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Biomedical subjects

J J Lamberti

Publications and source records attributed to J J Lamberti.

At least 73 records · Page 4Linked to original sources
PubMed1983

Congenital heart disease and pulmonary artery hypertension. I. Pulmonary vasoreactivity to 15% oxygen before and after surgery.

Pulmonary vasoreactivity at sea level was studied in 22 children before and in 15 children after corrective cardiac surgery for congenital heart disease and pulmonary artery hypertension; 8 children were studied both before and after cardiac surgery. During cardiac catheterization in 28 children, pulmonary and systemic hemodynamics were determined in room air and during breathing of 15% oxygen, which corresponds to a maximal hypoxic level commonly encountered during airplane travel. Before surgery, 19 of 22 children tolerated 15% oxygen (O2), which caused the following hemodynamic changes from room air status: the ratio of pulmonary to systemic arterial pressure increased from 0.70 to 0.78 (p less than 0.05), the ratio of pulmonary to systemic flow decreased from 2.2 to 2.0 (p greater than 0.05) and the ratio of pulmonary to systemic vascular resistance increased from 0.33 to 0.40 (p less than 0.02). In two children, severe pulmonary vasoconstriction developed within 5 minutes of 15% oxygen administration, requiring immediate discontinuation of hypoxia; neither patient had lasting deleterious effects. There was no evidence of increased pulmonary vasoreactivity in children with Down's syndrome compared with genetically normal children. After corrective surgery in 15 children (including both of the hyperreactors), no significant pulmonary vascular response to 15% oxygen was found. It is concluded that, in a small number of children with unrepaired congenital heart disease and pulmonary artery hypertension, pulmonary vascular hyperreactivity can be induced by breathing 15% oxygen; this reaction is life-threatening but reversible with the administration of 100% oxygen.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1983

Vascular consequences of subclavian artery transection for the treatment of congenital heart disease.

The acute and chronic consequences of subclavian artery transection were analyzed in the noninvasive vascular laboratory. Twenty-eight patients (aged 1 day to 4 2/12 years, median 2 months) underwent subclavian artery transection (23 Blalock-Taussig, four subclavian aortoplasty for coarctation or interrupted arch, and one division of aberrant left subclavian). Bilateral systolic brachial artery pressure (BAP) was measured by Doppler instrumentation to obtain a "BAP index": BAP1 = (operated side BAP/control side BAP). Velocity waveform tracings and bilateral forearm skin temperatures were also obtained during studies before and sequentially after operation (4 hours to 12 years). Five patients underwent exercise testing of the upper extremity. Nine patients were studied for manual preference and limb development. Before operation, mean BAP1 was 0.99. Immediately (4 to 48 hours) after operation, mean BAP1 was 0.39. Three weeks postoperatively, BAP1 was 0.62, and thereafter it remained at 0.70. All differences between preoperative, immediate postoperative and late postoperative BAP1 are significant (p less than 0.001). Exercise resulted in a significant (p less than 0.01) increase in BAP bilaterally. Forearm skin temperature was initially lower (p less than 0.01) on the operated side but approximated the control side by 1 week. Limb girth was less on the operated side (p less than 0.01), without evidence of altered manual preference. In conclusion, subclavian artery transection causes permanent reduction in BAP1. The affected limb appears to respond to increased metabolic demand by increasing limb blood flow.

Arm↗
PubMed1983

Coarctation in the first year of life. Patterns of postoperative effect.

From 1975 to 1982, 31 infants were operated upon in the first year of life for aortic coarctation and congestive heart failure. Operations performed were resection and end-to-end anastomosis (RETE) in 14, subclavian flap aortoplasty (SFA) in six, patch aortoplasty (PA) in five, and other procedures in six. Thirty of the thirty-one (97%) survived the operation. To assess the effect of operation, 26 infants were studied noninvasively with Doppler arm-to-leg pressure measurements at rest and with stress. Preoperatively, the median arm-to-leg gradient at rest was 77 mm Hg. Serial postoperative Doppler studies demonstrated progressive changes in arm-to-leg pressure gradients: 69% had residual arm-to-leg gradients that spontaneously resolved, 13% had residual gradients that persisted, 13% had progressive increase in gradient, and one child had neither early nor late gradient. Stress testing often unmasked gradients not present in the resting state. No differences were noted among the three surgical groups: RETE, SFA, and PA. From our experience, we have made four conclusions with regard to repair of coarctation of the aorta in infants. First, surgical survival is expected. Second, the effect of the operation is dynamic, with four patterns defined: (1) complete relief of coarctation, (2) transient residual coarctation, (3) persistent residual coarctation, and (4) recurrent coarctation. Third, optimal surgical therapy seems to be an eclectic approach. Fourth, physiological evaluation of coarctation in infants can be obtained by Doppler techniques in conjunction with stress testing.

