Afterload reduction therapy in patients following intraatrial baffle operation for transposition of the great arteries.

Patients with intraatrial baffle procedure for transposition of the great arteries (TGA) have diastolic dysfunction, decreased exercise capacity, stroke volume response and elevated systemic vascular resistance (SVR) during exercise. Angiotensin-converting enzyme (ACE) inhibitors improve exercise capacity in adults with congestive heart failure by improving diastolic function and decreasing SVR. We tested the hypothesis that ACE inhibitors decrease SVR and improve exercise capacity in patients after intraatrial baffle procedure for TGA. We studied the effects of enalapril in nine patients with TGA s/p intraatrial switch (mean age, 13.8 +/- 3 years) 7 to 21 years (mean, 12 +/- 4 years) after intraatrial baffle procedure. Enalapril (0.5 mg/kg/day, maximum dosage 20 mg bid) was administered for 12 months. Patients exercised using a cycle ergometer ramp protocol (0.25 W/kg/min) before enalapril (baseline), 1 month, 6 months, and 12 months after treatment initiation. Heart rate, blood pressure, cardiac output, respiratory rate, minute ventilation, oxygen consumption (VO2), total exercise time, work, and power were measured. SVR, cardiac index, and stroke volume index (SVI) were calculated. Two-tailed paired Student's t-test was used to compare data to those of normal control patients and the patients' baseline data. Patients had lower resting heart rate, cardiac index, maximum heart rate, cardiac index (CI), SVI, VO2, exercise time, work, and power and higher maximal SVR at baseline compared to normal control patients. There was no significant difference in total exercise time, work, power, VO2 (rest/peak), SVR, SVI, and CI after 12 months of therapy compared to patients' baseline values. We conclude that short-term (<1 year) use of enalapril does not improve exercise performance in patients with TGA in whom the intraatrial baffle procedure has been performed.

The importance of the maximum pulmonary artery regurgitant velocity following repair of tetralogy of Fallot: a pilot study.

BACKGROUND: Tetralogy of Fallot repairs invariably result in pulmonary regurgitation with the long term sequelae of ventricular dilatation and dysfunction. OBJECTIVE: The purpose of this study is to correlate pulmonary flow parameters with right ventricular size and function. MATERIALS AND METHODS: Pulmonary artery velocity was mapped by magnetic resonance flow analysis in seven children with pulmonary regurgitation following tetralogy of Fallot repair. Right and left ventricular volumes were determined by Simpson's rule from double oblique cine gradient echo images of the heart. The ejection fraction was calculated for each ventricle. Right ventricular enlargement was normalized for patient size by calculating the ratios of right ventricle end diastolic and end systolic volumes to the left ventricle end diastolic and end systolic volumes respectively (EDV RV:LV and ESV RV:LV). The maximum pulmonary artery antegrade and retrograde velocities and the ratio of the time for antegrade to regurgitant flow were compared to ventricular function and volume measurements by regression analysis. RESULTS: A significant linear relationship between the maximum regurgitant pulmonary artery velocity and EDV RV:LV was identified (r2 = 0.82). CONCLUSION: An elevated maximum pulmonary regurgitant velocity correlated well with the degree of right ventricular enlargement in patients following tetralogy of Fallot repair. If the results are verified by a larger study, the maximum pulmonary regurgitant velocity may be substituted for the more cumbersome direct measurement of right ventricular size.

Significance of a Q wave in lead I in the newborn.

We present 11 healthy newborns whose electrocardiograms had a pure Q wave in lead I and who did not have a myocardial infarction clinically. We propose that in the healthy newborn, a pure Q wave in lead I may be due to increased right ventricular mass, not myocardial infarction.

Hypertrophic obstructive cardiomyopathy in an infant of a diabetic mother: support by extracorporeal membrane oxygenation and treatment with beta-adrenergic blockade and increased intravenous fluid administration.

