Superoinferior ventricles with superior left ventricle and inferior right ventricle: a newly recognized form of congenital heart disease.

We report the first known case of supero-inferior ventricles with a superior morphologically left ventricle and an inferior morphologically right ventricle. This 2 1/2-year-old boy also had dextrocardia, double-outlet right ventricle [S,L,L], right-sided mitral atresia, left-sided tricuspid regurgitation, a large conoventricular type of ventricular septal defect, and pulmonary outflow tract stenosis. This very rare form of superoinferior ventricles appears to be due to excessive levorotation (approximately equal to 170 degrees) of discordant L-loop ventricles.

Resetting of the cardiopulmonary baroreflex 10 years after surgical repair of coarctation of the aorta.

OBJECTIVE: To characterise cardiopulmonary baroreflex responses and examine the effects of a 45 minute cycling bout late after successful repair of coarctation of the aorta. SUBJECTS: 10 young adults (mean (SEM) age 18.1 (2.6 years)) operated on for coarctation of the aorta 12.7 (3.5) years earlier, and 10 healthy controls. DESIGN: Forearm blood flow (venous occlusion plethysmography) and vascular resistance, left ventricular internal diastolic diameter, and central venous pressure estimated from an antecubital vein were measured in the supine position at baseline and during five minute applications of lower body negative pressure (LBNP) at -15 mm Hg (LBNP(-15)) and -40 mm Hg (LBNP(-40)). Venous samples were obtained at baseline and during LBNP(-40) for noradrenaline (norepinephrine), adrenaline (epinephrine), renin activity, and aldosterone. The tests were repeated after 45 minutes of moderate exercise. RESULTS: Baseline heart rate (78 (9) v 64 (6) beats/min), echocardiographic cardiac output (6.9 (1.1) v 5.0 (0.2) l/min), shortening fraction (41.7 (1.8)% v 33.3 (1.3)%), and forearm blood flow (3.4 (0.4) v 2.3 (0.3) ml/100 g/min) were higher in the coarctation group than in the controls (p < 0.05). Changes in forearm blood flow and forearm vascular resistance from baseline to LBNP(-40) were similar in both groups, but the relation between forearm vascular resistance and estimated central venous pressure or left ventricular internal diastolic diameter was shifted downward in the coarctation group. Plasma adrenaline was increased in the coarctation group (baseline: 3.2 (0.6) v 2.4 (0.3) pmol/l in controls; LBNP(-40): 687 (151) v 332 (42) pmol/l) (p < 0.05). Both groups showed a similar downward displacement of forearm vascular resistance (p < 0.05) after exercise. CONCLUSIONS: There appears to be resetting of the cardiopulmonary baroreflex to a lower forearm vascular resistance in young adults operated on for coarctation of the aorta, associated with hyperdynamic left ventricular function. Raised circulating adrenaline could contribute to the lower forearm vascular resistance.

Influence of the postoperative period and surgical procedure on ambulatory blood pressure-determination of hypertension load after successful surgical repair of coarctation of the aorta.

AIMS: This study quantified hypertension load using 24-h ambulatory blood pressure monitoring after successful repair of coarctation of the aorta less than (1) or more than 10 years previously (2) and examined the influence of the surgical procedure (anastomosis or subclavian flap). METHODS AND RESULTS: Ambulatory blood pressure recordings were obtained using an Accutracker II monitor every 30 min during the day and hourly, at night. Day and night systolic and diastolic values were higher in coarctation of the aorta than in controls: (day: systolic blood pressure/diastolic blood pressure: 133/71 +/- 6/4 vs 115/66 +/- 3/2 night: systolic blood pressure/diastolic blood pressure: 117/61 +/- 4/4 vs 107/57 +/- 3/2 mmHg, P < 0.01) and at all times, were higher in coarctation of the aorta (2) than in coarctation of the aorta (1). Clinical daytime systolic hypertension was observed in 20% of recordings from coarctation of the aorta (1) and 49% from coarctation of the aorta (2) while diastolic hypertension was not observed. However, systolic blood pressure and diastolic blood pressure responses to daily activities were significantly higher in coarctation of the aorta than in controls and this was more marked in coarctation of the aorta (2) than in coarctation of the aorta (1). Type of surgery did not affect either hypertension prevalence or blood pressure reactivity. CONCLUSIONS: These observations indicate exaggerated systolic blood pressure and diastolic blood pressure reactivity after repair of coarctation of the aorta, the prevalence of systolic hypertension doubling 10 years after surgery.

