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Biomedical subjects

M Lev

Publications and source records attributed to M Lev.

At least 109 records · Page 6Linked to original sources

The surgical anatomy of hypoplasia of aortic tract complex.

The surgical anatomy of 230 hearts with hypoplasia of the aortic tract complex or the hypoplastic left heart syndrome is described in detail. Recent work has indicated that this may be an operable entity. There were 105 hearts with aortic atresia and mitral stenosis, 95 hearts with aortic and mitral atresia, and 30 hearts with severe aortic and mitral stenosis. Special emphasis is given to the right atrium, right ventricle, and sizes of the ascending and transverse aorta. Attention is called to the pathological changes in the tricuspid orifice and valve and in the ventricular septum. It was of interest that many of the hearts had only a patent foramen ovale rather than a distinct atrial septal defect. In addition, the atrial septum was abnormally formed. The anatomic data presented may be of surgical import. Hypoplasia of the aortic tract complexes may be variations of premature narrowing of foramen ovale.

Aorta↗

Pathology of atrioventricular block.

This article provides a summary of the types of congenital atrioventricular block and the various acquired diseases in which atrioventricular block may occur. Some lesions found in atrioventricular block are illustrated.

Aortic Valve Stenosis↗

Closed chest permanent atrioventricular block in dogs.

Ten mongrel dogs underwent transcutaneous His bundle ablation by means of pulsed synchronized electrical shocks delivered between an electrode catheter adjacent to the His bundle and a metal plate behind the dog's back. Detailed histologic studies were performed 3 months after induction of stable complete atrioventricular (AV) block in nine dogs. The ventricular response ranged from 35 to 51 beats/min (bpm). Graded increases in overdrive ventricular pacing resulted in graded increases in pacemaker suppression up to a paced cycle length of 450 msec. All dogs showed extensive damage to the approaches to the AV node, the AV node, and the penetrating portion of the common bundle. This technique resulted in complete AV block with typical features of an infranodal pacemaker and correlated with the histologic findings of severe damage to the AV junction. The minimal myocardial damage suggests that this technique may be applicable for control of drug refractory supraventricular arrhythmias in humans.

Animals↗

Masked subaortic stenosis in ostium primum atrial septal defect: recognition and treatment.

Five patients with ostium primum atrial septal defect (ASD) and a cleft mitral valve had no hemodynamic evidence of left ventricular (LV) outflow tract obstruction on preoperative cardiac catheterization. After surgical closure of the ASD and repair of the mitral cleft, all 5 patients manifested subaortic stenosis with pressure gradients ranging from 10 to 120 mm Hg. Postoperative LV angiograms revealed systolic narrowing of the outflow tract, and the same outflow tract dynamics were recognized on reviewing the preoperative angiograms and echocardiograms. Persistence or exaggeration of the characteristic diastolic "goose-neck" deformity during LV systole in atrioventricular canal defects is diagnostic of a potential or actual subaortic obstruction. This diagnostic sign is also readily recognizable by 2-dimensional echocardiography, and when present, the surgeon should be alerted to explore the LV outflow tract because the outflow tract anatomy is not readily apparent at operation aimed solely at closing the ASD and repairing the cleft mitral valve.

Adolescent↗

Sudden death in three teenagers: conduction system studies.

The pathologic substrate for sudden death in the middle-aged or elderly adult is usually ischemic heart disease. In contrast, few data are available regarding the pathology of sudden death in teenagers. This report describes three teenagers without clinically suspected heart disease dying suddenly. Patient 1 (age 15, male) was known to have right ventricular premature ventricular beats. Postmortem examination revealed marked premature aging, sclerosis of the cardiac skeleton extending to the right side of the summit with fibrosis of the left and right bundle branches. Patient 2 (age 17, male) was a trained athlete who died during football scrimmage. Autopsy revealed moderate mitral valve prolapse and marked premature aging, sclerosis of the left side of the cardiac skeleton, which extended to the right ventricular side, and secondary involvement of the trifascicular conduction system with mononuclear cell infiltration. Patient 3 (age 19, female) died suddenly at home. Autopsy revealed mitral valve prolapse, thrombosis of the sinoatrial (SA) node artery, and premature aging, sclerosis of the left side of the cardiac skeleton, with involvement of the ventricular septum more on the right ventricular side and involvement of the atrioventricular bundle and trifascicular conduction system. In conclusion, unexpected deaths in three teenagers occurred with demonstrable pathologic findings in the heart. Two of the three patients had mitral valve prolapse, one of whom also had thrombosis or embolism of the sinoatrial node artery. All three had sclerosis of not only the left side but also the right side of the ventricular septum with involvement of the conduction system. The anatomic substrate demonstrated in these three patients could relate to lethal bradyarrhythmia or tachyarrhythmia, or both.