Aortic Coarctation↗
PubMed1979

Endocardial cushion defect associated with cor triatriatum sinistrum or supravalve mitral ring.

Clinical and angiographic or autopsy data, or both, on three children with a subdivided left atrium (cor triatriatum) and an associated endocardial cushion defect are reviewed. (One child had ostium primum defect, and two had complete atrioventricular [A-V] canal.) A fourth patient demonstrates the difficulties in differentiating subdivided left atrium from supravalve mitral stenosis in the presence of an endocardial cushion defect. The clinical findings are greatly influenced by the endocardial cushion defect. A pressure gradient between the pulmonary wedge and (left or right) ventricular end-diastolic pressures in patients with an endocardial cushion defect indicates pulmonary venous obstruction and should alert one to the possibility of these combined lesions. The exact diagnosis is made with injections of angiographic contrast medium into the proximal and distal left atrial chambers, to documented the respective relations of the pulmonary veins, left atrial appendage and A-V valves to these atrial chambers. All three patients with an endocardial cushion defect and a subdivided left atrium had an associated patent ductus arteriosus. The common association of subdivided left atrium with intracardiac, pulmonary venous and aortic anomalies is again demonstrated.

Cardiac Catheterization↗
PubMed1979

The prosthetic (Teflon) central aortopulmonary shunt for cyanotic infants less than three weeks old: results and long-term follow-up.

The expanded microporous polytetrafluoroethylene (PTFE) 4 mm vascular prosthesis has been used to create a central aortopulmonary shunt in 20 critically ill infants less than 3 weeks old. The infants ranged from 1 to 18 days old (5.25 days), and from 1.5 to 4.0 kg (2.9 kg). Conduit length ranged from 2 to 6 cm (4 cm). Sixteen patients had atresia of the tricuspid or pulmonary valve. There were 6 early deaths (30%), only 1 of which was shunt related. The mean preoperative arterial oxygen saturation was 62% (range, 33 to 80%), and mean postoperative saturation was 87% (range, 78 to 90%). There were 5 late deaths, 1 probably caused by shunt failure. Nine long-term survivors have done well. Follow-up ranges from 1 to 36 months (18 months). Factors influencing conduit function are length, technical considerations, and pulmonary vascular resistance. Late restudy in 5 of 9 survivors confirms patency and demonstrates bidirectional pulmonary blood flow. Since PTFE shunt flow capability is fixed, the infant may require repair or a second shunt within 24 months of the initial procedure.

Aorta↗
PubMed1979

Ventricular fibrillation during cardiopulmonary bypass: long-term effects on myocardial morphology and function.

Mongrel dogs were subjected to hypothermic (28 degrees to 30 degrees C) cardiopulmonary bypass with hemodilution by 50%. In two groups of 8 dogs each, ventricular fibrillation was induced for 60 and 90 minutes, respectively, while the dogs were on bypass. A group of 6 dogs with the heart beating but nonworking served as control. Seven weeks after operation, hemodynamic measurements were made in the survivors (6 in each group) and the heart was fixed by perfusion with glutaraldehyde. Multiple transmural samples were taken from both ventricles. Light microscopy revealed solitary left ventricular scars (0.5 to 3 mm wide) in 2 hearts each from Groups 2 and 3. None of the hearts exhibited diffuse subendocardial fibrosis indicative of healed ischemic injury. All animals were hemodynamically normal. We conclude that in the nonhypertrophied heart, ventricular fibrillation up to 90 minutes with continuous bypass-sustained coronary perfusion (perfusion pressure at or above 70 mm Hg) offers protection from permanent myocardial injury.

Animals↗
PubMed1979

Calcific stenosis of the porcine heterograft.

