Echocardiographic detection of aneurysms of the interventricular septum associated with ventricular septal defect. A method of noninvasive diagnosis and follow-up.

Spontaneous closure of a ventricular septal defect is frequently accompanied by the formation of an aneurysm of the membranous septum. The exact anatomic basis for such an aneurysm varies. Some arise from redundant tissue from the endocardial cushions or from adherence of the tricuspid septal leaflet to the defect; the origin of others cannot be determined. Echocardiographic studies in 17 patients with the diagnosis of ventricular septal defect revealed in 7 an aneurysm of the membranous septum that was later confirmed by angiography. In no patient was an aneurysm missed or erroneously diagnosed in the echocardiographic study. Echocardiography can be a useful diagnostic and prognostic tool in the long-term management of patients with ventricular septal defect.     

Two dimensional echocardiographic recognition of the descending thoracic aorta.

Two dimensional echocardiography was used to identify the descending thoracic aorta in 106 subjects. In 12 of these subjects, contrast injection techniques were used to identify this structure as it descended posteriorly adjacent to the atrioventricular groove. The course of the descending thoracic aorta was mapped using both the long axis and transverse axis views. The normal descending thoracic aorta (26 subjects) measured 10 +/- 1.4 mm/m2 during diastole. Unusual M mode echocardiographic patterns of the descending aorta may be confused with other disease states; they are clarified with the two dimensional study. The size and appearance of the descending aorta in different types of cardiovascular disease, including aortic aneurysm, in 80 patients are described. It is anticipated that two dimensional echocardiography will prove to be a useful method of studying patients with aortic disease.     

Left ventricular wall stress in compensated aortic stenosis in children

It is known that children with aortic stenosis (AS) frequently have supernormal indexes of left ventricular (LV) pump function and remain compensated for many years. Factors causing this increase in pump performance have not been elucidated. A study was done on LV mechanics in 11 children with AS (aortic valve area 0.5 +/- 0.3 cm2/m2) and 10 normal subjects. The ejection fraction in the AS group (0.88 +/- 0.08) was significantly higher than in normal subjects (0.64 +/- 0.08, p less than 0.001). The mean velocity of fiber shortening was also higher in AS patients (1.80 +/- 0.35 circ/s) than in normal subjects (1.22 +/- 0.21 circ/s, p less than 0.001). The end-systolic volume index in patients with AS (9 +/- 8 ml/m2) was much lower than in normal subjects (27 +/- 8 ml/m2). LV mass in patients with AS was 180 +/- 58 g/m2 compared with 96 +/- 9 in normal subjects. LV wall stress was reduced throughout the cardiac cycle in patients with AS. Peak stress in patients with AS was 238 +/- 51 dynes/cm2 X 10(3) versus 439 +/- 85 in normal subjects. The end-systolic stress-end-systolic volume index ratio, an indicator of contractile state, was not elevated in patients with AS. It is suggested that diminished wall stress in concert with normal contractile function permits the supernormal pump function seen at rest in children with AS.     

Two dimensional echocardiographic recognition of the descending thoracic aorta: Value in differentiating pericardial from pleural effusions

The course of the descending thoracic aorta has recently been visualized with two dimensional echocardiography and its presence confirmed with contrast studies. In the parasternal short axis view, we used the location of the descending thoracic aorta to differentiate pericardial from pieural effusions in 40 patients. Sixteen patients, each with an isolated pericardial effusion, had an echo-free space between the descending thoracic aorta and left ventricular posterior wall. Nine patients, each with an isolated pleural effusion, had an echo-free space posterior to the descending aorta. Fifteen patients, each with both a pericardial and a pleural effusion, had echo-free spaces both between the descending thoracic aorta and left ventricular posterior wall and also posterior to the descending thoracic aorta. With one exception, all patients had anatomic confirmation of these findings. Forty-one patients undergoing cardiac surgery served as controls and none had a posterior echo-free space in relation to the descending thoracic aorta. At operation, no pericardial or pleural effusion was evident. The location of the descending thoracic aorta on two dimensional echocardiography serves as a valuable landmark in localizing the pericardial-pleural interface, thereby differentiating pericardial from pleural effusions.     

Two-dimensional echocardiographic prospective diagnosis of common truncus arteriosus in infants

Two-dimensional echocardiographic prospective diagnosis of truncus arteriosus was made in 7 infants. Two infants had truncus arteriosus type I, 3 patients had truncus arteriosus type II, 1 infant had truncal valve stenosis with an interrupted aortic arch, and 1 had type IV truncus arteriosus with pulmonary hypertension. Multiple imaging views were utilized to confirm the diagnosis. The parasternal long-axis view demonstrated the great vessel-ventricular septal override and the origin of the pulmonary arteries from the posterior aspect of the ascending truncus. The suprasternal notch image facilitated identification of the left- or right-sided aortic arch and the origin of the pulmonary arteries from the truncus. Transverse imaging sections at the base of the heart facilitated identification of the pulmonary artery origin of truncus arteriosus type I. Subcostal coronal and sagittal views imaged the common truncus and the ventricular septal defect.

