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L D Hillis

Publications and source records attributed to L D Hillis.

At least 19 recordsLinked to original sources
PubMed1995

Magnetic resonance imaging assessment of the severity of mitral regurgitation. Comparison with invasive techniques.

BACKGROUND: In the patient with mitral regurgitation who is being considered for valvular surgery, cardiac catheterization is usually performed to quantify the severity of regurgitation and to determine its influence on left ventricular volumes and systolic function. Magnetic resonance imaging (MRI) potentially provides a rapid, noninvasive method of acquiring these data. Thus, this study was done to determine whether MRI can reliably measure the magnitude of mitral regurgitation and evaluate the effect of regurgitation on left ventricular volumes and systolic function. METHODS AND RESULTS: Twenty-three subjects (14 women and 9 men 15 to 72 years of age) with (n = 17) or without (n = 6) mitral regurgitation underwent MRI scanning followed immediately by cardiac catheterization. The presence (or absence) of valvular regurgitation was determined, and left ventricular volumes and regurgitant fraction were quantified during each procedure. There was excellent correlation between invasive and MRI assessments of left ventricular end-diastolic (r = .95) and end-systolic (r = .95) volumes and regurgitant fraction (r = .96). All MRI examinations were completed in < 28 minutes. CONCLUSIONS: In the patient with mitral regurgitation, MRI compares favorably with cardiac catheterization for assessment of the magnitude of regurgitation and its influence on left ventricular volumes and systolic function.

Adolescent↗
PubMed1995

No association between plasma lipoprotein(a) concentrations and the presence or absence of coronary atherosclerosis in African-Americans.

Elevated plasma concentrations of lipoprotein(a) [Lp(a)] are associated with coronary atherosclerosis in Caucasians. Although African-Americans have a higher median plasma Lp(a) concentration than Caucasians, they do not have a greater incidence of coronary atherosclerosis. This study was performed to determine whether the plasma concentration of Lp(a) is associated with coronary atherosclerosis in African-Americans. The fasting plasma concentrations of Lp(a) and lipoproteins were measured in 140 African-American subjects (62 men, 78 women, aged 31 to 80 years) 18 +/- 16 months (mean +/- SD) after they underwent coronary angiography: 72 had angiographically normal coronary arteries and 68 had > 70% luminal diameter narrowing of one or more major epicardial coronary arteries. The groups were similar in age, sex, and other risk factors for atherosclerosis. The subjects with coronary artery disease had higher plasma concentrations of total cholesterol, triglycerides, and VLDL and LDL cholesterol (P = .04) and lower concentrations of HDL cholesterol (P = .0001) than subjects without coronary artery disease, but there was no significant difference in the plasma concentration of Lp(a). The distribution of apolipoprotein(a) alleles by size was also not significantly different between the two groups. These results suggest that the plasma concentration of Lp(a) is not an independent risk factor for coronary artery disease in African-Americans.

Adult↗
PubMed1992

Effect of coronary angioplasty on late potentials one to two weeks after acute myocardial infarction.

In survivors of acute myocardial infarction (AMI), the restoration of anterograde flow in the infarct artery, even if accomplished beyond the time for myocardial salvage, may reduce the frequency of subsequent arrhythmic events and sudden death. Twelve subjects (8 men and 4 women, aged 39 to 69 years) with a first AMI, signal-averaged electrocardiographic late potentials, and an occluded infarct artery were prospectively identified. Seven (group I) had successful coronary angioplasty 6 to 15 days after AMI, and 5 (group II) were managed conservatively. Follow-up signal-averaged electrocardiography was performed 3 to 7 months later. From baseline to follow-up, the 7 group I subjects had a significant change in QRS duration (117 +/- 13 [mean + SD] to 102 +/- 10 ms), root-mean-square voltage (10.4 +/- 4.7 to 31.0 +/- 7.6 microV), and low-amplitude signal duration (47.5 +/- 8.5 to 32.4 +/- 5.2 ms) (p < or = 0.05 for all 3 variables). No group I patient had a late potential at follow-up. In contrast, the 5 group II patients showed no change in QRS duration or low-amplitude signal duration from baseline to follow-up, and all 5 had a late potential at follow-up. At follow-up, the root-mean-square voltage was significantly greater and the low-amplitude signal and QRS durations significantly less in group I than in group II (p < 0.05 for all 3 variables). Thus, in our patients, the mechanical restoration of anterograde perfusion in an occluded infarct artery 1 to 2 weeks after AMI caused the resolution of signal-averaged electrocardiographic late potentials.

Adult↗
PubMed1992

Markedly increased periprocedure mortality of cardiac catheterization in patients with severe narrowing of the left main coronary artery.

