Friedrich A. O. Eckner

Single (Primitive) Ventricle

Single ventricle is that condition in which both atrioventricular (A-V) orifices enter a common ventricular sinus, from which the arterial trunks emerge with their coni. The following types of single ventricle were found: (1) with regular (noninverted) transposition in levocardia; (2) with inverted transposition in levocardia; (3) with normal position of arterial trunks in levocardia; (4) in dextrocardia, and (5) in mesocardia. This entity is differentiated from common ventricle which is basically a heart with a large ventricular septal defect. Single ventricle does not include mitral and tricuspid atresia by definition, nor does it include straddling tricuspid orifice, in which two distinct ventricles are present. The concept of single ventricle herein defined differs from de la Cruz and Millers concept of double-inlet left ventricle which includes straddling tricuspid orifice. Embryologically in single ventricle we are dealing with persistence of the primitive state of the bulboventricular loop, due to a lack of expansion of the atrial canal to the right during the process of absorption of the bulbus.

Straddling and Displaced Atrioventricular Orifices and Valves with Primitive Ventricles

Fourteen cases of straddling or displaced atrioventricular (A-V) orifices and valves are presented. There are three types: (1) straddling tricuspid orifice entering both primitive ventricles with the mitral valve entering the left ventricle (nine cases), (2) displaced tricuspid orifice into the primitive left ventricle, with no A-V orifice in the primitive right ventricle (three cases), and (3) displaced tricuspid orifice with straddling mitral valve, in which the mitral valve has connections in both primitive ventricles, with the tricuspid entering the primitive left ventricle (two cases). Pathologically, these hearts are not single ventricle since there is a primitive right ventricle containing a portion of sinus as well as conus. Embryologically, however, these hearts are related to single ventricle, all being due to insufficient or no passage of the atrial canal region to the right during the process of absorption of the bulbus. Selective angiocardiography may differentiate straddling A-V orifices from single ventricle by showing immediate filling of both ventricles by injection into the right or left atrium.

Pathologic Anatomy of Dextrocardia and Its Clinical Implications

This is a morphologic study of 41 cases of dextrocardia for the purpose of clarifying terminology and evaluating the clinical import of the morphologic data. Dextrocardias are classified as dextroversion, mirror-image dextrocardia, and mixed dextrocardia. When the atrial septum does not identify the atria, it was found possible to make the presumptive diagnosis of dextroversion or mirror-image dextrocardia. The mutual relations of the visceral situs with the atrial situs, the presence or absence of splenic abnormalities, the type of dextrocardia, and the systemic and pulmonic venous return were investigated, as well as the type of complex that is characteristic of each type of dextrocardia. The most important morphologic data useful for clinical application were found to be the position of the aortic and pulmonic annuli, the course of the pulmonary trunk, the entry of the inferior and superior venae cavae, and the course of the anterior descending coronary artery.

The pathologic anatomy of mesocardia

Abstract Mesocardia is that condition in which the longitudinal axis of the heart lies in the mid-sagittal plane and the heart has no apex. Thirteen cases of mesocardia are presented. There were 5 cases of mesoversion, associated with situs solitus of the viscera and normal spleen; 2 cases of presumptive mesoversion, associated with situs inversus of viscera and abnormal spleen; 4 of mixed mesocardia with atrial situs solitus and ventricular inversion, with situs solitus of viscera with or without abnormal spleens; 1 of presumptive mixed mesocardia with atrial situs inversus and normal ventricles, with situs inversus of organs with normal spleen; and 1 case of indeterminate type with situs inversus of viscera and abnormal spleen. Thus, from the stand-point of position of chambers, the type of hearts found in mesocardia resembled those found in dextrocardia and levocardia. If the spleen was normal, then the atrial situs in all cases agreed with that of the viscera and the venous return was normal. Mesocardia reflects that embryonic condition before the formed heart points to the right or left and acquires an apex.

