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Biomedical subjects

M H Paul

Publications and source records attributed to M H Paul.

At least 37 records · Page 2Linked to original sources
PubMed1987

Preparation of the left ventricle for anatomical correction in patients with simple transposition of the great arteries. Surgical guidelines.

Pulmonary artery banding in combination with an aortopulmonary shunt was performed on 16 patients with simple transposition of the great arteries to prepare the left ventricle for anatomical correction. Three groups were identified after operation: Group I (four patients) had increased pulmonary blood flow and tight pulmonary artery banding; Group II (four patients) had increased pulmonary blood flow and moderate pulmonary artery banding; Group III (eight patients) had normal pulmonary blood flow and moderate pulmonary artery banding. Postoperative low cardiac output was present in all patients in Group I, whereas mild heart failure was present in two patients in Group II and in two in Group III. There was one hospital death (6%). The follow-up period was 125 patient-months. Left ventricular systolic pressure rose from 63 +/- 11 torr before the operation to 101 +/- 35 torr after the procedure in Group I (p less than 0.05), from 59 +/- 10 to 93 +/- 33 torr in Group II (p less than 0.05), and from 55 +/- 10 to 84 +/- 16 torr in Group III (p less than 0.005). The increase in left ventricular muscle mass was from 44 +/- 2 gm/m2 preoperatively to 108 +/- 12 gm/m2 after operation in Group I (p less than 0.01), from 43 +/- 3 to 93 +/- 8 gm/m2 in Group II (p less than 0.02), and from 46 +/- 3 to 55 +/- 14 gm/m2 in Group III (p = no statistically significant difference). The postoperative change in left ventricular end-diastolic volume was from 100% +/- 17% to 133% +/- 23% of normal in Groups I and II (p less than 0.05) and from 123% +/- 29% to 107% +/- 36% of normal in Group III (p = no statistically significant difference). In preparing the left ventricle for anatomical correction, avoidance of severe pulmonary artery banding decreases the incidence of postoperative myocardial dysfunction, a moderate degree of volume overload and pulmonary artery banding provides the most effective stimulus for ventricular growth, and a small to moderate atrial septal defect is advantageous because it ensures the volume preload necessary for the development of the left ventricle.

Arteriovenous Shunt, Surgical↗
PubMed1987

Factors that exaggerate the deleterious effects of pulmonary insufficiency on the right ventricle after tetralogy repair. Surgical implications.

Postoperative cardiac catheterization data of 74 patients with pulmonary insufficiency after tetralogy repair were analyzed. Two groups were identified: Group A, 26 patients with normal right ventricular function (ejection fraction 95% +/- 5.5%, end-systolic volume 110% +/- 17% of predicted normal) and Group B, 48 patients with right ventricular dysfunction (ejection fraction 80% +/- 18% [p less than 0.001], and end-systolic volume 218% +/- 75% of predicted normal [p less than 0.001]). There was no significant difference between the two groups with respect to frequency of previous palliative procedures, age at operative repair, operative techniques, methods of myocardial protection, and follow-up period. Right ventricular dysfunction in Group B was associated with significant distal pulmonary stenosis (right ventricle-pulmonary artery pressure gradient 28 +/- 13 torr in Group A versus 55 +/- 20 torr in Group B, p less than 0.001), moderate pulmonary regurgitation (regurgitant fraction 18% +/- 11% in Group A versus 32% +/- 10% in Group B, p less than 0.001), and large transannular outflow patch (ratio of patch diameter to descending aorta diameter 1.31 +/- 0.16 in Group A versus 2.50 +/- 0.28 in Group B, p less than 0.001). Pulmonary valve insertion was performed in 42 patients in Group B. Eighteen had subsequent cardiac catheterization. Right ventricular function recovered completely (end-systolic volume 122% +/- 24%, and ejection fraction 92% +/- 7% of predicted) in five of six patients (83%) who had valve insertion within the first 2 years after tetralogy repair. In contrast, right ventricular function remained abnormal in all 12 patients who had valve insertion later than 2 years after tetralogy repair (p less than 0.05). Patients with residual pulmonary stenosis and/or a large transannular outflow patch are at risk for the development of right ventricular dysfunction from pulmonary insufficiency after tetralogy repair. Early correction of these residual lesions and control of pulmonary insufficiency may prevent long-term deterioration in right ventricular function.

