Yuchi Han - Academia.edu (original) (raw)

Papers by Yuchi Han

Research paper thumbnail of Effects of Age-related Aortic Root Anatomic Changes on Left Ventricular Outflow Tract Pace-mapping Morphologies: A Cardiac Magnetic Resonance Imaging Validation Study

Journal of cardiovascular electrophysiology, Jan 20, 2015

Outflow tract ventricular arrhythmias (OT VAs) are common and catheter ablation is an effective t... more Outflow tract ventricular arrhythmias (OT VAs) are common and catheter ablation is an effective treatment option. We sought to investigate the relationship between age-related anatomic aortic root changes and QRS morphology during left ventricular outflow tract (LVOT) pace-mapping using cardiac magnetic resonance (CMR) imaging. Fifty-one patients undergoing CMR imaging were divided into three groups based on age (< 40, 40-60, > 60 years). We measured the angle of the aortic root, the aorta to ventricular septal angle, the distance between the right coronary cusp (RCC) and left coronary cusp (LCC), and the distance between the ascending and descending aorta. Additionally, we evaluated the QRS morphologies obtained during pace-mapping from the LVOT. In older patients, LCC was more superior to the RCC (P < 0.01). Age was positively correlated with the aortic root angle (r(2) = 0.481, P < 0.01) as well as the distances between the ascending and descending aorta at a level be...

Research paper thumbnail of Altered Right Ventricular Kinetic Energy Work Density and Viscous Energy Dissipation in Patients with Pulmonary Arterial Hypertension: A Pilot Study Using 4D Flow MRI

PLOS ONE, 2015

Right ventricular (RV) function has increasingly being recognized as an important predictor for m... more Right ventricular (RV) function has increasingly being recognized as an important predictor for morbidity and mortality in patients with pulmonary arterial hypertension (PAH). The increased RV after-load increase RV work in PAH. We used time-resolved 3D phase contrast MRI (4D flow MRI) to derive RV kinetic energy (KE) work density and energy loss in the pulmonary artery (PA) to better characterize RV work in PAH patients. 4D flow and standard cardiac cine images were obtained in ten functional class I/II patients with PAH and nine healthy subjects. For each individual, we calculated the RV KE work density and the amount of viscous dissipation in the PA. PAH patients had alterations in flow patterns in both the RV and the PA compared to healthy subjects. PAH subjects had significantly higher RV KE work density than healthy subjects (94.7±33.7 mJ/mL vs. 61.7±14.8 mJ/mL, p = 0.007) as well as a much greater percent PA energy loss (21.1±6.4% vs. 2.2±1.3%, p = 0.0001) throughout the cardiac cycle. RV KE work density and percent PA energy loss had mild and moderate correlations with RV ejection fraction. This study has quantified two kinetic energy metrics to assess RV function using 4D flow. RV KE work density and PA viscous energy loss not only distinguished healthy subjects from patients, but also provided distinction amongst PAH patients. These metrics hold promise as imaging markers for RV function.

Research paper thumbnail of Impact of end-diastolic and end-systolic phase selection in the volumetric evaluation of cardiac MRI

Journal of Magnetic Resonance Imaging, 2015

Research paper thumbnail of Increased reproducibility in RV mass measurement at end-systole

Journal of Cardiovascular Magnetic Resonance, 2015

Research paper thumbnail of The impact of gender on cardiovascular system calcification in very elderly patients with severe aortic stenosis

The international journal of cardiovascular imaging, Jan 29, 2015

There is an established sex difference in cardiovascular disease among pre-menopausal women and a... more There is an established sex difference in cardiovascular disease among pre-menopausal women and age-matched men, with men having greater susceptibility to cardiovascular and coronary artery disease. Cardiovascular calcification may be linked to the atherosclerotic process and resulting disease, but the sex difference regarding coronary artery disease susceptibility and calcification is incompletely understood. We thought to measure calcium volume in different chest vascular beds in very elderly men and women with severe aortic stenosis (AS). Computed tomography scans of 94 patients with severe AS were calcium volume scored on Aquarius iNtuition Terarecon (Terarecon Inc., CA, USA) work stations. Coronary beds, aortic valve, mitral valve apparatus, and the thoracic aorta were examined. A significant sex difference in the mean total calcium volume of the coronary arteries was found in elderly (p = 0.001), with men having greater levels of calcification. There is also a significant sex ...

