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Biomedical subjects

B Vidne

Publications and source records attributed to B Vidne.

At least 37 records · Page 2Linked to original sources
PubMed2000

Repeated thrombolysis in multiple episodes of obstructive thrombosis in prosthetic heart valves: a report of three cases and review of the literature.

BACKGROUND AND AIM OF THE STUDY: Thrombolysis is an emerging method to open thrombosed prosthetic heart valves. However, its applicability and safety in multiple recurrent thrombotic episodes is unclear. METHODS: Among 16 patients with thrombosed prosthetic valves treated with thrombolysis during a 33-month period, three patients (one mitral and two tricuspid) experienced four episodes each, and these were treated with repeated thrombolytic therapy. Data on patient demographics, clinical presentation, diagnosis, treatment and outcome are presented. RESULTS: Thrombolysis was successful in 10/12 episodes (83%); there was delayed response in one episode (8%), and partial response in one episode (8%). There were no major complications. However, a fifth thrombotic episode occurred in two patients with tricuspid prostheses, mandating re-do surgery. CONCLUSION: Thrombolysis in re-thrombosed prosthetic heart valves is feasible, highly successful and safe, and may therefore be used judiciously in selected patients who could not, or would not, undergo redo surgery. A high recurrence rate in the tricuspid position may implicate earlier surgical intervention, which should be individualized.

Adult↗
PubMed2000

Mid-term clinical and echocardiographic follow up of patients with CarboMedics valves in the tricuspid position.

BACKGROUND AND AIM OF THE STUDY: Debate continues regarding tricuspid valve replacement (TVR) with a mechanical prosthesis. Experience with bileaflet prostheses is limited; hence the study aim was to explore early and mid-term outcome and hemodynamic data in patients with bileaflet CarboMedics prosthetic valves in the tricuspid position. METHODS: The study population included 25 patients (21 females, four males; mean age 50.5 +/- 13.4 years) who underwent TVR with a CarboMedics valve over a six-year period. Routine clinical examinations and details of transthoracic echocardiography (TTE) were reviewed. Additional TTE, transesophageal echocardiography (TEE) and fluoroscopy were performed as indicated. The number of previous cardiac operations was zero, one and two in 36%, 32% and 32% of patients, respectively. Previous tricuspid surgery was performed in eight cases (32%); concurrent mitral valve replacement was performed in 17 (68%). The hospital mortality rate was 24% and late mortality rate 12%. Seventeen early survivors (13 females, four males) were followed up for 46 +/- 28 months (range: 4-96 months). RESULTS: Among early survivors, the mean and peak transvalvular gradients were 4.0 +/- 1.7 and 7.9 +/- 3.3 mmHg, respectively. Commonly observed INR levels were >2.5 in seven patients (41%), and >3.0 in only three (18%). Five patients (29% of mid-term survivors) experienced a total of 13 episodes of obstructive valve thrombosis, mostly with inappropriate anticoagulation. One patient required emergency re-do surgery; the others responded initially to thrombolysis or intensified antithrombotic treatment, but experienced at least two additional relapses. Aside from thrombotic episodes, all patients but two were in NYHA functional class II-III, and all but four required diuretics. CONCLUSION: TVR with bileaflet mechanical valves carries a high perioperative mortality and mid-term morbidity. Among patients with poor or fair anticoagulation, these valves were associated with a high incidence of obstructive valve thrombosis. If poor patient compliance is anticipated, insertion of a bioprosthesis should be encouraged.

Echocardiography↗
PubMed2000

The influence of aprotinin on myocardial function after liver ischemia-reperfusion.

