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Aernout M Beek

Publications and source records attributed to Aernout M Beek.

14 recordsLinked to original sources
PubMed2006

Septal ablation in hypertrophic obstructive cardiomyopathy improves systolic myocardial function in the lateral (free) wall: a follow-up study using CMR tissue tagging and 3D strain analysis.

AIMS: Alcohol septal ablation (ASA) has been successful in the treatment of symptomatic hypertrophic obstructive cardiomyopathy (HOCM). The aim of this study is to evaluate the effects of ethanol-induced myocardial infarcts on regional myocardial function using cardiac magnetic resonance (CMR) tissue tagging and 3-dimensional (3D) strain analysis. METHODS AND RESULTS: In nine patients (age 52+/-15 years) who underwent ASA, CMR was performed prior to and 6 months after the procedure. Regional myocardial mass was evaluated using cine imaging. Myocardial tagging was used to calculate systolic 3D myocardial strain values. These strain values were used to calculate the shortening index (SI), a robust parameter for myocardial contraction. Maximum end-systolic (ES) SI and systolic SI rate were quantified in three circumferential segments: septum, adjacent, and remote (lateral) myocardium. Compared with baseline, septal and non-septal mass decreased at follow-up (from 72+/-27 to 59+/-21 g; P=0.008 and from 131+/-34 to 109+/-30 g; P=0.008, respectively). In the septum, maximum ES SI and SI rate remained unchanged after ASA. In adjacent myocardium, ES SI remained unchanged, whereas SI rate improved (from -56.5+/-21.1 to -70.0+/-16.7%/s; P=0.02). Both ES SI and SI rate improved significantly in remote myocardium (from -16.9+/-2.8 to -18.8+/-3.2%; P=0.02 and from -70.3+/-9.2 to -86.1+/-15.0%/s; P=0.01, respectively). CONCLUSION: Reduction of left ventricular (LV) outflow tract obstruction in symptomatic HOCM is associated with a significant reduction in myocardial mass and improvement of intramural systolic function in the lateral (remote) wall, indicating reversed LV remodelling.

Adolescent↗
PubMed2006

Cardiovascular magnetic resonance imaging for the assessment of right heart involvement in cardiac and pulmonary disease.

In most patients with heart disease left ventricular dysfunction is the principle physiologic disorder leading to heart failure and is an important prognostic factor. Various imaging methods have been developed for the evaluation of left ventricular function and a substantial body of literature is available describing these methods. The right ventricle (RV) may be predominantly involved in certain cardiac or pulmonary pathological conditions such as arrhythmogenic right ventricular cardiomyopathy or pulmonary hypertension. Also in many congenital or acquired cardiac diseases primarily affecting the left ventricle (LV), right heart involvement has an important role in disease prognosis. The RV is difficult to evaluate using two-dimensional (2D) cross-sectional imaging modalities due to its complex shape and orientation. Cardiovascular magnetic resonance imaging (CMR) is a virtually three-dimensional (3D) tomographic technique which has entered the mainstream of clinical cardiovascular imaging over the last decade. Compared to other imaging methods CMR allows the accurate quantification of RV volumes, myocardial mass, and transvalvular flow with the added benefit of tissue characterisation and without the use of ionising radiation. The manuscript presents a review of the contemporary use of CMR for the evaluation of right heart involvement in various cardio-pulmonary diseases.

Diagnostic Techniques, Cardiovascular↗
PubMed2006

Clinical applications of cardiovascular magnetic resonance imaging.

Cardiovascular magnetic resonance imaging (MRI) has evolved from an effective research tool into a clinically proven, safe and comprehensive imaging modality. It provides anatomic and functional information in acquired and congenital heart disease and is the most precise technique for quantification of ventricular volumes, function and mass. Owing to its excellent interstudy reproducibility, cardiovascular MRI is the optimal method for assessment of changes in ventricular parameters after therapeutic intervention. Delayed contrast enhancement is an accurate and robust method used in the diagnosis of ischemic and nonischemic cardiomyopathies and less common diseases, such as cardiac sarcoidosis and myocarditis. First-pass magnetic contrast myocardial perfusion is becoming an alternative to radionuclide techniques for the detection of coronary atherosclerotic disease. In this review we outline the techniques used in cardiovascular MRI and discuss the most common clinical applications.

Cardiovascular Diseases↗
PubMed2005

Early onset and progression of left ventricular remodeling after alcohol septal ablation in hypertrophic obstructive cardiomyopathy.