Research paper thumbnail of RV dyssynchrony in PAH as evidenced by slice to slice minimum volume timing

Journal of Cardiovascular Magnetic Resonance, 2015

Research paper thumbnail of CMR RV size assessment should include RV to LV volume ratio

Journal of Cardiovascular Magnetic Resonance, 2015

Research paper thumbnail of Accuracy and reproducibility of T1rho mapping sequences

Journal of Cardiovascular Magnetic Resonance, 2015

Research paper thumbnail of Continuous adaptive radial sampling of k-space from real-time physiologic feedback in MRI

Journal of Cardiovascular Magnetic Resonance, 2015

Research paper thumbnail of Beat to beat volumetric analysis in arrhythmia using real time CMR

Journal of Cardiovascular Magnetic Resonance, 2015

Research paper thumbnail of The Influence of Mitral Annuloplasty on Left Ventricular Flow Dynamics

The Annals of thoracic surgery, Jan 12, 2015

Mitral valve (MV) repair using annuloplasty rings is the preferred method of treatment for MV reg... more Mitral valve (MV) repair using annuloplasty rings is the preferred method of treatment for MV regurgitation, but the impact of annuloplasty ring placement on left ventricular intraventricular flow has not been studied. Annuloplasty rings of varying sizes were placed in 5 healthy sheep (intercommissural ring sizes were 24, 26, 28, 30, and 32 mm), and three-dimensional phase contrast magnetic resonance imaging (4D flow MRI) was performed before and 1 week after ring placement. Normal diastolic flow consisted of diastolic intraventricular vortices that naturally unwound during systole. Postsurgical intraventricular flow was highly disturbed in all sheep, and the disturbance was greatest for undersized rings. Ring size was highly correlated with the diastolic inflow angle (Pearson's r = -0.62, p < 0.1, 95% confidence interval: -0.92 to 0.14). There was a mean angle increase of mean diastolic inflow angle increase of 12.3 degrees (< 30 mm, p < 0.01, 95% confidence interval: ...

Research paper thumbnail of Effects of Age-related Aortic Root Anatomic Changes on Left Ventricular Outflow Tract Pace-mapping Morphologies: A Cardiac Magnetic Resonance Imaging Validation Study

Journal of cardiovascular electrophysiology, Jan 20, 2015

Outflow tract ventricular arrhythmias (OT VAs) are common and catheter ablation is an effective t... more Outflow tract ventricular arrhythmias (OT VAs) are common and catheter ablation is an effective treatment option. We sought to investigate the relationship between age-related anatomic aortic root changes and QRS morphology during left ventricular outflow tract (LVOT) pace-mapping using cardiac magnetic resonance (CMR) imaging. Fifty-one patients undergoing CMR imaging were divided into three groups based on age (< 40, 40-60, > 60 years). We measured the angle of the aortic root, the aorta to ventricular septal angle, the distance between the right coronary cusp (RCC) and left coronary cusp (LCC), and the distance between the ascending and descending aorta. Additionally, we evaluated the QRS morphologies obtained during pace-mapping from the LVOT. In older patients, LCC was more superior to the RCC (P < 0.01). Age was positively correlated with the aortic root angle (r(2) = 0.481, P < 0.01) as well as the distances between the ascending and descending aorta at a level be...

Research paper thumbnail of RV mass measurement at end-systole: Improved accuracy, Reproducibility, and reduced segmentation time

Journal of magnetic resonance imaging : JMRI, Jan 31, 2015

To evaluate the accuracy, reproducibility, and contouring time of RV mass in end-systole (ES) and... more To evaluate the accuracy, reproducibility, and contouring time of RV mass in end-systole (ES) and end-diastole (ED). Magnetic resonance imaging (MRI) has been shown to be accurate and reproducible for the evaluation of right ventricular (RV) volume and function. RV mass, assessed in end-diastolic (ED) phase, is one of the least reproducible variables. The choice of end-systolic (ES) phase could offer an alternative to improve reproducibility, since the selection of the basal slice and the visualization of the usually thin RV wall are easier in this phase. To evaluate accuracy, 11 sheep were imaged in vivo and their RV free walls were weighed after removing epicardial fat. To evaluate reproducibility, 30 normal subjects and 30 subjects with pulmonary arterial hypertension (PAH) were imaged and interobserver and intraobserver variabilities were assessed in the ES and the ED. Segmentation time was recorded after visual selection of ES and ED phases. ES RV mass measurement has less abso...