We have encountered two cases of late calcification of the porcine heterograft. A patient in chronic renal failure died of sepsis and endocarditis fifteen months after replacement of the mitral and tricuspid valves. At postmortem examination, both heterograft valves exhibited severe calcification and thrombosis. A second patient with rheumatic heart disease and sickle cell disease underwent mitral valve replacement for severe regurgitation. Thirty months later, cardiac catheterization revealed prosthetic valve stenosis. The valve was replaced successfully, and the excised heterograft exhibited severe calcification with restriction of leaflet motion. Although calcification of the porcine heterograft is known to occur in patients with infection or disorders of calcium metabolism, dysfunction of the heterograft is rare in our experience.

Adolescent↗
PubMed1979

Detection, prediction, and significance of perioperative myocardial infarction following aorta-coronary bypass.

One hundred consecutive patients undergoing aorta-coronary bypass grafting (ACBG) alone, without ventricular venting, were prospectively studied to determine the incidence and consequence of perioperative myocardial infarction (PMI) and the clinical variables that were predictive of PMI. Incidence was determined by serial electrocardiography (ECG) 100 patients; serum CK, GOT, and LDH (100 patients). CK isoenzymes (qualitative 100 patients, quantitated 50 patients); vectorcardiography (VCG) (78 patients); and 99mtechnetium pyrophosphate scintigraphy (TcPyp) (52 patients). The incidence of PMI by ECG was 9%; an additional 8% of cases was diagnosed by enzymes alone. The incidence of diagnostic change by VCG was 19% and by scintigraphy, 25%. Using at least one changed variable of the remaining three as the reference standard, the relative sensitivity and relative specificity of given variables in the diagnosis of PMI were as follows: ECG 67% and 100%, respectively; VCG 85% and 94%; scintigraphy 92% and 97%; and serum enzymes 86% and 96%. By univariate analysis, unstable angina was the only significant predictor of PMI. The operative mortality rate was 2% and the mortality rate at 12 months was 5%. There was a significantly greater mortality rate in patients with PMI diagnosed by ECG (p less than 0.01), in patients with unstable angina pectoris before operation (p less than 0.05), and in women (p less than 0.05).

Analysis of Variance↗
PubMed1979

Earlier operation for left-sided Pseudomonas endocarditis in drug addicts.

Three consecutive patients with Pseudomonas endocarditis were treated by early operation with no deaths. The indications for operation were severe failure, systemic embolization, and infection refractory to antibiotics. The organism is aggressive, characterized by early invasion of the myocardium. Wide débridement of the anulus is necessary to remove any vegetations or intramyocardial abscessed wall. Because multiple valve infection is common, it is important to evaluate all four cardiac valves at the time of operation. Removing a second rim of the mitral anulus for separate culture at the time of mitral valve replacement may demonstrate the degree to which the valve resection has removed all infection. Early operation is necessary for reinfection of the prosthetic valve; however, metastatic abscess should also be considered in the face of continued signs of infection postoperatively. Patients should receive a 6 week postoperative course of antibiotics which have been shown by in vitro testing to be serum bactericidal in at least a 1:8 dilution. The operative findings of invasion of the myocardium by the organism and the surgical success in this small series have resulted in our recommending earlier operation in patients with these indications.

Adult↗
PubMed1978

Surface cooling (20 degrees C) and circulatory arrest in infants undergoing cardiac surgery. Results in ventricular septal defect, complete atrioventricular canal, and total anomalous pulmonary venous connection.

During a six-year period, 46 severely symptomatic infants (average age, 5.1 months) underwent correction of ventricular septal defect (22 patients), total anomalous pulmonary venous connection (13 patients), and complete atrioventricular canal (11 patients), with the use of surface cooling to 20 degrees C. Cardiac repair was performed during circulatory arrest, and rewarming was performed with a pump oxygenator. Ten patients undergoing repair of ventricular septal defects were studied hemodynamically at 21 degrees C, before repair and at 37 degrees C after rewarming. Heart rate, left ventricular systolic pressure, maximum dp/dt, cardiac index, stroke work, and oxygen consumption were reduced substantially at 21 degrees C. Systemic vascualr resistance was increased at 21 degrees C. All changes were reversible with repair and rewarming. A protocol for hemodilution and crystalloid volume loading was devised to maintain urine output after early patients were noted to demonstrate renal dysfunction. With this protocol, survival rates were 89% for patients with ventricular septal defects, 67% for those with atrioventricular canal defects, and 85% for those with total anomalous pulmonary-venous connection.

Blood Pressure↗
PubMed1978

Cardiac assist devices.

