Effectiveness of the bidirectional Glenn shunt procedure for volume unloading in the single ventricle patient.
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Adolescent↗
Biomedical subjects
H Laks
Publications and source records attributed to H Laks.
Value of metabolic imaging with positron emission tomography for evaluating prognosis in patients with coronary artery disease and left ventricular dysfunction.
Patients with coronary artery disease (CAD) and severe left ventricular (LV) dysfunction have a high but variable annual mortality and some may benefit from myocardial revascularization. This study aimed to evaluate the prognostic value of positron emission tomography (PET), and its interrelation with the choice of medical therapy or revascularization for predicting survival and improvement in symptoms of heart failure in patients with CAD and LV dysfunction. Ninety-three consecutive patients with angiographic CAD and a mean LV ejection fraction of 0.25 who underwent cardiac PET studies for assessment of hypoperfused yet viable myocardium ("mismatch pattern") using N-13 ammonia and 18-F deoxyglucose were followed up for an average of 13.6 months. Fifty patients underwent medical treatment and 43 underwent revascularization. The Cox model analysis showed that the extent of mismatch had a negative effect (p = 0.02), whereas revascularization had a positive effect on survival (p = 0.04). The annual survival probability of patients with mismatch receiving medical therapy was lower than of those without mismatch (50 vs 92%, p = 0.007). Patients with mismatch who underwent revascularization had a higher survival rate than those treated medically (88 vs 50%, P = 0.03). The presence of mismatch also predicted improvement in heart failure symptoms after revascularization (p < 0.001). These results suggest that the presence of mismatch in patients with CAD and severe LV dysfunction is associated with poor annual survival with medical therapy. Revascularization in patients with PET mismatch appears to be associated with improved survival and heart failure symptoms.
Aged↗
Fumarate-enriched blood cardioplegia results in complete functional recovery of immature myocardium.
Amino acid enrichment of cardioplegic solutions has been shown to improve both the metabolic and functional recovery of ischemic myocardium. However, because of the marked systemic vasodilatation involved, use of amino acid enrichment is limited to the periods of induction and reperfusion. Fumarate is a Krebs' cycle intermediate whose conversion to succinate is responsible for the generation of adenosone triphosphate and the oxidation of the reduced form of nicotinamide-adenine nucleotide which is the pathway by which aspartate exerts its effect. Fumarate may also function as a free-radical scavenger and is involved in calcium transport. To determine if fumarate-enriched blood cardioplegia would improve the functional recovery of the neonatal heart, 14 neonatal piglet hearts were isolated and placed on a blood-perfused working heart circuit. After the baseline functional and metabolic assessment was done, cold ischemic arrest was initiated with either standard blood cardioplegic solution (group I; N = 7) or fumarate-enriched (13 mmol/L) blood cardioplegic solution (group II; N = 7). Cardioplegic solution was given at a pressure of 40 mm Hg every 20 minutes for 2 hours, and topical hypothermia was used. Sixty minutes after warm whole blood reperfusion, the functional recovery at left atrial pressures of 3, 6, 9, and 12 mm Hg was 70%, 66%, 66%, and 65%, respectively, in group I, versus 102%, 106%, 105%, and 109%, respectively, in group II (p < 0.05). The tissue creatinine phosphate levels after reperfusion were significantly higher in group II hearts (15.0 +/- 1.2 mumol/g dry heart tissue) than in group I hearts (9.2 +/- 1.9 mumol/g dry heart tissue), although the adenosine triphosphate levels were not significantly different.(ABSTRACT TRUNCATED AT 250 WORDS)
Adenosine Triphosphate↗
Spontaneous closure of fenestrations in an interatrial Gore-Tex patch: application to the Fontan procedure.
