Biomedical subjects

T D Ruddy

Publications and source records attributed to T D Ruddy.

At least 37 records · Page 2Linked to original sources

PubMed1990

Comparison of left ventricular function and myocardial perfusion for evaluating perioperative cardiac risk of abdominal aortic surgery.

The measurement of left ventricular function by gated blood pool scanning and of myocardial perfusion by dipyridamole thallium imaging were compared in a prospective study of patients who had abdominal aortic aneurysm or aortoiliac occlusive disease to determine which measurement was the better predictor of postoperative cardiac complications. Sixty-six men and 19 women (mean age 67 years) underwent both tests before admission for surgery. Fifty-six had repair of an abdominal aortic aneurysm, and 29 had reconstruction for aortoiliac occlusive disease. In 17 patients the left ventricular ejection fraction was less than 50%. Dipyridamole thallium imaging was positive, showing redistribution, in 45 patients. Postoperative cardiac complications occurred in 33 patients. The sensitivity of dipyridamole thallium imaging (91%) was significantly (p less than 0.01) greater than that observed with gated blood pool scanning (27%). However, the specificity of gated blood pool scanning (85%) was similar to that of dipyridamole thallium imaging (71%). Diagnostic accuracy was greatest with dipyridamole thallium imaging (79% versus 62% [p less than 0.02]). Dipyridamole thallium imaging is superior to gated blood pool scanning for perioperative evaluation of vascular surgical patients.

Aged↗

PubMed1989

Nifedipine, but not propranolol, improves left ventricular systolic and diastolic function in patients with hypertension.

The effects of nifedipine and propranolol on cardiac function both at rest and at peak exercise were compared in 22 hypertensive patients whose diastolic blood pressures remained in excess of 95 mm Hg despite diuretic therapy. In this double-blind, placebo-controlled study, left ventricular systolic and diastolic function at rest and at peak exercise during bicycle ergometry was assessed by first-pass radionuclide angiography using the Baird Scinticor before and after treatment with either nifedipine or propranolol. Both agents effectively reduced blood pressure in the supine and upright positions and at peak exercise. Nifedipine was associated with a significant increase in cardiac output and stroke volume at rest and at peak exercise, while propranolol decreased cardiac output at rest and at peak exercise. Systemic vascular resistance decreased with nifedipine treatment at rest and at peak exercise, but increased significantly with propranolol. Nifedipine increased ejection fraction in patients at rest and also increased maximal oxygen consumption at peak exercise, while propranolol decreased maximal oxygen consumption at peak exercise. At rest and at peak exercise, nifedipine increased peak filling rate, but time to peak filling rate was not affected by either drug. The fraction of total diastolic filling at the midpoint of diastole was significantly increased by nifedipine therapy at rest but was not affected by propranolol therapy. Nifedipine significantly decreased atrial filling volume while propranolol had no effect. Propranolol therapy did not result in any improvement in left ventricular function. In contrast, nifedipine improved left ventricular systolic and diastolic function at rest and peak exercise. Future selection of an antihypertensive agent should include consideration of the impact of therapy on left ventricular function.

Adult↗

PubMed1989

Differentiation of restrictive cardiomyopathy from pericardial constriction: assessment of diastolic function by radionuclide angiography.

Diastolic filling variables were studied in 12 patients with the hemodynamic features of constriction, of whom 5 had restrictive cardiomyopathy, 5 had pericardial constriction and 2 had combined pericardial constriction and restrictive cardiomyopathy. The values were compared with those in 10 normal subjects of comparable age. The filling fractions between 10% and 70% of the diastolic time interval were greater in patients with pericardial constriction than in those with restrictive cardiomyopathy (p less than 0.01 between 20% and 50%, p less than 0.05 at 10%, 60% and 70%), with no overlap. The filling fractions in patients with pericardial constriction were also greater than those in normal subjects between 10% and 60% of the diastolic time interval. The filling fraction was lower in patients with restrictive cardiomyopathy than in normal subjects at 40% of the diastolic time interval (p less than 0.05). The time to peak filling rate in patients with pericardial constriction was shorter (110 +/- 14 ms) than in those with restrictive cardiomyopathy (195 +/- 45 ms, p less than 0.01) or in normal subjects (173 +/- 32 ms, p less than 0.01). The percent of atrial contribution to left ventricular filling was higher in those with restrictive cardiomyopathy (45 +/- 17%) than in those with pericardial constriction (21 +/- 6%, p less than 0.05) or in normal subjects (24 +/- 9%, p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1989

