Ernesto Castillo

Left Ventricular Concentric Remodeling Is Associated With Decreased Global and Regional Systolic Function The Multi-Ethnic Study of Atherosclerosis

Background—The transition from compensatory concentric remodeling to myocardial failure is not completely understood in humans. To investigate determinants of incipient myocardial dysfunction, we examined the association between concentric remodeling and regional LV function in asymptomatic participants of the Multi-Ethnic Study of Atherosclerosis (MESA). Methods and Results—Myocardial tagged MRI was performed. Regional myocardial function expressed as peak systolic midwall circumferential strain (Ecc) was analyzed in 441 consecutive studies by HARP (Harmonic Phase) tool. Peak Ecc was correlated with the extent of concentric remodeling determined by the ratio of left ventricular mass to end-diastolic volume (M/V ratio). In men, a gradual decline in peak global Ecc was seen with increasing M/V ratio (test for trend, P<0.001). Among women, however, Ecc tended to be lower only in the fifth compared with the first quintile of M/V ratio (P=0.1). The association of lower Ecc with increasing M/V ratio was regionally heterogeneous but was particularly prominent in the LAD region in men (test for trend, P<0.001) and in women (test for trend, P=0.02). In the right coronary and left circumflex artery territories, these associations were less marked in both genders. Conclusions—In this cross-sectional study of asymptomatic individuals, concentric left ventricular remodeling was related to decreased regional systolic function. The reduction in regional function, which was more pronounced in the left anterior descending coronary artery territory, may reflect the local transition from compensatory remodeling to myocardial dysfunction.

Magnetic Resonance Imaging Findings in Patients Meeting Task Force Criteria for Arrhythmogenic Right Ventricular Dysplasia

Introduction: Magnet resonance imaging (MRI) findings in patients meeting Task Force criteria for the diagnosis of arrhythmogenic right ventricular dysplasia (ARVD) have not been systematically described. We report qualitative and quantitative MRI findings in ARVD using state‐of‐the‐art MRI.

Quantitative assessment of regional myocardial function with MR-tagging in a multi-center study: interobserver and intraobserver agreement of fast strain analysis with Harmonic Phase (HARP) MRI

PURPOSE To assess the reproducibility of Harmonic Phase (HARP) analysis of myocardial MR tagged images acquired in the Multi-Center Study of Atherosclerosis (MESA). METHODS Using the HARP method, three independent observers performed two separate quantitative strain analyses of myocardial cine MR-tagging images blindly in 24 participants. The images were obtained in four different centers and analyzed at a single core lab. Each study comprised 3 short-axis slices subdivided in 12 segments (24 x 3 x 12 = 864 segments), each with three layers. Normal strains (circumferential [Ecc] and radial [Err]), principal strains (Lambda1, Lambda2), and the angle alpha (between Ecc-Lambda2) were calculated. Intraclass correlation coefficient (R) for peak systolic strains, and all pooled systolic and diastolic strain data were used to determine inter- and intraobserver agreement. Two observers also visually graded study quality. R values were related to the image quality in different myocardial regions and layers. RESULTS Overall, HARP yielded an excellent inter- and intraobserver agreement for peak systolic strain data (for Ecc, R = 0.84 and 0.89, respectively) and all systolic pooled data (for Ecc, interobserver R = 0.82, intraobserver R = 0.69-0.76). Both inter and intraobserver agreement were lower for diastolic pooled data (R = 0.69 and 0.58-0.62, respectively). There was a direct relationship between image quality and performance of the HARP analysis, with increasing inter- and intraobserver R values in studies with longer tag persistence. Both inter- and intraobserver agreement were better in the anterior and septal myocardial regions, and in the midwall layer. The intraobserver agreement was similar among the three observers. CONCLUSION Employing the HARP method for quantitative strain analysis of myocardial MR tagged images provides a high inter- and intraobserver agreement. These good results are obtained in case of good to excellent MR image quality.