BACKGROUND: Alcohol septal ablation (ASA) reduces left ventricular outflow tract (LVOT) pressure gradient in patients with hypertrophic obstructive cardiomyopathy (HOCM), which leads to left ventricular remodeling. We sought to describe the early to midterm changes and modulating factors of the remodeling process using cardiac MRI (CMR). METHODS AND RESULTS: CMR was performed at baseline and 1 and 6 months after ASA in 29 patients with HOCM (age 52+/-16 years). Contrast-enhanced CMR showed no infarct-related hyperenhancement outside the target septal area. Septal mass decreased from 75+/-23 g at baseline to 68+/-22 and 58+/-19 g (P<0.001) at 1- and 6-month follow-up, respectively. Remote, nonseptal mass decreased from 141+/-41 to 132+/-40 and 111+/-27 g (P<0.001), respectively. Analysis of temporal trends revealed that septal mass reduction was positively associated with contrast-enhanced infarct size and transmural or left-sided septal infarct location at both 1 and 6 months. Remote mass reduction was associated with infarct location at 6 months but not with contrast-enhanced infarct size. By linear regression analysis, percentage remote mass reduction correlated significantly with LVOT gradient reduction at 6-month follow-up (P=0.03). CONCLUSIONS: Left ventricular remodeling after ASA occurs early and progresses on midterm follow-up, modulated by CMR infarct size and location. Remote mass reduction is associated with infarct location and correlates with reduction of the LVOT pressure gradient. Thus, myocardial hypertrophy in HOCM is, at least in part, afterload dependent and reversible and is not exclusively caused by the genetic disorder.

Adult↗
PubMed2005

Standardizing the definition of hyperenhancement in the quantitative assessment of infarct size and myocardial viability using delayed contrast-enhanced CMR.

PURPOSE: To evaluate a standardized definition of delayed hyperenhancement in the analysis of contrast-enhanced cardiac magnetic resonance (ceCMR) imaging. PATIENTS AND METHODS: CeCMR was performed in 15 patients with chronic ischemic heart disease. Delayed hyperenhancement was analyzed both by visual analysis by an experienced team of observers, and after thresholding the window setting of the images at 2, 3, 4, 5, and 6 SD above the mean signal intensity of remote, normal myocardium in the same slice. In each patient, total infarct size (TIS) and segmental infarct extent (SIE) were calculated. RESULTS: TIS and SIE were 22.9 +/- 12.2 mL and 32 +/- 28% after visual analysis. Thresholding the window setting at 2, 3, 4, and 6 SD above signal intensity of remote caused a 40%, 31%, and 17% increase (p < 0.007) and a 7% decrease (p = NS) in TIS, and a 75%, 41%, and 16% increase and 22% decrease in SIE (p < 0.001), respectively. There was no difference between visual analysis and analysis after thresholding at 5 SD. CONCLUSION: Analyzing ceCMR with a standardized definition of hyperenhancement related to the signal of remote, nonenhanced myocardium may result in considerable overestimation of infarct size at the usual cut-off of 2 SD.

Contrast Media↗
PubMed2005

Delayed contrast enhancement and perfusable tissue index in hypertrophic cardiomyopathy: comparison between cardiac MRI and PET.

UNLABELLED: Delayed contrast enhancement (DCE) visualized by cardiac MRI (CMR) is a common feature in patients with hypertrophic cardiomyopathy (HCM), presumed to be related to myocardial fibrosis. The pathophysiologic basis of hyperenhancement in this patient group, however, remains unclear as limited histologic comparisons are available. The present study compares the perfusable tissue index (PTI), an alternative marker of myocardial fibrosis obtained by PET, with DCE-CMR in HCM. METHODS: Twenty-one patients with asymmetric septal HCM, 12 chronic myocardial infarction (MI) patients, and 6 age-matched healthy control subjects were studied with DCE-CMR and PET. PET was performed using (15)O-labeled water and carbon monoxide to obtain the PTI. RESULTS: No hyperenhancement was observed in control subjects and the PTI was within normal limits (1.10 +/- 0.07 [mean +/- SD]). In MI patients, the extent of hyperenhancement (25% +/- 16% [mean +/- SD]) was inversely related to the decrease in the PTI (0.94 +/- 0.12; r = -0.65, P < 0.05). Average hyperenhancement in HCM was 14% +/- 12%, predominantly located in the interventricular septum. The PTI in the hypertrophied interventricular septum, however, was not reduced (1.12 +/- 0.13). Furthermore, in contrast to MI patients, there was a modest positive correlation between the extent of DCE and the PTI in HCM (r = 0.45, P < 0.05). CONCLUSION: DCE in the hypertrophied septum of HCM patients is not accompanied by a decline in the PTI, and there is a positive correlation between the extent of DCE and the PTI. These results suggest that hyperenhancement may not be caused solely by fibrotic replacement scarring in this patient group. Other pathologic changes associated with HCM may also cause gadolinium-diethylenetriaminepentaacetic acid hyperenhancement.