Research paper thumbnail of Ablation of outflow tract ventricular tachycardia

Current treatment options in cardiovascular medicine, 2015

Ventricular tachycardia in patients with structurally normal hearts is most frequently due to ade... more Ventricular tachycardia in patients with structurally normal hearts is most frequently due to adenosine-sensitive, triggered activity. The most common sites of origin are the right and left ventricular outflow tracts. Patients may present with symptoms such as palpitations, or less commonly cardiomyopathy. Treatment options include beta blockers, calcium channel blockers, sodium channel blockers, potassium channel blockers, and catheter ablation. Catheter ablation is highly effective and when performed by a skilled electrophysiologist, can be considered first-line treatment. Knowledge of outflow tract and surrounding anatomy is vital to optimizing results. In this review, we discuss outflow tract anatomy and electrocardiographic morphology, as well as techniques for optimizing ablation outcomes.

Research paper thumbnail of Adherence to Thresholds

Academic Radiology, 2015

The publisher regrets that this article has been temporarily removed. A replacement will appear a... more The publisher regrets that this article has been temporarily removed. A replacement will appear as soon as possible in which the reason for the removal of the article will be specified, or the article will be reinstated. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.

Research paper thumbnail of Impact of age, sex, and indexation method on MR left ventricular reference values in the framingham heart study offspring cohort

Journal of Magnetic Resonance Imaging, 2014

To determine normative values for left ventricular (LV) volumes, mass, concentricity, and ejectio... more To determine normative values for left ventricular (LV) volumes, mass, concentricity, and ejection fraction (EF) and investigate associations between sex, age, and body size with LV parameters in community-dwelling adults. In all, 1794 Framingham Heart Study Offspring cohort members underwent LV short-axis oriented, contiguous multislice cine steady-state free precession MR of the left ventricle; from these a healthy referent group (n = 852, 61 ± 9 years, 40% men) free of clinical cardiac disease and hypertension (SBP &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 140, DBP &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 90 mmHg, never used antihypertensive medication ≥30 years prior to scanning) was identified. Referent participants were stratified by sex and age group (≤55, 56-65, &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;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;65 years); LV parameters were indexed to measures of body size. Men have greater LV volumes and mass than women both before and after indexation to height, powers of height, and body surface area (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01 all), but indexation to fat-free mass yielded greater LV volume and mass in women. In both sexes, LV volumes and mass decrease with advancing age, although indexation attenuates this association. LVEF is greater in women than men (68 ± 5% vs. 66 ± 5%, P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01) and increases with age in both sexes (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05). Among nonhypertensive adults free of cardiac disease, men have greater LV volumes and mass with sex differences generally persisting after indexation to body size. LV volumes and mass tend to decrease with greater age in both sexes. Female sex and advanced…

Research paper thumbnail of Assessing Myocardial Disease Using T1ρ MRI

Current cardiovascular imaging reports, 2014

There is great interest to use magnetic resonance imaging (MRI) for non-invasive assessment of my... more There is great interest to use magnetic resonance imaging (MRI) for non-invasive assessment of myocardial disease in ischemic and non-ischemic cardiomyopathies. Recently, there has been a renewed interest to use a magnetic resonance imaging (MRI) technique utilizing spin locking radiofrequency (RF) pulses, called T1ρ MRI. The spin locking RF pulse creates sensitivity to some mechanisms of nuclear relaxation such as (1)H exchange between water and amide, amine and hydroxyl functional groups in molecules; consequently, there is the potential to non-invasively, and without exogenous contrast agents, obtain important molecular information from diseased myocardial tissue. The purpose of this article is to review and critically examine the recent published literature in the field related to T1ρ MRI of myocardial disease.

