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Biomedical subjects

A S Agatston

Publications and source records attributed to A S Agatston.

At least 19 recordsLinked to original sources
PubMed2001

Effects of gender and age on the cardiac baroreceptor reflex in hypertension.

The present study examined whether alterations in the cardiac baroreceptor reflex in hypertension may be a function of constitutional differences associated with gender and age. These hypotheses were tested using a cross-sectional design that compared 20 normotensive and 21 hypertensive men and women of varying age for differences in baroreceptor reflex sensitivity and response latency for heart rate, obtained using a modified bolus phenylephrine (Oxford) method. Relative to their respective normotensive controls, baroreceptor reflex sensitivity was reduced in hypertensive men, but not in hypertensive women. Among normotensive subjects, men had greater baroreceptor reflex sensitivity than women. Independent from the effects associated with differences in blood pressure, age was not a significant predictor of reduction in baroreceptor reflex sensitivity. However, a combination of high blood pressure and older age was associated with a significant increase in baroreceptor reflex response time. In summary, gender and aging interacted with hypertension to alter two different aspects of the baroreceptor reflex. These results provide a preliminary indication that a decline in arterial baroreflex sensitivity may be more specific to hypertension in men than in women. Prolongation in baroreflex response latency in older hypertensive subjects also suggested that aging and hypertension may have a synergistic effect on cardiac parasympathetic function.

Adult↗
PubMed1998

Metastatic renal cell carcinoma invading right ventricular myocardium without caval involvement.

We examined a 56-year-old man who presented with dyspnea and lower extremity edema. A 2-D echocardiogram showed a large mass within the right ventricle which spared the right atrium and the inferior vena cava. Pathologic evaluation identified a renal cell carcinoma with sarcomatoid features. The tumor had metastasized to and invaded the right ventricular myocardium without right atrial or caval involvement. This pattern of metastases is rare and suggests that this tumor's aggressive nature contributed to the degree of myocardial invasion as well as the patient's rapid demise.

Carcinoma, Renal Cell↗
PubMed1996

Ultrafast computed tomography as a diagnostic modality in the detection of coronary artery disease: a multicenter study.

BACKGROUND: Ultrafast computed tomography (CT), by acquiring images of the proximal coronary arteries, detects coronary calcifications and has been demonstrated to be highly sensitive for the detection of coronary artery disease in many small studies. The aim of this study was to determine the relationship between ultrafast CT scanning and coronary angiography in a large number of symptomatic patients. METHODS AND RESULTS: The study population consisted of 710 patients from six participating centers. A multivariate logistic regression model was used to evaluate the individual contributions of age, number of calcified vessels, and the calcium score for the probability of angiographically significant disease. Of the 710 patients enrolled, 427 patients had significant angiographic disease, and coronary calcification was detected in 404, yielding a sensitivity of 95%. Of the 23 patients without calcifications, 19 (83%) had single-vessel disease at angiography. Of the 283 patients without angiographically significant disease, 124 had negative ultrafast CT coronary studies, for a specificity of 44%. An increasing number of vessels with calcification present on ultrafast CT was found to increase specificity for the presence of obstructive coronary artery disease in at least one vessel (P < .0001). As the log of the calcium score increases, the probability of multivessel obstructive disease increases (P < .0001). CONCLUSIONS: Ultrafast CT scanning is an noninvasive, non-exercise-dependent test with an excellent sensitivity for the detection of coronary artery disease. The presence of calcifications in multiple vessels and in younger populations correlates with higher specificities for obstructive disease, making ultrafast CT coronary scanning a very useful diagnostic test.

Adult↗
PubMed1993

Differences in prevalence and extent of coronary artery calcium detected by ultrafast computed tomography in asymptomatic men and women.