A comparison of dipyridamole-thallium imaging and exercise testing in the prediction of postoperative cardiac complications in patients requiring arterial reconstruction.

The individual and combined predictive values of dipyridamole-thallium imaging and exercise testing were compared in a prospective study of 70 patients who had abdominal aortic aneurysms or aortoiliac occlusive disease that required surgical repair. All patients were evaluated clinically by the same cardiologist and had exercise stress testing and dipyridamole-thallium imaging before admission for surgery. Ten patients were excluded from the study because they had evidence of severe ischemia when tested (ST segment depression greater than 2 mm on exercise testing, severe multivessel disease on thallium imaging). The remaining 60 patients were operated on (abdominal aortic aneurysm repair, 40; aortobifemoral repair, 17; femorofemoral graft, 3). The test results were withheld from the surgeon, anesthetist, and cardiologist before surgery. A total of 22 patients experienced major cardiac complications postoperatively (acute pulmonary edema, 17; acute myocardial, infarction, 5; cardiac death, 2). Thallium imaging showed myocardial ischemia in 31/60 patients. Exercise testing was positive (greater than or equal to 1 mm ST segment depression) in 10/60 patients. Dipyridamole-thallium imaging with a high sensitivity and reasonable specificity is the initial test of choice. Exercise testing is a poor screening test because of its low sensitivity. The combination of the two tests gives the highest positive predictive value and the greatest likelihood ratio. Thus patients assessed initially and found to have positive thallium scan results may be further stratified by exercise testing.

Adult↗

PubMed1988

Technetium-99m red blood cell labeling in patients treated with doxorubicin.

Radionuclide angiography is useful in monitoring cardiotoxicity of doxorubicin, but in vivo RBC labeling in these patients is believed to be poorer than that in general patients. The left ventricle-to-background activity ratio (R) was not significantly lower in patients treated with doxorubicin (3.24 +/- 1.15, N = 13) than in control patients (3.89 +/- 1.60, N = 14). With both modified in vivo and in vitro labeling, R was significantly improved in patients treated with doxorubicin (4.37 +/- 0.91, N = 8, and 4.37 +/- 1.22, N = 13, respectively). However, with the modified in vivo method, labeling efficiency remained a function of hematocrit, whereas the in vitro method removed this dependency. Both modified in vivo and in vitro labeling result in improved image quality over in vivo labeling in patients treated with doxorubicin, and the choice of method can be based on other factors.

Doxorubicin↗

PubMed1988

The relationship of cardiac diastolic dysfunction to concurrent hormonal and metabolic status in type I diabetes mellitus.

The presence of diabetic cardiomyopathy and its relationship to concurrent hormonal and metabolic status have not been defined in patients with uncomplicated type I diabetes mellitus. Accordingly, radionuclide left ventricular angiograms and simultaneous metabolic profiles were obtained in 8 type I diabetic patients who had no major diabetic complications and in 11 normal subjects. Occult coronary artery disease was excluded by electrocardiogram exercise testing. Hemodynamics and systolic function did not differ between the groups. However, the peak filling rate (PFR; end-diastolic volumes per s) was less in the diabetic patients at rest [mean, 4.1 +/- 0.2 (+/- SE) vs. 4.8 +/- 0.2; P less than 0.05] and during aerobic (6.8 +/- 0.2 vs. 8.30 +/- 0.3; P less than 0.01) and anaerobic exercise (8.8 +/- 0.3 vs. 9.8 +/- 0.4; P less than 0.05). The time to PFR was prolonged in the diabetic patients at rest (174 +/- 10 vs. 133 +/- 7 ms; P less than 0.01) and during anaerobic exercise (126 +/- 5 vs. 103 +/- 6 ms; P less than 0.01). Plasma glucose and insulin levels were elevated in the diabetic patients at rest and during exercise. Otherwise, the metabolic and hormonal levels did not differ between the groups. In the diabetic patients, no single metabolic or hormonal parameter correlated with PFR or time to PFR. Impairment of diastolic filling also did not correlate with level of glycosylated hemoglobin or duration of diabetes. The alteration in diastolic filling present in type I diabetic patients who have no other diabetic complications may represent the earliest functional effect of diabetic cardiomyopathy.