In early reports, coronary arteriography in patients with left main (LM) coronary artery disease (CAD) had a substantial risk, but recent reports suggest that arteriography in these subjects is now associated with a low mortality. The present study was performed to examine the periprocedure mortality in patients with LMCAD undergoing catheterization, to compare the periprocedure mortality in these patients with that in subjects with less CAD and to identify the variables associated with pericatheterization mortality in this patient cohort. Of 4,009 patients undergoing elective coronary arteriography from 1978 to 1992, 176 had LMCAD. Of the 10 deaths during or within 24 hours of catheterization, 5 occurred in these 176 subjects. This periprocedure mortality of 2.8% in patients with LMCAD was > 20 times that of those without LMCAD (0.13%). In comparison with the 171 patients with LMCAD who survived, the 5 who died were older (67 +/- 8 vs 58 +/- 12 years), and had more severe LMCAD (92 +/- 10% vs 72 +/- 16%) and a lower cardiac index (1.9 +/- 0.4 vs 2.6 +/- 0.7 liters/min/m2) (p < 0.05 for all 3 variables). Thus, even in the 1980s and early 1990s, patients with LMCAD have a high pericatheterization mortality, especially those who are older and have severe LMCAD.

Age Factors↗
PubMed1992

Comparison of single and biplane ventriculography for determination of left ventricular volume and ejection fraction.

This study was done to compare single and biplane left ventriculography in quantitating left ventricular (LV) volumes and ejection fraction. LV volumes and ejection fraction were measured from a 30 degrees right anterior oblique single plane ventriculogram and a 30 degrees right anterior oblique 60 degrees left anterior oblique biplane ventriculogram in 152 men (aged 59 +/- 9 [mean +/- standard deviation] years), of whom 102 had hypokinesia, akinesia, or dyskinesia. There was excellent agreement between the results of single and biplane ventriculography with respect to LV end-diastolic volume (r = 0.96), end-systolic volume (r = 0.98) and ejection fraction (r = 0.97). The end-diastolic and end-systolic volumes measured by biplane ventriculography were consistently slightly larger than those measured by single plane, whereas ejection fractions measured by the 2 techniques were remarkably similar, even for the 46 patients with biplane ejection fractions less than 0.50 and the 102 with hypokinesia, akinesia or dyskinesia. Thus, LV volumes and ejection fractions determined by single plane ventriculography correlate very well with those determined by biplane ventriculography, even in patients with hypokinesia, akinesia, or dyskinesia and depressed LV systolic performance. Biplane ventriculography appears to provide little information that cannot be obtained reliably from single plane.

Adult↗
PubMed1992

Recurrent coronary vasoconstriction caused by intranasal cocaine: possible role for metabolites.

OBJECTIVE: To define the temporal characteristics of cocaine-induced coronary vasoconstriction in humans and to assess the relation between cocaine-induced coronary vasoconstriction and the blood concentration of cocaine and its main metabolites. DESIGN: Randomized, double-blind, controlled clinical trial. SETTING: Cardiac catheterization laboratory of a large teaching hospital. PATIENTS: Eighteen patients (16 men and 2 women, 37 to 65 years of age) having catheterization for evaluation of chest pain. MEASUREMENTS: At catheterization, patients received intranasal saline (8 patients) or cocaine, 2 mg/kg body weight (10 patients). Cineangiographic examination of the left coronary artery and quantitation of the blood concentration of cocaine and its metabolites were done before (baseline) and 30, 60, and 90 minutes after administration of intranasal saline or cocaine. RESULTS: In response to cocaine, proximal coronary arterial diameter decreased from 2.4 +/- 1.6 mm (mean +/- SD) at baseline to 2.0 +/- 1.4 mm at 30 minutes (P less than 0.05). This change corresponded temporally to the peak blood concentration of cocaine. At 60 minutes, the cocaine concentration decreased and coronary artery diameter returned to baseline (2.3 +/- 1.6 mm) (P greater than 0.05 compared with baseline). At 90 minutes, all patients had recurrent vasoconstriction (1.9 +/- 1.4 mm, P less than 0.05) despite a further decrease in the blood cocaine concentration. This vasoconstriction corresponded temporally with an increasing blood concentration of cocaine's main metabolites, benzoylecgonine and ethyl methyl ecgonine. No changes were observed in the control group. CONCLUSION: Intranasal cocaine causes recurrent coronary vasoconstriction, which may be due to its metabolites.

Administration, Intranasal↗
PubMed1992

Influence of collateral filling of the occluded infarct-related coronary artery on prognosis after acute myocardial infarction.

