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A Ardehali

Publications and source records attributed to A Ardehali.

44 records · Page 3Linked to original sources
PubMedDate not supplied

A comparison of distribution between simultaneously or sequentially delivered antegrade/retrograde blood cardioplegia.

UNLABELLED: Commercially available cardioplegia delivery systems now allow for antegrade (aortic root, coronary ostia, saphenous vein graft) perfusion to occur either sequentially or simultaneous with retrograde (coronary sinus) perfusion. This study was designed to compare the total flow and local distribution of sequential versus simultaneous antegrade/retrograde cardioplegia delivery. METHODS: Explanted human hearts diagnosed with idiopathic cardiomyopathy underwent a cold cardioplegic arrest and bicaval cardiectomy. Thirty-seven degree centigrade blood cardioplegia containing colored microspheres was then delivered antegrade (red color) at a pressure of 80 mmHg or retrograde (blue color) at a pressure of 40 mmHg. In the sequential group (n = 6), cardioplegia was delivered antegrade and then retrograde for 2 minutes, respectively. For the simultaneous group (n = 6), cardioplegia was delivered both antegrade and retrograde for 2 minutes. The ventricular myocardium was then sampled at 12 representative sites to determine regional cardioplegic flow. RESULTS: Mean total cardioplegia delivery/minute was 0.69 +/- 0.62 mL/g per minute for sequential cardioplegia, and 0.46 +/- 0.19 mL/g per minute for simultaneous cardioplegia (p > 0.05, NS). At the 12 ventricular sites sampled, mean regional cardioplegic flow (mL/g per min) was in general slightly greater for sequential delivery. However, this was not statistically significant (p > 0.05, NS). CONCLUSION: The data suggest that there may be a slight advantage in total cardioplegia delivery and regional cardioplegia delivery when using sequential rather than simultaneous cardioplegia delivery. However, this difference was not statistically significant and is likely not of clinical significance. Therefore, we would recommend using either sequential or simultaneous antegrade/retrograde cardioplegia based upon whichever technique facilitates the conduct of the individual operation.

Aorta↗
PubMedDate not supplied

Temporary mechanical support with the BVS 5000 assist device during treatment of acute myocarditis.

BACKGROUND: Ventricular support with the BVS 5000 (Abiomed) has been used as temporary circulatory assist for the failing heart. Our purpose is to summarize four cases illustrating the role of mechanical unloading in acute myocarditis. METHODS: Four patients aged 16- to 33-year old presented with congestive heart failure 4 to 20 days after a flu-like syndrome. All patients were in severe cardiogenic shock +/- renal and liver dysfunction. Ejection fraction ranged from 5% to 26%. Indications for ventricular assist were failure of maximal medical treatment with > or = two inotropes +/- intra-aortic balloon pump. Myocardial biopsy revealed acute myocarditis in three patients and severe edema in one despite a characteristic clinical course. Two patients received immunotherapy with OKT3. Biventricular assist was used in three patients and left ventricular assist only was used in one. Mean support time was 8.3 days (7 to 11). RESULTS: All patients had recovery of myocardial function and were discharged from the hospital in good condition. CONCLUSION: The BVS 5000 device provides a safe, simple, and effective method to support the circulation during acute myocarditis. We hypothesize that this may facilitate myocardial recovery by decompressing the distended ventricle. Ventricular assist devices should be used early in the presence of hemodynamic deterioration on maximal medical therapy.

Acute Disease↗
PubMedDate not supplied

An improved valve-spreading catheter for producing reversible graded acute aortic regurgitation.

A valve-spreading catheter capable of producing graded reversible acute aortic regurgitation has been described. We modified this device to improve its safety and steerability. The modified valve-spreading catheter was composed of a removable core flexible guidewire and a caged catheter. The guidewire could easily and safely be steered into the left ventricle. The caged catheter could then be advanced over the guidewire to the aortic valve area with greater safety and ease. Opening of the caged catheter resulted in graded reversible acute aortic regurgitation. The modified valve-spreading catheter was used in 5 anesthetized mongrel dogs to create reversible graded acute aortic regurgitation, demonstrating its safety, and thus its utility. This device qualifies as an ideal instrument for creating variable and transient acute aortic regurgitation in intact animals.

Acute Disease↗
PubMedDate not supplied

Expression of major histocompatibility antigens and vascular adhesion molecules on human cardiac allografts preserved in University of Wisconsin solution.