Coronary artery calcium is a marker of atherosclerosis in asymptomatic subjects. Ultrafast computed tomography (CT) can detect and quantify coronary calcium, simply and noninvasively, with greater sensitivity than can other techniques. The prevalence and extent of coronary calcium in a large population of asymptomatic men and women were measured and compared. Coronary calcium studies were performed in an asymptomatic population of 1,396 male and 502 female subjects (age range 14 to 88 years). The prevalence of calcium, and the distribution of total calcium scores (which reflect the amount of calcium present) were determined and compared for men and women at 5- and 10-year intervals. The prevalence of calcium in women was half that of men, until the age of 60 years when the difference diminished. The mean total calcium score distributions of men between the ages of 40 and 69 years were virtually identical to those of women between the ages of 50 and 79. The quantitative data obtained by Ultrafast CT showed very close agreement with autopsy studies of coronary calcium. Ultrafast CT is a sensitive technique to measure coronary calcium in both men and women. The differences in prevalence and extent of coronary calcium appear to be parallel to those observed in the clinical incidence of coronary artery disease in men and women. Ultrafast CT may have a greater impact on the treatment of women than of men, because it can be used to provide objective evidence of coronary atherosclerosis.

Adolescent↗
PubMed1993

Coronary artery diameter and coronary risk factors: a study with ultrafast computed tomography.

Coronary artery dilation has been described as an early effect of atherosclerosis. No noninvasive technique has been available to measure coronary size. In this study coronary diameters were measured in 100 asymptomatic subjects (89 men and 11 women, mean age 40 +/- 6 years) by means of ultrafast computed tomography (UFCT), with 3 mm thick ECG gated scans. Subjects without evidence of coronary calcium were studied. The diameter of the left main (LD) and right (RD) coronary arteries were measured. Total coronary diameter, TD = LD + RD, was determined, and univariate analysis was performed with respect to total, high-density lipoprotein and low-density lipoprotein cholesterol, mean blood pressure, age, body surface area, and triglycerides. Mean LD was 4.23 +/- 0.85 mm, and mean RD was 3.06 +/- 1.08 mm. TD increased with body surface area (p < 0.001). No other variable showed any significant effect on TD in this group without evidence of atherosclerosis. UFCT can be used to noninvasively measure coronary artery diameters and may be a useful technique to detect early changes of atherosclerosis in individual patients and in population studies.

Adult↗
PubMed1992

Doppler echocardiography.

In the past year, Doppler echocardiography has continued to transform the "echo laboratory" into a "cardiac imaging and hemodynamics laboratory." Evaluation of blood flow through the cardiac chambers and great vessels is moving from semiquantitative to quantitative. The potential for measuring mitral regurgitant flow more precisely has been demonstrated by evaluating the zone of flow acceleration that occurs on the left ventricular side of the mitral valve. Direct imaging of pulmonary venous return to the left atrium using transesophageal Doppler echocardiography has also allowed more precise quantification of mitral regurgitation. Left ventricular systolic function may be better quantified in patients with mitral regurgitation by calculating the ratio of the change in pressure to the change in time from the continuous wave spectrum of regurgitant flow. The practical application of transmitral flow.in evaluating diastolic function has been applied to cardiac amyloidosis.

Blood Flow Velocity↗
PubMed1991

Comparison of serial quantitative evaluation of calcified coronary artery plaque by ultrafast computed tomography in persons with and without obstructive coronary artery disease.

Coronary artery calcium indicates atherosclerosis. Ultrafast computed tomography (CT) can noninvasively visualize and quantify coronary calcium, permitting the natural history of calcified plaque to be studied. This pilot study evaluates the ability of ultrafast CT to follow the progression of calcified plaque within the coronary arteries in patients with and without obstructive coronary artery disease (CAD). Twenty-five subjects had serial ultrafast CT scans of the coronary arteries a mean of 406 days apart. Changes in the number of calcific deposits, calcified plaque area and volume, calcium density and total calcium score were measured. In the 20 patients with calcium on the first study, there were statistically significant increases in mean peak CT number, total calcified plaque volume, total calcified plaque area and total calcium score (p less than 0.0001 for all). Subjects with proved obstructive CAD (n = 10) on angiography had a 48% increase in calcified plaque volume compared with 22% in asymptomatic subjects (n = 10). Comparison of serial studies showed that smaller calcific deposits often coalesced into single larger calcific deposits. Ninety-eight percent (235 of 241) of deposits identified on the first study were accounted for on the second study. Patients with obstructive CAD had a higher number of new calcific deposits than did those in the asymptomatic group (55 vs 18, p = 0.058). Serial ultrafast CT accurately tracks the progression of coronary artery calcium. It is a useful technique for assessing changes in calcified plaque formation in both asymptomatic subjects and in patients with obstructive CAD. It may be useful for studying the natural history of CAD and the effects of intervention on the course of CAD.