Adolescent↗

Rare type of intrapulmonary drainage of one lung by the other with total anomalous pulmonary venous return.

A rare form of obstructed total anomalous pulmonary venous drainage is presented. A neonate with asplenia, pulmonary atresia and complex congenital heart disease also had drainage of the left lung forming a venous confluence that proceeded in an intrapulmonary fashion through the right lung. A hypoplastic pulmonary venous channel then emerged from the right upper lobe leading to the superior vena cava. Pulmonary venous obstruction was suspected on initial plain chest X-ray examination and on angiography, which revealed the pulmonary artery to be larger than anticipated. Administration of prostaglandin E1 may allow augmentation of pulmonary blood flow and angiographic definition of this association in infants with asplenia complex.

Abnormalities, Multiple↗

Hypoplasia of the right ventricular myocardium with ventricular tachycardia.

A 20-year-old woman died suddenly after having had recurrent ventricular tachycardia for five years. An ECG showed two distinct varieties of ventricular tachycardia, both characterized by left bundle-branch block. Pathologic examination showed what we considered to be a type of Uhl's anomaly. Most of the compact layer of the right ventricle was replaced by fat, with the trabeculated areas intact but showing severe fibrosis and chronic inflammation. Patches of such degeneration were also found in the septum and the left ventricle. The conduction system disclosed a septated bundle of His.

Adult↗

Coarctation in Taussig-Bing malformation of the heart. Surgical significance.

In a review of 126 heart specimens of simple complete transposition of the great arteries with ventricular septal defect (VSD), coarctation was noted in eight (6%). In 105 Taussig-Bing heart specimens, coarctation and/or aortic outflow tract obstruction was noted in 56 (53%) (p less than 10(-10). This was similar to our surgical experience in 26 patients with transposition and VSD or Taussig-Bing heart. Six of nine patients with Taussig-Bing heart also had coarctation of the aorta, whereas all 17 patients with transposition and VSD had a normal aorta. Four patients with Taussig-Bing heart underwent coarctation repair and pulmonary artery banding at 2 to 7 days of age. The remaining two patients with Taussig-Bing heart did not have a hemodynamically significant coarctation. Five of the six patients with Taussig-Bing heart and coarctation underwent a Senning procedure between the ages of 7 weeks and 3 1/2 years. In four (all less than 4 months of age) the VSD could not be closed through the tricuspid valve. A right ventriculotomy was done in two and contributed to their deaths. In the other two patients the VSD was left alone and the pulmonary artery banded. Both remain well. The fifth child, aged 3 1/2 years, had the VSD closed through the tricuspid valve but died in the postoperative period of renal failure. The sixth patient is awaiting further operation following coarctation repair and pulmonary artery banding. We conclude that the presence of coarctation strongly suggests that Taussig-Bing heart malformation exists rather than transposition and VSD. Pulmonary artery banding and coarctation repair are the initial procedures of choice in the management of these critically ill newborn infants. Increasing cyanosis and failure to thrive will necessitate further operation. Closure of the VSD through the tricuspid valve in these infants is difficult. Pulmonary artery banding in association with a Senning procedure is preferable to a right ventriculotomy. Closure of the VSD is then planned at a later stage.

Aortic Coarctation↗

The conduction system in Pompe's disease.