The impact of cold storage of cardiac allografts on expression of major histocompatibility complex antigens and vascular adhesion molecules is not known. We obtained serial endomyocardial biopsy specimens at harvest, on implantation, and approximately 15 minutes after reperfusion from six consecutive human cardiac allografts stored in University of Wisconsin solution. Cold ischemia time was 187 +/- 45 minutes. A fourth endomyocardial biopsy specimen was obtained from the recipients of cardiac allografts 1 week after operation. Expression of major histocompatibility complex antigens and vascular adhesion molecules was studied by immunohistochemistry. The intensity was scored blindly by a semiquantitative method. On vascular endothelial cells, the expression of major histocompatibility complex class I and II antigens was strong; ICAM-1 expression was moderate, and expression of VCAM-1 and ELAM-1 was weak to absent. The expression of these antigens on vascular endothelial cells did not change in sequential biopsy specimens. The expression of major histocompatibility complex class I antigens on myocardial cells was weak and remained unchanged. Myocardial cells did not express major histocompatibility complex class II antigens, ICAM-1, VCAM-1, or ELAM-1 on serial examinations. During cold storage of cardiac allografts in University of Wisconsin solution, the expression of major histocompatibility complex antigens and vascular adhesion molecules on endothelial cells and myocardial cells remains unchanged.

Adenosine↗
PubMedDate not supplied

Experimental cardiac allograft vasculopathy in mice.

Cardiac allograft vasculopathy is the most common cause of death in heart transplant recipients after the first postoperative year. The pathogenesis of cardiac allograft vasculopathy is not clearly defined. To better study this disease, a genetically well-defined and reproducible animal model such as the mouse is needed. We performed heterotopic, intraabdominal heart transplantation between two inbred strains of mice. The B10.A strain served as donors, and the B10.BR strain served as recipients. No immunosuppressive therapy was administered. The allografts in groups I (n = 6) and II (n = 6) were harvested at 30 and 50 days after operation, respectively. All allografts had palpable contractions at the time of harvest. The cardiac allografts from both groups showed mild to moderate acute cellular rejection. In groups I and II, 55% +/- 26% and 60% +/- 18% of arteries showed intimal thickening, respectively. Pathologically, the vascular lesions were characterized with varying degrees of intimal thickening, subendothelial mononuclear cell infiltration and fibrosis, frequent disruption of the internal elastic lamina, and perivascular inflammation. These findings are characteristic of cardiac allograft vasculopathy seen clinically. Isografts (n = 6) showed no vascular lesions. The heterotopic transplantation of B10.A-strain hearts into B10.BR recipients provides a useful murine model for future studies in the pathogenesis and treatment of cardiac allograft vasculopathy.

Animals↗
PubMedDate not supplied

Orthotopic heart transplantation and concurrent coronary bypass.

Lack of donor organ availability is an increasing problem in heart transplantation. Methods to safely increase the donor pool are desperately needed. We report four cases of coronary artery bypass during orthotopic heart transplantation for donor hearts with normal ventricular function and subclinical coronary artery disease. An aggressive approach toward utilizing hearts from older donors with normal ventricular function may expand the donor pool and decrease the waiting period, with its attendant death, for patients awaiting heart transplantation.

Aged↗
PubMedDate not supplied

University of Wisconsin solution versus Stanford cardioplegic solution and the development of cardiac allograft vasculopathy.

BACKGROUND: University of Wisconsin (intracellular) solution has been shown to offer some distinct benefits of myocardial preservation over Stanford (extracellular) solution, including a more rapid functional recovery, improved adenosine triphosphate preservation, and a tendency for less postoperative inotropic agents. However intracellular solutions with high potassium content have been reported to cause a functional if not structural endothelial injury in laboratory experiments. METHODS: Because of this information we retrospectively viewed our follow-up angiographic data for the development of the cardiac allograft vasculopathy in a consecutive series of 195 heart transplant recipients. These patients were treated in identical fashion, with the same immunosuppression regimen, except for the type of cardioplegia used--Stanford solution (group I n = 95) and University of Wisconsin solution (group II n = 100). RESULTS: With a mean follow-up of 24 months after transplantation, a significant difference was seen in the development of cardiac allograft vasculopathy in group II (22%) versus group I (14%, p < 0.03). Although significant differences were observed with univariate analysis with respect to donor age and ischemic time favoring group I and with multivariate statistical analysis with respect to overall rejections favoring group II, the only significant variable for the difference in the development of allograft vasculopathy was University of Wisconsin cardioplegic solution (p < 0.003). A subgroup of 30 patients previously randomized for a functional study comparing the two cardioplegic agents showed a tendency for statistical significance with a freedom from allograft vasculopathy of 93% in group I, as compared with 83% in group II, after 13 months follow-up (p = 0.09). The overall probability of being free of vasculopathy at 24 months was 86% for group I and 70% for group II. CONCLUSIONS: The data support the conclusion that University of Wisconsin intracellular solution is associated with an increased incidence of vasculopathy versus Stanford solution and warrants investigation for modification of this preservation agent in heart transplantation.

Adenosine↗