Serial magnetic resonance imaging based assessment of the early effects of an ACE inhibitor on postinfarction left ventricular remodeling in rats

2005 ◽  
Vol 83 (12) ◽  
pp. 1109-1115 ◽  
Author(s):  
Fabrice Prunier ◽  
Laurent Marescaux ◽  
Florence Franconi ◽  
Alain Thia ◽  
Pierre Legras ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Experimental Studies ◽  
Left Ventricular ◽  
7 Tesla ◽  
Sham Operation ◽  
Resonance Imaging ◽  
Serial Magnetic Resonance Imaging ◽  
Lv Mass ◽  
Lv Remodeling

In vivo assessment of treatment efficacy on postinfarct left ventricular (LV) remodeling is crucial for experimental studies. We examined the technical feasibility of serial magnetic resonance imaging (MRI) for monitoring early postinfarct remodeling in rats. MRI studies were performed with a 7-Tesla unit, 1, 3, 8, 15, and 30 days after myocardial infarction (MI) or sham operation, to measure LV mass, volume, and the ejection fraction (EF). Three groups of animals were analyzed: sham-operated rats (n = 6), MI rats receiving lisinopril (n = 11), and MI rats receiving placebo (n = 8). LV dilation occurred on day 3 in both MI groups. LV end-systolic and end-diastolic volumes were significantly lower in lisinopril-treated rats than in placebo-treated rats at days 15 and 30. EF was lower in both MI groups than in the sham group at all time points, and did not differ between the MI groups during follow-up. Less LV hypertrophy was observed in rats receiving lisinopril than in rats receiving placebo at days 15 and 30. We found acceptable within- and between-observer agreement and an excellent correlation between MRI and ex vivo LV mass (r = 0.96; p < 0.001). We demonstrated the ability of MRI to detect the early beneficial impact of angiotensin-converting enzyme (ACE) inhibitors on LV remodeling. Accurate and noninvasive, MRI is the tool of choice to document response to treatment targeting postinfarction LV remodeling in rats.

Relation of B-type natriuretic peptide to left ventricular wall stress as assessed by cardiac magnetic resonance imaging in patients with dilated cardiomyopathy

2007 ◽  
Vol 85 (8) ◽  
pp. 790-799 ◽  
Author(s):  
P. Alter ◽  
H. Rupp ◽  
M.B. Rominger ◽  
A. Vollrath ◽  
F. Czerny ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Cardiac Magnetic Resonance ◽  
Magnetic Resonance ◽  
Wall Stress ◽  
Left Ventricular ◽  
Ventricular Wall ◽  
Resonance Imaging ◽  
Sphere Model ◽  
Lv Mass ◽  
Systolic Wall Stress

Ventricular loading conditions are crucial determinants of cardiac function and prognosis in heart failure. B-type natriuretic peptide (BNP) is mainly stored in the ventricular myocardium and is released in response to an increased ventricular filling pressure. We examined, therefore, the hypothesis that BNP serum concentrations are related to ventricular wall stress. Cardiac magnetic resonance imaging (MRI) was used to assess left ventricular (LV) mass and cardiac function of 29 patients with dilated cardiomyopathy and 5 controls. Left ventricular wall stress was calculated by using a thick-walled sphere model, and BNP was assessed by immunoassay. LV mass (r = 0.73, p < 0.001) and both LV end-diastolic (r = 0.54, p = 0.001) and end-systolic wall stress (r = 0.66, p < 0.001) were positively correlated with end-diastolic volume. LV end-systolic wall stress was negatively related to LV ejection fraction (EF), whereas end-diastolic wall stress was not related to LVEF. BNP concentration correlated positively with LV end-diastolic wall stress (r = 0.50, p = 0.002). Analysis of variance revealed LV end-diastolic wall stress as the only independent hemodynamic parameter influencing BNP (p < 0.001). The present approach using a thick-walled sphere model permits determination of mechanical wall stress in a clinical routine setting using standard cardiac MRI protocols. A correlation of BNP concentration with calculated LV stress was observed in vivo. Measurement of BNP seems to be sufficient to assess cardiac loading conditions. Other relations of BNP with various hemodynamic parameters (e.g., EF) appear to be secondary. Since an increased wall stress is associated with cardiac dilatation, early diagnosis and treatment could potentially prevent worsening of the outcome.