These echocardiographic images were contrasted with and discriminated from those of an infant with aorticopulmonary window with intact ventricular septum. Although cardiac catheterization and angiography may be required to assess pulmonary arterial pressure, pulmonary vascular resistance, and the distal pulmonary arterial anatomy in truncus arteriosus, 2-dimensional echocardiography can be used to correctly establish the morphologic diagnosis of truncus arteriosus in infants.     

Anuloaortic ectasia: A clinical and echocardiographic study

Twenty-six patients with an aortic root diameter ≥ 3.7 cm by 2-dimensional echocardiography (2-D echo) were studied. Group I consisted of 14 patients (mean age 50 ± 14 years) with idiopathic anuloaortic ectasia and group II consisted of 12 patients (mean age 60 ± 12 years) with secondary causes of aortic root dilatation. Patients in group I had a significantly larger aortic root diameter at the level of the aortic valve (5.0 ± 0.7 cm) and 2 cm above the aortic valve (5.3 ± 1.2 cm) as assessed by echo than did patients in group II (4.1 ± 0.3 and 4.4 ± 0.4 cm, respectively, p < 0.025). The diameter of descending thoracic aorta was slightly larger in patients in group II (3.1 ± 0.8 vs 2.7 ± 0.5 cm, difference not significant). Over a mean follow-up period of 18 months, in group I, aortic dissection developed in 3 patients and severe aortic regurgitation and congestive heart failure in 2; 7 patients had aortic root grafting, aortic valve replacement or both. The 3 patients in group I with aortic dissection had an aortic root diameter ≥ 5.3 cm, but 4 asymptomatic patients also had a diameter > 5 cm. Only 1 patient in group II required surgery for aortic dissection. Thus, 2-D echo is useful in identifying and following high-risk patients with anuloaortic ectasia.     

Coronary thrombolysis by intravenous streptokinase in acute myocardial infarction: Acute and follow-up studies

Coronary arteriography was performed before, immediately after, and 9 to 14 days after administering i.v. Streptokinase (850,000 to 1,500,000 IU) to 43 patients within 6 hours of myocardial infarction. Ventricular function was determined by contrast ventriculography before and 9 to 14 days later and by radionuclide studies at clinical follow-up 8 months later. Early reperfusion occurred in 49% of patients, but in only 35 % was it sustained. In patients with sustained reperfusion, early ventricular dysfunction was significantly reduced 9 to 14 days and 10 months later, and frequency of infarction, sudden death, and angina pectoris was not increased at follow-up. No serious bleeding occurred.     

Relation of the echocardiographic estimate of left ventricular size to mortality in infants with severe left ventricular outflow obstruction

The relation of left ventricular size, as estimated with echocardiography, to mortality was evaluated in three groups of infants with severe left ventricular outflow obstruction. Group I consisted of 17 patients with combined aortic and mitral stenosis or atresia associated with definite hypoplasia of the left ventricle. Group II consisted of eight patients with the primary diagnosis of severe aortic stenosis. Group III consisted of 12 patients with severe coarctation of the aorta. The left ventricular enddiastolic dimension measured with M mode echocardiography and the cross-sectional area of the left ventricular cavity as seen in the parasternal long axis view of the two dimensional echocardiogram were used as indexes of left ventricular volume.All patients with symptomatic outflow obstruction and a left ventricular end-diastolic dimension of less than 13 mm died in infancy. However, five patients with a hypoplastic left ventricle proved at angiography or at autopsy, or both, were found to have a ventricular end-diastolic dimension of 13 mm or greater. Two dimensional echocardiography showed that the left ventricle in these patients was foreshortened and spherical in shape. The cross-sectional area of the left ventricle of each patient in group I was less than 1.6 cm². This was below the range of cross-sectional areas found in a group of normal infants (1.8 to 3.5 cm² ± 2 standard deviations about the mean). Three patients in groups II and III had a slightly reduced left ventricular area (1.7 cm²) and none of these patients survived infancy.Measurement of the cross-sectional area of the left ventricle is a useful method of determining left ventricular size in infants suspected of having the hypoplastic left ventricle syndrome. Patients who have reduced left ventricular volume as assessed by this technique are at very great risk even if surgical relief of the outflow obstruction is attempted.     

Hemodynamic effects of dobutamine in children.