Research paper thumbnail of Clinical echocardiographic indices of left ventricular diastolic function correlate poorly with pulmonary capillary wedge pressure at 1 year following heart transplantation

The International Journal of Cardiovascular Imaging, 2015

Clinical echocardiographic assessment of left ventricular (LV) systolic and diastolic function is... more Clinical echocardiographic assessment of left ventricular (LV) systolic and diastolic function is routinely performed following orthotopic heart transplantation (OHT). The purpose of this study was to determine whether echocardiographic indices of LV diastolic function correlate with pulmonary capillary wedge pressure (PCWP) in the transplanted heart. Patients who had OHT between June 2009 and November 2011 underwent transthoracic echocardiography and right heart catheterization (RHC) at approximately 1 year post transplantation. We retrospectively assessed 33 potential parameters of LV diastolic function using 2-dimensional, spectral Doppler and tissue Doppler echocardiography. We measured PCWP by RHC. We compared echocardiographic measures with PCWP using linear regression analysis. Ninety-five patients (mean age 49 ± 13 years, 73 males, mean LV ejection fraction 62 ± 10 %) were included in the study. Overall, echocardiographic parameters of LV diastolic function demonstrated poor correlation with PCWP. By linear regression, the parameter that most strongly correlated with PCWP was left atrial (LA) minimum area in the apical 4-chamber view (p = 0.002, r(2) = 0.1). Comparing patients with PCWP ≤ 12 mmHg and those with PCWP &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;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; 12 mmHg, the parameter that demonstrated the most significant difference was LA minimum area in the apical 2-chamber view (p = 0.002), and comparing patients with PCWP ≤ 15 mmHg and those with PCWP &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;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; 15 mmHg, the most significant difference was peak early diastolic velocity of the mitral annulus (p = 0.02). In patients with cardiac allografts, clinical echocardiographic measures of LV diastolic function correlate poorly with PCWP.

Research paper thumbnail of LV Infarct Size and Peri-Infarct Zone Measurements: A Comparison of High Resolution 3D and Conventional 2D Late Gadolinium Enhancement

Research paper thumbnail of Transient Steady-State Free Precession Coronary Vein MRI

Research paper thumbnail of Effects of Age-related Aortic Root Anatomic Changes on Left Ventricular Outflow Tract Pace-mapping Morphologies: A Cardiac Magnetic Resonance Imaging Validation Study

Journal of cardiovascular electrophysiology, Jan 20, 2015

Outflow tract ventricular arrhythmias (OT VAs) are common and catheter ablation is an effective t... more Outflow tract ventricular arrhythmias (OT VAs) are common and catheter ablation is an effective treatment option. We sought to investigate the relationship between age-related anatomic aortic root changes and QRS morphology during left ventricular outflow tract (LVOT) pace-mapping using cardiac magnetic resonance (CMR) imaging. Fifty-one patients undergoing CMR imaging were divided into three groups based on age (< 40, 40-60, > 60 years). We measured the angle of the aortic root, the aorta to ventricular septal angle, the distance between the right coronary cusp (RCC) and left coronary cusp (LCC), and the distance between the ascending and descending aorta. Additionally, we evaluated the QRS morphologies obtained during pace-mapping from the LVOT. In older patients, LCC was more superior to the RCC (P < 0.01). Age was positively correlated with the aortic root angle (r(2) = 0.481, P < 0.01) as well as the distances between the ascending and descending aorta at a level be...

Research paper thumbnail of Altered Right Ventricular Kinetic Energy Work Density and Viscous Energy Dissipation in Patients with Pulmonary Arterial Hypertension: A Pilot Study Using 4D Flow MRI