We reviewed current concepts and techniques of cardiac assistance, including orthotopic and heterotopic cardiac allografting. Whereas intraaortic balloon counterpulsation has had the greatest clinical use, other techniques are now becoming available, including the implantable abdominal left ventricular assistance device, and much effort is being expended on the development of artificial hearts and their power sources. Despite the present technical shortcomings, exciting advances have occurred in the clinical management of intractable acute or chronic ventricular failure and cardiogenic shock since the introduction of circulatory assistance in man. The continued development and implementation of these techniques will help reduce the still unacceptably high mortality rate in this group of patients.

Assisted Circulation↗
PubMed1978

Ventriculographic features predictive of surgical outcome for left ventricular aneurysm.

Although clinical and hemodynamic stability predicted outcome very well when left ventricular aneurysm was electively resected in 25 patients (95% survival), more discriminate criteria were essential for 20 patients undergoing urgent operation for severe myocardial decompensation (50% survival). Three methods of ventriculographic analysis primarily sensitive to the function of the non-aneurysmal left ventricle were evaluated. These methods separated patients undergoing urgent operation into a population with high operative risk (less than 18% survival) and a population with low operative risk (greater than 82% survival). These criteria also separated 15 patients undergoing operation within three months of myocardial infarction into a group with excellent prognosis (greater than 85% survival) and a group with poor prognosis (less than 15% survival). The high operative risk in patients undergoing urgent operation or operation within three months of myocardial infarction, when non-aneurysmal ventricular function is poor, may be too high; it should be undertaken only under unusual circumstances.

Adult↗
PubMed1977

Hypertrophic cardiomyopathy with midventricular obstruction associated with mitral stenosis: partial relief of the obstruction by papillary muscle and trabecular resection.

A patient is reported with hypertrophic cardiomyopathy where midventricular obstruction was found in association with mitral stenosis. Partial relief of the intraventricular obstruction was obtained by extensive papillary and trabecular muscle resection in the mid-left ventricular area, in conjunction with mitral valve replacement with a porcine heterograft.

Adult↗
PubMed1977

Does local cardiac hypothermia during cardiopulmonary bypass protect the myocardium from long-term morphological and functional injury?

Twenty-eight dogs were subjected to 90 minutes of hypothermic (30 degrees C) cardiopulmonary bypass with moderate hemodilution. In 6 dogs the heart was vented and beating for 60 minutes. Eight dogs underwent ventricular fibrillation with coronary perfusion (VF + CP). In 14 dogs the aorta was cross-clamped for 60 minutes while the myocardium was protected by local cardiac hypothermia (ICA + LCH). Eighteen animals survived. Hemodynamic studies at seven weeks revealed no major differences among the three groups. At postmortem examination, no gross scarring was noted in any heart. Microscopical examination of 14 hearts was completely-normal. In the VF + CP group, 2 hearts had isolated microscopical scars. Similar linear subendocardial scars (less than or equal to 1.5 X 0.5 mm) were noted in 2 hearts subjected to ICA + LCH. Survival after 60 minutes of VF + CP or ICA + LCH did not result in long-term morphological injury to or functional impairment of the myocardium.

Animals↗
PubMed1977

[Validity of thermodilution cardiac output determination in the presence of pulmonary insufficiency (author's transl)].

The thermodilution (TD) technique can be considered as the most useful method for cardiac output (CO) determinations in clinical routine. However, surgical procedures for pulmonary stenosis or atresia frequently induce pulmonary insufficiency (PI) of various degree; due to abnormal flow conditions, this may interfere with the validity of transvenous CO-determinations. This experimental study shows that the TD technique is accurate even in the presence of PI. This observation may be explained by the fact that PI results, on the one hand, in a higher distribution volume and, on the other hand, in an increased transit time of the indicator; both of these factors have opposite effects on CO calculations, thus possibly leading to a balance of either error.

Animals↗
PubMed1977

An unusual form of late stenosis after aortic valve replacement with a cloth-covered Starr-Edwards prosthesis.

A 24-year-old man presented with late stenosis of a cloth-covered Starr-Edwards valve (model 2320). Fibrous ingrowth occurred at the inflow orifice of the valve and all three struts were adherent to the aortic wall, creating a "tunnel" form of obstruction. The stenotic valve was replaced with a porcine heterograft, and the small aortic root was enlarged with a Dacron patch. This form of late prosthetic valve stenosis should have been prevented by enlargement of the aortic root at the time of valve insertion and by long-term anticoagulant therapy.

Adult↗