BACKGROUND: The beneficial effect of aprotinin, a naturally occurring protease inhibitor, on preservation of organs such as the liver, kidney and lung has been documented. OBJECTIVE: To explore the effects of hepatic ischemia and reperfusion on both liver and myocardial function, using a dual isolated perfused organ model with and without aprotinin. METHODS: Isolated rat livers were stabilized for 30 minutes with oxygenated modified Krebs-Henseleit solution at 37 degrees C. Livers were then perfused continuously with KH or KH + aprotinin 10(6) KIU/L for an additional 135 min. Livers of two other groups were made globally ischemic for 120 min, then perfused for 15 min with KH or with KH + aprotinin. Isolated hearts (Langendorff preparation) were stabilized for 30 min and then reperfused with KH or KH + aprotinin exiting the liver for 15 min. The liver's circuit was disconnected, and hearts were re-circulated with the accumulated liver + heart effluent for an additional 50 min. RESULTS: In the ischemia and ischemia + aprotinin groups, portal vein pressure (1 and 15 min reperfusion) was 331 +/- 99% and 339 +/- 61% vs. 308 +/- 81% and 193 +/- 35% of baseline, respectively (P < 0.03 vs. ischemia). There were no other differences in the enzyme leakage between aprotinin-treated or untreated ischemic livers. Left ventricular pressure was stable in the controls. However, LV pressure in groups perfused with ischemic liver effluent declined within 65 min reperfusion, whether aprotinin treated or not (84 +/- 8% and 73 +/- 5% of baseline, respectively, P < 0.004 only for ischemia vs. control). CONCLUSION: When aprotinin was used, LV pressure was inclined to be higher while liver portal vein pressure was lower, thus providing protection against liver and heart reperfusion injury.

Animals↗
PubMed2000

Iatrogenic left ventricular-right atrial fistula following mitral valve replacement and tricuspid annuloplasty: diagnosis by transthoracic and transesophageal echocardiography.

Acquired left ventricle-to-right atrium communications are a known complication of valvular heart surgery. Previous reports have described the clinical features and diagnosis using cardiac catheterization. We report two cases of acquired left ventricle-to-right atrium fistula following mitral valve replacement. Particular emphasis is placed on the diagnosis using transthoracic and transesophageal echocardiography, obviating the need for cardiac catheterization before repair.

Aged↗
PubMed1999

Usefulness of dobutamine radionuclide ventriculography for prediction of left ventricular function improvement after coronary artery bypass grafting for ischemic cardiomyopathy.

Ventricular function may improve after coronary artery bypass grafting (CABG) in patients with ischemic cardiomyopathy depending on the amount of contractile myocardial reserve. Based on the studies using dobutamine echocardiography to predict regional wall improvement after revascularization, we investigated the benefit of low-dose dobutamine radionuclide ventriculography for assessing functional contractile reserve in this population. The study group included 56 patients with ischemic cardiomyopathy (mean left ventricular [LV] ejection fraction [EF] of 23 +/- 5%) and multivessel disease, who were referred for viability assessment. All underwent radionuclide ventriculography before and during infusion of 5 and 10 microg/kg/min of dobutamine. An increase in global LVEF from rest to dobutamine was calculated, and 10% was considered the cutoff value to predict ventricular improvement after CABG. Of the 35 patients who underwent CABG 1 month later, 29 were available for repeated radionuclide ventriculography after 12 +/- 5 months. Of these, 15 showed improvement (delta LVEF > or = 5%, mean 10 +/- 5%) and 14 did not (delta LVEF < 5%, mean -1 +/- 3%). The increase in EF with dobutamine had the highest univariate predictive value of all parameters evaluated. The sensitivity, specificity, and positive and negative predictive values of dobutamine radionuclide ventriculography were 67%, 93%, 91%, and 72%, respectively. We conclude that dobutamine radionuclide ventriculography is a useful method to assess contractile reserve and predict ventricular functional improvement after CABG in patients with ischemic cardiomyopathy.

Adrenergic beta-Agonists↗
PubMed1999

The natural history of aortic valve disease after mitral valve surgery.