Adult↗

PubMed1987

Prognostic importance of thallium uptake by the lungs during exercise in coronary artery disease.

We studied the value of thallium imaging as compared with clinical and exercise-test variables in predicting cardiac events occurring over five years in 525 consecutive patients referred for thallium-exercise testing in 1979. Follow-up was obtained on 467 patients (89 percent). There were 105 cardiac events--25 cardiac deaths, 33 myocardial infarctions, and 47 coronary bypass procedures. A Cox survival analysis identified increased thallium uptake by the lungs, a marker of left ventricular dysfunction during exercise, as the best predictor of a cardiac event (relative risk ratio = 3.5; 95 percent confidence interval, 2.2 to 5.4). The next most powerful predictors were a history of typical angina, a previous myocardial infarction, and ST-segment depression during exercise (relative risk ratios = 2.1, 1.8, and 1.7, respectively). No combination of variables made up for the loss in prognostic power when the variable of increased thallium uptake by the lungs was removed from the model. Cardiac events occurred over five years in 10 (5 percent) of 192 patients with a normal thallium scan, 41 (25 percent) of 163 patients with an abnormal thallium scan but normal thallium activity in the lungs, and 54 (67 percent) of 81 patients with increased thallium uptake by the lungs (P less than 0.0001). We conclude that increased uptake of thallium by the lungs during exercise predicts a high risk of subsequent cardiac events.

Angina Pectoris↗

PubMed1987

Left ventricular ejection fraction response during exercise in asymptomatic systemic hypertension.

To study the effect of mild-to-moderate elevations in diastolic blood pressure (BP) on systolic left ventricular (LV) function, 28 hypertensive patients and 20 normal subjects underwent upright exercise first-pass radionuclide angiography. All were asymptomatic, had normal rest and exercise electrocardiographic findings and no evidence of LV hypertrophy or coronary artery disease. LV function at rest was similar in the 2 groups, but with exercise hypertensive patients had a greater end-systolic volume (69 +/- 19 vs 51 +/- 19 ml, p less than 0.002) and lower ejection fraction (EF) (0.59 +/- 0.09 vs 0.72 +/- 0.07, p less than 0.0001), stroke volume (101 +/- 28 vs 130 +/- 36 ml, p less than 0.005) and peak oxygen uptake (23 +/- 7 vs 33 +/- 9 ml/kl/min, p less than 0.05). Hypertensive patients were separated into 3 groups: group 1-12 patients with an increase in EF with exercise greater than or equal to 0.05; group 2-7 patients with a change in EF with exercise less than 0.05; and group 3-9 patients with a decrease in EF with exercise greater than or equal to 0.05. Group 3 hypertensive patients were older, had a higher heart rate at rest and lower peak oxygen uptake. Rest LV function was similar in the 3 hypertensive subgroups, but exercise end-systolic volumes were higher in groups 2 and 3. Exercise thallium-201 images was normal in all but 1 of 14 hypertensive group 2 or 3 patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1987

Measurement of both left ventricular function and regional myocardial perfusion with 133Xe in dogs.

