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Biomedical subjects

B Vidne

Publications and source records attributed to B Vidne.

At least 55 records · Page 3Linked to original sources
PubMed1993

Giant left main pseudoaneurysm obstructing the left anterior descending coronary artery demonstrated by transesophageal echocardiography and coronary angiography.

Left main pseudoaneurysm is a rare angiographic finding in young adults. We describe a 23-year-old male who presented with an acute anterior wall myocardial infarction. Coronary angiography and transesophageal echocardiography reveal a huge aneurysm of the distal left main obstructing the left anterior descending artery (LAD), which was defined by history as a pseudoaneurysm. The pseudoaneurysm was successfully resected and mammary artery was used to repair the distal left main and to bypass the LAD.

Adult↗
PubMed1993

The effect of vitamin D3 deficiency on the isolated chick heart: hemodynamic, P-31 NMR and membrane studies.

The purpose of this study was to investigate whether vitamin D3 deficiency affects the cardiac function of chick hearts directly or whether the influence is secondary through the hormone's effect on serum calcium levels. To this end, three experimental groups were studied: (a) the control group of vitamin D3 supplemented chicks, Ds, (b) vitamin D3 deficient chicks, Dd, and (c) vitamin D3 supplemented hypocalcemic chicks raised on decreased calcium levels, Dh. The three groups were compared by checking hemodynamic, metabolic and membrane parameters. Total and ionized serum calcium concentrations in the Dh and Dd groups were found to be lower than in the Ds group. Perfusion of the isolated hearts with solutions containing various calcium concentrations (1, 1.5 and 2.5 mM) induced enhanced contractility levels, the magnitude of which was dependent on the difference between the in vivo and perfusate calcium levels. Thus, the inotropic effect was similar and more enhanced for the two hypocalcemic groups. The differences in hemodynamic behaviour could not be explained by variations in the levels of the high energy compounds and acidity, since similar ATP, creatine phosphate and intracellular pH levels were detected for both Ds and Dd groups. However, membrane studies revealed an increase in the number of slow calcium channels for the two hypocalcemic groups and this may be the possible mechanism for the differences in the contractile activity. In conclusion, our study strongly suggests that the effects of vitamin D3 on the heart is mediated only indirectly through its effect on serum calcium levels.

Animals↗
PubMed1992

The effects of halothane, enflurane and isoflurane on the isolated rat heart recovering from cardioplegic arrest.

The direct cardiac effects of volatile anesthetics following cardioplegic ischemia were investigated in isolated, paced rat hearts. In one series of experiments, the hearts were perfused with oxygenated Krebs Henseleit solution for a 15-minute stabilization period and then the effect of the volatile anesthetic was tested. In another series of experiments, after the stabilization period, the hearts were subjected to cardioplegic (KCl 20mEq/L) ischemia at 30 degrees C for 30 minutes and then the effect of the volatile anesthetic was tested. Halothane, enflurane or isoflurane was introduced to the Krebs Henseleit solution at 0.7 and 1.4 minimal alveolar concentration. All the volatile anesthetics decreased myocardial contractility in a dose dependent manner both before and after cardioplegic arrest. Halothane decreased coronary flow, while isoflurane and enflurane increased coronary flow in both the cardioplegic and non-cardioplegic hearts. The influence of the anesthetics was transient and ceased once they were withdrawn. Ischemic cardioplegia did not affect the response to volatile anesthetics.

Animals↗
PubMed1990

Cor triatriatum sinistrum: diagnosis by Doppler echocardiography.

Cor triatriatum (CTT) sinistrum is a rare, congenital left ventricular inflow anomaly. Previous reports have used cardiac angiography, two-dimensional echocardiography, transesophageal echocardiography and magnetic resonance imaging to establish the diagnosis prior to surgery. We report a case of CTT diagnosed by echocardiography whose hemodynamic significance was established by the use of pulsed wave and color Doppler techniques. Immediate surgery was recommended based on anatomical and hemodynamic parameters.

Cor Triatriatum↗
PubMed1990

Functional changes in the brainstem auditory pathways following open-heart surgery.

Measurements of the auditory brainstem responses (ABR) were used to assess the functional integrity of the brainstem auditory pathways following open-heart surgery. Recording of ABR was performed in 31 patients before and after open-heart surgery. The values of ABR measurements were compared to those of a control group of normal-hearing subjects. Postoperative aberrations in ABR were observed in 12 patients. Brainstem transmission time measured as wave I to wave V interpeak latency (I-V IPL) was prolonged in 6 patients and shortened in 8 patients. Concomitant impairment in hearing function was not present, and therefore, these changes most probably reflected a functional alteration in the neurological status of the brainstem. Possible explanations of the postoperative changes in I-V IPL are discussed, however, further studies are needed to clarify the pathogenesis of these changes. Measurement of ABR may prove to be an important adjunct in the overall assessment of the neurological status following open-heart surgery.