In infants with hypertrophic obstructive cardiomyopathy (HOCM) on extracorporeal membrane oxygenation (ECMO), conventional treatment with inotropes, fluid restriction, and diuretics may be detrimental. This case reports an infant of a diabetic mother with HOCM on ECMO illustrating beneficial effects of beta adrenergic blockade and increased fluid administration.

Evaluation of magnetic resonance imaging in coarctation of the aorta: the importance of multiple imaging planes.

Coarctation of the aorta can be evaluated reliably and noninvasively by magnetic resonance imaging. However, the value of different imaging planes in the evaluation of restenosis or aneurysm has not previously been studied. Our purpose was to study the relative sensitivity for oblique coronal and oblique parasagittal magnetic resonance imaging to detect restenosis or aneurysm formation in children following surgical repair or balloon angioplasty of coarctation of the aorta. The study included magnetic resonance imaging studies in 27 children. Each exam included ECG gated, spin-echo imaging in oblique coronal and oblique parasagittal planes. Recoarctation was defined as a greater than 50% narrowing of the aorta. Aneurysms were defined as focal dilatation of the aorta in the region of coarctation 20% or greater than the adjacent aortic diameter. Recoarctation was detected in 11 children, but in both views in only five children. Aneurysms were detected in 15 children, but in both views in only three children. Recoarctation and aneurysm detection were both statistically more likely to be detected if oblique coronal and oblique parasagittal views were obtained, indicating that multiple imaging planes are necessary to completely evaluate magnetic resonance imaging of coarctation.

Intussusception of the catheter sheath: a nonemergency.

Percutaneous balloon dilatation angioplasty is a common therapeutic modality in patients with congenital heart disease. We report three cases of the catheter sheath telescoping into the hub of the sheath after removal of the balloon catheter. Although initially it appeared as though the sheath was torn, in actuality it was intact. We report this problem so others can avoid needless searching and concern for the "missing" catheter tip.

Left ventricular function at rest and during exercise in congenital complete heart block: a radionuclide angiographic evaluation.

This study evaluates intrinsic cardiac performance during upright exercise in patients with congenital complete heart block. Left ventricular ejection fraction and volume were measured at rest and peak upright exercise with radionuclide angiography in 5 patients aged 11 to 39 years with congenital complete heart block: 4 were in New York Heart Association class I and 1 was in class II. The resting cardiac output was maintained at a normal level by an increase in end-diastolic volume rather than by a decrease in end-systolic volume. The left ventricular ejection fraction was normal at rest in all patients, but an abnormal response to exercise was noted in 3 patients. There was no appreciable change in the end-diastolic volume during exercise. Thus, patients with congenital complete heart block utilize the Starling mechanism to maintain normal resting cardiac output, but the response to exercise is usually abnormal even in the absence of symptoms.

Inappropriate secretion of antidiuretic hormone after open heart surgery.

After open heart surgery for the closure of an atrial septal defect, acute brain syndrome developed in a 5-year-old girl, this being documented by laboratory evidence of the syndrome of inappropriate antidiuretic hormone secretion (SIADH). Irritability and total disorientation were the first symptoms observed. She completely recovered after being treated with hypertonic saline solution and fluid restriction. The potentially serious outcome of the SIADH warrants early recognition and appropriate measures in children who suffer acute brain syndrome after open heart surgery.

The natural history of hypertrophic cardiomyopathy in infants of diabetic mothers.

Eleven infants of diabetic mothers with hypertrophic cardiomyopathy have been followed for 30 to 40 months. All infants presented with cardiorespiratory distress and were found to have disproportionate septal hypertrophy on echocardiogram. Cardiac catheterization was done in four infants; three had significant subaortic obstruction. One infant had remarkable improvement after treatment with propranolol. Two infants who received digoxin did poorly and responded favorably to cessation of therapy. The natural history of HCM-IDM appears to be benign, with a resolution of symptoms within two to four weeks and a resolution of septal hypertrophy within two to 12 months. Most of the infants need only supportive care; if pharmacologic intervention is deemed necessary, propranolol appears to be the drug of choice. The natural history of this entity is that of spontaneous regression of symptoms and septal hypertrophy irrespective of therapy.

