Search PubMed⌕ Search

Biomedical subjects

Z Vered

Publications and source records attributed to Z Vered.

At least 55 records · Page 3Linked to original sources

Improved posterobasal segment function after thrombolysis is associated with decreased incidence of significant mitral regurgitation in a first inferior myocardial infarction.

OBJECTIVES: This study was designed to investigate the association between wall motion abnormalities and the occurrence of ischemic mitral regurgitation in patients with a first inferior or posterior myocardial infarction and to reassess the role of thrombolytic treatment in these patients. BACKGROUND: We previously demonstrated that thrombolytic therapy reduces the incidence of significant mitral regurgitation in patients with a first inferior myocardial infarction, but the mechanisms responsible for this decrease were not clear. METHODS: Wall motion score on two-dimensional echocardiography (16 segments) and mitral regurgitation grade (0 to 3) on Doppler color flow imaging were assessed in 95 patients (in 47 after thrombolysis) at 24 h, 7 to 10 days and 1 month after myocardial infarction. Significant mitral regurgitation was defined as moderate or severe (grade 2 or 3). RESULTS: Multivariate analysis revealed that the presence of an advanced wall motion abnormality of the posterobasal segment of the left ventricle was the most significant independent variable associated with significant mitral regurgitation: odds ratio (OR) 15.0, 90% confidence interval (CI) 1.4 to 165.6 at 24 h; OR 2.8, CI 0.9 to 9.3 at 7 to 10 days; OR 4.2, CI 1.2 to 11.4 at 1 month. Thrombolysis reduced the prevalence of advanced wall motion abnormalities in the posterobasal segment at 24 h (55% vs. 75%, OR 0.5, CI 0.2 to 0.99), 7 to 10 days (44% vs. 73%, OR 0.3, CI 0.1 to 0.7) and 1 month (36% vs. 56%, OR 0.4, CI 0.2 to 0.9). CONCLUSIONS: There is a strong association between advanced wall motion abnormalities in the posterobasal segment and significant mitral regurgitation. In this study group, thrombolysis reduced the prevalence of advanced wall motion abnormalities in the posterobasal segment and thereby reduced the incidence of significant mitral regurgitation.

Echocardiography↗

Improved left ventricular function after thiamine supplementation in patients with congestive heart failure receiving long-term furosemide therapy.

PURPOSE: We have previously found thiamine (vitamin B1) deficiency in patients with congestive heart failure (CHF) who had received long-term furosemide therapy. In the present study, we assessed the effect of thiamine repletion on thiamine status, functional capacity, and left ventricular ejection fraction (LVEF) in patients with moderate to severe CHF who had received furosemide in doses of 80 mg/d or more for at least 3 months. PATIENTS AND METHODS: Thirty patients were randomized to 1 week of double-blind inpatient therapy with either i.v. thiamine 200 mg/d or placebo (n = 15 each). All previous drugs were continued. Following discharge, all 30 patients received oral thiamine 200 mg/d as outpatients for 6 weeks. Thiamine status was determined by the erythrocyte thiamine-pyrophosphate effect (TPPE). LVEF was determined by echocardiography. RESULTS: TPPE, diuresis, and LVEF were unchanged with i.v. placebo. After i.v. thiamine, TPPE decreased (11.7% +/- 6.5% to 5.4% +/- 3.2%; P < 0.01). LVEF increased (0.28 +/- 0.11 to 0.32 +/- 0.09; P < 0.05), as did diuresis (1,731 +/- 800 mL/d to 2,389 +/- 752 mL/d; P < 0.02), and sodium excretion (84 +/- 52 mEq/d to 116 +/- 83 mEq/d, P < 0.05). In the 27 patients completing the full 7-week intervention, LVEF rose by 22% (0.27 +/- 0.10 to 0.33 +/- 0.11, P < 0.01). CONCLUSIONS: Thiamine repletion can improve left ventricular function and biochemical evidence of thiamine deficiency in some patients with moderate-to-severe CHF who are receiving longterm furosemide therapy.