Adolescent↗
PubMed1987

Experience with St. Jude Medical valve prosthesis in children. A word of caution regarding right-sided placement.

Thirty-six children aged 6 months to 18 years, underwent insertion of 37 St. Jude Medical cardiac prostheses. In 20, the valve was placed in the aortic or mitral position, and in 16 in the pulmonary or tricuspid position. There was one (2.8%) hospital death. All patients received maintenance doses of salicylates and dipyridamole after the operation. Follow-up data are available for all patients for 12 to 24 postoperative months. There was no incidence of valve dysfunction or thromboembolic complication in any of the 20 patients with valves in the systemic (left) side of the circulation, and all manifested improvement in their functional class. In contrast, six (37%) of the 16 patients with valves in the pulmonary (right) side of the circulation developed dysfunction of the prosthesis 1 to 6 months after insertion. Prosthesis failure was associated with fibrous tissue growing into the struts, leading to leaflet immobilization. At 2 years, the actuarial functional life was 100% for mitral and aortic valves and 70% for pulmonary and tricuspid valves. The data illustrate the excellent hemodynamic function of the St. Jude Medical valve in children. The absence of thromboembolic complications warrant continued implantation of the prosthesis in the left side without warfarin anticoagulation therapy, but the high incidence of valve dysfunction in the pulmonary position does not justify its continued use in the right side.

Adolescent↗
PubMed1986

Long-term results of porcine valve insertion for pulmonary regurgitation following repair of tetralogy of Fallot.

Between January 1975 and January 1985, 49 patients, aged 2 to 20 years, underwent porcine valve insertion for control of pulmonary regurgitation following repair of tetralogy of Fallot. In 9 patients the valve was placed at the time of the repair; in the remaining 40, valve insertion was performed 2 to 5 years postoperatively. The primary indications for valve implantation included progressive cardiomegaly and evidence of right ventricular (RV) dilatation or dysfunction. Operative technique emphasized ample enlargement of the RV outflow tract and main pulmonary artery to allow for insertion of a large valve and prevention of turbulence or stenosis. There was 1 hospital death (2%). Follow-up is available on remaining patients 1 to 10 years postoperatively. Considerable prosthetic valvar stenosis or regurgitation occurred in 7 patients (14%) 3 to 8 years following insertion, including one after subacute bacterial endocarditis. The complication-free actuarial life was 82%, and the functional actuarial life was 84% at 10 years for the prosthesis. The data suggest that the porcine valve has a good long-term durability when inserted in the pulmonary position in pediatric patients.

Adolescent↗
PubMed1986

Fontan type operation for complex lesions. Surgical considerations to improve survival.