Abstract 695: Significant Hypertrophy and Reduced Systolic Function Predict Intramyocardial Fibrosis in Patients with Hypertrophic Cardiomyopathy Undergoing Cardiac Magnetic Resonance Imaging

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Ronen Rubinshtein ◽  
James F Glockner ◽  
Bernard J Gersh ◽  
Philip A Araoz ◽  
Michael J Ackerman ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Hypertrophic Cardiomyopathy ◽  
Magnetic Resonance ◽  
Systolic Function ◽  
Left Ventricular ◽  
Prognostic Impact ◽  
Resonance Imaging ◽  
Post Contrast ◽  
Septal Thickness ◽  
Lv Mass

Background: Contrast enhanced magnetic resonance imaging (CE-MRI) is a useful tool to define cardiac morphology, systolic function, and the presence of late gadolinium enhancement (LGE). In patients (pts) with hypertrophic cardiomyopathy (HCM), LGE may represent intra-myocardial fibrosis. We explored the association between left ventricular (LV) morphology and function to the presence and amount of LGE in pts with HCM. Methods: 424 HCM pts (age = 55 ± 16 years, 41% females), without prior history of septal ablation/myectomy, underwent CE-MRI (GE 1.5T) during a 6-year period. LV volumes, diameter, ejection fraction (EF), septal shape and thickness, and the presence of obstructive physiology were assessed from standard steady state free precession pulse sequences. The presence and amount of LGE were traced from a dynamic post contrast inversion recovery pulse sequence. Morphologic and functional findings were then compared with presence and amount of LGE. Results: Over half of the pts [239/424 (56%)] had LGE, most commonly localizing to RV insertion points [174/239 pts, (73%)]. The extent of LGE ranged from 0.4–65% of LV mass. Univariate (morphologic) predictors of LGE were: reverse curve septal shape [OR = 7.8, (95% CI, 3.9–15.6)], septal thickness ≥ 16 mm (OR = 4.5, 2.4–8.2), LV mass ≥ 150 grams (OR = 2.6, 1.7–3.8)], LVEF<50% (OR = 4.6, 1.3–16), and presence of obstructive physiology (OR = 1.8, 1.02–3). The percentage of LV mass involved with LGE increased with higher LV mass, increased septal wall thickness, and decreasing LVEF (Spearman rank = 0.2– 0.4, p<0.0001 for all). Multivariate analysis (adjusting for all morphologic and functional parameters) showed that septal thickness ≥ 16mm (p = 0.0001), LV mass ≥ 150 grams (p = 0.01) and LVEF < 50% (p = 0.02) were independent predictors of LGE on CE-MRI. Conclusions: LGE, as determined by CE-MRI, was seen in over half of the patients with HCM. Decreased LVEF, increased septal thickness, and increased LV mass were associated with the presence of LGE. The clinical and prognostic impact of these morphological features warrants further investigation.

P4360Personalised shape models of the left ventricle from 3D echocardiography: an initial comparison to cardiac magnetic resonance imaging

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
D Zhao ◽  
K Gilbert ◽  
C R McDougal ◽  
V Y Wang ◽  
H Houle ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Cardiac Magnetic Resonance ◽  
Magnetic Resonance ◽  
Cardiac Magnetic Resonance Imaging ◽  
Left Ventricular ◽  
Patient Specific ◽  
Resonance Imaging ◽  
Shape Models ◽  
Lv Mass ◽  
3D Echo