The concept of the partial Fontan procedure, first described with the adjustable atrial septal defect (ASD) and more recently with the fenestrated technique, has become an accepted approach for the management of high-risk patients undergoing the Fontan procedure. Experience with both techniques has shown that a patent ASD placed in a prosthetic interatrial baffle may close spontaneously over a period of weeks to months. The mechanism and timing of spontaneous closure, as well as the effect of antiplatelet therapy on this process, are poorly understood. To better define this process, the interatrial septum of 15 mongrel dogs was excised and replaced with a fenestrated Gore-Tex (W.L. Gore, Flagstaff, AZ) patch. Postoperative echocardiography confirmed the patency of the ASD and left-to-right shunting. Animals were sacrificed 4 to 6 weeks postoperatively, or sooner if infection or other postoperative complications developed. Eight animals underwent no antiplatelet or anticoagulation therapy postoperatively, and 7 received antiplatelet therapy with aspirin. Patches were removed at the end of the study period and analyzed. By 6 weeks, all 2.7-mm and 4-mm holes had closed spontaneously in all animals that had not received antiplatelet therapy. The earliest closure occurred at 1 week. With antiplatelet therapy, hole closure was found to be delayed but not prevented, and was complete by 6 weeks in all but 1 animal. Histologic examination of the explanted patches revealed that closure was accomplished primarily through the ingrowth of fibrous tissue, accompanied by an inflammatory cell infiltrate.(ABSTRACT TRUNCATED AT 250 WORDS)
Animals↗
Truncal valve repair: initial experience with infants and children.
The truncal valve regurgitation that frequently arises in patients with truncus arteriosus accounts for increased operative and late mortality. Five patients underwent truncal valve repair at UCLA Medical Center between August 1990 and September 1991. This group consisted of 2 infants who underwent complete repair and 3 who underwent valve repair together with right ventricle-pulmonary artery conduit replacement. The techniques used for repair were individualized according to the specific valve morphology, and consisted of the suturing of partially developed commissures, suspension of the cusps, resection of redundant portions of the cusps, annuloplasty at the commissures, and resection of excrescences on the surface of valve leaflets. In 1 infant who had a severely dysplastic truncal valve, stenosis and regurgitation recurred and progressed, and he died 4 months after truncal valve replacement. The remaining 4 patients, who were followed for from 8 to 21 months after repair, are in New York Heart Association class I, and have minimal or no aortic regurgitation. Except in patients with severely deformed and dysplastic valves, truncal valve repair can be an attractive and successful alternative to valve replacement.
Child↗
Cardiac decompression after operation for congenital heart disease in infancy.
Between January 1987 and July 1992, 641 infants (less than 1 year of age) underwent cardiac surgical procedures through a median sternotomy incision at the UCLA Medical Center. In 36 (5.6%), to achieve cardiac decompression, the chest was left open after the operation, or was re-opened immediately postoperatively because of low cardiac output. The incidence of cardiac decompression was 31% (4/13) after the Norwood procedure and 24% (7/29) after truncus arteriosus repair. Opening of the chest reduced intrathoracic pressure and allowed complete expansion of the lungs. Delayed sternal closure was carried out in 27 patients at a mean of 5 days (range, 2 to 14 days) postoperatively. By the time of chest closure, left atrial pressure had decreased from a mean of 12 +/- 1.4 to 8.4 +/- 0.8 mm Hg (p < 0.004), and inotropic drug support with dopamine and dobutamine had also decreased significantly. Thirteen (36%) patients died of low cardiac output and multiorgan failure (4 of them after delayed chest closure) that was complicated by sepsis in 2. The incidence of sternal wound infection was relatively low at 5.6% (2/36); 1 patient died of generalized sepsis complicating multiorgan failure and the second case occurred in a patient who survived long term after sternectomy. With optimal ventilatory and inotropic drug support and meticulous wound care, delayed sternal closure may improve the survival of infants in low cardiac output after cardiac surgical procedures.
Female↗
Conversion of atriopulmonary to cavopulmonary anastomosis in management of late arrhythmias and atrial thrombosis.
The original atriopulmonary connection or "classic" Fontan operation is associated with several late complications such as arrhythmias, right atrial dilatation, and thromboembolism. This report describes our experience with 3 patients who presented with the acute onset of atrial arrhythmias and upon further evaluation were found to have significant hemodynamic lesions. After failing medical management, all 3 patients were treated successfully with surgical conversion of their atriopulmonary connection to a lateral tunnel cavopulmonary Fontan. The postoperative course of these patients was uneventful. However, long-term evaluation is needed to assess the efficacy of this technique in the prevention of postoperative morbidity.
Acute Disease↗
Acute hemodynamic effects of adjustable atrial septal defect closure in the lateral tunnel Fontan procedure.