A technique to measure left ventricular (LV) function and myocardial perfusion was validated in 12 dogs. 133Xe in saline was injected into the left atrium (LA) or LV and two data sets were obtained using gamma camera imaging: 1) A first pass gated scan for LV function; followed by 2) Sequential images for regional myocardial perfusion. LV ejection fraction and wall motion measurements from the 133Xe blood pool images were compared to ejection fraction (r = 0.88, P less than 0.01) and wall motion (r = 0.83, P less than 0.01) data from 99mTc labeled blood pool scans. The perfusion measurements obtained with the 133Xe method were compared to microsphere data (r = 0.79, P less than 0.01). Measurements after LV 133Xe injection were similar to data following LA injection. Thus, quantitative assessment of global LV function, regional wall motion and myocardial perfusion is possible with LA or LV 133Xe injection and gamma camera imaging.

Animals↗

PubMed1987

Quantitative analysis of dipyridamole-thallium images for the detection of coronary artery disease.

To determine if the detection of coronary artery disease by dipyridamole-thallium imaging is improved by quantitative versus qualitative analysis, and combining quantitative variables, 80 patients with chest pain (53 with and 27 without coronary artery disease) who underwent cardiac catheterization were studied. Segmental thallium initial uptake, linear clearance, monoexponential clearance and redistribution were measured from early, intermediate and delayed images acquired in three projections. Normal values were determined from 13 other clinically normal subjects. When five segments per view were used for quantitative analysis, sensitivity and specificity were 87 and 63%, respectively, for uptake, 77 and 67% for linear clearance, 60 and 60% for monoexponential clearance and 62 and 56% for redistribution. Of the four variables, uptake and linear clearance were the most sensitive (p less than 0.01) and specificity did not differ significantly. Using three segments per view, the specificity of uptake increased (p less than 0.05) to 78% without a significant change in sensitivity (85%). With this approach, sensitivity and specificity did not differ from those of qualitative analysis (85 and 78%, respectively). Stepwise logistic regression analysis demonstrated that the best quantitative thallium correlate of the presence of coronary artery disease was a combination variable of "either abnormal uptake or abnormal linear clearance, or both." Using five segments per view, the model's specificity (85%) was greater than that of uptake alone (p less than 0.02), with similar sensitivity (92%). Using three segments per view, the model's specificity (93%) was greater than that of uptake alone (p less than 0.05) and of qualitative analysis (p less than 0.05), with similar sensitivity (85%).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1987

Myocardial uptake and clearance of thallium-201 in normal subjects: comparison of dipyridamole-induced hyperemia with exercise stress.

Thallium-201 uptake and clearance after dipyridamole infusion may differ from that after exercise stress because the hemodynamic effects of these two interventions are different. In this study of normal volunteers, thallium kinetics after dipyridamole (n = 13) were determined from three serial image sets (early, intermediate and delayed) and from serial blood samples and compared with thallium kinetics after exercise (n = 15). Absolute myocardial thallium uptake was greater after dipyridamole compared with exercise (p less than 0.0001), although the relative myocardial distribution was similar. The myocardial clearance (%/h) of thallium was slower after dipyridamole than it was after exercise. Comparing dipyridamole and exercise, the differences in clearance were large from the early to the intermediate image (anterior, -11 +/- 17 versus 24 +/- 5, p = 0.0005; 50 degrees left anterior oblique, -7 +/- 11 versus 15 +/- 8, p = 0.004; 70 degrees left anterior oblique, 3 +/- 9 versus 21 +/- 6, p = 0.001). In contrast, the differences in clearance were small from the intermediate to the delayed image (anterior, 15 +/- 4 versus 20 +/- 2, p = 0.025; 50 degrees left anterior oblique, 15 +/- 4 versus 19 +/- 3, p = 0.13; 70 degrees left anterior oblique, 15 +/- 3 versus 18 +/- 2, p = 0.047). Thallium uptake and clearance in the liver, splanchnic region and spleen were greater after dipyridamole (p less than 0.001). Blood thallium levels were greater after dipyridamole (p less than 0.05) and cleared more slowly (p = 0.07). Thus, myocardial thallium-201 uptake and clearance after dipyridamole infusion differ from thallium kinetics after exercise. This difference is, in part, related to associated differences in extracardiac and blood kinetics. Diagnostic criteria for the detection of abnormal thallium-201 clearance must be specific for the type of intervention.