PLOS ONE, 2015

Right ventricular (RV) function has increasingly being recognized as an important predictor for m... more Right ventricular (RV) function has increasingly being recognized as an important predictor for morbidity and mortality in patients with pulmonary arterial hypertension (PAH). The increased RV after-load increase RV work in PAH. We used time-resolved 3D phase contrast MRI (4D flow MRI) to derive RV kinetic energy (KE) work density and energy loss in the pulmonary artery (PA) to better characterize RV work in PAH patients. 4D flow and standard cardiac cine images were obtained in ten functional class I/II patients with PAH and nine healthy subjects. For each individual, we calculated the RV KE work density and the amount of viscous dissipation in the PA. PAH patients had alterations in flow patterns in both the RV and the PA compared to healthy subjects. PAH subjects had significantly higher RV KE work density than healthy subjects (94.7±33.7 mJ/mL vs. 61.7±14.8 mJ/mL, p = 0.007) as well as a much greater percent PA energy loss (21.1±6.4% vs. 2.2±1.3%, p = 0.0001) throughout the cardiac cycle. RV KE work density and percent PA energy loss had mild and moderate correlations with RV ejection fraction. This study has quantified two kinetic energy metrics to assess RV function using 4D flow. RV KE work density and PA viscous energy loss not only distinguished healthy subjects from patients, but also provided distinction amongst PAH patients. These metrics hold promise as imaging markers for RV function.

Research paper thumbnail of Impact of end-diastolic and end-systolic phase selection in the volumetric evaluation of cardiac MRI

Journal of Magnetic Resonance Imaging, 2015

Research paper thumbnail of Increased reproducibility in RV mass measurement at end-systole

Journal of Cardiovascular Magnetic Resonance, 2015

Research paper thumbnail of The impact of gender on cardiovascular system calcification in very elderly patients with severe aortic stenosis

The international journal of cardiovascular imaging, Jan 29, 2015

There is an established sex difference in cardiovascular disease among pre-menopausal women and a... more There is an established sex difference in cardiovascular disease among pre-menopausal women and age-matched men, with men having greater susceptibility to cardiovascular and coronary artery disease. Cardiovascular calcification may be linked to the atherosclerotic process and resulting disease, but the sex difference regarding coronary artery disease susceptibility and calcification is incompletely understood. We thought to measure calcium volume in different chest vascular beds in very elderly men and women with severe aortic stenosis (AS). Computed tomography scans of 94 patients with severe AS were calcium volume scored on Aquarius iNtuition Terarecon (Terarecon Inc., CA, USA) work stations. Coronary beds, aortic valve, mitral valve apparatus, and the thoracic aorta were examined. A significant sex difference in the mean total calcium volume of the coronary arteries was found in elderly (p = 0.001), with men having greater levels of calcification. There is also a significant sex ...

Research paper thumbnail of RV dyssynchrony in PAH as evidenced by slice to slice minimum volume timing

Journal of Cardiovascular Magnetic Resonance, 2015

Research paper thumbnail of CMR RV size assessment should include RV to LV volume ratio

Journal of Cardiovascular Magnetic Resonance, 2015

Research paper thumbnail of Accuracy and reproducibility of T1rho mapping sequences

Journal of Cardiovascular Magnetic Resonance, 2015

Research paper thumbnail of Continuous adaptive radial sampling of k-space from real-time physiologic feedback in MRI

Journal of Cardiovascular Magnetic Resonance, 2015

Research paper thumbnail of Beat to beat volumetric analysis in arrhythmia using real time CMR

Journal of Cardiovascular Magnetic Resonance, 2015

Research paper thumbnail of The Influence of Mitral Annuloplasty on Left Ventricular Flow Dynamics

The Annals of thoracic surgery, Jan 12, 2015

Mitral valve (MV) repair using annuloplasty rings is the preferred method of treatment for MV reg... more Mitral valve (MV) repair using annuloplasty rings is the preferred method of treatment for MV regurgitation, but the impact of annuloplasty ring placement on left ventricular intraventricular flow has not been studied. Annuloplasty rings of varying sizes were placed in 5 healthy sheep (intercommissural ring sizes were 24, 26, 28, 30, and 32 mm), and three-dimensional phase contrast magnetic resonance imaging (4D flow MRI) was performed before and 1 week after ring placement. Normal diastolic flow consisted of diastolic intraventricular vortices that naturally unwound during systole. Postsurgical intraventricular flow was highly disturbed in all sheep, and the disturbance was greatest for undersized rings. Ring size was highly correlated with the diastolic inflow angle (Pearson's r = -0.62, p < 0.1, 95% confidence interval: -0.92 to 0.14). There was a mean angle increase of mean diastolic inflow angle increase of 12.3 degrees (< 30 mm, p < 0.01, 95% confidence interval: ...