Aged↗

Echocardiographic assessment of prosthetic valve endocarditis.

Prosthetic valve endocarditis is still a very serious complication, carrying an incidence of death between 30 and 70% in some series. Therefore early and accurate diagnosis is crucial. Early (less than 60 days post surgery) endocarditis is usually a fulminant disease, where staphylococcal infection is most common. Late prosthetic endocarditis resembles more closely other forms of the disease. Conventional echocardiography is useful in the evaluation of prosthetic valve function, but it is very limited in the demonstration of infective lesions, primarily because of acoustic shadowing. Transoesophageal echocardiography (TE) enables high resolution imaging of the heart without chest wall interference, and viewing of the heart from the posterior (atrial, low pressure) side, where most of the vegetations are expected to be found in both mitral and tricuspid positions. It also enables better visualization of the left ventricular outflow tract, where aortic prosthetic vegetations tend to be present. Furthermore, transoesophageal echocardiography allows accurate diagnosis of some of the common complications of endocarditis: abscess/cavity formation; mycotic aneurysm; prosthetic valve dehiscence and regurgitation. In spite of these advantages, limitations should be recognized. Struts are commonly seen on transoesophageal echocardiography following surgery and should not be confused with vegetations. Similarly, normal prosthetic regurgitation should not be confused with paravalvar leakage. Nevertheless, transoesophageal echocardiography, when expertly used, changes the possibility for early and more accurate diagnosis of prosthetic valve endocarditis dramatically. Transoesophageal echocardiography should be included among the major criteria in the diagnosis and follow-up of prosthetic valve endocarditis.

Adult↗

Exogenous insulin-like growth factor II enhances post-infarction regional myocardial function in swine.

OBJECTIVES: Insulin-like growth factor II (IGF-II) promotes cardiac myocyte growth and contractility in vitro. This study was designed to investigate the effect of exogenous IGF-II on regional myocardial function at the area of infarct in the pig. METHODS: Myocardial infarction was induced in 12 female anaesthetized pigs by affigel blue beads, embolizing microvessels of the left anterior descending coronary artery distribution. In the experimental group (n = 6), IGF-II (0.12 microgram.kg-1 in two animals and 0.6 microgram.kg-1 in four) was incorporated into the beads and delivered by them to the infarct area. Myocardial function was followed echocardiographically, and the excised heart was analysed immunohistochemically and histopathologically. RESULTS: Myocardial function in injured zones, inversely related to an echocardiographic segmental wall motion score (mean +/- SEM), was similar between the two groups at baseline, but at 4 weeks post-infarction was significantly (P = 0.008) reduced in the control group (0.58 +/- 0.38 vs 3.42 +/- 0.84), in contrast to nearly baseline values in the experimental group (0.58 +/- 0.33 vs 1.17 +/- 0.42, P = 0.41). Cardiac performance in injured segments was significantly better after myocardial injury in the experimental group (P = 0.04). Tissue samples from both groups (4 weeks post-infarction), stained with haematoxylin and eosin demonstrated peri-infarct myocyte hypertrophy, corresponding to regions selectively stained by an antibody for CD56, which highlights growing cardiac myocytes. By image analysis semi-quantification, staining for CD56 was significantly (P = 0.04) higher in the peri-infarct region of the experimental group, as compared with controls (106.5 +/- 2.8 vs 92 +/- 4.4 gray level units). Microvessels stained for von-Willebrand factor were similar in number in both groups (P = 0.8), as were mesenchymal cells stained for vimentin (P = 0.7). CONCLUSIONS: Exogenous IGF-II, delivered to the infarct area ameliorates regional cardiac function in the pig, perhaps by inducing peri-infarct myocyte growth.

Animals↗

Percutaneous balloon pericardiostomy for treatment of cardiac tamponade.