Adult↗

PubMed1987

Inotropic effect of enoximone in patients with severe heart failure: demonstration by left ventricular end-systolic pressure-volume analysis.

Left ventricular end-systolic pressure-volume analysis was employed to assess the inotropic effect of the phosphodiesterase inhibitor enoximone (formerly MDL-17,043) in nine patients with severe heart failure (New York Heart Association class IV symptoms, mean ejection fraction = 0.22). Left ventricular pressure-volume loops were constructed using high fidelity left ventricular pressure measured with micromanometer-tipped catheters and simultaneous left ventricular volume obtained by gated blood pool imaging. Afterload was reduced with the vasodilator nitroprusside to generate the baseline left ventricular end-systolic pressure-volume relation, a relatively load-independent measure of contractile function. The intravenous administration of enoximone (mean dose 75 mg) shifted the end-systolic pressure-volume point upward and leftward from the baseline pressure-volume relation in eight of the nine patients, demonstrating a positive inotropic effect of this agent. The maximal rate of left ventricular pressure development (peak positive dP/dt) increased from 1,030 +/- 142 to 1,381 +/- 219 mm Hg/s (p less than 0.01) on enoximone despite a significant decrease in preload (as assessed by left ventricular end-diastolic pressure and volume) and a small, insignificant decrease in mean arterial pressure. Two patients developed angina after enoximone administration; both patients had coronary artery disease and experienced a greater than 30% increase in heart rate-systolic blood pressure product. Thus, enoximone has a significant inotropic effect in patients with severe heart failure. Like other inotropic drugs, it has the potential to increase myocardial oxygen demand and thereby precipitate ischemia.

Blood Pressure↗

PubMed1987

Diastolic function in patients with severe heart failure: comparison of the effects of enoximone and nitroprusside.

To assess whether the phosphodiesterase inhibitor enoximone has a specific, direct effect on left ventricular diastolic function distinct from its inotropic and vasodilator actions, we compared the effects of enoximone and the pure vasodilator nitroprusside in 11 patients with severe heart failure. Mean (+/- SEM) left ventricular ejection fraction was 0.20 +/- 0.03. Simultaneous left ventricular pressure and radionuclide angiographic volume were obtained at baseline, during infusion of nitroprusside, and after intravenous administration of enoximone. Left ventricular end-diastolic pressure (LVEDP) and volume (LVEDV) decreased with both agents (p less than .01 vs control); LVEDP was lower for nitroprusside than for enoximone (p less than .01) despite a similar LVEDV. Nitroprusside decreased the time constant of exponential left ventricular pressure decay, TL (measured by the logarithmic method), from 84 +/- 10 to 65 +/- 8 msec (p less than .01) but had no significant effect on TD (measured by the derivative method), maximum negative dP/dt, or the peak rate of early diastolic filling. Enoximone shortened TL from 86 +/- 12 to 61 +/- 9 msec (p less than .01) and increased maximum negative dP/dt from 897 +/- 101 to 1135 +/- 134 mm Hg/sec (p less than .01) but did not affect TD or the peak filling rate. The left ventricular diastolic pressure-volume relation was shifted downward in only three of 11 patients on nitroprusside and three of 11 patients on enoximone, and these shifts were attenuated by adjusting for simultaneous changes in right atrial pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

Diastole↗

PubMed1987

The importance of defining left ventricular area at risk in vivo during acute myocardial infarction: an experimental evaluation with myocardial contrast two-dimensional echocardiography.