Abstract Background The heart constantly adapts to maintain cardiac output. In the longer term, this process (remodeling) can manifest as changes in ventricular volume, sphericity, and/or wall thickness, amongst several other morphological indices. Previous studies have shown the significance of remodeling in evaluations of survival, and as a determinant of the clinical course of heart failure. Yet surprisingly, diagnostic measures, typically of left ventricular (LV) mass and ejection fraction, neglect much of the shape information that is available through imaging. A recent UK Biobank study revealed that morphometric atlases show more compelling associations with cardiovascular risk factors, than do LV mass and volumes. While it has been possible to construct shape models from cardiac magnetic resonance imaging (MRI), such a framework is still under development for echocardiography (echo). Purpose Despite MRI being long regarded as the gold standard, it is greatly limited by high costs, long scan times and incompatibility with ferromagnetic cardiac devices. In contrast, echo has presented as a convenient alternative, whilst also offering good temporal resolution. The advancements of 3D echo now provide adequate spatial resolution and thus elicit the possibility of conducting more complex analyses on this modality. With the ability to extract LV geometry directly from 3D echo acquisitions, we sought to create dynamic, 3D patient-specific models–and subsequently compare these results to those derived from MRI. Methods As part of an ongoing study, 8 volunteers with no known cardiovascular problems (nor family history thereof), were recruited for non-invasive imaging. Cine MRI and 3D echo of the LV were acquired within a 2 hour session. A Siemens Avanto Fit 1.5 T MRI scanner and Siemens ACUSON SC2000 Ultrasound System with a 4Z1c Transducer were used. 3D models of the LV were generated independently from echo (EchobuildR 2.7 prototype software, Siemens Ultrasound) and MRI acquisitions (Cardiac Image Modeller v8.1), and registered to fiducial landmarks (apex, base plane, right ventricular inserts) and myocardial contours. Results Euclidian distances between 1682 corresponding points sampled from the surface of echo/MRI models were calculated, and used as a discrepancy measure (Figure). Across the 8 cases, we found an average root mean square deviation (RMSD) of 5.71 mm at end-systole and 6.03 mm at end-diastole. The maximum RMSD for a single model was 9.47 mm (case 8, ES). Conclusion We demonstrate that it is possible to create shape models from 3D echo examinations for comparison with MRI. As more cases are collected, we will devise methods to objectively quantify the mismatch that may arise between models derived from the two modalities. The establishment of such a framework would not only provide previously unavailable measures of shape and function, but in turn leverage the significantly wider clinical reach of echocardiography.

Gated magnetic resonance imaging of normal and hypertrophied murine hearts

1997 ◽  
Vol 272 (5) ◽  
pp. H2394-H2402 ◽  
Author(s):  
F. M. Siri ◽  
L. A. Jelicks ◽  
L. A. Leinwand ◽  
J. M. Gardin
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Body Mass ◽  
Left Ventricular ◽  
High Heart Rate ◽  
Resonance Imaging ◽  
Group Of Seven ◽  
Lv Mass ◽  
Noninvasive Assessment ◽  
Transgenic Murine Models

Transgenic murine models are being used increasingly to explore the molecular basis of heart disease. Until recently, there were no means for noninvasive assessment of changes in mass and function of the murine heart because of its very small size and high heart rate. Transthoracic echocardiography has now been utilized to obtain noninvasive estimates of murine left ventricular (LV) wall thicknesses, internal dimension, and mass. However, this approach is based on one-dimensional (M-mode) measurements of the LV at its midwall that take no account of variations in LV chamber and wall dimensions along other minor axes and at other anatomic levels. Thus asymmetries in LV geometry, which can affect LV mass estimates, may be undetected. In this study, gated (diastolic) magnetic resonance imaging (MRI) was utilized to obtain two-dimensional images of the LV at four anatomic levels in intact, anesthetized mice. In 17 normal CD-1 mice (body mass, 18-47 g; gravimetric LV mass, 51-135 mg), LV mass estimates produced from the MRI data correlated well (r = 0.87) with LV mass determined gravimetrically. In addition, this approach identified changes in LV mass and wall thickness-to-chamber diameter ratio in a group of seven aortic-constricted mice (body mass, 32-39 g; gravimetric LV mass, 119-198 mg) with compensated and decompensated LV hypertrophy. These findings suggest that utility of MRI for serial, noninvasive assessment of experimentally induced alterations in mass and geometry of the murine heart.

6071Extent of hypertensive exposure in relation to vascular brain injury and cognitive impairment using heart-brain magnetic resonance imaging; The Heart-Brain Connection Study

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
R Amier ◽  
N Marcks ◽  
A M Hooghiemstra ◽  
R Nijveldt ◽  
M A Van Buchem ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Cognitive Impairment ◽  
Magnetic Resonance ◽  
Brain Magnetic Resonance Imaging ◽  
Volume Ratio ◽  
Left Ventricular ◽  
Resonance Imaging ◽  
Lv Mass ◽  
Patient Groups ◽  
Brain Connection