Adult↗
PubMed1990

Quantification of coronary artery calcium using ultrafast computed tomography.

Ultrafast computed tomography was used to detect and quantify coronary artery calcium levels in 584 subjects (mean age 48 +/- 10 years) with (n = 109) and without (n = 475) clinical coronary artery disease. Fifty patients who underwent fluoroscopy and ultrafast computed tomography were also evaluated. Twenty contiguous 3 mm slices were obtained of the proximal coronary arteries. Total calcium scores were calculated based on the number, areas and peak Hounsfield computed tomographic numbers of the calcific lesions detected. In 88 subjects scored by two readers independently, interobserver agreement was excellent with identical total scores obtained in 70. Ultrafast computed tomography was more sensitive than fluoroscopy, detecting coronary calcium in 90% versus 52% of patients. There were significant differences (p less than 0.0001) in mean total calcium scores for those with versus those without clinical coronary artery disease by decade: 5 versus 132, age 30 to 39 years; 27 versus 291, age 40 to 49 years; 83 versus 462, age 50 to 59 years; and 187 versus 786, age 60 to 69 years. Sensitivity, specificity and predictive values for clinical coronary artery disease were calculated for several total calcium scores in each decade. For age groups 40 to 49 and 50 to 59 years, a total score of 50 resulted in a sensitivity of 71% and 74% and a specificity of 91% and 70%, respectively. For age group 60 to 69 years, a total score of 300 gave a sensitivity of 74% and a specificity of 81%. The negative predictive value of a 0 score was 98%, 94% and 100% for age groups 40 to 49, 50 to 59 and 60 to 69 years, respectively. Ultrafast computed tomography is an excellent tool for detecting and quantifying coronary artery calcium.

Adult↗
PubMed1989

The significance of increased left ventricular outflow tract velocities in the elderly measured by continuous wave Doppler.

Forty-four elderly patients (mean age 80 +/- 7 years) with elevated left ventricular outflow tract velocities and corresponding outflow tract gradients documented by continuous wave Doppler are reported (mean peak gradient 50 +/- 28). They had severe left ventricular hypertrophy, small left ventricular end-diastolic dimensions, and supernormal ejection fractions. Thirty-nine percent had a history of hypertension. They were predominantly female, had uniform concentric left ventricular hypertrophy, and had a high incidence of congestive heart failure. Diastolic function was found to be reduced in the elderly group compared to young patients with hypertrophic cardiomyopathy and to age- and sex-matched normal controls. It is concluded that most elderly patients with increased left ventricular outflow tract velocities are etiologically distinct from young patients with hypertrophic cardiomyopathy.

Adult↗
PubMed1987

The postcardiotomy syndrome following transvenous pacemaker insertion.

We describe a syndrome of fever, pericarditis, and symptomatic pericardial effusion beginning 2 months after transvenous insertion of a permanent pacemaker in a 75-year-old woman. The syndrome improved dramatically following pericardiocentesis and resolved after subsequent administration of indomethacin. Although right ventricular perforation during pacemaker insertion was not recognized, inadvertent perforation leading to the postcardiotomy syndrome is postulated.

Aged↗
PubMed1986

Regression of severe alcoholic cardiomyopathy after abstinence of 10 weeks.

Alcoholic cardiomyopathy usually has a poor prognosis, but the case presented here documents a dramatic regression of left ventricular dysfunction in a patient with alcoholic cardiomyopathy. Ejection fraction determined by echocardiography increased from 12% at the time of presentation to 45% 10 weeks later. This was associated with clinical resolution of congestive heart failure and a decrease in cardiac and left ventricular size documented by chest x-ray and echocardiography.

Cardiac Catheterization↗