We report our findings in the microscopic examination of the conduction system in four infants with glycogen storage disease, one of whom had adequate electrophysiologic studies. The electrophysiologic studies in the latter case showed P-A and A-H intervals at the lower limits of normal, but the H-V interval was just above the normal mean. This suggests that the rapid conduction was not localized in the anatomic counterpart of the H-V interval. The short P-R interval in the ECG may be related to the enlargement of cells, which may in turn be related to increased glycogen content. The relationship of glycogen per se to the speed of conduction is unknown. We found that the summit of the ventricular septum bulged, probably because of the generally increased cell size, and that the topography of the atrioventricular conducting system was different from normal. This is possibly related both to an increase in the cell sizes of the specialized conducting tissue itself and to deforming effects of this bulging summit of the ventricular septum. New microscopic details of the components of the conducting system are described in these cases.

Cardiomegaly↗

Reentry confined to the atrioventricular node: electrophysiologic and anatomic findings.

A patient with recurrent disabling, paroxysmal supraventricular tachycardia refractory to drug treatment underwent electrophysiologic studies. The paroxysmal supraventricular tachycardia was found to be due to atrioventricular (A-V) nodal reentry. The patient died shortly after surgical His bundle section and detailed anatomic studies were performed. These showed fatty infiltration of the approaches to the sinoatrial node, atrial preferential pathways, and A-V node and common bundle. The A-V node was mechanically damaged and the common His bundle was completely severed. These abnormalities were clearly delineated and there was no evidence of an atrio-His bundle bypass tract to an accessory A-V node. Specifically, the central fibrous body and pars membranacea were defined and no atrial muscular fibers pierced these structures to joint the A-V bundle. It is concluded that paroxysmal supraventricular tachycardia due to A-V nodal reentry can be confined to the A-V node.

Atrioventricular Node↗

Distal aortopulmonary septal defect, aortic origin of the right pulmonary artery, intact ventricular septum, patent ductus arteriosus and hypoplasia of the aortic isthmus: a newly recognized syndrome.

The association of distal aortopulmonary septal defect, aortic origin of the right pulmonary artery, intact ventricular septum and interruption or coarctation of the aortic isthmus has not previously been reported as a syndrome. This combination of anomalies was encountered in five new patients and was previously reported in three. Two patients have undergone surgery with successful results. In contrast to the sagittally oriented conventional proximal aortopulmonary septal defect, the patients in this series had a more distal type of defect, possibly representing a partial persistence of the common arterial trunk. The pulmonary arterial bifurcation may malattach to this undivided truncal segment and, as a result, the right pulmonary artery may be partially or completely shifted into the aorta. This abnormal right pulmonary arterial origin may lead to "steal" from the aortic flow during embryogenesis and to hypoplasia of the aortic arch. This concept is supported by the angiographic observation that the greater the rightward displacement of the right pulmonary artery, the greater the hypoplasia of the arch. The diagnostic angiographic sign is a strikingly high origin of the right pulmonary artery together with aortic arch hypoplasia or atresia. Closure of the aortopulmonary septal defect with implantation of the right pulmonary artery in the pulmonary trunk and repair of the aortic arch anomaly is the recommended surgical treatment.

Aortic Coarctation↗

Sequelae of atriotomy and ventriculotomy on the endocardium, conduction system and coronary arteries.

The endocardium was analyzed in all four chambers of 99 hearts with various types of congenital heart defects in which surgical repair was performed more than 6 weeks before death. The findings were compared with those of normal hearts in similar age groups. In some cases the endocardium was microscopically examined. This study revealed that in many cases all four chambers had fibroelastosis of the endocardium (diffuse regardless of the type of surgery done previously). These data suggest that diffuse fibroelastosis can occur as a result of surgical intervention and may be related to blocked lymphatic drainage. Sudden death in some patients long after surgery for congenital heart disease and the failure of the chambers to regress to normal size in some cases after total surgical repair may be related to fibroelastosis of the chambers. The sinoatrial node may be injured in atriotomy and in the performance of the Mustard procedure. Ventriculotomy may injure the right bundle branch. Ventriculotomy may also injure the coronary supply to the right ventricle or rarely the anterior descending coronary artery.