OBJECTIVES: The present study evaluates the long-term course of aortic valve disease and the need for aortic valve surgery in patients with rheumatic mitral valve disease who underwent mitral valve surgery. BACKGROUND: Little is known about the natural history of aortic valve disease in patients undergoing mitral valve surgery for rheumatic mitral valve disease. In addition there is no firm policy regarding the appropriate treatment of mild aortic valve disease while replacing the mitral valve. METHODS: One-hundred thirty-one patients (44 male, 87 female; mean age 61+/-13 yr, range 35 to 89) were followed after mitral valve surgery for a mean period of 13+/-7 years. All patients had rheumatic heart disease. Aortic valve function was assessed preoperatively by cardiac catheterization and during follow-up by transthoracic echocardiography. RESULTS: At the time of mitral valve surgery, 59 patients (45%) had mild aortic valve disease: 7 (5%) aortic stenosis (AS), 58 (44%) aortic regurgitation (AR). At the end of follow-up, 96 patients (73%) had aortic valve disease: 33 AS (mild or moderate except in two cases) and 90 AR (mild or moderate except in one case). Among patients without aortic valve disease at the time of the mitral valve surgery, only three patients developed significant aortic valve disease after 25 years of follow-up procedures. Disease progression was noted in three of the seven patients with AS (2 to severe) and in six of the fifty eight with AR (1 to severe). Fifty two (90%) with mild AR remained stable after a mean follow-up period of 16 years. In only three patients (2%) the aortic valve disease progressed significantly after 9, 17 and 22 years. In only six patients of the entire cohort (5%), aortic valve replacement was needed after a mean period of 21 years (range 15 to 33). In four of them the primary indication for the second surgery was dysfunction of the prosthetic mitral valve. CONCLUSIONS: Our findings indicate that, among patients with rheumatic heart disease, a considerable number of patients have mild aortic valve disease at the time of mitral valve surgery. Yet most do not progress to severe disease, and aortic valve replacement is rarely needed after a long follow-up period. Thus, prophylactic valve replacement is not indicated in these cases.

Adolescent↗
PubMed1999

Isoflurane and sodium nitroprusside reduce the depressant effects of protamine sulfate on isolated ischemic rat hearts.

UNLABELLED: The administration of protamine sulfate (protamine) to reverse the action of heparin is associated with adverse reactions. We studied the effects of protamine and isoflurane on isolated, perfused rat hearts previously subjected to cardioplegic ischemia. Hearts were perfused with oxygenated Krebs-Henseleit (KH) solution for 30 min, then subjected to cardioplegic ischemia for 30 min (KCl 16 mEq/L at 31 degrees C) and 5 min reperfusion. Drug exposure lasted 15 min, and the recovery period was 60 min. Test groups were control, protamine (10 microg/mL), isoflurane (1.5%), protamine +/- isoflurane, sodium nitroprusside (SNP) (2.5 ng/mL), and SNP +/- protamine. Left ventricular developed pressure (LVP), coronary flow, and myocardial oxygen consumption were depressed by protamine to 30% +/- 4%, 47% +/- 4%, and 39% +/- 4% of baseline (P < 0.001 versus control), respectively. Isoflurane and SNP afforded partial protection from the effects of protamine: LVP was 57% +/- 5% and 51% +/- 3% of baseline, respectively (P < 0.05 versus protamine alone and control); coronary flow was 70% +/- 6% and 97% +/- 12% of baseline, respectively (P < 0.05 versus protamine alone; P < 0.05 for isoflurane versus control); and O2 consumption was 69% +/- 6% and 88% +/- 15% of baseline, respectively (P < 0.05 versus protamine; P < 0.05 for isoflurane versus control). In this model, protamine-induced myocardial depression and coronary vasoconstriction were less pronounced in the presence of either isoflurane or SNP. IMPLICATIONS: We examined the interactions of isoflurane, sodium nitroprusside, and protamine in a rat heart model and found that both isoflurane and sodium nitroprusside partially protect the heart from the depressant effects of protamine. This finding is significant, as these drugs are often used in heart surgery.