Percutaneous balloon pericardiostomy was performed in eight severely ill patients with malignancy (seven patients) and chronic renal failure (one patient). To investigate the feasibility of balloon pericardiostomy as a bedside procedure, echocardiography was used in addition to fluoroscopy in monitoring the procedure. The pericardium was entered from the standard subxiphoid site. An 18 to 25 mm, 3 or 4 cm long, balloon catheter, introduced over a stiff guidewire was inflated across the parietal pericardium. Creation of a pericardial opening was obtained in each of the eight patients. Bleeding from the needle entry site was the only complication observed in one patient. The balloon catheter could be localized by echocardiography only in 2/8 cases. Two patients died, 3 and 14 days after the procedure, from the primary disease; six patients were still alive at follow-up ranging from 32 to 342 days. No recurrence of cardiac tamponade was observed in any patient. Percutaneous balloon pericardiostomy is efficacious and safe in relieving pericardial tamponade and preventing its recurrence in severely ill patients. Fluoroscopy is needed to monitor the procedure. The value of echocardiography is limited for follow-up controls of pericardial effusion.

Adult↗

Alteration of lipid profile in hyperlipidemic rabbits by allicin, an active constituent of garlic.

BACKGROUND: The effect of garlic on the serum lipid profile has been the subject of controversy. This study was therefore designed to examine the effects of allicin, an active constituent of garlic, on the lipid profile in a rabbit model. METHODS: Allicin was produced by reacting alliin, synthesized in our laboratory, with purified alliinase. Nineteen New Zealand White rabbits were fed a cholesterol-rich diet (0.25% cholesterol) for 18 weeks. Ten rabbits received freshly produced allicin (3 mg/kg orally) starting at 8 weeks, and nine received placebo. There was no significant difference between the lipid profiles of the two groups at baseline up to 8 weeks. RESULTS: From day 28 of allicin supplementation a significant difference was found between the allicin and placebo groups in the graph regression lines describing the influence of allicin on serum cholesterol: Y = 41.39 + 8.69 multiplied by day (control) versus Y = -877.24 + 17.67 multiplied by day (allicin). The same trend was found for low-density lipoprotein concentrations: Y = 10.3 + 8.4 multiplied by (control) versus Y = -750.4 + 15.7 multiplied by day (allicin). The serum high-density lipoprotein levels also differed significantly between the groups: Y = 20.29 + 0.24 multiplied by day (control) versus Y = -109.9 + 1.65 multiplied by day (allicin). CONCLUSIONS: Our results indicate that allicin has a beneficial effect on the serum lipid profile in hyperlipidemic rabbits, and should be further tested clinically.

Animals↗

[Atrial septal aneurysm and paroxysmal atrial fibrillation].

A 48-year-old man was admitted because of treatment-resistant, paroxysmal atrial fibrillation. Transthoracic, 2-dimensional echocardiography revealed a "mass" within the left atrium, thought to be a tumor. Transesophageal echocardiography showed it to be an atrial septal aneurysm. There is a relationship between atrial septal aneurysm and atrial supraventricular tachyarrhythmias and systemic emboli.

Atrial Fibrillation↗

Absence of tachycardia during tilt test predicts failure of beta-blocker therapy in patients with neurocardiogenic syncope.

Not all patients with neurocardiogenic syncope respond to beta-blockers. To determine whether differences in heart rate response to head-up tilt test with and without isoproterenol may predict drug efficacy, we evaluated 32 consecutive patients with a history of syncope, who were treated with beta-blockers after a positive tilt test. During the tilt test 21 patients (group A) with a baseline heart rate of 72 +/- 15 beats/min had tachycardia (mean 131 +/- 15) during tilt, before syncope, whereas 11 patients (group B) with a baseline heart rate of 68 +/- 13 beats/min did not (mean 86 +/- 13; p < 0.001). There were no significant differences between groups with regard to demographic and clinical characteristics or mean heart rate and mean arterial pressure in the supine position and during syncope. However, the proportion of patients requiring isoproterenol for provocation of syncope was significantly higher in group A compared with group B (15 of 21 vs 1 of 11; p < 0.001). All patients were treated with beta-blockers (propranolol or metoprolol). During a follow-up period of 18 +/- 6 months only one patient in group A had syncope and a positive tilt test compared with six patients in group B (9% vs 54%; p < 0.01). Development of tachycardia was a better predictor of drug efficacy than an isoproterenol-induced positive tilt test. The six nonresponders from group B were subsequently treated with disopyramide. During a mean follow-up period of 9 +/- 3 months, only one patient had syncope and another had a positive response to tilt test.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Antagonists↗

