Biomedical subjects

B Munt

Publications and source records attributed to B Munt.

15 recordsLinked to original sources

PubMed2006

Treating the right patient at the right time: Access to echocardiography in Canada.

The Canadian Cardiovascular Society is the national professional society for cardiovascular specialists and researchers in Canada. In the spring of 2004, the Canadian Cardiovascular Society Council formed the Access to Care Working Group ('Working Group') to use the best science and information available to establish reasonable triage categories and safe wait times for access to common cardiovascular procedures. The Working Group decided to publish a series of commentaries to initiate a structured national discussion on this important issue, and the present commentary proposes recommended wait times for access to echocardiography. 'Emergent' echocardiograms should be performed within 24 h, 'urgent' within seven days and 'scheduled' (elective) within 30 days. A framework for a solution-oriented approach to improve access is presented.

Canada↗

PubMed2005

Percutaneous valve repair and replacement techniques.

Valvular heart disease is a significant cause of morbidity and mortality. Rates increase with age and the prevalence will increase as the population ages. Several factors have led to an interest in expanding percutaneous valve repair and replacement techniques to more lesions in more patients. This review explores current percutaneous valve repair and replacement techniques in mitral stenosis, mitral regurgitation, aortic stenosis and aortic regurgitation in adults, outlines the future directions, and discusses some technique-related issues.

Endoscopy↗

PubMed2002

Failure of resting echocardiography and cardiac catheterization to identify pulmonary hypertension in two patients with type I Gaucher disease.

Pulmonary hypertension (PHT) is a complication of Gaucher disease. Screening with echocardiography is recommended for Gaucher patients. Two patients naive to enzyme replacement therapy are presented in whom resting echocardiography revealed no evidence of PHT. One of the patients also had normal pulmonary artery pressures at cardiac catheterization. The diagnosis of PHT was made with open lung biopsy in one patient and dobutamine echocardiography in the other. In both cases, diagnosis of PHT altered patient management. Resting echocardiographic assessment may fail to identify PHT in patients with Gaucher disease.

Adult↗

PubMed2000

Three-dimensional echocardiographic assessment of annular shape changes in the normal and regurgitant mitral valve.

OBJECTIVES: To compare mitral annular shape and motion throughout the cardiac cycle in patients with normal hearts versus those with functional mitral regurgitation (FMR). BACKGROUND: The causes of mitral regurgitation without valvular disease are unclear, but the condition is associated with changes in annular shape and dynamics. Three-dimensional (3D) imaging provides a more comprehensive view of annular structure and allows accurate reconstructions at high spatial and temporal resolution. METHODS: Nine normal subjects and 8 patients with FMR undergoing surgery underwent rotationally scanned transesophageal echocardiography. At every video frame of 1 sinus beat, the mitral annulus was manually traced and reconstructed in 3D by Fourier series. Annular projected area, nonplanarity, eccentricity, perimeter length, and interpeak and intervalley spans were determined at 10 time points in systole and 10 points in diastole. RESULTS: The mitral annulus in patients with FMR had a larger area, perimeter, and interpeak span than in normal subjects (P <.001 for all). At mid-systole in normal annuli, area and perimeter reach a minimum, nonplanarity is greatest, and projected shape is least circular. These cyclic variations were not significant in patients with FMR. Annular area change closely paralleled perimeter change in all patients (mean r = 0.96 +/- 0.07). CONCLUSIONS: FMR is associated with annular dilation and reduced cyclic variation in annular shape and area. Normal mitral valve function may depend on normal annular 3D shape and dimensions as well as annular plasticity. These observations may have implications for design and selection of mitral annular prostheses.

Adult↗

PubMed2000

Mesalamine-induced chest pain: a case report.

Cardiac side effects of mesalamine are uncommon. A young man with ulcerative colitis who developed recurrent chest pain and electrocardiographic changes while on mesalamine is presented. Various causes of mesalamine-induced chest pain are discussed.

Adult↗

PubMed2000

Transient obstruction of the mitral valve by a massive thrombus complicating percutaneous valvuloplasty.

Percutaneous transseptal mitral valvuloplasty was attempted in a patient with severe rheumatic mitral stenosis. Introduction of the balloon into the left atrium resulted in thrombotic occlusion of the mitral valve. Circulatory arrest ensued. The thrombus was disrupted during cardiopulmonary resuscitation. Thrombolysis was administered and the patient recovered uneventfully.