Anesthetics, Inhalation↗
PubMed1998

[First year's experience of the Post-Operative Cardiac Care Unit, Schneider Children's Medical Center].

In the past 10 years there has been a growing preference for early, complete correction of congenital heart disease. The first year of operation of this cardiac unit is described. 216 operations were performed: 15% in the neonatal age group and 35% in the newborn to 1-year-old groups; 2% were palliative procedures. Mortality was 4.9%. Average stay in the ICU was 3.2 days, with a median of 2.25. Average length of ventilation was 35 hours, with a median of 17.5. Complications were: diaphragm paralysis in 13 (6%), 2/3 of which were recurrent operations; in 2 patients (0.9%) we had to plicate the diaphragm. There was severe neurological damage in 2 which deteriorated to brain death in 1. There was peripheral, reversible neurological damage in 4 (1.8%), and acute renal failure in 3%, with half of them requiring dialysis. 75% of these children died and there was superficial infection in 4.1%, deep wound infection in 1.3%, bacteremia in 4.1%, superior vena cava syndrome in 3 (1.3%) and chylothorax in 2 of them (0.9%). 1 patient (0.45%) required a ventricle-peritoneal shunt after acute viral meningitis. We are encouraged by our results to offer early complete correction to all children with congenital heart disease.

Child↗
PubMed1998

Analyses of coronary graft patency after aprotinin use: results from the International Multicenter Aprotinin Graft Patency Experience (IMAGE) trial.

OBJECTIVE: We examined the effects of aprotinin on graft patency, prevalence of myocardial infarction, and blood loss in patients undergoing primary coronary surgery with cardiopulmonary bypass. METHODS: Patients from 13 international sites were randomized to receive intraoperative aprotinin (n = 436) or placebo (n = 434). Graft angiography was obtained a mean of 10.8 days after the operation. Electrocardiograms, cardiac enzymes, and blood loss and replacement were evaluated. RESULTS: In 796 assessable patients, aprotinin reduced thoracic drainage volume by 43% (P < .0001) and requirement for red blood cell administration by 49% (P < .0001). Among 703 patients with assessable saphenous vein grafts, occlusions occurred in 15.4% of aprotinin-treated patients and 10.9% of patients receiving placebo (P = .03). After we had adjusted for risk factors associated with vein graft occlusion, the aprotinin versus placebo risk ratio decreased from 1.7 to 1.05 (90% confidence interval, 0.6 to 1.8). These factors included female gender, lack of prior aspirin therapy, small and poor distal vessel quality, and possibly use of aprotinin-treated blood as excised vein perfusate. At United States sites, patients had characteristics more favorable for graft patency, and occlusions occurred in 9.4% of the aprotinin group and 9.5% of the placebo group (P = .72). At Danish and Israeli sites, where patients had more adverse characteristics, occlusions occurred in 23.0% of aprotinin- and 12.4% of placebo-treated patients (P = .01). Aprotinin did not affect the occurrence of myocardial infarction (aprotinin: 2.9%; placebo: 3.8%) or mortality (aprotinin: 1.4%; placebo: 1.6%). CONCLUSIONS: In this study, the probability of early vein graft occlusion was increased by aprotinin, but this outcome was promoted by multiple risk factors for graft occlusion.

Adult↗
PubMed1997

[Prosthetic heart valve thrombosis: a 3-year experience].

A series of 12 patients with 16 episodes of prosthetic heart-valve thrombosis over 3 years is presented. Most episodes affected mitral or tricuspid bileaflet prostheses. All patients were inadequately anticoagulated at the time of thrombosis. The clinical presentation was acute and severe in 6 patients, and subacute or chronic in the rest. Physical examination was suggestive of stuck valves in most cases. Transthoracic echocardiography revealed increased transvalvular gradients in most. However, clearer evidence of valve thrombosis was obtained from transesophageal echocardiography or fluoroscopy. 9 patients eventually had their valves re-replaced successfully, and the preoperative diagnosis was confirmed in all. 5 patients were operated as soon as the diagnosis was established. and an additional 4 were operated after failure of anticoagulation. In 4 patients the valve leaflets became completely mobile after a course of thrombolysis. Prosthetic valve thrombosis is a severe and potentially fatal complication in patients with mechanical heart valves. Alertness of physicians at all levels- the general practitioner, the internist and the cardiologist- to the possibility of valve thrombosis and to its clinical presentation may lead to prompt and earlier diagnosis and to comprehensive therapy.