The value of dobutamine stress echocardiography in evaluation of patients after the first uncomplicated acute myocardial infarction.

UNLABELLED: Dobutamine stress echocardiography (DSE) is an already established method to investigate coronary artery disease (CAD). We performed a regional wall motion score based on the DSE test in a group of 36 consecutive patients (24 men and 7 women; mean age 57 years) 19 of whom were treated with thrombolytic agents a week after a first uncomplicated myocardial infarction and compared the results with a submaximal exercise test--regarding symptoms compatible with myocardial ischemia, test duration, peak heart rate, systolic blood pressure, ECG changes and arrhythmias. Seventeen of these patients underwent coronary angiography and the results were compared with the DSE score. In total, 576 myocardial segments were analyzed according to coronary artery distribution. Except for 2 patients, we found a good correlation between mean wall motion abnormalities and significant angiographic findings. No complications occurred during DSE. IN CONCLUSION: predischarge DSE after a first acute myocardial infarction (AMI) is a safe and useful method to investigate the severity of CAD. These preliminary results indicate that DSE is an important contribution to the evaluation of patients after AMI.

Adult↗

Persistence of normal right ventricular Doppler filling pattern early after tricuspid valve excision.

Two patients with acute tricuspid bacterial endocarditis in which a normal right ventricular Doppler filling pattern was demonstrated early following valvectomy are reported. After surgery, on pulsed Doppler examination, the sample volume positioned at the right atrioventricular level revealed a normal M-shaped filling pattern. A pathologic monophasic pattern was documented a few months later. Our findings suggest that early after surgery the preserved gradient throughout ventricular diastole leads to a passive and active filling similar to normal. Only at a later stage is the grossly dilated right atrium unable to maintain active filling, and the 'A' wave disappears despite the fact that sinus rhythm is maintained. Tricuspid valve diastolic motion represents a product of the several factors that determine atrioventricular gradient, but the valve itself appears not to be involved in the generation of a normal filling pattern.

Acute Disease↗

Does external ultrasound accelerate thrombolysis? Results from a rabbit model.

BACKGROUND: Prior in vitro and in vivo studies have reported that external ultrasound accelerates thrombolysis at intensities too low to have a direct effect on clot dissolution in the absence of a thrombolytic agent. The present study was undertaken to examine the ultrasound effect on thrombolysis and reocclusion in a rabbit thrombosis model. METHODS AND RESULTS: Blood clots were produced in a femoral artery segment with endothelial damage and distal stenosis. Recombinant tissue-type plasminogen activator (rTPA) was infused at 30 micrograms.kg-1.min-1 for 60 minutes. Femoral artery flow was measured every 5 minutes for 2 hours. Rabbits were randomized to four groups with continuous wave ultrasound on or off with or without intravenous injection of 17 mg/kg aspirin (+US/-US/+Asp/-Asp). Ultrasound frequency and intensity were 1 MHz and 6.3 W/cm2. In seven of eight and five of five rabbits given rTPA and -US/-Asp or -US/+Asp, respectively, reflow was observed, persisting to the end of the observation period. In five of nine and four of five rabbits given rTPA and +US/-Asp or +US/+Asp, reflow was achieved, but persistent reocclusion was subsequently observed in five of five and two of four of these rabbits, respectively. Overall, femoral artery patency was worse and reocclusion occurred more often when ultrasound was added to rTPA (P = .002 by nonparametric ANOVA). However, initial reflow occurred more rapidly with ultrasound exposure (21 +/- 10 and 33 +/- 6 minutes for the +US/+Asp and +US/-Asp groups, respectively) compared with without ultrasound (46 +/- 13 and 74 +/- 14 minutes for the -US/+Asp and -US/-Asp groups, respectively) (P = .03 by ANOVA). CONCLUSIONS: Although time to initial reflow was shortened by ultrasound, it was associated with less reperfusion and more reocclusion in this model. A possible explanation for these results is ultrasound-induced platelet activation counterbalancing its thrombolysis-accelerating effect.