Twenty-five of 49 patients who underwent a Fontan type operation had complex lesions other than tricuspid atresia with ventriculoarterial concordance. Three patients had significant subaortic stenosis. Thirty-four palliative operations, including nine Glenn shunts, were performed before the Fontan operation. Direct atriopulmonary anastomosis was performed in 21 patients. In four, valved conduits were used. Twelve patients had right atrioventricular valve patch closure (three had running and nine had interrupted suture technique). On the basis of the presence of increased or decreased pulmonary blood flow before any surgical intervention, patients were divided into Group 1 (previous pulmonary artery banding, N = 8) and Group II (pulmonic stenosis, N = 17). Postoperatively, in Group I, 87% had significant effusions, mean right atrial pressure was higher (20.6 +/- 6.5 torr), and hospital stay longer (31 days). In Group II, 40% had significant effusions, mean right atrial pressure was lower (16.5 +/- 4.3 torr), and hospital stay shorter (15 days). Significant atrioventricular valve patch disruption occurred in three patients (two had running suture technique), and conduit occlusion occurred in two. Four patients (three with subaortic stenosis and pulmonary artery banding) without an established Glenn shunt required Fontan takedown for persistent low cardiac output, two of whom died (2/25 or 8%). There were three late deaths (3/23 or 13%). Nineteen of 20 surviving patients observed from 2 months to 6 years are doing well. We believe that early Fontan takedown in patients with persistent low cardiac output, interrupted suture technique for atrioventricular valve closure, avoidance of valved conduits, and a preliminary Glenn shunt in patients with pulmonary artery banding and/or subaortic stenosis can further improve the results with the Fontan operation for complex lesions.

Adolescent↗
PubMed1986

The Damus-Stansel-Kaye procedure. Should the aortic valve or subaortic valve region be closed?

Two patients (one with transposition of the great arteries and another with Taussig-Bing anomaly) underwent the Damus-Stansel-Kaye procedure (Group I). Significant aortic valve insufficiency developed postoperatively in both patients. In contrast, seven patients with a univentricular heart and subaortic stenosis from a variety of reasons underwent creation of an aortopulmonary window (Group II), a procedure very similar to the proximal main pulmonary artery-aortic root anastomosis of the Damus-Stansel-Kaye procedure. Aortic valve insufficiency had not developed after up to 7 years of follow-up in this group (average 43 months). Postoperative angiograms suggest that aortic valve incompetence in Group I may have been caused by prolapse of the aortic valve. The valvular structures are subjected to high systolic pressures and face a dilated, low-pressure right ventricle. Aortic root distortion may have contributed, as well. In Group II patients, the aortic valve structures face a small, thick-walled chamber. The orientation of the aortic valve vis-a-vis the right ventricle changed postoperatively in Group I but not in Group II patients. Our experience suggests that the aortic valve or subaortic valve region should be closed at the initial repair in patients with low pulmonary vascular resistance who are undergoing the Damus-Stansel-Kaye procedure, to minimize the need for reoperation for aortic valve insufficiency.

Aorta↗
PubMed1986

Effects of elevated coronary sinus pressure on left ventricular function after the Fontan operation. An experimental and clinical correlation.

An experimental model was devised to evaluate the effects of elevated coronary sinus pressure on left ventricular performance. Thirteen mongrel dogs were used. The coronary sinus was cannulated and its entire blood flow diverted into a reservoir. The pressure in the coronary sinus was increased from 5 to 25 torr by elevating the drainage reservoir in a stepwise fashion. Cardiac index, coronary arteriovenous difference, rate of rise of left ventricular pressure, left ventricular systolic time intervals, and coronary blood flow were measured. When the coronary sinus pressure reached 15 torr, there was a significant decrease in cardiac index (3.60 +/- 0.5 to 2.70 +/- 0.6 L/min/m2, p less than 0.001), coronary blood flow (13.7 +/- 3.1 to 7.0 +/- 2.1 ml/min, p less than 0.001), rate of rise of left ventricular pressure (1,567 +/- 275 to 1,331 +/- 314, p less than 0.05), and an increase in coronary arteriovenous difference (62.8% +/- 9.3% to 70.5% +/- 5.4% saturation, p less than 0.03). These experimental results were correlated with postoperative catheterization findings in 24 patients with the Fontan procedure. Patients with a mean right atrial pressure less than 15 torr had a left ventricular ejection fraction of 93% +/- 6% of predicted, whereas patients with a right atrial pressure of 15 torr or more had a left ventricular ejection fraction of 75% +/- 13% of predicted (p less than 0.001). These experimental and clinical data strongly suggest that elevated coronary sinus pressure has deleterious effects on ventricular function after the Fontan procedure. Modifications of the procedure, such as using the rudimentary right ventricle when feasible or diverting coronary sinus flow to the pulmonary venous atrium, might decrease coronary sinus hypertension and improve long-term results.