OBJECTIVES: This study evaluated the acute hemodynamic changes with atrial septal defect closure in the postoperative period in patients undergoing the Fontan procedure. BACKGROUND: The adjustable atrial septal defect is a modification of the Fontan procedure designed to improve cardiac output and reduce systemic venous hypertension during the postoperative period. Limited information is available on the effects of inter-atrial shunting on the physiology of direct cavopulmonary connection. METHODS: In 11 patients (aged 9 months to 14.5 years), the atrial septal defect was closed 8 h to 4.6 days (mean 1.7 days) postoperatively. Indications for closure included mean right atrial pressure < 15 mm Hg or arterial oxygen saturation < 80%, or both. RESULTS: Data presented are mean values +/- 1 SD. Mean right atrial pressure was 13.4 +/- 3.0 mm Hg on admission to the intensive care unit, 10.0 +/- 2.0 mm Hg (p = 0.02) immediately before closure and 11.4 +/- 2.8 mm Hg (p = 0.02) after closure. There was a significant decrease in cardiac output, as calculated from arteriovenous oxygen saturation difference (26 +/- 9%, p = 0.003), Doppler aortic flow (19 +/- 9%, p = 0.0002) and ventricular volumes by two-dimensional echocardiography (20 +/- 8%, p = 0.0001). Arterial oxygen saturation increased from 82 +/- 5% to 94 +/- 4% (p = 0.0001), and arteriovenous oxygen saturation difference increased from 25 +/- 8% to 33 +/- 9% (p = 0.0001). Systemic oxygen delivery decreased from 727 +/- 354 to 655 +/- 325 ml/min per m2 (p = 0.02). One patient required reopening of the atrial septal defect. CONCLUSIONS: These data demonstrate that a controlled right to left atrial shunt improves cardiac output and systemic oxygen delivery and facilitates the postoperative management of patients after the Fontan procedure. Atrial septal defect closure increases systemic saturation to normal values and prevents potential systemic embolization but significantly decreases oxygen delivery and might limit exercise tolerance.
Adolescent↗
Simultaneous arterial and coronary sinus cardioplegic perfusion: an experimental and clinical study.
UNLABELLED: The existence of inhomogeneous distribution of coronary flow with antegrade or retrograde perfusion alone has led to alternating between these delivery routes to maximize their individual benefits. Concern over myocardial damage prevented the simultaneous application of antegrade and retrograde cardioplegic blood delivery. Based upon the predominance of retrograde drainage via Thebesian veins, and evidence that pressure-controlled intermittent coronary sinus occlusion during antegrade cardioplegic delivery enhances its distribution and protective properties, this study tests (a) the hypothesis that simultaneous aortic and coronary sinus perfusion is safe during aortic clamping, and (b) reports initial clinical application of this combined strategy in 174 patients. Five minipigs (25-30 kg) underwent 1 hr of aortic clamping with simultaneous aortic (antegrade) and coronary sinus (retrograde) perfusion at 200 ml/min with normal blood (37 degrees C) before and after 30 minutes of perfusion with either warm (37 degrees C) or cold (4 degrees C) blood cardioplegia (BCP). Furthermore, the combined strategy was used in 174 high-risk patients (NYHA class III-IV) at 3 university hospitals to perform myocardial protection during CABG or valve replacement, or a combination of both. Included were 16 patients in cardiogenic shock and 24 undergoing reoperation. In both the clinical and the experimental studies the coronary sinus pressure was always < 40 mmHg in beating or arrested hearts. EXPERIMENTAL: Compared to control values (81.4 +/- 0.4% tissue water content), no right-ventricular (80.8 +/- 0.8%) or left-ventricular (79.5 +/- 0.3%) edema developed, no lactate was produced (control: -1.0 +/- 0.5 mg/100 g/min, empty beating: -0.64 +/- 5, and BCP arrest: -8.6 +/- 6.6).(ABSTRACT TRUNCATED AT 250 WORDS)
Animals↗
The safety of simultaneous arterial and coronary sinus perfusion: experimental background and initial clinical results.