Dobutamine is useful for augmenting cardiovasuclar function in adults. However, no information is available on the action of dobutamine in children. To determine its hemodynamic effects in children, we infused dobutamine into 12 children with congenital heart disease during diagnostic cardiac catheterization. We administered dobutamine in two doses: first 2 and then 7.75 microgram/kg per min for 10 minutes each. We meaured heart rate, cardiac output, systemic and pulmonary arterial, right atrial and pulmonary capillary blood pressures before and during the infusion of dobutamine. Systemic and pulmonary vascular resistances, cardiac index and stroke index were calculated. Cardiac output, cardiac index, stroke volume, stroke index and systemic arterial phasic and mean blood pressures increased sugnificantly (P less than 0.05) and pulmonary capillary mean blood pressure decreased significantly (P less than 0.05) during the infusion of each dose of dobutamine compared with control values. Heart rate, pulmonary and right atrial mean blood pressure and systemic and pulmonary vascular resistance were unchanged with either dose of dobutamine. We noted no adverse effect from the drug.     

Clinical and echocardiographic evaluation of the St. Jude cardiac valve prosthesis: follow-up of 126 patients

One hundred twenty-six patients with a St. Jude valve prosthesis were followed up clinically and studied by combined M-mode echocardiography and phonocardiography. Fifty patients underwent aortic valve replacement, 58 underwent mitral valve replacement and 18 underwent a combination of the two. The early postoperative mortality rate was 8% for aortic, 6.9% for mitral and 6% for combined valve replacement. Follow-up ranged from 2 to 46 months (mean +/- SD 28 +/- 9). The late postoperative mortality rate was 5%; in patients who survived, improvement in New York Heart Association functional class occurred in 97%. Major thromboembolic events occurred in two patients and anticoagulation-related complications occurred in three patients. Valve-related complications occurred in 14 patients and included bacterial endocarditis (6 patients), paravalvular leak (5 patients), severe hemolysis (1 patient), thrombosis of valve (1 patient) and possible mechanical valve failure (1 patient). In 7 of these 14 patients, repeat surgery was required and 5 patients survived. Abnormal echocardiographic findings in these seven patients included a shortened aortic closure (A2) to mitral valve opening interval, increased left atrial and left ventricular size and initial diastolic rounding of the St. Jude valve motion in the patient with the thrombosed valve. It is concluded that the St. Jude valve prosthesis is associated with favorable functional results and a low complication rate for a mean follow-up period of 28 months. Combined M-mode echocardiography and phonocardiography may be useful in assessing patients with suspected complications related to the St. Jude cardiac valve.     

Fetal hydrops in a newborn with hypoplastic left heart syndrome: tricuspid valve "stopper"

Fetal hydrops in a newborn infant with hypoplastic left heart syndrome led to the discovery of tricuspid stenosis and insufficiency from an unusual malformation of the right venous valve of the embryonic sinus venosus. This unfortunate combination of lesions precluded surgical palliation for the hypoplastic left heart.     

Atrial alternans: Experimental echocardiographic and hemodynamic demonstration during programmed pacing

Simultaneous hemodynamic and echocardiographic recordings were used to demonstrate mechanical atrial alternans during programmed atrioventricular (A-V) pacing in five open chest dogs. Each animal was studied in two stages, first with the A-V conduction system intact (phase I) and later after the experimental induction of complete A-V block (phase II). Atrial alternans was demonstrated during rapid atrial stimulation at cycle lengths ranging from 250 to 120 ms. During phase I, rapid atrial pacing resulted in complex combinations of variable A-V conduction disturbances with superimposed atrial and ventricular alternans. During phase II, atrial alternans could be observed during a programmed prolonged pause in ventricular activity. It is anticipated that this method will facilitate recognition of atrial alternans in various clinical situations and shed further light on its possible hemodynamic significance.     

Circulation in neonates with intracranial arteriovenous fistula and cardiac failure

Two newborn infants with severe cardiac failure caused by a large cerebral arteriovenous communication were studied with complete cardiac catheterization, indicator-dilution curves and angiography. In one infant, studied at age 10 hours, a large right to left shunt through the patent ductus was seen with retrograde aortic flow into the left carotid artery. The entire flow in the descending aorta was supplied from the ductus. The second infant, studied at age 5 days, had a 20 percent right to left shunt through the foramen ovale and the ductus was closed. Hypoxia was caused by inadequate oxygenation of pulmonary venous blood, atrial right to left shunting and possibly ductal right to left shunting. The hemodynamic findings in cases of cerebral arteriovenous fistula would seem to depend on the patient's age at the time the studies are carried out and the severity of the lesion. Cardiac output was more than twice the normal value and blood flow through the arteriovenous fistula was probably greater than 4 liters/min per m².     