Anticoagulants↗

PubMed1999

Physical examination in valvular aortic stenosis: correlation with stenosis severity and prediction of clinical outcome.

BACKGROUND AND METHODS: The goal of this study was to examine the ability of physical examination to predict valvular aortic stenosis severity and clinical outcome in 123 initially asymptomatic subjects (mean age 63 +/- 16 years, 70% men) followed up for a mean of 2.5 +/- 1.4 years. RESULTS: Doppler aortic jet velocity correlated with systolic murmur intensity (P =.003) and timing (P =.0002), a single second heart sound (P =.01), and carotid upstroke delay (P <.0001) and amplitude (P <.0001). However, no physical examination findings had both a high sensitivity and a high specificity for the diagnosis of severe valvular obstruction. Clinical end points were reached in 56 subjects (46%), including 8 deaths and 48 valve replacements for symptom onset. Univariate predictors of outcome included carotid upstroke delay (P =.0008) and amplitude (P =.0006), systolic murmur grade (P <.0001) and peak (P =.0003), and a single second heart sound (P =.003). On multivariate Cox regression analysis, the only physical examination predictor of outcome was carotid upstroke amplitude (P =.0001). CONCLUSIONS: Although physical examination findings correlate with stenosis severity, echocardiography still is needed to exclude severe obstruction reliably when this diagnosis is suspected.

Aortic Valve Stenosis↗

PubMed1998

Diastolic filling in human severe sepsis: an echocardiographic study.

OBJECTIVE: To determine if nonsurvivors have a more abnormal pattern of left ventricular relaxation than survivors with severe sepsis. DESIGN: Prospective, observational, cohort study. SETTING: Intensive care unit in a university-affiliated tertiary care hospital. PATIENTS: Twenty-four adults with severe sepsis. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Baseline clinical and hemodynamic variables, Acute Physiology and Chronic Health Evaluation (APACHE) II scores and Doppler echocardiographic mitral inflow pattern (analyzed for normalized peak early filling rate [E/VTI, systolic volumes/sec], deceleration time [msec], and early to atrial filling velocity ratio [E/A]). There were seven deaths. The patients did not differ in baseline demographics, inotropic infusions, hemodynamic measurements or ventilatory settings or variables. Nonsurvivors had a more abnormal pattern of left ventricular relaxation (E/VTI, 4.7 [range 3.8 to 5.8] vs. 5.8 [range 3.8 to 8.9], p= .04; deceleration time, 235 [range 209 to 367] vs. 182 [range 155 to 255], p = .002). E/A showed a nonsignificant trend in the same direction (0.9 [range 0.8 to 1.6] vs. 1.2 [range 0.7 to 1.9], p = .12). In a multivariate analysis, deceleration time (p< .004) and APACHE II score (p < .02) were the only independent predictors of mortality. CONCLUSION: Severe sepsis nonsurvivors have a more abnormal echocardiographic pattern of left ventricular relaxation than survivors.

APACHE↗

PubMed1998

Staphylococcus aureus pericarditis with tamponade complicating coronary angioplasty and stenting.

Infectious complications of coronary angioplasty and stenting are uncommon. A 70-year-old man is presented who underwent percutaneous transluminal coronary angioplasty (PTCA) and stenting of an occluded left anterior descending artery. This was complicated by Staphylococcus aureus pericarditis with tamponade. He was successfully treated with a closed drainage and antibiotics. This is the first reported case in the literature that documents purulent pericarditis and tamponade following percutaneous revascularization.

Aged↗

PubMed1997

Quantitative three-dimensional echocardiography by rapid imaging from multiple transthoracic windows: in vitro validation and initial in vivo studies.

Three-dimensional echocardiography has demonstrated superiority over two-dimensional techniques in the determination of left ventricular mass and volumes. We describe a technique based on a magnetic tracking system which provides rapid three-dimensional image acquisition from multiple acoustic windows. Interactive three-dimensional border tracking and reconstruction with a piecewise smooth subdivision model accurately reproduced phantom volume (calculated volume = 1.00 true volume - 0.6 ml, r = 1.000, standard error of the estimate = 1.3 ml), in vitro heart volume (calculated volume = 1.02 true volume - 1.3 ml, r = 1.000, standard error of the estimate = 0.4 ml), in vitro heart mass (calculated mass = 0.98 true mass + 1.4 gm, r = 0.998, standard error of the estimate = 2.5 gm), and in vivo stroke volume (calculated stroke volume = 1.18 Doppler stroke volume - 17.9 ml, r = 0.990, standard error of the estimate = 2.8 ml). The three-dimensional in vivo data sets, which include views from three acoustic windows, were acquired in less than 90 seconds. We conclude that this method of three-dimensional echocardiographic data acquisition and analysis overcomes limitations inherent in currently available systems.

