First-pass radionuclide angiographie (FPRNA) analysis, using the standard, single-fixed region of... more First-pass radionuclide angiographie (FPRNA) analysis, using the standard, single-fixed region of interest (ROI)drawn at end-diastole, often underestimates the left ventricular ejection fraction (LVEF)as determined by other standard techniques. This study examined the hypothesis that correction for the anatomic motion of the aortic valve plane toward the apex during systole, which results in im proper inclusion of aortic counts within the
Journal of the American College of Cardiology, Jan 7, 2015
Anticoagulation for atrial fibrillation has become more complex due to the introduction of new an... more Anticoagulation for atrial fibrillation has become more complex due to the introduction of new anticoagulant agents, the number and kinds of patients requiring therapy, and the interactions of those patients in the matrix of care. The management of anticoagulation has become a "team sport" involving multiple specialties in multiple sites of care. The American College of Cardiology, through the College's Anticoagulation Initiative, convened a roundtable of experts from multiple specialties to discuss topics important to the management of patients requiring anticoagulation and to make expert recommendations on issues such as the initiation and interruption of anticoagulation, quality of anticoagulation care, management of major and minor bleeding, and treatment of special populations. The attendees continued to work toward consensus on these topics, and present the key findings of this roundtable in a state-of- the-art review focusing on the practical aspects of anticoag...
Journal of the American College of Cardiology, Jan 29, 2014
A report from panel members appointed to the Eighth Joint National Committee titled "2014 Ev... more A report from panel members appointed to the Eighth Joint National Committee titled "2014 Evidence-Based Guideline for the Management of High Blood Pressure in Adults" has garnered much attention due to its major change in recommendations for hypertension treatment for patients ≥60 years of age and for their treatment goal. In response, certain groups have opposed the decision to initiate pharmacologic treatment to lower blood pressure (BP) at systolic BP ≥150 mm Hg and treat to a goal systolic BP of <150 mm Hg in the general population age ≥60 years. This paper contains 3 sections-an introduction followed by the opinions of 2 writing groups-outlining objections to or support of maintaining this proposed strategy in certain at-risk populations, namely African Americans, women, and the elderly. Several authors argue for maintaining current targets, as opposed to adopting the new recommendations, to allow for optimal treatment for older women and African Americans, helpin...
Left ventricular hypertrophy (LVH) is a major independent predictor of cardiovascular disease (CV... more Left ventricular hypertrophy (LVH) is a major independent predictor of cardiovascular disease (CVD) survival and is more prevalent in blacks than whites. In a large biracial population, we evaluated the ability of electrocardiography (ECG)-determined LVH (ECG-LVH) to reclassify CVD/coronary heart disease (CHD) events beyond traditional risk factors in blacks and whites. The analysis included 14,489 participants (mean age 54 ± 5.7 years; 43.5% men; 26% black) from the ARIC cohort, with baseline (1987-1989) ECG, followed up for 10 years. Predicted risk for incident CVD and CHD were estimated using the 10-year Pooled Cohort and Framingham risk equations (base models 1A/1B), respectively. Models 2A and 2B included respective base model plus LVH by "any" of 10 traditional ECG-LVH criteria. Net reclassification improvement (NRI) was calculated, and the distribution of risk was compared using models 2A and 2B versus models 1A and 1B, respectively. There were 792 (5.5%) 10-year Po...
Journal of the American College of Cardiology, 2014
The current paper details the recommendations arising from an NIH-NHLBI/NCI-sponsored symposium h... more The current paper details the recommendations arising from an NIH-NHLBI/NCI-sponsored symposium held in November 2012, aiming to identify key components of a radiation accountability framework fostering patient-centered imaging and shared decision-making in cardiac imaging. Symposium participants, working in 3 tracks, identified key components of a framework to target critical radiation safety issues for the patient, the laboratory, and the larger population of patients with known or suspected cardiovascular disease. The use of ionizing radiation during an imaging procedure should be disclosed to all patients by the ordering provider at the time of ordering, and reinforced by the performing provider team. An imaging protocol with effective dose ≤3 mSv is considered very low risk, not warranting extensive discussion or written informed consent. However, a protocol effective dose &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;20 mSv was proposed as a level requiring particular attention in terms of shared decision-making and either formal discussion or written informed consent. Laboratory reporting of radiation dosimetry is a critical component of creating a quality laboratory fostering a patient-centered environment with transparent procedural methodology. Efforts should be directed to avoiding testing involving radiation, in patients with inappropriate indications. Standardized reporting and diagnostic reference levels for computed tomography and nuclear cardiology are important for the goal of public reporting of laboratory radiation dose levels in conjunction with diagnostic performance. The development of cardiac imaging technologies revolutionized cardiology practice by allowing routine, noninvasive assessment of myocardial perfusion and anatomy. It is now incumbent upon the imaging community to create an accountability framework to safely drive appropriate imaging utilization.