Adult↗
PubMed1989

Unusual drainage of the inferior caval vein in left atrial isomerism.

Two of the 26 cases of left atrial isomerism in our clinical material had an unusual drainage of the inferior caval vein. In one, the inferior caval vein crossed from left to right infradiophragmatically and then drained into the right-sided morphologically left atrium. In the second case, there was azygos continuation to both right and left superior caval veins. These variations have major surgical significance.

Child, Preschool↗
PubMed1989

The effect of colloid osmotic pressure on the survival of sheep following cardiac surgery.

The occurrence of late complications in implanted cardiac prosthetic valves has emphasized the need for the development of an animal model in which these complications are reproducible. Sheep constitute an excellent model for chronical and pathological studies of prosthetic devices. In our experience, survival of sheep following implantation of prosthetic valves is closely related to postoperative serum colloid osmotic pressure (C.O.P.). The normal range as measured in 28 healthy sheep was 16.67 +/- 0.55 mm Hg. A protocol was developed to maintain the colloid hydrostatic pressure gradient (C.H.P.G.) as close as possible to the normal physiological range, and to delay the extubation until the C.O.P. was within this range, and the C.H.P.G. greater than 7 mm Hg. Using the above protocol, a new tri-leaflet polyurethane valve was inserted into eight, five to seven month old sheep in place of the mitral and tricuspidal valves. One hour after terminating the extacorporeal circuit, the C.O.P. was measured at 13.10 +/- 0.96; but within five to six hours, it rose to 17.1 +/- 1.1. During the same period, the C.H.P.G. increased from 3.02 +/- 0.96 to 7.6 +/- 0.50 mm Hg. The postoperative period was uneventful, and all animals survived. We have thus concluded that the routine measurement and monitoring of C.O.P. constitutes a guide of great clinical importance.

Animals↗
PubMed1988

Effective technique of sternum closure in high-risk patients.

A successful technique of closing the sternum in a selected group of poor-risk patients involves the combination of a mattress suture and a fixative single-wire suture, both of 0 stainless-steel monofilament. Our technique was used on 100 high-risk patients and compared with double control groups, one consisting of 200 normal-risk patients and the second of 100 high-risk patients. We found that the incidence of wound infections was reduced to 1% with our new technique compared with 3% and 1% in the control groups (the high- and normal-risk groups, respectively). There was neither dehiscence nor mediastinitis in the study group, compared with 1% and 0.5% incidences of these complications in the controls. Also, there was no mortality in the combined-closure group compared with mortality of 0.5% and 1% in the control groups. We believe that this closure effectively strengthens the complex of bone and wire, improving the stability of the chest by giving a correct axis to the sternum. It is also cost-effective and easy to perform and does not prolong operation time.

Aged↗
PubMed1988

Effect of experimental cardioplegia methods on normal and hypertrophied rat hearts.

The purpose of this study was to evaluate whether the addition of verapamil hydrochloride to oxygenated glucose-rich cardioplegic solution would improve myocardial preservation. The Langendorff preparation of the isolated rat heart was used. Groups of normal (WKY) and hypertrophied (SHR) hearts were treated by five different cardioplegic methods and subjected to 90 or 30 minutes of ischemia at 28 degrees to 29 degrees C and reperfusion at 37 degrees C. The following cardioplegic solutions were used: Group A, cold (16 degrees C) Krebs-Henseleit (KH) glucose free only; Group B, KH with KCL (30 mEq/L) (16 degrees C); Group C, same as B with verapamil (10 microM); Group D, perfusion with oxygenated KH solution containing KCL (30 mEq/L) for 15 minutes prior to ischemia; and Group E, same as D with verapamil (10 microM). Recovery of contraction amplitude, ischemic contracture, coronary perfusate volume, the amount of creatine kinase in the coronary perfusate, heart rate, time of revival, O2 consumption, and ischemic contracture were measured. After 30 minutes of ischemia, we did not find any significant difference among the combinations tested with respect to contraction amplitude recovery. The hearts recovered fully. After 90 minutes of ischemia, we found that the best-protected groups in the normal hearts were Groups D and E. In the hypertrophied hearts, the addition of verapamil to the enhancement solution was harmful. The use of enhancement solution without verapamil prior to ischemia provided the best myocardial protection in the hypertrophied hearts.

Animals↗
PubMed1987

Surgical revascularization following failed percutaneous transluminal coronary angioplasty.