Abstract Background Preserving brain health into advanced age has become one of the great challenges of modern medicine. Hypertension is highly prevalent and considered an independent contributor to cognitive impairment. Vascular brain injury, induced by exposure of the cerebral microcirculation to increased pressure and pulsatility, is the hypothesized link between hypertension and cognitive impairment. Hypertensive exposure can be assessed by cardiovascular magnetic resonance imaging markers, e.g. aortic stiffness by pulse wave velocity (PWV), left ventricular mass index (LVMi) and left ventricular (LV) concentricity by mass-to-volume ratio. Purpose To investigate the extent of hypertensive exposure in relation to cerebral small vessel disease (CSVD) and cognitive impairment, using heart-brain magnetic resonance imaging. Methods We included 559 participants aged 68±9 years from the Heart-Brain Connection study, consisting of three patient groups (i.e. heart failure, vascular cognitive impairment and carotid occlusive disease) and controls. LVMi, LV mass-to-volume ratio, aortic PWV and CSVD were assessed by 3.0 T heart-brain magnetic resonance imaging. Impairment in ≥1 major cognitive domain was assessed by comprehensive neuropsychological testing. Effect modification for patient groups was investigated by interaction terms; results are reported pooled or stratified accordingly. Results Overall prevalence of CSVD was 68.7% and prevalence of cognitive impairment was 26.9%. Figure 1 provides a visual overview of hypertensive exposure markers in relation to brain outcome. Aortic PWV (odds ratio [OR] 1.17, p=0.003 in patient groups only), LVMi (OR in carotid occlusive disease 5.69, p=0.006; OR in other groups 1.30, p=0.017) and LV mass-to-volume ratio (OR 1.81, p<0.001) were all associated with CSVD. Both aortic PWV (OR 1.07, p=0.009) and LV mass-to-volume ratio (OR 1.27, p=0.007) were also associated with cognitive impairment. Relations were independent of sociodemographics and cardiac index, and mostly persisted after correction for systolic blood pressure or medical history of hypertension. The relations of hypertensive exposure markers with cognitive impairment were attenuated when presence of CSVD was added as co-variate, (indirectly) supporting the hypothesis that CSVD is the link between hypertension and cognitive impairment. Figure 1 Conclusion Hypertensive exposure markers were independently associated with CSVD and cognitive impairment. Our findings indicate that hypertensive exposure markers relate to brain structure and function beyond clinical blood pressure or medical history. Acknowledgement/Funding Netherlands Cardiovascular Research Initiative; Dutch Heart Foundation; NFU; ZonMW; KNAW

scholarly journals Expedient assessment of post-infarct remodeling by native cardiac magnetic resonance imaging in mice

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Cajetan Immanuel Lang ◽  
Praveen Vasudevan ◽  
Piet Döring ◽  
Ralf Gäbel ◽  
Heiko Lemcke ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Contractile Function ◽  
Ischemia Reperfusion ◽  
Healing Process ◽  
Left Ventricular ◽  
7 Tesla ◽  
Wall Thickening ◽  
Resonance Imaging ◽  
Single Plane

AbstractNovel therapeutic strategies aiming at improving the healing process after an acute myocardial infarction are currently under intense investigation. The mouse model plays a central role for deciphering the underlying mechanisms on a molecular and cellular level. Therefore, we intended to assess in-vivo post-infarct remodeling as comprehensively as possible using an expedient native magnetic resonance imaging (MRI) in the two most prominent infarct models, permanent ligation (PL) of the left anterior descending artery (LAD) versus ischemia reperfusion (I/R). Mice were subjected to either permanent or transient (45 min) occlusion of the LAD. After 3 weeks, examinations were performed with a 7-Tesla small animal MRI system. Data analysis was performed with the freely available software Segment. PL resulted in a massive dilation of the left ventricle, accompanied by hypertrophy of the non-infarcted myocardium and a decline of contractile function. These effects were less pronounced following I/R compared to healthy animals. Single plane assessments were not sufficient to capture the specific differences of left ventricular (LV) properties between the two infarct models. Bulls-eye plots were found to be an ideal tool for qualitative LV wall assessment, whereas a multi-slice sector-based analysis of wall regions is ideal to determine differences in hypertrophy, lateral wall thinning and wall thickening on a quantitative level. We combine the use of polar map-based analysis of LV wall properties with volumetric measurements using simple CINE CMR imaging. Our strategy represents a versatile and easily available tool for serial assessment of the LV during the remodeling process. Our study contributes to a better understanding of the effects of novel therapies targeting the healing of damaged myocardium.

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