Adolescent↗

Anatomic substrate for congenital atrioventricular block in middle-aged adults.

Congenital atrioventricular block is usually a benign disorder not necessitating pacing. In some patients slowing of rate and/or mortality have been noted with aging. However an anatomic substrate has not been established for the progressive slowing of the escape rate. In this study we report an anatomic substrate in two such patients who were dying in congestive heart failure, ages 49 and 42, respectively. Multiple pre-mortem ECG's in both cases revealed wide QRS escape rhythms, and escape rates of approximately 35 and 28 beats/minute, respectively. Conduction system examination by serial section in both cases revealed lack of connection between the atrial septum with the peripheral conduction system with total replacement by fat of the AV nodal approaches and AV node, and advanced sclerosis of the summit of the ventricular septum which was more marked on the right side. In addition, the His bundle showed marked septation in case one and fragmentation in case two. Sclerosis of the summit of the ventricular septum involved the branching bundle and the bundle branches in both cases. In conclusion, both patients had the characteristic lesions of congenital atrioventricular block, namely replacement of the AV node and AV nodal approaches by fat, with lack of connection to the peripheral conduction system, and one also had a fragmented His bundle. In addition premature aging of the summit of the ventricular septum may have reflected the long-standing hemodynamic stresses of chronic bradycardia. This in turn resulted in trifascicular involvement of the conduction system leading to a shifting of the escape rhythm distally eventuating in a slower idioventricular escape rhythm.

Adult↗

An antibody against revertant forms of cell-wall deficient bacterial variant in sera from patients with Crohn's disease.

Sera from patients with Crohn's disease or ulcerative colitis, and from controls were examined by indirect immunofluorescence for antibody against two strains of pseudomonas-like cell-wall-defective bacterial variants. Serum samples from 22 of 25 patients with Crohn's disease produced fluorescence of both revertant cell-wall-defective bacterial strains. Intensity of fluorescence correlated positively with the degree of disease activity. Sera from 23 patients with ulcerative colitis and from 15 control subjects did not produce any significant staining of either of the two revertant cell-wall-defective bacterial strains. Absorption of sera with Escherichia coli, Bacteroides thetaiotaomicron, and Pseudomonas aeruginosa did not alter the intensity of fluorescence in patients with Crohn's disease, whereas similar absorption of sera from patients with ulcerative colitis and controls abolished the slight staining of cell-wall-defective strains produced by 29% of unabsorbed serum samples.

Antibodies, Bacterial↗

A method of study of the pathology of the conduction system for electrocardiographic and His bundle electrogram correlations.

There have been advances in electrophysiology which have necessitated a more thorough semi-quantitative analysis of the entire conduction system to yield data useful for correlation purposes. Thus an attempt is made to modify and expand our previous method of studying in conduction system pathologically. This method thus includes the study of the sinoatrial (SA) node and its approaches, the atrial preferential pathways, the approaches to the atrioventricular (AV) node, the AV node, the penetrating and branching portions of the AV bundle, the bundle branches, the peripheral Purkinje nets, and the remainder of the atrial and ventricular myocardium. The SA node and its approaches are studied in a longitudinal manner. This gives a better insight into the pathologic changes than does a study in the transverse direction. The approaches to the AV node, bundle and bundle branches are studied in an oblique manner, rather than horizontally apicalward, or from the posterior to the anterior septal region. The horizontal manner does not give sufficient sampling of the AV node and bundle unless complete serial sections are made. Sectioning from the posterior to the anterior septal wall makes difficult an evaluation of the right bundle branch. In conduction system correlation with Wolff-Parkinson-White and Lown-Ganong-Levine syndromes complete serial sectioning of both AV rims is advisable. Where complete serial sectioning is impossible in large adult hearts, retaining every fifth section may be permissible. In the study of congenitally abnormal hearts, it is advisable to embed the entire heart as a unit. If that is impossible because of the size of the heart, then very careful judicious planning of the fashioning of the blocks is necessary, so that displaced SA nodes, and anterior AV nodes and bundles are not overlooked.

Arrhythmias, Cardiac↗