Previous studies showed that long-term morbidity and mortality after acute myocardial infarction (AMI) are influenced by the presence or absence of anterograde flow in the infarct artery. In comparison with patients with anterograde flow, those whose infarct artery remains occluded are more likely to have unstable angina, recurrent AMI, congestive heart failure and sudden death. This study was performed to assess the influence of collateral filling of the infarct artery on long-term morbidity and mortality in surviving patients of initial AMI in whom the infarct artery was occluded. Over a 12.5-year period, 146 subjects (108 men and 38 women, aged 25 to 76 years) with AMI, no anterograde flow in the infarct artery, and no disease of other coronary arteries were medically treated and followed for 42 +/- 28 (mean +/- standard deviation) months. Of these subjects, 120 had angiographic evidence of collateral filling of the infarct artery (group I), whereas the remaining 26 did not (group II). The groups were similar in age, sex, cardioactive medications, left ventricular performance and infarct artery. They were also similar in incidence of unstable angina (19% of group I, 31% of group II; p = not significant [NS]), recurrent AMI (12% of group I, 8% of group II; p = NS), congestive heart failure (16% of group I, 12% of group II; p = NS) and cardiac death (16% of group I, 19% of group II; p = NS). Thus, angiographic evidence of collateral filling of the infarct artery in surviving patients of AMI exerts no demonstrable influence (beneficial or detrimental) on long-term morbidity or mortality.

Adult↗
PubMed1992

Accuracy of various methods of measuring the transvalvular pressure gradient in aortic stenosis.

This study was done to assess the accuracy of various techniques of measuring the pressure gradient and valve area in patients with aortic stenosis (AS). In 18 patients with AS, the pressure gradient was quantitated from (1) simultaneous left ventricular and ascending aortic pressures (LV-AO), (2) nonsimultaneous LV-AO pullback, (3) LV and femoral arterial (FA) pressures unadjusted for the time delay of the FA tracing (LV-FA unadjusted), and (4) LV-FA adjusted for time delay. In comparison to simultaneous LV-AO, the pressure gradient was greater with LV-FA unadjusted and less with LV-FA adjusted for time delay (p less than 0.05). In nine patients with a mean gradient less than 35 mm Hg, the difference in valve area between simultaneous LV-AO and pullback averaged 0.17 +/- 0.10 cm2; between LV-AO and LV-FA unadjusted, the difference averaged 0.11 +/- 0.14 cm2; and between LV-AO and LV-FA adjusted, the difference averaged 0.52 +/- 0.36 cm2. These differences in valve area resulted in a discordant classification of the severity of AS in eight of the nine patients. Thus the use of an LV-AO pullback or an LV-FA gradient for assessing the severity of AS may yield inaccurate results, especially in patients with low (less than 35 mm Hg) gradients.

Aged↗
PubMed1992

The natural history of isolated left ventricular diastolic dysfunction.

STUDY OBJECTIVE: To assess the natural history of isolated left ventricular diastolic dysfunction. PATIENTS AND METHODS: Follow-up (average duration, 68 months) was obtained in 51 patients with isolated left ventricular diastolic dysfunction at cardiac catheterization, characterized by (1) an elevated left ventricular end-diastolic pressure; (2) normal left ventricular end-diastolic and end-systolic volumes; (3) normal left ventricular ejection fraction; (4) no coronary artery disease; and (5) no valvular disease. RESULTS: During follow-up, seven patients died, but only one died of cardiac causes. Of the 44 living subjects, 20 (45%) noted new-onset symptoms of congestive heart failure, with 11 (25%) of these requiring hospitalization, and 12 (27%) required hospitalization for recurrent chest pain. CONCLUSIONS: Isolated left ventricular diastolic dysfunction is associated with a low cardiac mortality; at the same time, however, it is associated with substantial morbidity.

Adult↗
PubMed1992

Hemodynamic effects of intranasal cocaine in humans.

Intranasal cocaine, 2 to 3 mg/kg body weight, is a commonly used local anesthetic for rhinolaryngologic procedures, and many persons who abuse it ingest a similar amount. Previous studies in humans showed that this dose of cocaine causes coronary vasoconstriction, and studies in animals showed that larger amounts given intravenously diminish myocardial performance. This study assessed the hemodynamic effects of intranasal cocaine, 2 mg/kg, in humans. In 15 patients (8 men and 7 women, aged 30 to 70 years) referred for cardiac catheterization, heart rate, systemic arterial pressure, cardiac index, pulmonary capillary wedge and pulmonary artery pressures and left ventricular pressure and its first derivative (dP/dt) were measured before and 15, 30 and 45 min after intranasal administration of saline solution (n = 5) or cocaine, 2 mg/kg (n = 10). No variable changed with saline solution. In those given cocaine, there was an increase in heart rate (17 +/- 16%, mean +/- SD), mean systemic arterial pressure (8 +/- 7%), cardiac index (18 +/- 18%) and positive and negative dP/dt (18 +/- 20% and 15 +/- 22%, respectively) (p less than 0.05 for all). Thus, intranasal cocaine in a dose similar to that used medicinally or "recreationally" does not exert a deleterious influence on intracardiac pressures and left ventricular performance.