Cardiovascular responses to dynamic submaximal exercise in children previously treated with anthracycline.

This study assessed the long-term (5-year) outcome of pediatric low-dose anthracycline therapy on the circulatory response to moderate exercise. Thirteen patients (13 +/- 4 years old) and 15 age-matched control subjects completed a maximal cycle ergometer protocol as well as two 5-minute cycling tests at 33% and 66% maximal oxygen uptake (V(O2)max) for determination of cardiac index (carbon dioxide rebreathing). V(O2)max was lower in patients than in control subjects (1.3 +/- 0.5 L/min vs 2.3 +/- 0.6 L/min) (p< 0.05). Smaller relative increases in cardiac index for similar increases in relative exercise intensities were found in patients (33% V(O2)max, 73% vs 116%; 66% V(O2)max, 115% vs 192%), as a result of smaller increases in stroke index from rest (33% V(O2)max, 33% vs 54%; 66% V(O2)max, 33% vs 69%; p< 0.05). Similarly, despite normal resting systolic function, patients exhibited a lower stroke index and higher heart rate for any given value of oxygen uptake (milliliters per minute per square meter). Children who had survived cancer exhibited stroke index impairment during exercise similar in intensity to that of recreational activities or play, attesting to a limited inotropic reserve.

Peripheral blood flow responses to exercise after successful correction of coarctation of the aorta.

OBJECTIVES: The purpose of this study was to characterize peripheral flow kinetics in response to progressive discontinuous maximal exercise in 10 patients who underwent repair of coarctation of the aorta and 11 age-matched healthy adolescents. BACKGROUND: An impairment of leg blood flow has been suggested on the basis of exaggerated femoral muscle lactate accumulation in patients with successful repair of coarctation. Few data are available describing blood flow kinetics of the exercising leg in such patients. METHODS: Duplex ultrasound provided transcutaneous measurements of peak systolic and end-diastolic flow velocities of the femoral, humeral and renal arteries at rest and immediately after mild, moderate and maximal exercise intensities for computation of mean velocity, resistance index and femoral blood flow. RESULTS: Femoral mean velocity and femoral blood flow increased linearly with exercise intensity in both groups, but the slope of this increase was significantly lower in patients. Similarly, humeral mean velocity increased significantly less in patients than in control subjects. Femoral resistance index sharply decreased from that at rest (patients [mean +/- SE] 1.4 +/- 0.04; control subjects 1.4 +/- 0.03) to mild exercise intensity in both groups (patients 0.69 +/- 0.03; control subjects 0.72 +/- 0.03). A further decrease was observed at maximal exercise in patients (0.60 +/- 0.04, p = 0.08) but not in control subjects (0.69 +/- 0.02). CONCLUSIONS: These observations suggest that despite a greater exercise-induced femoral vasodilation, patients with successful correction of coarctation of the aorta demonstrate an impaired lower limb blood flow in response to strenuous dynamic exercise. In the absence of stenosis at rest, this alteration could result from exaggerated flow turbulence in the descending aorta distal to the site of correction because of loss of elasticity at the site of the resection of the coarcted segment.

Selective digestive decontamination in multiple trauma patients: cost and efficacy.