Animals↗
PubMed1986

Persistent low cardiac output after the Fontan operation. Should takedown be considered?

Four of 44 patients who had undergone the Fontan operation had persistent low cardiac output necessitating takedown of the shunt 6 to 65 hours (average 23 hours) postoperatively. All four were in a group of 22 patients with complex lesions other than tricuspid atresia with ventriculoarterial concordance. The development of postoperative right atrial hypertension (average 24 torr), hepatomegaly, marked ascites, and decreasing lung compliance led to severe systemic hypotension with systolic arterial pressure ranging from 55 to 82 torr (average 68 torr), persistent metabolic acidosis, and oliguria despite massive colloid and crystalloid infusions (11,000 ml/m2/24 hr) and inotropic support. At reoperation the atriopulmonary anastomosis, which was found to be wide open, was taken down and an atrial septal defect was created in all patients. Three patients were left with a Glenn shunt and an aortopulmonary shunt to the left lung. One patient had bilateral aortopulmonary shunts. Two patients who survived reoperation had immediate postoperative improvement in systolic arterial and mean right atrial pressure (average 100 torr and 11.5 torr, respectively). Both are well 5 months and 4 years later. Repeat Fontan operation remains a possibility with acceptable risks because of the presence of the Glenn shunt in both patients. We believe that takedown should be considered in patients with persistent low cardiac output after the Fontan operation.

Cardiac Output, Low↗
PubMed1986

Surgical approach to severely symptomatic newborn infants with tetralogy of Fallot and absent pulmonary valve.

The surgical management of severely symptomatic newborn infants with tetralogy of Fallot and absent pulmonary valve has been controversial, and the results of a variety of operative approaches have not been satisfactory. We report on a technique for the treatment of these patients, which consists of (1) ligation of the main pulmonary artery to eliminate pulmonary regurgitation, excessive right ventricular stroke output, and secondary pulmonary artery dilation and airway obstruction and (2) insertion of a subclavian-pulmonary artery polytetrafluoroethylene shunt to provide pulmonary blood flow. The procedure was used in four neonates. Two patients operated on at 2 and 3 days of age are doing well 15 and 19 months postoperatively. The other two, operated on at 3 and 4 weeks of age after unsuccessful prolonged medical treatment and positive-pressure ventilation, failed to show long-term improvement and died of sepsis and respiratory failure 3 and 5 months after operation. This experience, though limited, suggests that early surgical intervention to control pulmonary regurgitation prevents progressive pulmonary artery dilatation and secondary bronchial compression, decreases the need for prolonged preoperative and postoperative ventilation, and improves the outcome of these critically ill neonates.

Humans↗
PubMed1985

Functional aortic valve atresia in transposition of the great arteries.

The criterion for the diagnosis of functional atresia of a patient semilunar valve is met when the pressure in a ventricle remains lower than that in the related great artery throughout systole so that no forward flow can occur. Functional pulmonary valve atresia has been well recognized in infants with normally related great arteries and massive tricuspid valve incompetence. The cardiac physiology and anatomy of an infant with transposed great arteries and functional aortic valve atresia is reported for the first time. The peak systolic pressure in the right ventricle was 30 mm Hg and in the aorta 64 mm Hg. The causes for right ventricular incompetence were abnormalities of the tricuspid valve and hypoplasia of the ventricular free wall. Three other cases with similar ventricular anatomy and physiology but with anatomic atresia of the aortic valve are reviewed. The possibility that under these physiologic circumstances during fetal life functional atresia develops first, and that anatomic fusion of idle semilunar cusps develops as a secondary phenomenon, is discussed.

Aortic Valve↗
PubMed1985

Hemodynamic effects of intravenous nitroglycerin in pediatric patients after heart surgery.