Research paper thumbnail of Effects of Age-related Aortic Root Anatomic Changes on Left Ventricular Outflow Tract Pace-mapping Morphologies: A Cardiac Magnetic Resonance Imaging Validation Study

Journal of cardiovascular electrophysiology, Jan 20, 2015

Outflow tract ventricular arrhythmias (OT VAs) are common and catheter ablation is an effective t... more Outflow tract ventricular arrhythmias (OT VAs) are common and catheter ablation is an effective treatment option. We sought to investigate the relationship between age-related anatomic aortic root changes and QRS morphology during left ventricular outflow tract (LVOT) pace-mapping using cardiac magnetic resonance (CMR) imaging. Fifty-one patients undergoing CMR imaging were divided into three groups based on age (< 40, 40-60, > 60 years). We measured the angle of the aortic root, the aorta to ventricular septal angle, the distance between the right coronary cusp (RCC) and left coronary cusp (LCC), and the distance between the ascending and descending aorta. Additionally, we evaluated the QRS morphologies obtained during pace-mapping from the LVOT. In older patients, LCC was more superior to the RCC (P < 0.01). Age was positively correlated with the aortic root angle (r(2) = 0.481, P < 0.01) as well as the distances between the ascending and descending aorta at a level be...

Research paper thumbnail of RV mass measurement at end-systole: Improved accuracy, Reproducibility, and reduced segmentation time

Journal of magnetic resonance imaging : JMRI, Jan 31, 2015

To evaluate the accuracy, reproducibility, and contouring time of RV mass in end-systole (ES) and... more To evaluate the accuracy, reproducibility, and contouring time of RV mass in end-systole (ES) and end-diastole (ED). Magnetic resonance imaging (MRI) has been shown to be accurate and reproducible for the evaluation of right ventricular (RV) volume and function. RV mass, assessed in end-diastolic (ED) phase, is one of the least reproducible variables. The choice of end-systolic (ES) phase could offer an alternative to improve reproducibility, since the selection of the basal slice and the visualization of the usually thin RV wall are easier in this phase. To evaluate accuracy, 11 sheep were imaged in vivo and their RV free walls were weighed after removing epicardial fat. To evaluate reproducibility, 30 normal subjects and 30 subjects with pulmonary arterial hypertension (PAH) were imaged and interobserver and intraobserver variabilities were assessed in the ES and the ED. Segmentation time was recorded after visual selection of ES and ED phases. ES RV mass measurement has less abso...

Research paper thumbnail of Ablation of outflow tract ventricular tachycardia

Current treatment options in cardiovascular medicine, 2015

Ventricular tachycardia in patients with structurally normal hearts is most frequently due to ade... more Ventricular tachycardia in patients with structurally normal hearts is most frequently due to adenosine-sensitive, triggered activity. The most common sites of origin are the right and left ventricular outflow tracts. Patients may present with symptoms such as palpitations, or less commonly cardiomyopathy. Treatment options include beta blockers, calcium channel blockers, sodium channel blockers, potassium channel blockers, and catheter ablation. Catheter ablation is highly effective and when performed by a skilled electrophysiologist, can be considered first-line treatment. Knowledge of outflow tract and surrounding anatomy is vital to optimizing results. In this review, we discuss outflow tract anatomy and electrocardiographic morphology, as well as techniques for optimizing ablation outcomes.

Research paper thumbnail of Adherence to Thresholds

Academic Radiology, 2015

The publisher regrets that this article has been temporarily removed. A replacement will appear a... more The publisher regrets that this article has been temporarily removed. A replacement will appear as soon as possible in which the reason for the removal of the article will be specified, or the article will be reinstated. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.