A double-blind randomized placebo-controlled study was carried out to evaluate the efficacy and the cost of selective digestive decontamination (SDD) to prevent nosocomial pneumonia in multiple-trauma patients. Nosocomial infections, particularly pneumonia, were more frequent in the placebo group. The most common infectious agent was Staphylococcus: Staphylococcus aureus in the placebo group and Staphylococcus epidermidis in the SDD group. Methicillin-resistant Staphylococcus epidermidis was detected more often in the SDD group. No methicillin-resistant Staphylococcus aureus was observed in this study. Fewer patients in the SDD group required antibiotherapy. SDD resulted in a saving of about 41% in drug expenditure.

[Idiopathic dilatation of the pulmonary artery. Echocardiographic aspects]. / Dilatation idiopathique de l'artère pulmonaire. Aspects échocardiographiques.

The authors compared 30 patients with at least one clinical sign of idiopathic dilatation of the pulmonary artery, with a group of 20 normal control subjects in order to establish diagnostic criteria for this condition. In the first group, 17 had characteristic radiological findings and 13 others had clinical signs of idiopathic dilatation of the pulmonary artery. Comparison with the control group showed significant differences (p < 0.05) in 4 parameters: 1) the diameter of the pulmonary artery at the bifurcation/m2 body surface area (2.8 +/- o.4 cm versus 2.4 +/- 0.4 cm), 2) the diameter of the aorta 2 cm beyond the aortic valve/m2 of body surface area (1.7 +/- 0.3 cm versus 2.1 +/- 0.7 cm), 3) the ratio of pulmonary artery/aortic diameters at the valve rings (1.4 +/- 0.2 versus 1.1 +/- 0.02); 4) the ratio of the aorta 2 cm beyond the valve/aortic ring (1.02 +/- 0.07 versus 1.09 +/- 0.09). The diagnostic criteria of idiopathic dilatation of the pulmonary artery in the absence of cardiac or pulmonary disease are: 1) ratio of pulmonary artery diameter at its bifurcation/aortic ring diameter or 2 cm beyond the aortic valve of > or = 1.4; 2) ratio of pulmonary/aortic ring diameters > or = 1.5.

Predictive factors for spontaneous closure of atrial septal defects diagnosed in the first 3 months of life.

OBJECTIVES: To establish the rate of spontaneous closure of atrial septal defects diagnosed before age 3 months, 101 infants (mean age 26 days) with an interatrial shunt confirmed by Doppler echocardiography were followed up for an average of 265 +/- 190 days. BACKGROUND: Even if interatrial shunts in the newborn are frequently encountered, little is known about their natural history. METHODS: Defect diameter on two-dimensional echocardiography and width of color flow jet were measured in the subcostal view. Right and left ventricular diameters and atrial septal curvature were also studied. Kaplan-Meier curves were obtained to predict age of spontaneous closure in relation to initial defect diameter. RESULTS: There was no significant correlation between the diameter of the atrial septal defect and right ventricular/left ventricular ratio or type of septal curvature (vertical or concave toward the left atrium). The classic predominance of girls over boys was observed only for defects > 5 mm. An overall rate of spontaneous closure of 87% was observed. Frequency and timing of closure were inversely correlated to atrial septal defect diameter: closure occurred in 100% (32 of 32) of defects in group 1 (diameter < 3 mm), 87% of defects (39 of 45) in group 2 (diameter 3 to 5 mm), 80% of defects (16 of 20) in group 3 (diameter 5 to 8 mm). Spontaneous closure did not occur in four patients of group 4 (defect > or = 8 mm) during an average follow-up interval of 417 days (range 294 to 597 days). CONCLUSIONS: These results suggest that infants with an atrial septal defect < 3 mm need not be followed up as 100% of these defects will be closed by age 18 months; those with a defect 3 to 5 or 5 to 8 mm should be evaluated by the end of the 12th and the 15th month, respectively, when > 80% of these defects will be closed. An atrial septal defect with a diameter > or = 8 mm may have little chance of closing spontaneously and the possibility of surgical correction should be considered. Defects < 3 mm probably do not constitute a cardiac malformation in light of their natural evolution and gender distribution.