Tricuspid and pulmonic valve echoes in tricuspid and pulmonary atresia.

An echocardiographic pattern of normal tricuspid valve motion in a patient with tricuspid atresia, and pulmonic valve motion in a patient with transposition of the great vessels and pulmonary atresia were documented. The recordings of the valve motion resulted in an initial erroneous diagnosis. Although M-mode echocardiography is very useful for the initial diagnostic evaluation of critically ill newborn infants with complex congenital heart diseases, on occasion recording of valvular echoes may result in conflicting clinical and pathologic correlation.

The noninvasive assessment of anomalous origin of the left coronary artery from the pulmonary artery.

We present a patient with anomalous origin of the left main coronary artery from the pulmonary artery. We correlate the findings of echocardiography and myocardial imaging with angiography, and discuss the value of the noninvasive techniques in the diagnosis and in the followup of such patients.

Tricuspid insufficiency associated with aneurysm of the ventricular septum.

Because of the anatomic relation of an aneurysm of the membranous ventricular septum (AMVS) to the tricuspid septal leaflet or because of the tricuspid septal leaflet involvement in the aneurysm formation, dysfunction of the tricuspid valve is likely to occur in patients with AMVS. The auscultatory manifestations of the resultant tricuspid insufficiency (TI) could be masked by the systolic murmur of the ventricular septal defect (VSD), which is often present in these patients. The presence of TI is suggested by phonocardiographic findings in five patients with AMVS and is further supported by intracardiac phonocardiography and angiocardiography. After inhalation of amyl nitrite, a pansystolic murmur appeared in three patients, and the intensity of the pansystolic murmur increased significantly in two patients. Inhalation of amyl nitrite reduces the systemic resistance, resulting in decreased systemic pressure and diminished intensity of the murmur of a small VSD. Augmentation of the systemic venous return is responsible for increased intensity of TI murmur.

Echocardiography in cystic fibrosis.

Echocardiograms were obtained for 25 patients with cystic fibrosis (CF) and 20 controls to evaluate this technique as a means of assessment of right ventricular changes in patients with CF. Right ventricular anterior wall thickness per square meter of body surface (RVAW/sq m) and right ventricular internal dimension per square meter of body surface (RVID/sq m) were compared with other techniques for detection of cor pulmonale. Significant correlations existed between both RVAW/sq m and RVID/sq m and the forced vital capacity, forced expiratory volume in one second, midmaximal expiratory flow rate, clinical score of severity of disease, and roentgenographic score of pulmonary involvement. The RVAW/sq m was slightly more sensitive than RVID/sq m; RVAW/sq m thickness on echocardiogram in vivo compared well with actual measurements at autopsy in five patients. No correlations were found between echocardiography and electrocardiograms, vectorcardiograms, thoracic index, or cardiothoracic ratio.

Echocardiography in endocardial cushion defects: a preoperative and postoperative study.

Echocardiographic studies were performed on 14 patients with endocardial cushion defects of different anatomic varieties. Four patients were studied again after operation. Patients with partial atrioventricular canal (PAVC) showed multiple systolic echoes on mitral valve echogram, with significant mitral-septal apposition in diastole. The left ventricular outflow (LVO) appeared significantly narrowed. The septal motions were paradoxic. After corrective operation, an increase in the width of the LVO was noted and mitral-septal apposition appeared to be less pronounced. Multiple systolic echoes, however, reappeared and persisted. The echocardiograms in patients with complete atrioventricular canal (CAVC) were characterized by wide excursion of an apparent single atrioventricular valve. The echoes of the mitral component of the common anterior leaflet moved anteriorly into the right ventricular cavity and overshadowed the tricuspid component in diastole. In addition, patients with CAVC and divided and medially attached common anterior leaflets had solitary mitral and tricuspid echograms. This feature differentiates this group of patients from those patients with CAVC with undivided freefloating common anterior leaflet.