UNLABELLED: Concern over myocardial damage from simultaneous arterial (antegrade) and coronary sinus (retrograde) perfusion has led to alternating between these delivery routes to maximize their individual benefits. Based upon predominant retrograde drainage via Thebesian veins, this study: (1) confirms experimentally the safety of simultaneous arterial and coronary sinus perfusion; and (2) reports initial clinical application of this combined strategy in 155 consecutive patients. EXPERIMENTAL: Five mini-pigs (25 to 30 kg) underwent 1 hour of aortic clamping with simultaneous aortic and coronary sinus perfusion at 200 mL/min with normal blood (37 degrees C) before and after 30 minutes of perfusion with either warm (37 degrees C) or cold (4 degrees C) blood cardioplegia. Coronary sinus pressure was always less than 30 mmHg. There was no right or left ventricular edema, lactate production, or lipid peroxidation as transmyocardial and myocardial conjugated dienes were unaltered, and postbypass recovered left ventricular end-systolic elastance (conductance catheter) and preload recruitable stroke work index 101% +/- 3% and 109% +/- 90%, respectively. CLINICAL: Simultaneous arterial/coronary sinus perfusion was used in 155 consecutive high risk patients (New York Heart Association Class III to IV) undergoing isolated coronary artery bypass grafting (CABG) (n = 109) and CABG+valve replacement/repair or aneurysm (n = 46). Included were 16 patients in cardiogenic shock and 24 undergoing reoperation. Mean aortic clamping time averaged 90 +/- 4 minutes (range 30 to 207), with 3.5 +/- 0.1 grafts per patient; all anastomoses were performed with the aorta clamped. Cold intermittent blood cardioplegia was used for distal anastomoses and valve implantation/repair in 123 patients, and warm continuous blood cardioplegia was used in 32 patients. Following a warm cardioplegic reperfusate, all patients received warm noncardioplegic blood perfusion simultaneously via grafts and coronary sinus. Coronary sinus pressure was always less than 40 mmHg. Of 18 patients requiring postoperative mechanical circulatory support (IABP), 16 had IABP placed preoperatively for cardiogenic shock. There were three postoperative myocardial infarctions (2%), and six patients died (3.9% mortality). CONCLUSION: These experimental and clinical findings overcome perceived concerns about myocardial damage from simultaneous arterial and coronary sinus perfusion, and suggest this approach may add to the armamentarium of cardioprotective strategies.
Anastomosis, Surgical↗
Technique for reoperative median sternotomy in the presence of a patent left internal mammary artery graft.
Damage to a patent left internal mammary artery (IMA) graft during reoperation can be catastrophic. An organized approach to reenter the mediastinum in the presence of a functioning left IMA graft is described. The sternum is opened using an oscillating saw to carefully divide the anterior and posterior tables. The right side is then dissected out first, exposing the aorta and right atrium. After placing pursestring sutures for cannulation, attention is turned to the left side. An IMA retractor is used to elevated the left edge of the sternum in incremental stages. The dissection is begun at the inferior end of the sternum, exposing the distal anastomosis first and then dissecting superiorly anterior to the IMA. A Doppler flow detector probe is used to assist in locating the artery in the adhesions.
Coronary Artery Bypass↗
Pulmonary atresia with ventricular septal defect in adults.
BACKGROUND: Multistage surgery culminating in completed hemodynamic repair is now performed for pulmonary atresia with ventricular septal defect (PA-VSD). Justification for operation in patients with an adequate collateral pulmonary circulation is controversial. Data on natural adult survival are scant but are necessary to provide the rationale for multistage reconstructive procedures. METHODS AND RESULTS: All cyanotic adults with PA-VSD in the UCLA Adult Congenital Heart Disease Center Registry from 1978 through 1992 formed the basis for this study. Registry data and echocardiographic, hemodynamic, and angiographic information were used to determine longevity, clinical course, and operative feasibility. Of 26 patients, 16 were unoperated when referred (group A), and 10 had been palliated before age 18 years (group B). Two thirds were 18 to 29 years old. Only 2 patients survived beyond age 40 years. Six died during follow-up at a mean age of 31 years (+/- 12.1 SD). Eight group A patients were in New York Heart Association class II, and 8 were in class III. Of the 26 group A and B patients, 20 had aortic regurgitation, which was moderate or severe in 10. Eight had cardiac failure. Of 11 group A patients who remained unoperated, 5 died. Twelve patients were considered eligible for surgery at > or = 18 years of age. Ten underwent completed hemodynamic repair with a mean post-operative right ventricular-to-left ventricular systolic pressure ratio of 0.45 (+/- 0.16 SD), and there were no early or late deaths. CONCLUSIONS: Even when collateral blood flow permits adult survival, all such patients are symptomatic. Mean life expectancy without operation did not exceed three decades. Aortic regurgitation and cardiac failure are significant negative variables. Nearly half of unoperated adults died during follow-up. Staged hemodynamic repair can be performed with a low surgical risk in properly selected adults with PA/VSD.