Journal of the American College of Cardiology, 1996
This study evaluated the use of gated single-photon emission computed tomographic (SPECT) myocard... more This study evaluated the use of gated single-photon emission computed tomographic (SPECT) myocardial perfusion images for determination of left ventricular ejection fraction. Gated SPECT has expanded the applications of myocardial perfusion imaging to include the evaluation of left ventricular size, regional wall motion and regional systolic thickening. Accurate automated or semi-automated methods for quantitation of left ventricular ejection fraction from tomographic perfusion images would provide additional valuable clinical information. Rest gated SPECT was performed on the stress distribution of technetium-99m sestamibi, using eight frames per cardiac cycle. Mid-horizontal long-axis and vertical long-axis gated tomographic perfusion images were analyzed after digital matrix inversion, which enhances edge detection, for ejection fraction determination. These ejection fractions were compared with those determined by contrast ventriculography (n = 54, including 45 biplane and 9 single plane) and first-pass radionuclide angiography (n = 38) in patients with coronary artery disease. Myocardial perfusion SPECT image inversion-derived ejection fractions were slightly lower (2.7 ejection fraction units, p &lt; 0.01), and first-pass ejection fractions were much lower (8.0 ejection fraction units, p &lt; 0.001) than those obtained with contrast ventriculography. There was excellent correlation between SPECT and contrast ventriculographic ejection fractions (r = 0.93) over a wide range of ejection fractions (14% to 89%). Good correlation was also observed between first-pass radionuclide angiography and both contrast ventriculography (r = 0.83) and SPECT (r = 0.87). Reproducibility of SPECT image inversion ejection fractions was excellent (intraobserver r = 0.99, interobserver r = 0.93). Semiautomated ejection fractions can be obtained from gated SPECT technetium-99m sestamibi perfusion images using the image inversion technique. These results are reproducible and correlate well with results of first-pass radionuclide angiography but are closer in value to those obtained with contrast ventriculography.
First-pass radionuclide angiographie (FPRNA) analysis, using the standard, single-fixed region of... more First-pass radionuclide angiographie (FPRNA) analysis, using the standard, single-fixed region of interest (ROI)drawn at end-diastole, often underestimates the left ventricular ejection fraction (LVEF)as determined by other standard techniques. This study examined the hypothesis that correction for the anatomic motion of the aortic valve plane toward the apex during systole, which results in im proper inclusion of aortic counts within the
Journal of the American College of Cardiology, Jan 7, 2015
Anticoagulation for atrial fibrillation has become more complex due to the introduction of new an... more Anticoagulation for atrial fibrillation has become more complex due to the introduction of new anticoagulant agents, the number and kinds of patients requiring therapy, and the interactions of those patients in the matrix of care. The management of anticoagulation has become a "team sport" involving multiple specialties in multiple sites of care. The American College of Cardiology, through the College's Anticoagulation Initiative, convened a roundtable of experts from multiple specialties to discuss topics important to the management of patients requiring anticoagulation and to make expert recommendations on issues such as the initiation and interruption of anticoagulation, quality of anticoagulation care, management of major and minor bleeding, and treatment of special populations. The attendees continued to work toward consensus on these topics, and present the key findings of this roundtable in a state-of- the-art review focusing on the practical aspects of anticoag...
Journal of the American College of Cardiology, Jan 29, 2014
A report from panel members appointed to the Eighth Joint National Committee titled "2014 Ev... more A report from panel members appointed to the Eighth Joint National Committee titled "2014 Evidence-Based Guideline for the Management of High Blood Pressure in Adults" has garnered much attention due to its major change in recommendations for hypertension treatment for patients ≥60 years of age and for their treatment goal. In response, certain groups have opposed the decision to initiate pharmacologic treatment to lower blood pressure (BP) at systolic BP ≥150 mm Hg and treat to a goal systolic BP of <150 mm Hg in the general population age ≥60 years. This paper contains 3 sections-an introduction followed by the opinions of 2 writing groups-outlining objections to or support of maintaining this proposed strategy in certain at-risk populations, namely African Americans, women, and the elderly. Several authors argue for maintaining current targets, as opposed to adopting the new recommendations, to allow for optimal treatment for older women and African Americans, helpin...