Percutaneous transluminal coronary angioplasty (PTCA) was performed on 200 patients and failed in 36, 12 of whom underwent myocardial revascularization within 3 hours after the angioplasty attempt. Elective operations were performed without complications in the other 24 cases. The 12 emergency operations were necessitated by major complications during or after PTCA, viz, coronary occlusion (6 patients) coronary dissection (2) and failed catheter passage or dilation with severe myocardial ischemia (4). Three of these 12 patients had signs of acute myocardial infarction preoperatively, and new infarction appeared postoperatively in two cases. All eight patients with ST-segment elevation preoperatively had raised levels of myocardial enzymes postoperatively, and two of them had new Q-waves. Three of the 12 patients required inotropic drugs following revascularization. There was one postoperative death. When complications arise in PTCA, emergency operation should be undertaken. When PTCA fails, but without complications, surgery can be electively performed.

Aged↗
PubMed1986

Endocarditis caused by Haemophilus aegyptius.

Endocarditis due to Haemophilus is uncommon. This is the first reported case caused by Haemophilus aegyptius. The course of the disease was complicated by pericarditis, congestive heart failure, and myocardial abscess formation. Surgical removal of the damaged aortic valve was not beneficial. The biologic properties of the organism included urea degradation, absence of indole metabolism, and absence of the enzyme ornithine decarboxylase.

Abscess↗
PubMed1986

Combined effect of glucose and verapamil in experimental cardioplegia.

In this study, we determined whether pre-ischemic enhancement of the ATP level and the addition of verapamil (a calcium blocker) to the cardioplegic solution could improve myocardial protection during cardiac arrest. Using the Langendorff preparation of the isolated rat heart plus different cardioplegic solutions, five groups of normal rat hearts and five groups of hypertrophied rat hearts were subjected to 90-minute ischemic periods at 28 degrees +/- 1 and reperfusion of 30 minutes at 37 degrees C. Group A received no cardioplegic solution; Group B received KCl, 30 mEq/L; Group C received type B perfusion with verapamil; and Group D received 15 minutes of pre-ischemic oxygenated enhancement perfusion containing KCl, 30 mEq/L, and glucose as substrate at 37 degrees C. Group E received the same perfusion as Group D, with the addition of verapamil to the enhancement perfusion. Light and E/M microscopy was performed on representative samples of left ventricular muscle. We found that pre-ischemic enhancement with KCl, glucose, and verapamil was only protective in the normal hearts after 90 minutes of ischemia. In hypertrophied hearts, the addition of verapamil to the enhancement solution was harmful. The use of pre-ischemic enhancement solution without verapamil provided the best myocardial protection after 90 minutes of ischemia in the hypertrophied hearts.

Journal Article↗
PubMed1986

Primary angiosarcoma of the heart detected by two-dimensional echocardiography.

A 24-year-old woman with a history of syncope and recurrent hemopericardium was urgently hospitalized with signs of severe right-sided heart failure. Two-dimensional echocardiography demonstrated a largedechogenic mass that compressed the right ventricle. The patient was referred for emergency surgery. A large angiosarcoma originating in the right atrium was excised, and the patient was treated with chemotherapy. The role of echocardiography in the detection of cardiac tumors is discussed.

Adult↗
PubMed1985

Haemodynamics of coronary artery-saphenous vein bypass.

The velocity distribution of a suspension of red blood cell ghosts in an idealized model of the coronary artery-saphenous vein bypass has been investigated with the aid of laser Doppler anemometry. Pulsatile flow simulated pressure variations in the ascending aorta and ghost cell velocities were determined by the Doppler shift of scattered laser light. Using four different model bypasses it was demonstrated that turbulent flow at the graft-coronary intersection can be delayed by decreasing the discontinuity in diameter between the bypass vein and coronary artery, and also by reducing the bypass vein and host coronary artery intersection angle.

Biomedical Engineering↗
PubMed1985

Familial membranous subaortic stenosis.

Familial occurrence of membranous subaortic stenosis (MSS) is described in three families. The defect was found in 2 siblings in two of these families, and in 3 siblings of the third family. The importance of early diagnosis and treatment of MSS is emphasized. We suggest early evaluation of first-degree relatives of patients with MSS for the possibility of this defect.

Adolescent↗
PubMed1984

Intermittent poppet dislodgment in a Braunwald-Cutter prosthesis: noninvasive diagnosis and successful surgical treatment.

A 65 year old patient had his mitral and aortic valves replaced with two Braunwald-Cutter prostheses in 1973. Seven years later, he presented with intermittent aortic insufficiency demonstrated by echocardiography, fluoroscopy and angiography. At emergency surgery, the occluders (poppets) of both prostheses were found within the left ventricular cavity. The valves were excised and replaced with Björk-Shiley prostheses and the patient recovered. Aortic occluder escape is rare and usually fatal. Mitral occluder escape of the Braunwald-Cutter prosthesis has not been described previously.

Aged↗