[Percutaneous aortic valvuloplasty in children, non invasive evaluation and criteria of success]. / La valvuloplastie aortique percutanée chez l'enfant, évaluation non invasive et critères de succès.

The results of percutaneous aortic valvuloplasty in 15 children (average 8.4 years) were evaluated by echocardiography and non-invasive criteria of the indication of this procedure were defined. The aortic valve was unthickened in 7 patients (Group I) and dystrophic in the other 8 (Group II). Valvuloplasty decreased the transvalvular pressure gradient by 47 +/- 33%. Aortic regurgitation was aggravated in 4 patients. The reduction in pressure gradient was significantly greater in Group I than in Group II (64 +/- 19% vs 31 +/- 35%, p < 0.05). In Group I, in contrast to Group II, the results remained stable after an average follow-up of 14.5 months. When the maximal instantaneous pressure gradient on Doppler examination was < 80 mmHg, the peak-to-peak gradient at catheterisation was on average 21% less, whereas when the Doppler gradient was 80 mmHg or more, the percentage difference was only 8%. The myocardial mass index was over the 95th percentile in 7/8 patients with gradients > 80 mmHg whilst it was only increased in 1 patient with a gradient < 80 mmHg. Electrocardiographic LVH was observed in 6 of the 8 patients with a gradient > 80 mmHg but in none of the others. Although valvuloplasty reduced the transvalvular pressure gradient, the results were much less satisfactory in the dystrophic valves. The following indications were proposed for this techniques: a Doppler maximal pressure gradient > or = 80 mmHg, associated with at least one criterion of left ventricular hypertrophy.

Use of acetylsalicylic acid to improve patency of subclavian to pulmonary artery Gore-Tex shunts.

In order to assess the influence of acetylsalicylic acid (ASA) on function and patency of Gore-Tex shunts, angiographic features of 62 Gore-Tex shunts were assessed, 31 without and 31 with postoperative ASA. Groups were selected on the basis of similar angiographic follow-up duration. Mean follow-up was 709 days for the group without ASA and 739 days for the group with it. The average daily dose of ASA was 4.5 mg/kg/day started a mean of 6.7 days after surgery. Clinical characteristics were similar between the two groups except for age at surgery which was 581 days in the group without ASA (operated between 1983 and 1987) and 303 days in the group with (operated between 1987 and 1991), reflecting the fact that patients were operated upon earlier after 1987. Preoperative Gore-Tex diameter was similar between the two groups, but three patients in the group with ASA had a Gore-Tex shunt as small as 4 mm. At angiography, four conduits were diagnosed as nonpatient (two in each group), 20 had a localized stenosis (11 of 28 in the group without ASA and nine of 23 in the group with ASA). Patency index (angiographic Gore-Tex diameter/preoperative Gore-Tex diameter) was similar in the two groups: 68.5% in the group without ASA and 69.7% in the group with ASA. Pulmonary artery growth index was 57% in the group without ASA and 91% in the group with ASA. No risk factor for thrombosis or decreased patency was found.(ABSTRACT TRUNCATED AT 250 WORDS)

Sex differences in the evolution of the electrocardiographic QT interval with age.

OBJECTIVE: To investigate sex differences in the evolution of the QT interval with age. SUBJECTS AND METHODS: A community-based representative North American population sample of 14,379 children and adults aged from birth to 75 years. The measured QT intervals (QTm) were determined by a computer algorithm and QTm, corrected for heart rate (HR), was expressed as QT index: QTI = (QTm/Tp) x 100, where QTp is the predicted QT from the formula QTp (ms) = 656/(1 + HR/100). MAIN RESULTS: The QTI values of females were significantly longer than of males in all age groups from 15 to 50 years tested at yearly intervals. This difference was due to a 20 ms drop in rate-corrected QT values in adolescent males after puberty, whereas QT values of females remained unchanged throughout the growth, maturation and reproductive years. The new QT prediction formula explained 83% of total QT variance in females and 82% in males after adjustment for heart rate and for the observed significant influence of ventricular excitation time (QRS duration) on QT interval in both sexes and a correction for QT age trend in males. CONCLUSIONS: The sex difference in the QT interval is due to QT shortening in males after puberty rather than QT prolongation in women during reproductive years. The fact that QRS duration is a significant determinant of the QT interval has important theoretical implications for attempts to model the ventricular repolarization process and it indicates that the traditional concept of reverse sequence of ventricular repolarization is not universally valid in all myocardial regions.

