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Biomedical subjects

R M Freedom

Publications and source records attributed to R M Freedom.

At least 19 recordsLinked to original sources
PubMed1979

The sensitivity of contrast echocardiography in detecting intracardiac shunts.

While contrast echocardiography has been shown to delineate intracardiac shunts, no information is available concerning the sensitivity of the method. This study establishes the relative sensitivity of the technique in detecting and localizing shunts by comparing the contrast echocardiograms with the simultaneously recorded cardiogreen dye curves in 26 children during cardiac catheterization. The echocardiograms substantiated isolated intracardiac shunting as small as 5%. There were no false-positive or false-negative echocardiograms in patients with or without shunt defects. This report demonstrates the contrast echocardiographic technique to be extremely sensitive in detecting intracardiac communications. It reviews the diagnostic patterns necessary for diagnosis and proposes the technique as a sensitive, safe, and accurate alternate method of study in the cardiac catheterization laboratory.

Adolescent↗
PubMed1979

Indicator dilution curves in the diagnosis of D-transposition of the great arteries in infancy.

Paired right and left atrial indicator dilution curves performed in a series of 17 patients with D-transposition of the great arteries (D-TGA) were reviewed. Taken together, the patterns obtained from patients who had trivial mixing between the pulmonary and systemic circulations were distinctive and easily recognizable. In the presence of substantial degrees of intracardiac mixing, however, the paired curves recorded become virtually identical and cannot be distinguished from curves recorded from patients with other forms of cyanotic congenital heart disease characterized by obligatory admixture. Thus paired atrial dye curves demonstrate a high degree of diagnostic specificity for the infant with D-TGA at greatest risk, normally those with a small intracardiac shunt. Such a procedure should facilitate early balloon atrial septostomy and obviate deterioration in the infant's condition due to prolonged catheter manipulation and/or angiography.

Humans↗
PubMed1979

Aortic vasa vasorum in cyanotic congenital heart disease.

Three cases for longstanding untreated cyanotic congenital heart disease are presented. In addition to collateral circulation from bronchial, intercostal, and inferior phrenic arteries, thoracic aortic vasa vasorum were visualized. We believe this may represent an additional collateral pathway to the lungs. The angiography of these cases is presented.

Adolescent↗
PubMed1979

Echocardiographic recognition of atrioventricular valve stenosis associated with endocardial cushion defect: pathologic and surgical correlates.

The association of either mitral or tricuspid stenosis with endocardial cushion defects has been well recognized pathologically but is infrequenctly diagnosed clinically. M mode echocardiographic features such as markedly disproportionate ventricular size, abnormal mitral or tricuspid diastolic echoes or failure to define adequately an atrioventricular (A-V) valve are strongly suggestive of associated stenosis of that valve. In this study mitral stenosis in association with endocardial cushion defect was correctly diagnosed in four of five patients. In the fifth patient (the first seen) the condition was easily diagnosed retrospectively. Tricuspid stenosis was similarly diagnosed prospectively in three of four patients. Significant stenosis was not overlooked or misdiagnosed in any patient with an endocardial cushion defect. Significant stenosis of an A-V valve in association with endocardial cushion defect carries a high mortality. It is important to recognize the combined lesion clinically because infants with it are not suitable for total surgical correction. Palliative surgical procedures with aggressive medical therapy probably offer the infant the best chance of surviving until ventricular growth may render corrective surgery feasible.

Aorta↗
PubMed1979

Ventricular morphology in the univentricular heart.

The ventricle morphology is described in hearts in which the entire atrial inputs are committed to a single chamber in the ventricular mass, this being considered the criterion for definition of the univentricular heart. Such a definition does not exclude from the univentricular category hearts with two chambers in their ventricular mass providing that the second chamber does not receive a direct atrial input. Three types of ventricular morphology were identified: hearts with a main chamber of left ventricular pattern and a rudimentary chamber of right ventricular pattern; hearts with a main chamber of right ventricular pattern and a rudimentary chamber of left ventricular pattern and hearts with a sole chamber in their ventricular mass of indeterminate pattern. Hearts may also exist of right or left ventricular type without rudimentary chambers. Variation was noted in type and position of the rudimentary chambers. Chambers of either right or left ventricular type were found supporting either or both great arteries (outlet chambers), and also without a direct outlet (trabecular pouches). Right ventricular rudimentary chambers were usually anterior but could be right or left sided; left ventricular chambers were posterior but again could be right or left sided. Hearts with these ventricular morphologies possessed either double inlet atrioventricular connexions, or absence of the right or left atrioventriuclar connexion. In double inlet ventricles, cases were observed with two valves, a common valve, one imperforate valve, and with straddling atrioventricular valves. A straddling valve was also found in hearts with absence of one atrioventricular connexion. Further variation was found in the pattern of arterial connexions. It is concluded that ventricular morphology is an important feature of the iniventricular heart but must be considered in the context of other important and variable features.