Twenty patients with congenital heart disease, ages 8 months to 6 years, received 1 to 5 micrograms/kg/min iv nitroglycerin after intracardiac repair to assess the hemodynamic effects of, and the pulmonary vascular response to, the drug in pediatric cardiac patients. Before surgery all patients had systemic-to-pulmonary blood flow ratios equal to or greater than 2.5:1. The pulmonary arterial pressure (PAP) was equal to aortic pressure in 14 patients and normal in six. The pulmonary vascular resistance (PVR) was elevated (more than 4 units) in five patients. After surgery, the right and left atrial pressures, PAP, and cardiac index were measured by thermodilution, and the systemic vascular resistance (SVR) and PVR were calculated. Intravenous nitroglycerin produced a significant drop in SVR at higher doses only (1602 +/- 359 to 1590 +/- 324 dynes X sec X cm-5, p = NS, at 2 micrograms/kg/min vs 1602 +/- 359 to 1247 +/- 417 dynes X sec X cm-5, p less than 0.01, at 5 micrograms/kg/min). Similarly, improvement in cardiac index was apparent only at higher doses (3.33 +/- 1.25 to 3.49 +/- 0.90 liters/min/m2, p = NS, at 2 micrograms/kg/min vs 3.33 +/- 1.25 to 3.82 +/- 0.98 liters/min/m2, p = NS, at 5 micrograms/kg/min). Also, the effect on the pulmonary vascular bed was most marked at higher doses and in patients with elevated PAP (175 +/- 27 to 148 +/- 28 dynes X sec X cm-5, p = NS, in patients with normal PAP vs 305 +/- 78 to 214 +/- 76 dynes X sec X cm-5, p less than .001, in patients with elevated PAP).(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac Output↗
PubMed1984

Surgical management of occluded conduits after the Fontan operation in patients with Glenn shunts.

Five complete conduit occlusions occurred in four patients with the Glenn shunt 2 months to 2 years after the Fontan operation. The possible reasons for complete conduit occlusion were severe dehydration, high pulmonary vascular resistance, and intraoperative manipulation of the conduit. In one patient in whom complete conduit occlusion developed twice, no possible cause could be identified. Surgical approaches included replacement of the occluded conduit in three patients and creation of an atrial septal defect and left aortopulmonary shunt in the fourth patient. All patients who had replacement of the occluded conduit survived. The fourth patient had severe cyanosis and hypoxemia from marked reduction of flow through the Glenn shunt because of reversal of flow through large venous collaterals. He subsequently died of Candida sepsis. A fifth patient (previously reported) who had complete conduit occlusion also died after a similar procedure. We believe that in patients with a Glenn shunt who develop complete conduit occlusion after the Fontan operation, conduit excision and a secondary Fontan operation, preferably without the use of woven Dacron, should be done instead of establishing an atrial septal defect and aortopulmonary shunt to the left lung.

Adolescent↗
PubMed1984

The surgical management of left ventricular outflow tract obstruction due to tricuspid valve pouch in complete transposition of the great arteries.

Subpulmonary stenosis in transposition of the great arteries, resulting from a tricuspid valve pouch bulging into the left ventricular outflow tract through a ventricular septal defect, can be missed at the time of operation in the flaccid, nonbeating heart unless preoperative diagnosis has been established. In our experience, six patients were found to have this lesion. In four patients the tricuspid valve pouch was recognized preoperatively. At operation, retraction of the tricuspid valve pouch into the right ventricle, patch closure of the ventricular septal defect, and a Mustard procedure were performed in three patients; the fourth is awaiting correction following initial palliation with a subclavian-pulmonary shunt. In the other two, the ventricular septal defect was partially or completely obliterated by a tricuspid valve pouch that was missed preoperatively and during exploration at the time of the Mustard procedure. Residual left ventricular outflow tract obstruction was subsequently corrected with a left ventricle-pulmonary artery valved conduit. Echocardiographic and angiocardiographic examinations offer helpful signs for the diagnosis of tricuspid valve pouch. Transatrial retraction of the redundant tricuspid valve tissue into the right ventricle, patch closure of the ventricular septal defect, and Mustard operation are the procedures of choice. A left ventricle-pulmonary artery valved conduit may be required for residual unresectable left ventricular outflow tract obstruction.