Myocardial Biopsy in Dogs

Full-thickness biopsies of ventricular dog myocardium, beating and in arrest, have been studied by conventional fixation (immersion in fixative solution), by the use of cryostat sections thawed on slides, and by freeze drying of tissue blocks. Three types of artifacts were found and could be related (1) to cutting into the beating heart, (2) to thawing of frozen sections on slides, and (3) to the failure of fixative solutions to immobilize still reactive myocardium immediately. The method described yields a biopsy specimen of sufficient diameter to delineate the cutting artifacts. For histological preparation freeze drying appears to be the method of choice.

Cor triatriatum in the adult: Complicated by mitral insufficiency and aortic dissection☆

Abstract A case of cor triatriatum, complicated by acquired mitral insufficiency and aortic dissection with survival to the fifth decade is presented. A diastolic pressure gradient was recorded between the left ventricle and the proximal left atrial chamber which was entered by the transseptal catheter, but no transmitral gradient was present at surgery. Indicator, injected in the left ventricle, was not detected during sampling from the transseptal catheter, despite the demonstration of considerable mitral regurgitation by left ventricular angiocardiography. Cor triatriatum should be suspected, even in the adult patient, when such apparently anomalous hemodynamic observations as those present in this patient are encountered.

Pathologic measurements in aortic atresia

Detailed autopsy measurements were performed in 13 infants with hypoplastic left ventricle and aortic atresia. Emphasis was placed on the evaluation of changes in the right ventricle, since its function may be important in determining surgical survival. Other important aspects were the ascending aortic and transverse aortic arch diameter, the presence of left atrial obstruction, and the size of the left atrium. The development of improved 2DE and Doppler imaging will permit preoperative and sequential evaluation of these parameters. Measurements performed in this study may serve as a basis for selection of infants for palliative surgery; these procedures are being undertaken more frequently in this hitherto fatal lesion. The measurements may also serve as a basis for noninvasive serial studies of these infants postoperatively.

Polysaccharide synthesis in tissue sections - Evaluation of methods as an example of quality control in histochemistry

SummaryBiochemical methods for demonstration of enzyme activity are test tube models outside the organization of cell. Their application to the complicated organization of the cell present problems to histochemistry. The morphological and chemical preservation of tissue which is desirable in histochemistry leads to a multiplicity of reactions when “test tube” methods are applied. For example, the histochemical phosphorylase and glycosyltransferase reactions rest on the assumption that one can distinguish between preexisting glycogen and newly formed polysaccharides. We used frozen dried canine myocardium and liver for examination of the authenticity of histochemical phosphorylase and glycosyltransferase (branching enzyme, UDPG-glycogen transglycosylase) reactions as described in histochemical reference books. We were unable to distinguish between preexisting glycogen and supposedly newly formed polysaccharides with methods presently used for this purpose (Iodine stain, differential digestion with amylases, acid hydrolysis). Tissue without PAS stainable glycogen remained so after substrate incubation. When preexisting glycogen was present, the amounts of stainable polysaccharides after incubation were invariably less. Therefore, we could not prove beyond doubt that any polysaccharide synthesis due to enzyme reaction had oceured. The prescribed controls, perhaps adequate for biochemical “test tube” reactions, have to be redefined for meaningful histochemical procedures.

Histochemical study of enzyme systems in frozen dried tissue

SummaryCytochrome oxidase, succinic dehydrogenase, phosphorylase and branching enzymes were consistently demonstrated in frozen dried paraffin embedded dog myocardium if the appropriate solvent for deparaffinization was used. No modification of the incubating medium was necessary for cytochrome oxidase. For succinic dehydrogenase a 0.8 M succinate solution was used instead of the usual 0.2 M solution and phenazine methosulfate had to be added to the incubating medium. No primer or activators were necessary for demonstration of phosphorylase and branching enzyme activities.

Computerized tomography in occlusive infantile arteriopathy

SummaryUse of computerized tomography (CT) in the diagnosis of arterial calcification of infancy, including coronary obstructive disease, has not been previously reported. We were able to demonstrate by CT scan the abnormal arteries present in this disease. The calcified arteries in this infant, who died of bowel infarction at three weeks of age, were easily delineated in CT scans of the chest, abdomen, and extremities. Autopsy sections revealed intact elastic fibers in the abnormal arteries, indicating that the basic pathologic process does not primarily involve these fibers.