Quantitative Ischemia Detection During Cardiac Magnetic Resonance Stress Testing by Use of FastHARP

Background—Because ECG alterations caused by ischemia cannot be reliably detected in the high-field MRI environment, detection of wall motion abnormalities is often used to ensure patient safety during stress testing. However, an experienced observer is needed to detect these abnormalities. In this study, we investigate the use of fast harmonic phase (FastHARP) MRI for the quantitative, operator-independent detection of the onset of ischemia during acute coronary occlusion. Methods and Results—Eight mongrel dogs underwent an acute 2-minute closed-chest coronary artery occlusion while continuous FastHARP images were acquired. Full regional wall strain was determined every other heartbeat in a single short-axis imaging slice. After 5 minutes of reperfusion, a second 2-minute ischemic episode was induced during the acquisition of conventional cine wall-motion images. The time at which ECG alterations were observed during the first ischemic period was recorded. The time from occlusion to the detection of ischemia, based on a consensus of 2 blinded observers, was determined for MRI. No significant ischemia was present in 2 animals. In the remaining animals, the onset of ischemia was detected significantly earlier by FastHARP than by cine MRI (9.5±5 versus 33±14 seconds, P <0.01). HARP ischemia detection preceded ECG changes, on average, by 54 seconds. Conclusions—The rapid acquisition and detection of induced ischemia with FastHARP MRI shows promise as a nonsubjective method to diagnose significant coronary lesions during MR stress testing.

Cardiac MRI: Recent progress and continued challenges

Cardiac MRI continues to develop and advance. MRI accurately depicts cardiac structure, function, perfusion, and myocardial viability with an overall capacity unmatched by any other single imaging modality. MRI is an accepted and widely utilized tool for cardiovascular research. Its clinical use has been limited, but is increasing because of its proven clinical efficacy, the proliferation of cardiac‐capable MRI systems, and the development of improved pulse sequences. The following article reviews the landmark developments in this field, with an emphasis on recent progress in the evaluation of ischemic or acquired heart disease. J. Magn. Reson. Imaging 2002;16:111–127. Published 2002 Wiley‐Liss, Inc.

Left Ventricular Concentric Remodeling Is Associated With Decreased Global and Regional Systolic Function

Background— The transition from compensatory concentric remodeling to myocardial failure is not completely understood in humans. To investigate determinants of incipient myocardial dysfunction, we examined the association between concentric remodeling and regional LV function in asymptomatic participants of the Multi-Ethnic Study of Atherosclerosis (MESA). Methods and Results— Myocardial tagged MRI was performed. Regional myocardial function expressed as peak systolic midwall circumferential strain (Ecc) was analyzed in 441 consecutive studies by HARP (Harmonic Phase) tool. Peak Ecc was correlated with the extent of concentric remodeling determined by the ratio of left ventricular mass to end-diastolic volume (M/V ratio). In men, a gradual decline in peak global Ecc was seen with increasing M/V ratio (test for trend, P<0.001). Among women, however, Ecc tended to be lower only in the fifth compared with the first quintile of M/V ratio (P=0.1). The association of lower Ecc with increasing M/V ratio was regi...

Cardiac MR imaging

There has been tremendous progress for MR imaging depiction of cardiac morphology and function. Further advances toward achieving faster acquisition with real-time imaging, higher resolution for plaque imaging, and quantitative analysis are taking place at a rapid pace.

Left Atrial Anatomic Remodeling in Atrial Fibrillation

In this issue of the Journal, Chang et al.1 report observations on the size and shape of the left atrial (LA) appendage and the LA itself in patients with paroxysmal atrial fibrillation (AF) undergoing pulmonary vein (PV) isolation. The estimated LA volume, mathematically calculated from the anteroposterior, superoinferior, and laterolateral LA diameters, is larger in patients with AF than in controls without atrial arrhythmias. The LA appendage is also larger and its opening to the LA is less eccentric (more “rounded”) in patients with AF. After a mean follow-up of 20 months, they observed that in patients without AF recurrence, appendage size decreased and the opening of the appendage to the LA became more eccentric, while estimated LA volume also decreased, but did not return to normal. The authors interpret the data as showing decreased LA and appendage stretch and recovery of muscle function. In contrast with this favorable evolution, in patients with AF recurrence, LA size and appendage size increased, while the opening of the appendage became less eccentric. This interpretation lacks the support of dynamic studies; however, it is consistent with previous echocardiographic observations demonstrating return of appendage systolic flow after cardioversion.2 Perhaps in favor