Administration, Intranasal↗
PubMed1992

Utility of various radionuclide techniques for distinguishing ischemic from nonischemic dilated cardiomyopathy.

BACKGROUND: Clinically, ischemic and nonischemic (idiopathic) dilated cardiomyopathy may be difficult to distinguish. Radionuclide ventriculography and exercise testing with thallium-201 scintigraphy are often used in an attempt to differentiate them noninvasively. With these techniques, the presence of (1) left ventricular (LV) regional asynergy, (2) depressed LV systolic function with normal right ventricular function, and/or (3) thallium-201 perfusion abnormalities traditionally has been regarded as evidence of ischemic heart disease. We assessed the incidence with which these abnormalities occur in patients with nonischemic-dilated cardiomyopathy. METHODS: Seventy-six patients (45 men, 31 women, aged 18 to 75 years) with invasively proven nonischemic-dilated cardiomyopathy underwent radionuclide ventriculography (n = 75) and provocative thallium-201 perfusion imaging (n = 17). RESULTS: Regional LV wall motion abnormalities were noted in 48% of patients, and 54% had LV systolic dysfunction without concomitant right ventricular dysfunction. Reversible and/or fixed exercise-induced thallium-201 perfusion abnormalities occurred in 94% of the patients studied. CONCLUSIONS: Radionuclide ventriculography and exercise testing with thallium perfusion imaging cannot be used reliably to differentiate ischemic from nonischemic dilated cardiomyopathy, since many patients with the latter have radionuclide evidence of LV segmental wall motion abnormalities, selective LV systolic dysfunction, and segmental perfusion abnormalities.

Adolescent↗
PubMed1991

Hemorrhagic events during therapy with recombinant tissue-type plasminogen activator, heparin, and aspirin for acute myocardial infarction. Results of the Thrombolysis in Myocardial Infarction (TIMI), Phase II Trial.

OBJECTIVES: To assess the effects of invasive procedures, hemostatic and clinical variables, the timing of beta-blocker therapy, and the doses of recombinant plasminogen activator (rt-PA) on hemorrhagic events. DESIGN: A multicenter, randomized, controlled trial. SETTING: Hospitals participating in the Thrombolysis in Myocardial Infarction, Phase II trial (TIMI II). INTERVENTIONS: Patients received rt-PA, heparin, and aspirin. The total dose of rt-PA was 150 mg for the first 520 patients and 100 mg for the remaining 2819 patients. Patients were randomly assigned to an invasive strategy (coronary arteriography with percutaneous angioplasty [if feasible] done routinely 18 to 48 hours after the start of thrombolytic therapy) or to a conservative strategy (coronary arteriography done for recurrent spontaneous or exercise-induced ischemia). Eligible patients were also randomly assigned to either immediate intravenous or deferred beta-blocker therapy. MEASUREMENTS: Patients were monitored for hemorrhagic events during hospitalization. MAIN RESULTS: In patients on the 100-mg rt-PA regimen, major and minor hemorrhagic events were more common among those assigned to the invasive than among those assigned to the conservative strategy (18.5% versus 12.8%, P less than 0.001). Major or minor hemorrhagic events were associated with the extent of fibrinogen breakdown, peak rt-PA levels, thrombocytopenia, prolongation of the activated partial thromboplastin time (APTT) to more than 90 seconds, weight of 70 kg or less, female gender, and physical signs of cardiac decompensation. Immediate intravenous beta-blocker therapy had no important effect on hemorrhagic events when compared with delayed beta-blocker therapy. Intracranial hemorrhages were more frequent among patients treated with the 150-mg rt-PA dose than with the 100-mg rt-PA dose (2.1% versus 0.5%, P less than 0.001). The extent of the plasmin-mediated hemostatic defect was also greater in patients receiving the 150-mg dose. CONCLUSIONS: Increased morbidity due to hemorrhagic complications is associated with an invasive management strategy in patients with acute myocardial infarction. Our findings show the complex interaction of several factors in the occurrence of hemorrhagic events during thrombolytic therapy.

Aspirin↗