Heart Septal Defects, Ventricular↗
PubMed1979

Problems in the nomenclature of the univentricular heart.

There are three main reasons why there are problems concerning the nomenclature of the univentricular heart. The first is that different authorities have used the same term to describe different varieties of the univentricular heart. The second is that many of the terms used in categorisation of these anomalies are derived from embryological concepts which are more or less speculative. The final reason, perhaps the major one, is that there is a lack of definition of a ventricle. Consequently there is no consensus as to precisely what constitutes a "univentricular" heart. Many of the heart described as "single" or "common" ventricle possess two chambers within their ventricular mass. For such hearts to be univentricular it is evident that one of these chambers cannot be a ventricle. Yet definitions have yet to be provided to distinguish ventricles from rudimentary chambers. The solutions to these problems can be produced firstly by using descriptive terms for categorisation of univentricular hearts which do not have multiple meanings. Secondly, the problems concerning usage of embryologic terms can be easily circumvented by eschewing all embryologic considerations in naming these malformations. The problem of definition of a ventricle is best solved by considering normal ventricles as possessing three portions -- an inlet portion, a trabecular portion and an outlet portion. It may then be proposed that the minimal requirements for a ventricle are that it possesses at least an inlet and a trabecular portion. Chambers without inlet portions are rudimentary chambers. Either ventricles or rudimentary chambers may possess a trabecular pattern of right or left ventricular type. Tue univentricular heart may then be categorised as composing all anomalies which have a sole chamber in their ventricular mass together with all anomalies which possess a rudimentary chamber.

Heart Septal Defects, Ventricular↗
PubMed1979

Congenital absence of the pulmonary valve associated with imperforate membrane type of tricuspid atresia, right ventricular tensor apparatus and intact ventricular septum: a curious developmental complex.

We have presented the unique clinical and morphological features of 3 patients with an imperforate tricuspid valve and right ventricular tensor apparatus. Thus, despite valve tissue and apparatus, there was not a perforate atrioventricular connection. This most uncommon type of tricuspid atresia' was associated in all 3 cases with a congenitally absent pulmonary valve, an underdeveloped right ventricle, and a curious distortion of the ventricular septum. Indeed, 2 of these patients demonstrated severe disproportionate ventricular septal thickening, although histopathologic examination did not substantiate those features usually associated with a hypertrophic cardiomyopathy. Rather, microscopic examination revealed a sinusoidal malformation consisting of normal myocardial cells separated by branching ethothelial-lined channels which communicated with the right ventricular cavity. In addition, gross examination of these 3 specimens revealed an abnormally persistent right venous valve in 2, which subdivided the right atrium. Finally, these cases provide further evidence that the term 'tricuspid atresia' oversimplifies the observed morphological features.

Abnormalities, Multiple↗
PubMed1978

Morphological and topographical variations of the outlet chamber in complex congenital heart disease: an angiocardiographic study.

The outlet chamber of the human heart can show considerable variations in its morphology and topography (relationship to main ventricular chamber), and such variations in anatomy and spacial relationship may be predictive of the associated intracardiac anatomy. Although there is considerable debate about whether the position of the outlet chamber is indicative of the type of bulboventricular loop (whether D- or L-), a right-sided and anterior outlet chamber has different implications than a left-sided, superior, and more posterior positioned one. The inflows into the outlet chamber can vary anatomically, and progressive changes in the calibers of these communications can adversely alter the natural history. One or both of the greak vessels, or neither, or a persistent truncus arteriosus can originate from the outlet chamber, and any significant morphological change in the outlet chamber may or may not adversely affect either the pulmonary or systemic blood supply, or both. Finally, any consideration of the outlet chamber raises important conceptual difference in terminologies. At present, there is not unanimity as to what constitutes either an outlet chamber (as compared to a "small right ventricle" in tricuspid atresia) or a single (primitive) ventricle. Any discussion of the morphological and topographical variations of the outlet chamber must be viewed with respect to the terminology employed.

Angiocardiography↗
PubMed1978

Truncal or aortic valve stenosis in functionally single arterial trunk. A clinical, hemodynamic and pathologic study of six cases.