Animals↗

PubMed1997

Exercise-induced left bundle branch block: a case report of false positive MIBI imaging and review of the literature.

Exercise-induced left bundle branch block is a relatively rare finding during exercise tolerance testing. A 36-year-old female with intermittent exercise-induced left bundle branch block, a MIBI study suggesting anterior ischemia and normal coronary arteries is reported. A review of the English and French language literature published from January 1985 to January 1996 is presented. Exercise-induced left bundle branch block has been reported in association with and without structural heart disease. Pooled mortality in the group with structural heart disease was 2.7% per year, and mortality was 0.17% per year when no structural heart disease was identified. Exercise-induced left bundle branch block has been reported to resolve with therapy. Noninvasive testing appears to have limited ability to detect or exclude coronary artery disease in this group. If a definitive cardiac diagnosis is required, strong consideration should be given to coronary angiography.

Adult↗

PubMed1992

Monitoring hemangioblastoma tumor burden using plasma erythropoietin levels.

We report a 39-year-old female patient with a hepatic hemangioblastoma, polycythemia and elevated plasma erythropoietin (Epo) levels. Following orthotopic liver transplantation (OLTx), her plasma Epo levels and hematocrit normalized but began to rise several months later. This rise correlated with the appearance of multiple lung metastases. The tumor was implicated as the source of excess Epo production using Northern analysis of a resected metastatic lung nodule. Based on our results, the measurement of plasma Epo levels in patients with Epo secreting tumors could be of general utility in assessing tumor burden.

Adult↗

PubMed1992

Ten year survival of a patient with advanced pulmonary hypertension and mixed connective tissue disease treated with immunosuppressive therapy.

Pulmonary hypertension is the most frequent cause of death in patients with mixed connective tissue disease. The pulmonary hypertension is progressive and difficult to treat effectively. These patients experience considerable morbidity secondary to diminished cardiac function. We describe a case in which sequential administration of cyclophosphamide and cyclosporine A favorably altered the clinical and hemodynamic course of this serious complication.

Adult↗

PubMed1985

A method for quantitating nanogram amounts of soluble protein using the principle of silver binding.

A highly sensitive and quantitative assay for measuring protein in solution based on the capacity of protein to bind silver is described. In this procedure, protein samples are first treated with glutaraldehyde and then exposed to ammoniacal silver. After 10 min, the reaction is terminated by the addition of sodium thiosulfate and the optical density measured at 420 nm. The useful range of the assay for the majority of standard proteins tested lies between 15 and 2000 ng. This represents a 100-fold increase in sensitivity over the Coomassie brilliant blue dye-binding procedure. There is little or no interference from carbohydrates, nonionic detergents, or ethanol, and pretreatment of protein samples with Bio-Gel P-2 to remove salts, thiol agents, EDTA, and sodium dodecyl sulfate makes this procedure compatible with most commonly used buffers. The cost in terms of silver utilization is nominal with a typical assay involving 10 samples tested in triplicate amounting to less than $0.02 U. S.

Animals↗

PubMed1983

Cholesterol levels in the blood of Atlantic salmonids.

Total cholesterol and high density lipids (HDL) were measured in the blood of Atlantic salmon (Salmo salar), brook trout (Salvelinus fontinalis) and rainbow trout (Salmo gairdneri) from a variety of dietary and environmental regimes. At spawning the total cholesterol of cage reared S. salar was high compared to sea ranched S. salar. Starvation of S. salar in freshwater for 6-11 months depressed total blood cholesterol levels, but not to unusually low levels. A cholesterol supplement of 0.02 g/100 g body weight to a chow diet of 0.38 g/100 g body weight had no significant effect on the total blood cholesterol level in Salvelinus fontinalis. The high proportion of HDL in the blood of S. salar is discussed in terms of its possible importance during the atherosclerotic lesion formation that normally accompanies spawning in these salmon.

Animals↗