Animals↗

Left ventricular pseudohypertrophy in cardiac tamponade: an echocardiographic study in a canine model.

OBJECTIVES: This study was designed to establish whether left ventricular pseudohypertrophy in cardiac tamponade can be reproducibly induced in an experimental canine model and to investigate the mechanism of its production. BACKGROUND: Past experimental and clinical studies have shown reduction of ventricular volumes resulting from cardiac tamponade. Left ventricular pseudohypertrophy, a transient thickening of myocardial walls, was recently described as a new echocardiographic sign of cardiac tamponade. METHODS: Cardiac tamponade was induced in seven anesthetized open chest dogs with serial bolus injections of 50 ml each of 0.9% saline solution into the pericardial sac. Under hemodynamic monitoring, M-mode and two-dimensional echocardiographic measurements were performed from a right parasternal window at each stage of graded cardiac tamponade. RESULTS: There was a progressive increase of interventricular septal and posterior wall diastolic thickness. Mean wall thickness (interventricular septal thickness + posterior wall thickness divided by 2) was 9.8 +/- 1.3 mm at baseline, 14.3 +/- 0.9 mm at peak tamponade and 9.0 +/- 1.5 mm after fluid withdrawal (p < 0.0001). Mean wall thickness correlated directly with the severity of cardiac tamponade, as estimated from the level of right arterial pressures (r = 0.75 and p < 0.0001), and with the decrease of left ventricular cavity volume (r = -0.67 and p < 0.0001). Left ventricular mass did not change significantly. CONCLUSIONS: Left ventricular pseudohypertrophy is a constant manifestation of cardiac tamponade in a canine model. The degree of myocardial thickening correlates with the reduction of ventricular dimensions and with the severity of hemodynamic compromise, representing a constant facet of heart remodeling in cardiac tamponade.

Animals↗

Effect of thrombolytic therapy on the evolution of significant mitral regurgitation in patients with a first inferior myocardial infarction.