Left ventricular hypertrophy (LVH) is a major independent predictor of cardiovascular disease (CV... more Left ventricular hypertrophy (LVH) is a major independent predictor of cardiovascular disease (CVD) survival and is more prevalent in blacks than whites. In a large biracial population, we evaluated the ability of electrocardiography (ECG)-determined LVH (ECG-LVH) to reclassify CVD/coronary heart disease (CHD) events beyond traditional risk factors in blacks and whites. The analysis included 14,489 participants (mean age 54 ± 5.7 years; 43.5% men; 26% black) from the ARIC cohort, with baseline (1987-1989) ECG, followed up for 10 years. Predicted risk for incident CVD and CHD were estimated using the 10-year Pooled Cohort and Framingham risk equations (base models 1A/1B), respectively. Models 2A and 2B included respective base model plus LVH by "any" of 10 traditional ECG-LVH criteria. Net reclassification improvement (NRI) was calculated, and the distribution of risk was compared using models 2A and 2B versus models 1A and 1B, respectively. There were 792 (5.5%) 10-year Po...
Journal of the American College of Cardiology, 2014
The current paper details the recommendations arising from an NIH-NHLBI/NCI-sponsored symposium h... more The current paper details the recommendations arising from an NIH-NHLBI/NCI-sponsored symposium held in November 2012, aiming to identify key components of a radiation accountability framework fostering patient-centered imaging and shared decision-making in cardiac imaging. Symposium participants, working in 3 tracks, identified key components of a framework to target critical radiation safety issues for the patient, the laboratory, and the larger population of patients with known or suspected cardiovascular disease. The use of ionizing radiation during an imaging procedure should be disclosed to all patients by the ordering provider at the time of ordering, and reinforced by the performing provider team. An imaging protocol with effective dose ≤3 mSv is considered very low risk, not warranting extensive discussion or written informed consent. However, a protocol effective dose &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;20 mSv was proposed as a level requiring particular attention in terms of shared decision-making and either formal discussion or written informed consent. Laboratory reporting of radiation dosimetry is a critical component of creating a quality laboratory fostering a patient-centered environment with transparent procedural methodology. Efforts should be directed to avoiding testing involving radiation, in patients with inappropriate indications. Standardized reporting and diagnostic reference levels for computed tomography and nuclear cardiology are important for the goal of public reporting of laboratory radiation dose levels in conjunction with diagnostic performance. The development of cardiac imaging technologies revolutionized cardiology practice by allowing routine, noninvasive assessment of myocardial perfusion and anatomy. It is now incumbent upon the imaging community to create an accountability framework to safely drive appropriate imaging utilization.
Journal of the American College of Cardiology, 1996
This study evaluated the use of gated single-photon emission computed tomographic (SPECT) myocard... more This study evaluated the use of gated single-photon emission computed tomographic (SPECT) myocardial perfusion images for determination of left ventricular ejection fraction. Gated SPECT has expanded the applications of myocardial perfusion imaging to include the evaluation of left ventricular size, regional wall motion and regional systolic thickening. Accurate automated or semi-automated methods for quantitation of left ventricular ejection fraction from tomographic perfusion images would provide additional valuable clinical information. Rest gated SPECT was performed on the stress distribution of technetium-99m sestamibi, using eight frames per cardiac cycle. Mid-horizontal long-axis and vertical long-axis gated tomographic perfusion images were analyzed after digital matrix inversion, which enhances edge detection, for ejection fraction determination. These ejection fractions were compared with those determined by contrast ventriculography (n = 54, including 45 biplane and 9 single plane) and first-pass radionuclide angiography (n = 38) in patients with coronary artery disease. Myocardial perfusion SPECT image inversion-derived ejection fractions were slightly lower (2.7 ejection fraction units, p &lt; 0.01), and first-pass ejection fractions were much lower (8.0 ejection fraction units, p &lt; 0.001) than those obtained with contrast ventriculography. There was excellent correlation between SPECT and contrast ventriculographic ejection fractions (r = 0.93) over a wide range of ejection fractions (14% to 89%). Good correlation was also observed between first-pass radionuclide angiography and both contrast ventriculography (r = 0.83) and SPECT (r = 0.87). Reproducibility of SPECT image inversion ejection fractions was excellent (intraobserver r = 0.99, interobserver r = 0.93). Semiautomated ejection fractions can be obtained from gated SPECT technetium-99m sestamibi perfusion images using the image inversion technique. These results are reproducible and correlate well with results of first-pass radionuclide angiography but are closer in value to those obtained with contrast ventriculography.
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Papers by Kim Williams