Research paper thumbnail of Impact of age, sex, and indexation method on MR left ventricular reference values in the framingham heart study offspring cohort

Journal of Magnetic Resonance Imaging, 2014

To determine normative values for left ventricular (LV) volumes, mass, concentricity, and ejectio... more To determine normative values for left ventricular (LV) volumes, mass, concentricity, and ejection fraction (EF) and investigate associations between sex, age, and body size with LV parameters in community-dwelling adults. In all, 1794 Framingham Heart Study Offspring cohort members underwent LV short-axis oriented, contiguous multislice cine steady-state free precession MR of the left ventricle; from these a healthy referent group (n = 852, 61 ± 9 years, 40% men) free of clinical cardiac disease and hypertension (SBP &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 140, DBP &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 90 mmHg, never used antihypertensive medication ≥30 years prior to scanning) was identified. Referent participants were stratified by sex and age group (≤55, 56-65, &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;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;65 years); LV parameters were indexed to measures of body size. Men have greater LV volumes and mass than women both before and after indexation to height, powers of height, and body surface area (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01 all), but indexation to fat-free mass yielded greater LV volume and mass in women. In both sexes, LV volumes and mass decrease with advancing age, although indexation attenuates this association. LVEF is greater in women than men (68 ± 5% vs. 66 ± 5%, P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01) and increases with age in both sexes (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05). Among nonhypertensive adults free of cardiac disease, men have greater LV volumes and mass with sex differences generally persisting after indexation to body size. LV volumes and mass tend to decrease with greater age in both sexes. Female sex and advanced…

Research paper thumbnail of Assessing Myocardial Disease Using T1ρ MRI

Current cardiovascular imaging reports, 2014

There is great interest to use magnetic resonance imaging (MRI) for non-invasive assessment of my... more There is great interest to use magnetic resonance imaging (MRI) for non-invasive assessment of myocardial disease in ischemic and non-ischemic cardiomyopathies. Recently, there has been a renewed interest to use a magnetic resonance imaging (MRI) technique utilizing spin locking radiofrequency (RF) pulses, called T1ρ MRI. The spin locking RF pulse creates sensitivity to some mechanisms of nuclear relaxation such as (1)H exchange between water and amide, amine and hydroxyl functional groups in molecules; consequently, there is the potential to non-invasively, and without exogenous contrast agents, obtain important molecular information from diseased myocardial tissue. The purpose of this article is to review and critically examine the recent published literature in the field related to T1ρ MRI of myocardial disease.

Research paper thumbnail of Clinical echocardiographic indices of left ventricular diastolic function correlate poorly with pulmonary capillary wedge pressure at 1 year following heart transplantation

The International Journal of Cardiovascular Imaging, 2015

Clinical echocardiographic assessment of left ventricular (LV) systolic and diastolic function is... more Clinical echocardiographic assessment of left ventricular (LV) systolic and diastolic function is routinely performed following orthotopic heart transplantation (OHT). The purpose of this study was to determine whether echocardiographic indices of LV diastolic function correlate with pulmonary capillary wedge pressure (PCWP) in the transplanted heart. Patients who had OHT between June 2009 and November 2011 underwent transthoracic echocardiography and right heart catheterization (RHC) at approximately 1 year post transplantation. We retrospectively assessed 33 potential parameters of LV diastolic function using 2-dimensional, spectral Doppler and tissue Doppler echocardiography. We measured PCWP by RHC. We compared echocardiographic measures with PCWP using linear regression analysis. Ninety-five patients (mean age 49 ± 13 years, 73 males, mean LV ejection fraction 62 ± 10 %) were included in the study. Overall, echocardiographic parameters of LV diastolic function demonstrated poor correlation with PCWP. By linear regression, the parameter that most strongly correlated with PCWP was left atrial (LA) minimum area in the apical 4-chamber view (p = 0.002, r(2) = 0.1). Comparing patients with PCWP ≤ 12 mmHg and those with PCWP &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;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; 12 mmHg, the parameter that demonstrated the most significant difference was LA minimum area in the apical 2-chamber view (p = 0.002), and comparing patients with PCWP ≤ 15 mmHg and those with PCWP &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;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; 15 mmHg, the most significant difference was peak early diastolic velocity of the mitral annulus (p = 0.02). In patients with cardiac allografts, clinical echocardiographic measures of LV diastolic function correlate poorly with PCWP.

Research paper thumbnail of LV Infarct Size and Peri-Infarct Zone Measurements: A Comparison of High Resolution 3D and Conventional 2D Late Gadolinium Enhancement

Research paper thumbnail of Transient Steady-State Free Precession Coronary Vein MRI