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Biomedical subjects

S Bharati

Publications and source records attributed to S Bharati.

At least 127 records · Page 7Linked to original sources

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↗

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↗

Two dimensional echocardiographic evaluation of Mustard operation for d- transposition of the great arteries.

Two dimensional sector scan echocardiography was used to evaluate the morphologic characteristics of the surgically revised atria in 17 patients with d-transposition of the great arteries who had undergone the Mustard operation. Echocardiographic imaging of the atria was obtained from various planar projections. Dimensional measurements of various segments of the systemic and pulmonary venous atria were obtained in each patient. Correlative hemodynamic, angiographic, postmortem and echocardiographic data showed that seven patients (Group I) had no structural abnormalities of the atria. These 7 patients served as controls for 10 other patients with structural abnormalities of the surgically created atria. One patient (Group II) showed stenosis of the junction of the superior vena cava and systemic venous atrium compared with findings in the control group. Three patients (Group III) had significantly reduced echocardiographic dimensions of the junction of the anterior and posterior segments of the pulmonary venous atrium. Six patients (Group IV) had increased echocardiographic dimensions of all components of the pulmonary venous atrium due to tricuspid regurgitation. These data show that qualitative and quantitative two dimensional sector echocardiography can reliably detect structural abnormalities of the surgically revised atria after the Mustard operation.

Adolescent↗

Primary oxalosis with pan-conduction cardiac disease: electrophysiologic and anatomic correlation.

A 27-year-old man with primary oxalosis and extensive visceral involvement was maintained on long-term chronic hemodialysis. He had an episode of presyncope associated with electrocardiographic findings of an erratic atrial rhythm, atrioventricular dissociation due to an accelerated junctional rhythm and right bundle branch block. Electrophysiologic studies showed irregular atrial depolarizations probably associated with multiple atrial pacemakers, atrial inexcitability, atrioventricular dissociation and infranodal conduction delay. These findings correlated well with extensive oxalate infiltration of the sinoatrial node and its approaches, the atrial preferential pathways, the approaches to the atrioventricular node, the atrioventricular node, and the His bundle and bundle branches. This is the first reported case of cardiac electrophysiologic abnormalities due to oxalate infiltration in a patient with primary oxalosis.

Adult↗

Radiotherapy as a cause of complete atrioventricular block in Hodgkin's disease. An electrophysiological-pathological correlation.

A 20-year-old man contracted Hodgkin's disease and was treated with mantle radiotherapy. Heart block developed 11 years later. Electrocardiograms revealed predominant atrioventricular (AV) block and occasional AV conduction. Intracardiac electrograms demonstrated that the site of AV block was above the level of the His bundle. A permanent transvenous pacemaker was implanted. Seven months later the patient died of complications from cryptococcal meningitis. Pathological study of the heart revealed marked arteriosclerosis with fibrosis of the epicardium, myocardium, and endocardium. Examination of the conduction system revealed extensive arteriolosclerosis of the sinoatrial node and its approaches. In addition, there was marked fibrosis of the approaches to the AV node, the AV bundle, and both bundle branches. There was no evidence of Hodgkin's disease. This case documents the rare occurrence of AV block due to tissue destruction by radiotherapy. There was a good correlation between block proximal to the His bundle recording site and fibrosis of the approaches to the AV node.

Adult↗

Prolonged prostaglandin E1 infusion: histologic effects on the patent ductus arteriosus.

An infant with Ebstein's malformation of the tricuspid valve and severe pulmonic stenosis underwent a 39-day course of prostaglandin E1 infusion, and a histologic study of the ductus arteriosus was undertaken after autopsy. There were marked alterations in the ductal and juxtaductal structures following this prolonged infusion of prostaglandin E1. The internal elastic lamella of the ductus was disrupted in many areas. The media showed widespread areas of disruption with cavity formation. The adventitia adjacent to the junction of the ductus with the pulmonary artery was thickened and infiltrated with mononuclear cells. The nerve trunks in the adventitia were markedly infiltrated with mononuclear cells and showed cavitation as well as considerable surrounding edema. Mucopolysaccharides were increased throughout the ductus. These changes produced increased fragility of the ductal and juxtaductal structures, thus increasing the likelihood of spontaneous aneurysms and rupture, or of tearing or rupture at the aortic and pulmonary junctions at the time of surgical closure of the ductus. Unusual fragility of the ductus, pulmonary artery, and aorta has been observed during ligation of the ductus following prostaglandin E infusions lasting seven and ten days. Additionally, another patient who had received prostaglandin E infusion for six days demonstrated aneurysmal fullness to the ductus arteriosus at autopsy. The histologic findings and intraoperative experience in this study suggest that there may be a real danger of spontaneous or surgically related rupture of the ductus arteriosus after prolonged infusion of prostaglandins.