Stenosis of the semilunar valve in the presence of a functionally single arterial trunk is uncommon. Three patients with truncus arteriosus, two with tetralogy of Fallot and pulmonary atresia and one with pulmonary atresia and intact septum were diagnosed as having stenosis of the truncal or aortic valve on the basis of clinical, echocardiographic, hemodynamic and angiocardiographic findings. Echocardiograms consistently showed multiple diastolic closure lines and abnormal semilunar valves in addition to the aortic override in five patients and hypoplastic right ventricle in the patient with pulmonary atresia and intact septum. Peak systolic gradients between the left ventricle and truncus (or aorta) at cardiac catheterization ranged from 20 to 47 mm Hg. Retrograde aortography confirmed a domed and stenotic semilunar valve. Cyanosis was progressive in the three patients with pulmonary atresia. Two patients had arterial anastomosis, and one had a right ventricle-pulmonary arterial graft in addition to aortic valvotomy. One of the three patients with truncus arteriosus underwent complete repair in addition to truncal valvotomy but he died in the post-operative period. The other two patients with truncus arteriosus died of intractable congestive cardiac failure before surgical intervention. It is suggested that the presence of semilunar valve stenosis in these patients adversely affects the prognosis. The myocardium is already jeopardized as a result of hypoxia in pulmonary atresia and left ventricular diastolic overload in patients with truncus arteriosus. The added burden of semilunar valve stenosis may further compromise the functional status of the myocardium.

Angiocardiography↗
PubMed1978

The criss-cross and superoinferior ventricular heart: an angiocardiographic study.

The angiocardiographic features of 11 patients with superoinferior and criss-cross type of atrioventricular (A-V) connections are presented. These unusual ventricular relations are thought to result from postseptation disturbances of ventricular looping. The angiocardiographic appearance of criss-cross is really an illusion, and the A-V connections among these patients are either concordant, discordant or straddling. The often small right A-V valve inflow and sinus portion of the ventricle, combind with the ventricular rotational anomaly, combine to give the angiocardiographic perception of criss-cross. A review of the 11 patients from this institution and those previously reported on suggests that most patients have a transposition of malposition of the great arteries; many have a small right ventricle, and about half have pulmonary outflow tract obstruction. In addition to the obvious embryologic, morphologic and clinical implications of these distorted ventricular loops, the criss-cross A-V hearts raise questions about the various segmental nomenclatures applied to these types of congenital heart disease.

Angiocardiography↗
PubMed1978

The prostaglandin challenge. Test to unmask obstructed total anomalous pulmonary venous connections in asplenia syndrome.

The patient with complex congenital heart disease, severe pulmonary outflow obstruction, and visceral heterotaxia, may have 'silent' obstruction of the pulmonary venous return. Severe reduction of pulmonary blood flow secondary to pulmonary stenosis or atresia in such patients may prevent the usual radiographic appearance of pulmonary oedema. If such obstructed anomalous pulmonary venous connections are not diagnosed before operation, construction of a systemic to pulmonary artery anastomosis will unmask the obstruction, usually resulting in pulmonary oedema and death. We have recently 'challenged' a neonate with dextrocardia, vesceral heterotaxia, presumed asplenia, and complex congenital heart disease including pulmonary atresia, with an infusion of prostaglandin E1 to increase pulmonary blood flow via his ductus arteriosus. This resulted in severe pulmonary oedema which partially resolved after the infusion was discontinued. This was interpreted as consistent with obstructed total anomalous pulmonary venous return. This was confirmed at necropsy. Thus, the infusion of prostaglandin E1 before operation in the patient with asplenia or similar cardiac disease may be of aid in unmasking 'silent' obstructions of the pulmonary veins, and is of obvious value in the preoperative assessment of such patients.

Heart Defects, Congenital↗
PubMed1978

Torsade de pointes ventricular tachycardia in a newborn infant.

A case of paroxysmal ventricular tachycardia of torsade de pointes variety occurring in a newborn infant is described. A rare problem in the newborn, ventricular tachycardia has been associated with congenital heart disease, electrolyte abnormality, and cardiac tumour. In this case, the association was with myocarditis. The arrhythmia was refractory to treatment, and the infant died.

Electrocardiography↗
PubMed1978

The reliability and practicality of single crystal echocardiography in the evaluation of single ventricle. Angiographic and pathological correlates.

A prospective clinical and echocardiographic diagnosis of single ventricle was made in 42 patients. Each was evaluated for the number of atrioventricular (A/V) valves, presence of an outflow chamber (OC), A/V valve-semilunar continuity, and orientation of the great arteries. Angiographic correlations were subsequently obtained in 40 and autopsies in 12. The overall diagnosis of single ventricle was substantiated in 39. Two other patients diagnosed as single ventricle by angiography were thought to have large ventricular septal defects on echocardiography. Tricuspid valve was interpreted as septum in one. The angiographic diagnosis of single ventricle was incorrect in another, correctly diagnosed by echocardiography and confirmed at pathology. The differential diagnosis also included A-V canal, L-transposition of the great arteries, double outlet right ventricle, and tricuspid atresia. This last condition has to be differentiated on clinical evidence. The echocardiograms were of particular value in determining the number of A/V valves. Two great arteries were demonstrated in 74% of patients and their relationship was correctly determined in 79% of these. Both imaging techniques agreed closely as to A/V valve-semilunar continuity and presence of an OC, but both showed some inaccuracies compared to pathological specimens. The echocardiogram helps both in planning catheterization and in evaluating the overall diagnosis.