Because the left ventricular "area at risk" is the most important determinant of ultimate infarct size, it would be useful to know the size of the area at risk during acute myocardial infarction to make therapeutic decisions. We therefore performed a series of experiments in four groups of dogs. In group I dogs (n = 15) we attempted to determine whether current methods of assessing left ventricular function during acute myocardial infarction reflect the true size of the area at risk. At each of two to five sequential stages, a more proximal coronary occlusion was performed to produce a larger area at risk until cardiovascular collapse occurred. At each stage, the area at risk (measured by myocardial contrast echocardiography), hemodynamic variables, and left ventricular ejection fraction (LVEF) were measured. Hemodynamic variables became abnormal when the area at risk was large (25% to 40% of the left ventricle), whereas LVEF became abnormal when the area at risk was of moderate size (18%). When cardiac output and LVEF were normalized to baseline values, a close inverse relationship was noted between these variables and area at risk. In contrast, there was a poor relationship between normalized mean arterial pressure and area at risk (r = .42). In group II dogs (n = 9) the area at risk was measured serially over 6 hr after coronary occlusion. The size of the area at risk remained unchanged regardless of the transmural extent of the ultimate infarct. The circumferential endocardial extent of the area at risk closely predicted the circumferential endocardial extent of the infarct at 6 hr in eight of nine dogs that developed an infarct. Group III dogs (n = 7) underwent the same protocol as group II dogs, but the duration of occlusion was 3 hr. The circumferential endocardial extent of the area at risk closely predicted the circumferential endocardial extent of the infarct. Group IV dogs (n = 5) underwent subtotal coronary occlusion. Although regional wall motion abnormalities were noted in this group, no area at risk could be defined. We conclude that although a close inverse relationship is noted between normalized cardiac output and area at risk, the absolute values for cardiac output and other hemodynamic variables become abnormal only when the area at risk is large (25% to 40%); measurement of LVEF may provide a better assessment of the size of the area at risk than hemodynamic variables.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

PubMed1986

Anterior ST segment depression in acute inferior myocardial infarction as a marker of greater inferior, apical, and posterolateral damage.

The clinical significance of anterior precordial ST segment depression during acute inferior myocardial infarction was evaluated in 67 consecutive patients early after onset of symptoms with gated blood pool scans, thallium-201 perfusion images, and 12-lead ECGs. Patients with anterior ST depression (n = 33) had depressed mean values for left ventricular ejection fraction (54 +/- 2% [mean +/- S.E.M.] vs 59 +/- 2%; p = 0.02), cardiac index (3.1 +/- 0.2 vs 3.6 +/- 0.2 L/m2; p = 0.03), and ratio of systolic blood pressure to end-systolic volume (2.0 +/- 0.1 vs 2.5 +/- 0.3 mm Hg/ml; p = 0.04) compared to patients with no anterior ST depression (n = 34). Patients with anterior ST depression had (1) lower mean wall motion values for the inferior, apical, and inferior posterolateral segments (p less than 0.05) and (2) greater reductions in thallium-201 uptake in the inferior and posterolateral regions (p less than 0.05). However, anterior and septal (1) wall motion and (2) thallium-201 uptake were similar in patients with and without ST depression. Thus, anterior precordial ST segment depression in patients with acute inferior wall myocardial infarction represents more than a reciprocal electrical phenomenon. It identifies patients with more severe wall motion impairment and greater hypoperfusion of the inferior and adjacent segments. The poorer global left ventricular function in these patients is a result of more extensive inferior infarction and not of remote septal or anterior injury.

Electrocardiography↗

PubMedDate not supplied

Hypertrophic cardiomyopathy. The importance of the site and the extent of hypertrophy. A review.