Cardiomyopathy, Hypertrophic↗
PubMed1983

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↗
PubMed1983

Successful surgical repair of aortic atresia associated with normal left ventricle.

Surgical repair of aortic atresia with a large ventricular septal defect and a normally developed left ventricle was accomplished in a 14 month old infant. Palliative surgery at age 23 days consisted of bilateral banding of pulmonary artery branches and replacement of the ductus arteriosus with a Goretex conduit. Corrective surgery was accomplished by closure of the ventricular septal defect, insertion of a valved conduit between the apex of the left ventricle and the subdiaphragmatic aorta, removal of the pulmonary artery bands and division of the pulmonary-aortic conduit. The patient has a mild coarctation of the aorta and remains asymptomatic at 2 years of age.

Aortic Valve↗
PubMed1983

Two-dimensional echocardiographic and angiocardiographic diagnosis of subpulmonary stenosis due to tricuspid valve pouch in complete transposition of the great arteries.

Two-dimensional echocardiograms and angiocardiograms were obtained in six infants and children, each with complete transposition of the great arteries, a ventricular septal defect and subvalvular pulmonary stenosis. In each case, the subpulmonary stenosis resulted from redundant tricuspid valve tissue which protruded through the ventricular septal defect and into the left ventricular outflow tract. Angio-echocardiographic correlations demonstrated features that allowed preoperative recognition of this unusual type of subpulmonary stenosis. The left ventricular angiogram in an anteroposterior orientation revealed a characteristic filling defect in the outflow tract during systole in each patient. Echocardiographic images of the left ventricular outflow tract and of the tricuspid valve demonstrated subpulmonary stenosis caused by protruding redundant tricuspid valve tissue (resembling a "pouch") in all six patients. These findings were contrasted with those from three patients with normally related great arteries and a similar, but nonobstructive, tricuspid valve pouch. Echocardiographic and angiocardiographic examination and correlation allowed preoperative diagnosis of this unusual form of subpulmonary stenosis in complete transposition of the great arteries. This is especially important because limited left ventricular intraoperative exploration may fail to reveal subpulmonary obstruction as the pouch may be flaccid in a relaxed arrested heart.

Angiocardiography↗
PubMed1983

Measurement of mitral valve orifice area in infants and children by two-dimensional echocardiography.

Two-dimensional echocardiograms of the mitral valve orifice area were obtained in 50 normal pediatric subjects, 15 patients with congenital mitral stenosis and 7 patients with tricuspid atresia. The mitral area was measured near the tips of the mitral valve leaflets from a diastolic cross-sectional image of the left ventricle. The cardiac images were recorded on videotape and later transferred to video disc for high resolution contour tracing. Contour analysis was performed by a special purpose microcomputer system for calculation of the enclosed calibrated area. In normal patients, there was an excellent correlation (r = 0.95) between mitral valve area (MVA) (in cm2) and body surface area (BSA) (in m2) described by MVA = 4.83 X BSA - 0.07. Each patient with mitral stenosis had a mitral valve area that measured less than the third percentile predicted from the normal regression formula. In eight patients in whom the Gorlin formula could be applied, there was excellent correlation (r = 0.95) between echocardiographic and hemodynamic measurements of mitral valve area. Each patient with tricuspid atresia had a very large mitral valve area (greater than 99th percentile of normal). It is concluded that noninvasive measurement of mitral valve orifice area can be accurately achieved by two-dimensional echocardiography in pediatric patients with congenital mitral stenosis, allowing serial measurement of their mitral valve area.

Child↗