Cardiac Catheterization↗

Infiltrative cardiomyopathy with conduction disease and ventricular arrhythmia: electrophysiologic and pathologic correlations.

Two cases are described, one of cardiac sarcoidosis and another of primary cardiac amyloidosis, in which correlation was made between electrophysiologic and postmortem conduction system studies. In Case 1 the electrocardiogram revealed right bundle branch block with first degree and intermittent third degree atrioventricular (A-V) block and recurrent unifocal paroxysmal ventricular tachycardia. Electrophysiologic studies disclosed normal sinus rhythm with prolonged A-H (175 ms) and H-V (60 MS) intervals and extrastimulus induction of repetitive ventricular firing. Postmortem examination revealed a sarcoid aneurysm of the posterior left ventricle and granulomatous infiltration of the A-V node, His bundle and bundle branches. In case 2 the electrocardiogram revealed sinus bradycardia, a prolonged S-T interval and recurrent ventricular fibrillation. Electrophysiologic studies demonstrated a prolonged sinus nodal recovery time (6,080 ms) and H-V (85 ms) interval. Postmortem examination revealed marked amyloid infiltration of the sinoatrial node, atria, proximal bundle branches and left and right ventricular myocardium. There was thus excellent correlation between electrophysiologic and pathologic findings. These cases indicate the importance of making a clinical diagnosis of the disease that might in some cases allow specific therapeutic intervention in addition to antiarrhythmic therapy.

Adult↗

Cardiac pathology of Marfan's syndrome. Can dissection and rupture of aortic aneurysms be prevented?

A 10-year-old boy with Marfan's disease suffered an acute dissection of an aortic aneurysm. A dacron sleeve (extending from 3 cm above the sinuses of Valsalva to just distal to the left subclavian artery) was placed around the aorta. 2 years later the child succumbed to aortic dissection and rupture distal to the sleeve. Autopsy showed (1) complete healing of the earlier dissection, and (2) lack of aneurysmal progression within the sleeve. Although the sleeve had provided effective support to the diseased aorta, it did not have sufficient length and should have been extended to include the region of the first and second intercostal arteries. The use of an extensive dacron sleeve is potentially useful as treatment prior to dissection.

Aortic Dissection↗

The anatomic substrate for preexcitation in corrected transposition.

We report three cases of corrected transposition (CT), all with Ebstein's disease, ventricular septal defect (VSD) and ventricular preexcitation. In cases 1 and 2, the ECG revealed sinus rhythm, with type A fusion preexcitation QRS complexes, suggesting left-sided Kent bundles and intact conduction system (CS). Complete serial section (SS) of the CS in both cases revealed an anterior CS and a Kent bundle in the posteroseptal wall of the morphologic right ventricle (MRV). Case 3 had intermittent preexcitation, with periods of complete atrioventricular (AV) block with narrow QRS escape rhythm. The preexcitation complexes suggested the presence of a left lateral Kent bundle. SS of the CS revealed a blind posterior and two anterior AV nodes, one on either side of the pulmonary trunk. The left anterior AV node was blind. The right anterior node formed the anterior bundle, which ended blindly. This bundle emerged again and joined a posterior bundle to form an interrupted sling around the closed VSD. In addition, there was a tenous Kent bundle at the posterolateral wall of the MRV. In summary: (1) preexcitation in CT with Ebstein's disease of the left AV valve is associated with Kent bundles; (2) fusion complexes reflected intact CS; and (3) intermittent preexcitation with AV block was associated with the presence of tenuous Kent bundl and discontinuity of the CS.

Atrioventricular Node↗

Idiopathic hypertrophic subaortic stenosis with split His bundle potentials. Electrophysiologic and pathologic correlations.

A 25-year-old white female had idiopathic hypertrophic subaortic stenosis proved by catheterization. The ECG revealed left bundle branch block. Electrophysiologic studies revealed normal PA and AH intervals, but the HB interval was prolonged (70 msec). The width of the His spike was 20 msec. A clear, reproducible split His potential was demonstrated with the atrial extrastimulus technique. Because the patient was symptomatic, a permanent pacemaker was inserted. One week later the patient died suddenly. Autopsy revealed an enlarged heart with a markedly thickened and sigmoid ventricular septum and a small and coarsely trabeculated lumen. Histologically the common bundle was situated on the right side of the septum. It was intact at its origin, but showed fibrotic changes more distally. The beginning of the left bundle branch was markedly disrupted as it traversed the septum. The right bundle was moderately fibrosed. There was excellent correlation between the electrocardiographic and electrophysiologic findings and the findings in the conduction system. The cause of the sudden death was related either to the outflow obstruction or to an arrhythmia, or both.

Adult↗