Use of transtelephonic electrocardiographic monitoring in children with suspected arrhythmias.

Arrhythmias in children can produce various symptoms and their assessment often is difficult with usual methods. Transtelephonic electrocardiographic monitoring was used in 136 symptomatic patients (palpitations [112], syncope [six], chest pain [18]) for a mean duration of 86 +/- 65 days; mean age was 11.1 +/- 4.8 years and 62% were female. Of 398 recordings sent (mean 2.9 per patient) 32 revealed significant arrhythmias (8%). Of the 67 patients reporting symptoms during the recording period, only 24 had documented arrhythmias - 23 supraventricular tachycardia and one junctional tachycardia. The negative predictive value is 100%, compared with a low positive predictive value of 36%; sensitivity and specificity are, respectively, 100 and 62%. Of the 24 patients with documented arrhythmias, 54% were treated versus 13% of those with normal recordings (P < 0.01). At the end of the follow-up (mean duration 1.6 +/- 1.2 years), 63% of the patients with negative recordings had not complained of further symptoms versus 22% of those with documented arrhythmias (P = 0.001). Transtelephonic electrocardiographic monitoring is an important tool for documenting infrequent arrhythmias in children and even more for reassuring the patient and his or her family in the absence of significant arrhythmias.

Usefulness of oral sotalol for the treatment of junctional ectopic tachycardia.

An infant with junctional ectopic tachycardia diagnosed at three weeks of age was treated with oral sotalol. At the first echocardiogram the shortening fraction was decreased. After one day of treatment the ventricular rate decreased from 230 to 130 beats per minute. Five months later sinus rhythm was restored, shortening fraction was normal and sotalol was withdrawn without relapse.

Decreased plasma atriopeptin response to volume-overloading maneuvers and exercise after atriopulmonary anastomosis of Fontan.

Atriopulmonary anastomosis results in a chronic right atrial pressure-volume overload. Water and salt retention is a frequent clinical observation in patients after atriopulmonary anastomosis. The purpose of this study was to examine if this could be related to an inability to increase already elevated circulating atriopeptin (ANP) in response to central volume-overloading conditions. Eighteen patients (mean age 16 +/- 6 years) with an atriopulmonary anastomosis underwent routine cardiac catheterization during which a 5-minute head-down 10 degrees tilt was performed. Peripheral venous and right atrial blood samples were obtained under basal conditions, and after tilting and angiography for determination of ANP concentrations. At a different time, circulating ANP levels were measured during a maximal graded exercise protocol. Increased circulating ANP concentrations were found under basal conditions (114 +/- 10 pg/ml). Tilting and cardioangiography resulted in significant increases in mean atrial pressure (basal: 12 +/- 0.7 mm Hg; tilt: 13.4 +/- 0.63 mm Hg; after angiography: 15.8 +/- 0.8 mm Hg), but not in atrial or peripheral ANP. Compared with the expected threefold increase in plasma ANP induced by maximal exercise in healthy control subjects, only a slight (0.25-fold) increase was found in patients. These observations suggest a reduced stimulus-release response after atriopulmonary anastomosis, which could be related to a loss of atrial stretch receptor sensitivity, achievement of the limit for maximal right atrial secretion, or an alteration in right atrial compliance, or a combination.