OBJECTIVES: This study was designed to test the hypothesis that reperfusion therapy with thrombolysis will prevent the development of significant mitral regurgitation in patients with inferior myocardial infarction. BACKGROUND: The value of thrombolytic therapy in patients with inferior or posterior wall myocardial infarction has been controversial. We hypothesized that successful reperfusion therapy with intravenous thrombolysis may reduce the incidence and severity of postinfarction mitral regurgitation in this patient group. METHODS: We prospectively studied 104 patients with a first inferior myocardial infarction. Thrombolytic therapy was administered to 55 patients (treatment group) 3.2 +/- 2.1 h after the onset of symptoms. The other 49 patients formed the control group. Doppler echocardiographic color flow imaging was performed in all patients within 24 h, at 7 to 10 days and at 28 to 30 days after myocardial infarction. Significant mitral regurgitation was defined as moderate or severe (grade 2 or 3). RESULTS: No significant differences in baseline clinical characteristics were observed between the treatment and control groups. The overall incidence rates of significant mitral regurgitation at 24 h, 7 to 10 days and at 28 to 30 days were 10 (10%) of 104 patients, 18 (17%) of 104 patients and 11 (11%) of 100 patients, respectively. Multivariate analysis reveals the following independent predictors of the occurrence of significant mitral regurgitation: female gender (at 7 to 10 days, odds ratio 5.3, 90% confidence interval [CI] 1.8 to 15.5; at 28 to 30 days, odds ratio 3.7, 90% CI 1.1 to 12.7), heart failure (at 7 to 10 days, odds ratio 7.7, 90% CI 2.2 to 26.9) and transient complete atrioventricular block (at 24 h of myocardial infarction, odds ratio 5.8, 90% CI 1.2 to 27). Compared with the control group, the treatment group exhibited marked reduction in the incidence of significant mitral regurgitation at 24 h (16% vs. 4%; odds ratio 0.1, 90% CI 0.0 to 0.7); at 7 to 10 days (24% vs. 11%; odds ratio 0.3, 90% CI 0.1 to 0.9) and at 28 to 30 days (15% vs. 7%; odds ratio 0.4, 90% CI 0.1 to 1.6). Severe (grade 3) mitral regurgitation developed in five patients in the control group but in no patient in the treatment group. CONCLUSIONS: Thrombolytic therapy in the patients with a first inferior myocardial infarction was associated with a reduced incidence of significant mitral regurgitation. These results support the use of such therapy in patients with inferior myocardial infarction.

Aged↗

Intracoronary injection of basic fibroblast growth factor enhances angiogenesis in infarcted swine myocardium.

OBJECTIVES: This study was performed to examine the effect of intracoronary exogenous basic fibroblast growth factor (bFGF) on angiogenesis in infarcted myocardial regions. BACKGROUND: Exogenous bFGF is a potent promoter of angiogenesis. Little information is available on its effect on myocardial angiogenesis. METHODS: Myocardial infarction was induced in 10 pigs by intracoronary injection of microscopic beads. Four pigs served as a control group; in six pigs slow-release bFGF was delivered by the beads. Cardiac performance was evaluated by repeated echocardiographic measurement and angiogenesis was evaluated by immunohistochemical studies 14 days later. RESULTS: As compared with control pigs, pigs treated with bFGF had higher microvessel counts (mean +/- SEM) in both viable tissue (141 +/- 27 per field vs. 39 +/- 4, p = 0.01) and nonviable tissue (329 +/- 26 per field vs. 95 +/- 7, p < 0.001) within the infarct area. No significant differences in total regional left ventricular wall motion were noted between the two groups throughout the 14-day study period. CONCLUSIONS: In the swine, direct intracoronary application of bFGF to infarcted myocardium enhances myocardial neovascularization within 2 weeks.

Animals↗

Reversible catecholamine-induced cardiomyopathy presenting as acute pulmonary edema in a patient with pheochromocytoma.

Cardiac injury caused by elevated levels of circulating catecholamines is a well-known phenomenon. We report a patient who, secondary to transient regional left ventricular dysfunction (despite normal coronary arteries), developed acute pulmonary edema. Echocardiography showed marked anteroapical hypokinesia and an apical thrombus. The diagnosis of pheochromocytoma was made by plasma catecholamine levels, abdominal ultrasound and finally at operation. The patient recovered completely long before surgical intervention was undertaken.

Adrenal Gland Neoplasms↗

From swirling to a mobile, pedunculated mass--the evolution of left ventricular thrombus despite full anticoagulation. Echocardiographic demonstration.

We describe the unusual evolution of a left ventricular thrombus following acute anterior myocardial infarction despite adequate anticoagulation. Serial echocardiographic examinations demonstrated the evolution from swirling in the left ventricle through a solid apical mass gradually dislodging into a mobile, pedunculated mass that was removed surgically to prevent embolization. This report emphasizes the need to follow echocardiographically left ventricular thrombi during treatment with anticoagulants, and to identify morphologic changes that may predict embolization. This case suggests that left ventricular thrombectomy should be considered in selected patients in whom a very high-risk thrombus morphology is detected.

Anticoagulants↗