Adolescent↗
PubMed1978

Endocardial cushion defect and significant hypoplasia of the left ventricle: a distinct clinical and pathological entity.

We have identified 12 patients with endocardial cushion defect and marked under-development of the left ventricle. Most of these patients had significant obstructive anomalies of the aortic arch. Pathologically, the left ventricle was very small, but without endocardial fibroelastosis, significant subaortic narrowing was evident, resulting from maladherent atrioventricular valve tissue to the left ventricular outflow tract, and the left ventricular posterior leaflet component of the atrioventricular valve was both grossly deficient and dysplastic. In all 12 a large ostium primum atrial communication was present, but the ventricular contribution to the defect was small. The clinical presentation of severe, intractable congestive heart failure in these neonatal patients would suggest the diagnosis of typical hypoplastic left heart syndrome. Important departures in some of these patients included a leftward, superior and counterclockwise frontal vector on the electrocardiogram and a widely split second sound. Selective biplane angiocardiography will reveal the underdeveloped left ventricle, with an elongated, fixed, 'gooseneck' deformity of the left ventricular outflow tract, severe 'mitral' regurgitation, and a small ascending aorta. Selective right ventriculography will opacify the very much larger right ventricle and pulmonary artery. Finally, these cases broaden the concept of double inlet right ventricle and exaggerated displacement of the atrioventricular canal towards the bulbus cordis.

Angiocardiography↗
PubMed1978

The tricuspid valve in pulmonary atresia and intact ventricular septum: a morphological study of 60 cases.

A morphologic study of the tricuspid valve was performed in 70 patients with pulmonary atresia and intact ventricular septum who had died and subsequently undergone autopsy. The right ventricular cavity was enlarged in 8 patients, normal in 4 patients, mildly underdeveloped in 18 patients, and markedly underdeveloped in 24 patients. In the patients with dilated and enlarged right ventricle, the tricuspid valve exhibited features of dysplasia or Ebstein's malformation (downward displacement), or both, with a dilated anulus. The majority of patients had restriction of the tricuspid valve apparatus and an underdeveloped anulus, usually of a severe degree. The right ventricle appeared to have normal dimensions in four patients, but the tricuspid valve and tensor apparatus, even in these patients, exhibited departures from the normal. This study suggests that in many of these patients adequate right ventricular growth will not be achieved because of inadequate right ventricular filling. This seems directly related to moderate or severe underdevelopment of the tricuspid valve.

Child, Preschool↗
PubMed1978

The straddling mitral valve: morphological observations and clinical implications.

The morphological features of 23 patients with straddling or overriding mitral valve are presented. Levocardia was present in 20 of 23; visceroatrial situs solitisu in 20 of 23, with 3 patients, 2 with asplenia and 1 with polysplenia, having visceral heterotaxia. A concordant D-ventricular loop was present in the 20 patients with visceroatrial situs solitus. Six of these had double outlet right ventricle; 2 had asplenia syndrome; 1 had D-transposition of the great arteries, ventricular defect and pulmonary atresia; 1 with tricuspid atresia and double outlet-outlet chamber; 1 with polysplenia syndrome; and 12 had endocardial cushion defect with marked underdevelopment of the left ventricle, and normally related great arteries. Left ventricular size was related to the amount of mitral valve (or left-sided component of a common atrioventricular valve) connected to it. In those patients in whom little effective mitral orifice was connected to the left ventricle, the left ventricle was diminutive. Endocardial fibroelastosis of the left ventricle was noted in only a single patient. Six of the 7 patients with double outlet right ventricle (including one with double outlet bulbus) had subpulmonary obstruction, and in one of these, this was related in part to the straddling mitral valve. In 1 patient with double outlet right ventricle, there was a double orifice mitral valve, and it was the accessory mitral orifice that straddled. The diagnosis of overriding mitral valve should be suspected in any patient with significant conotruncal anomalies and underdeveloped left ventricle, especially the patient with double outlet right ventricle, and in the patient with endocardial cushion defect, hypoplasia of the left ventricle, and obstructive anomalies of the aortic arch. In certain patients, selective left atriography, left ventriculography, and single and two dimensional echocardiography may be diagnostic of this condition.

Abnormalities, Multiple↗