, computed tomography, and ultrasound scans had all failed to identify the sites of infection, which were only confirmed at operation or necropsy.

Crescentic IgA nephropathy

We report five cases of crescentic IgA nephropathy. All are males, 16-60 years of age. One case each came to medical attention with uremia, nephrotic syndrome, and gross hematuria; two cases presented with microhematuria and proteinuria on routine urinalysis. All had hypertension, azotemia (serum creatinine 1.6-9.4 mg/dl), proteinuria (greater than 6 g/24 hr in four cases), hypoalbuminemia (less than 3 g/dl), and hematuria (gross in two cases). All progressed to end-stage renal failure renal failure ending in dialysis (three cases) or death from unrelated causes (two cases). Prednisone, 60 mg/day for 1 month in two patients (with two 1-g doses of iv methylprednisolone in 1 case) did not improve the serum creatinine level, but one patient subsequently experienced a less rapid fall in renal function. A crescentic glomerulonephritis was present in all biopsies (crescents in 31-80% of glomeruli; mean, 50%). The size and stage of the crescents were variable. Numerous glomeruli had focal or diffuse sclerosis. In all cases, there was a 3 or 4+ deposition of IgA. Low-intensity staining for IgG and IgM was noted in four and three patients, respectively. On electron microscopy, dense granular mesangial deposits were noted in all cases and in four patients capillary subepithelial deposits were also observed. This form of IgA nephropathy is not common, but some studies indicate that it may occur in about 5% of patients with IgA nephropathy.

Thallium-201 myocardial imaging in patients on chronic hemodialysis

10 long-term hemodialysis patients had immediate and redistribution thallium-201 myocardial imaging performed after a course of hemodialysis. Subjects had EKGs done on the same day before and after dialysis. 3 of the 10 subjects had resting thallium-201 myocardial imaging obtained on non-dialysis days. 60% of the electrocardiograms showed changes with dialysis. All 13 thallium studies were abnormal, showing multiple transient filling defects at rest. Most subjects had permanent filling defects as well. It is concluded that hemodialysis patients have a high frequency of abnormal thallium-201 myocardial images at rest. The cause of these abnormal studies is uncertain.

Inhibitory effect of circulating norepinephrine on epinephrine-induced renin secretion

The potential role of circulating catecholamines in the regulation of plasma renin concentration (PRC) was evaluated in conscious rats. PRC was very responsive to minor increases in circulating levels of epinephrine but a dose-response relationship was not seen. Circulating norepinephrine in concentrations within physiologic limits (up to 60-80-fold base line) was without effect on basal PRC. When the catecholamines were infused together in approximately equimolar concentrations, norepinephrine completely abolished the PRC rise induced by epinephrine. It is concluded that, in the rat, the circulating catecholamines contribute to the control of PRC by modulating renin secretion through stimulation-inhibition mechanisms.

Potentiation of beta-adrenergic affects on plasma renin concentration by pentobarbital anesthesia

Potentiation of renin release can be achieved by combining adrenergic stimulation and renal vasodilatation. To examine whether pentobarbital anesthesia influences plasma renin concentration (PRC) by its vasodilatory effect, experiments were performed in rats subjected to increasing levels of adrenergic activity. PRC was two- to fourfold higher in anesthetized than in conscious rats when the beta-adrenoceptor agonist isoproterenol HCl (0.05-3.2 micrograms kg-1 min-1) was infused. The sympathomimetic agent tyramine suppressed and the alpha-adrenoceptor blocker phenoxybenzamine enhanced to the same extent the isoproterenol-stimulated PRC in conscious and anesthetized animals. Chronic renal denervation did not abolish the isoproterenol-pentobarbital synergistic effect on PRC. These results are consistent with the view that the renin response to pentobarbital anesthesia is somehow related to the vascular effects of the anesthetic.

The effect of water deprivation on the osmotic release of renin

The effect of water deprivation on the osmotic release of renin was evaluated in conscious rats previously prepared with right nephrectomy and cannulations of left renal artery and lower abdominal aorta. The osmotic signal was a 4-min intrarenal infusion of 30% crystallized bovine serum albumin. Changes in aortic plasma concentration of renin (PRC) and total protein were followed serially. In normal hydropenic rats an increase in PRC was not detected with the oncotic challenge. Following a 48-hr period of water deprivation, the same external oncotic signal increased PRC threefold above baseline within 3 min. It is concluded that some intrarenal functional or structural change induced by water deprivation sensitizes the renin-secreting mechanism to colloid osmotic stimuli. It is suggested that this change could be related to the physical conditions of the renal interstitium.

Renin release by pentobarbital anesthesia in the rat: a role for vascular mechanisms

Studies were undertaken in intact rats to characterize the renin response to pentobarbital anesthesia and the mechanisms involved in this response. Aortic and peritoneal cavity cannulas were previously implanted to allow drug infusion, blood sampling and anesthesia to be performed without stress. A sustained 2-3-fold increase in plasma renin concentration (PRC) and a 10-15 mm Hg depression of mean arterial pressure were found in pentobarbital anesthesia. Circulating levels of epinephrine and norepinephrine were unchanged. Sympathetic stimulation by tyramine did not decrease and chronic renal denervation did not abolish the PRC rise by pentobarbital. Phenoxybenzamine given to conscious or anesthesized animals elevated PRC to similar levels. Propranolol was effective in suppressing PRC in anesthetized animals, regardless of the presence or absence of phenoxybenzamine. We concluded that the renin response to pentobarbital anesthesia is unrelated to changes in sympatho-adrenal activity. The response appears to be mediated by beta-adrenergic receptors. It is postulated that pentobarbital-induced relaxation of afferent arterioles or JG cells exposes previously concealed beta-receptor sites which increase the signal for the release of renin.