Noninvasive determination of systolic,diastolic and end-systolic blood pressure in neonates,infants and young children: Comparison with central aortic pressure measurements

Noninvasive determinations of systolic and diastolic blood pressure using the oscillometric method for pressure measurement were combined with externally recorded axillary pulse tracings to estimate end-systolic pressure in 32 neonates, infants and young children. Results were compared with central aortic pressure measurements made at the time of central aortic catheter placement. Studies were performed in patients aged 1 day to 48 months who weighed 0.9 to 18.1 kg. A wide range of systolic (41 to 141 mm Hg), diastolic (22 to 73 mm Hg) and end-systolic (30 to 111 mm Hg) pressure values were found. The mean absolute pressure differences and percent errors (pressure difference divided by central aortic pressure) were 1.8 mm Hg and 2.5% for systolic, 0.8 mm Hg and 0.8% for diastolic and 1.4 mm Hg and 2.1% for end-systolic pressure. No correlation was noted between percent error and age, weight, heart rate, cardiac index or systemic vascular resistance. The ability to perform reliable noninvasive pressure measurements should prove invaluable for clinical and research purposes. In addition, this method of end-systolic blood pressure determination enables sensitive indexes of left ventricular contractility to be measured noninvasively in small children.     

Two-dimensional echocardiographic features of interruption of the aortic arch

The 2-dimensional echocardiographic features of interruption of the aortic arch are presented based on analysis of the echocardiograms and angiograms from 8 infants: 2 with type A and 6 with type B interruption. Each infant had a patent ductus arteriosus, 6 had a conoventricular septal defect with leftward deviation of the conal septum, 1 had truncus arteriosus with truncal valve stenosis, and 1 had a distal aortopulmonary septal defect with an intact ventricular septum. Echocardiographic images obtained from the suprasternal notch or from a high parasternal approach demonstrated the interruption of the aortic arch and continuation of the patent ductus arteriosus into the descending aorta. These findings were compared with those in infants with aortic atresia and a hypoplastic ascending aorta or discrete coarctation of the aorta with tubular hypoplasia of the aortic arch. Types A and B interruption of the aortic arch were easily differentiated and the caliber of the patent ductus arteriosus was assessed. The characteristic conoventricular septal defect was readily visualized from an apex 2-chamber view or from a subcostal sagittal plane view. With this information subsequent angiography can be more expeditiously performed in this group of critically ill infants.     

Cardiac function in sickle cell anemia

Although ventricular dysfunction is suspected to underlie congestive heart failure in sickle cell anemia (SCA), ejection indexes of left ventricular (LV) pump performance have been found to be normal. The increased preload and decreased afterload of SCA increases the ejection phase indexes and might obscure true LV dysfunction. Therefore, the preload and afterload independent end-systolic stress-volume index was compared in 11 patients with SCA and in 11 normal volunteers. End-systolic pressure and echocardiographic LV dimensions were determined during rest, leg raise, hand-grip and amyl nitrite inhalation. Systemic vascular resistance (afterload) was decreased to 1,033 ± 314 dynes s cm⁻⁵ (mean ± standard deviation) in SCA from 1,701 ± 314 dynes s cm⁻⁵ in normal subjects. End-diastolic volume index (preload) was increased to 102 ± 24 ml/m² in SCA from 66 ± 10 ml/m² in normal subjects. Cardiac index was increased to 4.7 ± 1.1 liters/min/m² in SCA from 2.8 ± 0.8 liters/ min/m² in normal subjects. Ejection fractions were similar: 0.59 ± 0.09 in SCA versus 0.62 ± 0.07 in normal subjects. However, in patients with SCA, the ratio of resting end-systolic stress-volume index was decreased (1.5 ± 0.5 in SCA versus 2.8 ± 0.6 in normal subjects) and the slope of the end-systolic stress versus end-systolic volume index relation was decreased (2.7 ± 1.3 in SCA versus 4.4 ± 1.8 in normal subjects), suggesting LV dysfunction in those patients. Thus, LV muscle contractile performance is depressed in SCA. Increased preload and decreased afterload compensate for the LV dysfunction and maintain a normal ejection fraction and high cardiac output.     

Aortic mitochondrial synthesis of lipid and its response to cholesterol feeding.

The rates and products of lipid synthesis from acetate-I-14C were studied in mitochondria isolated from control and atherosclerotic rabbit aorta. More acetate was incorporated into fatty acids in the cholesterol-fed animals. The mechanism was one of chain elongation, and the resultant products were longer in chain length. The newly elongated fatty acids were esterified mostly into phospholipids, presumably those turning over most rapidly. A hypothesis is proposed for the pathogenetic sequence: Cholesterol feeding alters transport functions of the mitochondrial membranes of aortic smooth muscle cells. Respiration and redox state are altered and consequently acetate is incorporated more rapidly into fatty acids as an alternate mechanism for oxidation of the reduced form of nicotin-amide-adenine dinucleotide (NADH). Rapidly turning over phospholipids esterify these fatty acids and may transfer them ultimately to cholesterol. Esterified cholesterol is less exchangeable and commences to accumulate.