Adolescent↗
PubMed1995

Repeated repair of tetralogy of Fallot. Report of 11 cases and review of the literature.

Eleven patients underwent late repeated correction of tetralogy of Fallot in 1991-1993. The previous operation was repair of simple Fallot's tetralogy in seven cases, repair plus transannular patch in one case and repair of tetralogy and pulmonic atresia in three cases. The indications for reoperation were residual ventricular septal defect, right ventricular outflow tract (R.V.O.T.) obstraction, residual branch pulmonary artery stenosis, aneurysmal dilatation of R.V.O.T. Patch or combination of any of the above. At reoperation these defects were corrected. The post operative course was uneventful in eight patients. Two required mechanical ventilation for 2-3 days, and one underwent another operation for residual branch pulmonary artery stenosis. The functional and haemodynamic results were good in ten patients, and one had residual distal pulmonary artery stenosis. There were no death during 2 years of follow-up. Repeated correction of tetralogy of Fallot thus had low postoperative morbidity and good haemodynamic results. For the relatively few patients initially found to have tetralogy of Fallot and pulmonic atresia, the outcome may be less favorable.

Anastomosis, Surgical↗
PubMed1995

Definitive repair of tetralogy of fallot. A review of 104 cases.

Definitive repair of tetralogy of Fallot was performed on 104 children, including 42 younger than 2 years (24 < 1 year and 7 < 6 months). Twenty-two had previous shunt. Transannular patching was required in 60 cases and conduit grafts in two. During 60-day postoperative observation, five patients died. Of the 99 survivors, 93 recovered without complications, three required prolonged mechanical ventilation, two reoperation and one balloon dilatation for residual left pulmonary artery stenosis. Morbidity and mortality were not significantly higher in the patients younger than 12 months, although transannular patching was more common in that age group. Previous shunt operations entailed higher prevalence of distal stenosis and distortion of the pulmonary arteries, which often necessitated surgical repair, and also considerably increased postoperative morbidity and mortality. As the outcome in definitive repair of Fallot's tetralogy is favourable, even in patients younger than 12 months, and as preliminary shunt operations are associated with heightened perioperative morbidity and mortality rates in definitive repair, we advocate the definitive operation for all young patients with severe cyanosis or cyanotic spells.

Adolescent↗
PubMed1994

Ro 5-4864 has a negative inotropic effect on human atrial muscle strips that is not antagonized by PK 11195.

The effects of Ro 5-4864, a peripheral benzodiazepine receptor agonist (9 x 10(-6) M and 9 x 10(-5) M) and of PK 11195, a peripheral benzodiazepine receptor antagonist (3 x 10(-6) M and 3 x 10(-5) M), alone or together, on contraction parameters of human atrial muscle strips were studied. Atrial muscle strips were obtained from patients undergoing cardiac surgery. The strips were suspended in Krebs-Henseleit solution at 36.8 +/- 0.2 degrees C, connected to an isometric force transducer and then stimulated at 15 V above threshold and paced at 1.5 Hz. Ro 5-4864 at its higher concentration, alone or mixed with PK 11195 at both concentrations, depressed the contraction amplitude to 80% of the control value (P < 0.05). In conclusion, Ro 5-4864 had a small but significant depressant effect on the contraction amplitude of human atrial strips. Surprisingly, this effect was not reversed by the peripheral benzodiazepine receptor antagonist PK 11195.

Adult↗
PubMed1993

[Warm heart surgery].

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Cardiac Surgical Procedures↗