Hypertrophic cardiomyopathy is a diverse clinical and pathophysiologic entity that involves principally the left ventricle and is caused by asymmetric or concentric hypertrophy of unknown cause. If asymmetric, the hypertrophy is usually greatest in the ventricular septum, but variations occur in which the hypertrophy may be maximal at the apex, at the midventricular level, or, rarely, in the free wall of the left ventricle. Right ventricular involvement is usually less evident. The principal abnormality in systole is the obstruction to left ventricular outflow caused by upper septal hypertrophy narrowing the outflow tract and setting the stage for Venturi forces to cause systolic anterior motion of the anterior or posterior mitral leaflets. The time of onset and duration of mitral leaflet-septal contact determine the magnitude of the pressure gradient. Mitral regurgitation invariably accompanies the obstruction to outflow. Ventriculomyotomy-myectomy surgery, by thinning the septum and widening the outflow tract, abolishes the abnormal mitral leaflet motion and, consequently, the obstruction to outflow and the mitral regurgitation. This form of surgery more dramatically relieves the systolic abnormalities and the accompanying symptoms than any form of medical therapy available today. The extent of hypertrophy is believed to be the principal determinant of the impaired left ventricular relaxation and increased chambers stiffness (decreased compliance) that characterize diastole in hypertrophic cardiomyopathy. Relaxation is impaired by the contraction load (the obstruction), by a decrease in the principal relaxation loads, by a pathologic degree of nonuniformity of contraction and relaxation, and in all likelihood, by impaired inactivation of the biochemical processes responsible for contraction (? due to primary or ischemia-induced calcium overload). Calcium channel-blocking agents may dramatically improve left ventricular relaxation by speeding up the inactivation process, by decreasing the degree of nonuniformity, or by altering the contraction and relaxation loads in a favorable manner. Atrial and ventricular arrhythmias are responsible for a significant proportion of the morbidity and mortality, and their occurrence also appears to depend on the extent of hypertrophy. Thus, the major manifestations of hypertrophic cardiomyopathy in systole and diastole as well as the disturbances of rhythm appear to be related to the site and/or extent of the hypertrophic process.(ABSTRACT TRUNCATED AT 400 WORDS)

Angiography↗

PubMedDate not supplied

Potential utility of rubidium 82 PET quantification in patients with 3-vessel coronary artery disease.

BACKGROUND: Standard perfusion imaging may underestimate the extent of disease in 3-vessel coronary atherosclerosis. This study determined whether positron emission tomography quantification of perfusion reserve by use of rubidium 82 net retention defined a greater extent of disease than the standard approach in patients with 3-vessel disease. METHODS AND RESULTS: Rb-82 net retention was quantified as an estimation of absolute perfusion at rest and with dipyridamole stress by use of dynamic positron emission tomography imaging. The percent of abnormal myocardial sectors, as compared with a normal database, for a standard and quantification approach was determined. Twenty-three patients were evaluated. Defect sizes were larger in patients with 3-vessel disease (n = 13) by use of quantification methods: 44% +/- 18% of the myocardial sectors were abnormal by use of the standard approach versus 69% +/- 24% of sectors when measured by quantification of the stress-rest perfusion difference (P =.008). In patients with single-vessel disease (n = 10), defect sizes were smaller with quantification methods. CONCLUSIONS: Quantification of Rb-82 net retention to measure the stress-rest perfusion difference in the myocardium defined a greater extent of disease than the standard approach in this group of patients with triple-vessel disease. More accurate measurement of the extent of coronary artery disease could facilitate better risk stratification and identify more high-risk patients in whom aggressive intervention is required.

Aged↗

PubMedDate not supplied

Spontaneous drainage of paravalvular abscess diagnosed by transesophageal echocardiography.

Paravalvular abscesses, which occur in up to 30% of cases of native valve endocarditis, are being detected with increasing frequency with the use of transesophageal echocardiography. Abscesses of the mitral aortic intervalvular fibrosa have been described but only in association with native or prosthetic aortic valve endocarditis. We describe a patient with native mitral valve endocarditis complicated by an abscess in the fibrosa. A 51-year-old diabetic man presented with Staphylococcus aureus mitral valve endocarditis. A transesophageal echocardiographic study done 8 days after admission revealed two large masses at the base of the anterior mitral leaflet with extension into the fibrosa consistent with a paravalvular abscess that was not detected by precordial echocardiography. A repeat transesophageal echocardiographic study done 20 days after admission showed spontaneous drainage of the abscess and a subsequent fistula between the left atrium and left ventricle. This case highlights the important role that transesophageal echocardiography has in suspected and known cases of endocarditis. Its major advantage of delineating posterior cardiac structures allowed accurate diagnosis and serial evaluation of this previously unreported complication of endocarditis.

Abscess↗