Electrophysiologic effects of sotalol on the immature mammalian heart.

Sotalol is a beta-blocker with class III antiarrhythmic properties that has recently been used in children for the treatment of supraventricular and ventricular arrhythmias. However, little is known about its electrophysiologic effects on the immature heart. Using intracardiac electrocardiographic recordings and stimulation techniques, 15 canine neonates (8-15 days) and 15 adult mongrel dogs were studied with cumulative doses of sotalol (0.5, 1, 2, and 4 mg/kg plus an additional dose of 8 mg/kg for neonates). Heart rate decreased significantly in the two groups, but more in adult dogs (-43% in adult dogs versus -25% in neonates, p less than 0.05). There was no significant change for QRS duration and His-Purkinje system conduction time interval. QT and atrioventricular nodal conduction time intervals increased in adult dogs and neonates. Sinus node recovery time increased significantly in the two groups, but more in adult dogs. Refractory periods of the atrioventricular (AV) node increased significantly in neonates. Atrial flutter was no longer inducible in 12 of 15 neonates after the 2 mg/kg dose. Atrial effective refractory period increased significantly more in neonates (96%, p less than 0.001) than in adult dogs (58%, p less than 0.001). Ventricular effective refractory periods increased significantly both in neonates (46%) and adult dogs (50%), in a similar way. In conclusion, sotalol has greater electrophysiologic effects on the immature heart at the atrial level when compared to the adult, and similar effects on the refractory period of AV node and ventricle.

[Treatment of congenital pulmonary valve stenosis by percutaneous valvuloplasty]. / Traitement du rétrécissement pulmonaire valvulaire congénital par valvuloplastie percutanée.

The purpose of this study was to evaluate the efficacy technique and follow-up results of balloon valvuloplasty for congenital valvular pulmonary stenosis. Percutaneous dilatation was performed in 48 patients aged 0.5 to 21 years (m = 7.5 yrs) from two pediatric cardiology centers (Lyon and Montreal). The right ventricular peak systolic pressure ranged from 42 to 180 mmHg (m = 93) before dilatation and fell from 24 to 105 mmHg (m = 48) immediately after dilatation. The pulmonary valvular peak systolic pressure gradient ranged from 22 to 156 mmHg (m = 73) and fell to 4 to 70 mmHg (m = 27) after the procedure (P less than 0.001). Follow-up continuous doppler data was available from 33 patients at 1 to 37 months (m = 9.2 months) after dilatation. The maximal instantaneous gradient from right ventricle pulmonary artery ranged from 0 to 74 mmHg (m = 27).

[Results of the surgical treatment of critical aortic valve stenosis in the newborn infant]. / Résultats du traitement chirurgical de la sténose valvulaire aortique critique du nouveau-né.

Retrospective studies have been conducted in Lyon (33 patients) and Montreal (24 patients) in order to compare the results of transventricular valvotomy (TVV, 20 cases) and aortic valvotomy with cardiopulmonary bypass (CPB, 37 cases) in neonatal critical aortic stenosis. Clinical, echocardiographic, catheterization and operative data were analyzed in order to determine prognostic factors. Mortality rate was 59%: 30/34 perioperative deaths in the first month, and 4 late deaths after a reintervention for severe residual obstruction. Long term follow up was available for 23 patients (41%) for a 2 to 16 year period (mean 7.5). Five patients (7%) required a reintervention six years after the initial operation. Two of them required valve replacement. Eighteen patients (31%) surviving the initial operation, displayed a satisfactory result, being free of symptoms, endocarditis, reoperation and sudden death. Factors that influenced the outcome included severe heart failure, a left ventricular end-diastolic diameter below 14 mm, an aortic valve annulus below 8 mm, and a poor shortening fraction. Factors that did not influence the prognosis were age, pulmonary hypertension, and the anatomic type of the valve. Trans-aortic valvotomy with CPB was associated with a smaller operative mortality and a better long term result than TVV.