Adult↗
The impending crisis awaiting cardiac transplantation. Modeling a solution based on selection.
BACKGROUND: Each month, the number of transplant candidates added to the waiting list exceeds the number of transplantations performed, and many outpatients deteriorate to require transplantation urgently. The current list of 2400 candidates and the average wait of 8 months continue to increase. METHODS AND RESULTS: To determine the size at which the outpatient and critical candidate pools will stabilize, population models were constructed using current statistics for donor hearts, candidate listing, sudden death, and outpatient decline to urgent status and revised to predict the impact of alterations in policies of candidate listing. If current practices continue, within 48 months the predicted list will stabilize as the sum of an estimated 270 hospitalized candidates, among whom, together with newly listed urgent candidates, all hearts will be distributed and 3700 outpatient candidates with virtually no chance of transplantation unless they deteriorate to an urgent status. Decreasing the upper age limit now to 55 years would reduce the number listed each month by 30% and result within 48 months in a list of only 1490. The list could also be decreased by 30%, however, if it were possible to list only a candidate group with an 80% chance (compared with 52% estimated currently) of sudden death or deterioration during the next year. With this strategy, the waiting list would equilibrate within 48 months to one-third the current size, with 50% of hearts for outpatient candidates, who would then have an 11% chance each month of receiving a heart compared with 0% if recent policies prevail. Total deaths, with and without transplantation, would be minimized by this rigorous selection of outpatient candidates. CONCLUSIONS: This study implies that immediate provisions should be made to limit candidate listing and revise expectations to reflect the diminishing likelihood of transplantation for outpatient candidates. Future emphasis should be on improved selection of candidates at highest risk without transplantation.
Computer Simulation↗
Recipient mononuclear cell recognition and adhesion to graft endothelium after human cardiac transplantation. Lymphocyte recognition leads to monocyte adhesion.
Transendothelial migration of mononuclear cells is crucial in the development of allograft rejection and transplant coronary disease. Adhesion of circulating cells to endothelium is the initial step in transendothelial migration. Human aortic endothelial cell cultures were established from aortic tissue harvested at the time of organ donation for cardiac transplantation which allowed specific recipient mononuclear cell-graft endothelial interactions to be studied. Confluent untreated endothelial cells were incubated with recipient mononuclear cells for 15 min to assess adhesion. Adhesion of recipient mononuclear cells to endothelium derived from their graft was threefold higher than adhesion to nonspecific endothelium (93 +/- 20 vs. 30 +/- 11 cells/high power field, P < 0.005). Graft-specific adhesion was inhibited by preincubation of the endothelium with antibodies to class I HLA (34 +/- 16 cells/high power field, P < 0.005). Immunofluorescence performed after adhesion showed that 73 +/- 6% of both specific and nonspecific adherent cells were monocytes. The use of purified lymphocyte and monocyte preparations showed that graft-specific lymphocytes induce unrelated monocytes to become adherent. These results suggest that lymphocytes are primed in vivo to recognize endothelium derived from their graft which leads to a rapid increase in lymphocyte and monocyte adhesion. Such allo-recognition may involve endothelial class I HLA molecules.
CD3 Complex↗
Surgical management of pulmonary atresia with ventricular septal defect and multiple aortopulmonary collaterals.
Pulmonary atresia with ventricular septal defect and multiple aortopulmonary collaterals is a form of complex congenital heart disease that is the subject of continued controversy. Disagreement exists regarding the appropriateness of surgical therapy, the timing of operation, and the optimal techniques for repair (1,2). The reason for these differences centers around the diversity of morphologic and consequent physiologic forms with which this defect presents. The relatively small number of patients and large number of subgroups make meaningful comparison between differing treatment strategies difficult. We present here the approach to these patients that is currently employed at UCLA Medical Center.
Abnormalities, Multiple↗
Human mononuclear cell adhesion to porcine arterial endothelium.
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Animals↗
Surgical management of pulmonary atresia with ventricular septal defect and multiple aortopulmonary collaterals.
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Blood Vessel Prosthesis↗
The partial Fontan: controlled temporary systemic venous decompression after the Fontan procedure.
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Heart Atria↗