Adult↗
PubMed2004

Myocardial infarction after percutaneous transluminal septal myocardial ablation in hypertrophic obstructive cardiomyopathy: evaluation by contrast-enhanced magnetic resonance imaging.

OBJECTIVES: The aim of this study was to evaluate myocardial infarction induced by percutaneous transluminal septal myocardial ablation (PTSMA) in symptomatic patients with hypertrophic obstructive cardiomyopathy using contrast-enhanced (CE) magnetic resonance imaging (MRI). BACKGROUND: Contrast-enhanced MRI delineates the extent of myocardial infarction in coronary artery disease, but its role in ethanol-induced infarction has not been established. METHODS: Cine and CE MRI were performed before and one month after PTSMA in 24 patients. Size and location of the induced infarction were related to left ventricular (LV) mass reduction, enzyme release, volume of ethanol administered, LV outflow tract gradient reduction, and coronary ablation site. RESULTS: One month after PTSMA, regional hyperenhancement was visualized in the basal interventricular septum in all patients. Mean infarction size was 20 +/- 9 g, corresponding to 10 +/- 5% and 31 +/- 16% of total LV and septal mass, respectively. Total LV mass decreased from 219 +/- 64 to 205 +/- 64 g (p < 0.01), and septal mass from 76 +/- 25 to 68 +/- 22 g (p < 0.01). Total LV mass reduction exceeded septal mass reduction (p < 0.01). Infarction size correlated with peak creatine phosphokinase-MB (beta = 0.67, p < 0.01), volume of ethanol administered (beta = 0.47, p = 0.02), total LV and septal mass reduction (beta = 0.50, p = 0.02; beta = 0.73, p < 0.01), and gradient reduction (beta = 0.63, p < 0.01). Seven patients with exclusively right-sided septal infarction had smaller infarction size and less gradient reduction than remaining patients with left-sided or transmural infarction (p < 0.01). In five of these, PTSMA was performed distal in the target artery. CONCLUSIONS: Contrast-enhanced MRI allowed detailed evaluation of size and location of septal myocardial infarction induced by PTSMA. Infarction size correlated well with clinical indexes of infarct size.

Cardiac Catheterization↗
PubMed2003

Myocardial viability: rapid assessment with delayed contrast-enhanced MR imaging with three-dimensional inversion-recovery prepared pulse sequence.

Contrast-enhanced magnetic resonance (MR) imaging allows detection of nonviable myocardium. The authors compared a one-breath-hold three-dimensional inversion-recovery gradient-echo MR sequence with a multiple-breath-hold two-dimensional inversion-recovery gradient-echo MR sequence for the detection of nonviable myocardium. On the basis of a quantitative and qualitative approach, total myocardial area and contrast material-enhanced area, as well as the presence and spatial extent of hyperenhancement, were analyzed separately for each MR image obtained with each sequence in 10 patients with chronic ischemic heart disease. Findings for total myocardial area and contrast-enhanced area agreed well between the two sequences. A high level of agreement was also found for the presence of hyperenhancement (kappa = 0.84), while agreement was poor for the transmural extent of hyperenhancement (kappa = 0.32), which was attributed to the blurred appearance of the three-dimensional MR images. Findings with the one-breath-hold three-dimensional MR sequence allow assessment of nonviable myocardium with good agreement with those with the multiple-breath-hold two-dimensional MR sequence.

Adult↗
PubMed2003

Delayed contrast-enhanced magnetic resonance imaging for the prediction of regional functional improvement after acute myocardial infarction.

OBJECTIVES: We evaluated whether delayed contrast-enhanced magnetic resonance imaging (DCE-MRI) using an extracellular contrast agent could predict improvement of dysfunctional but viable myocardium after acute reperfused myocardial infarction (MI). BACKGROUND: The transmural extent of hyperenhancement at DCE-MRI has been related to improvement of function in reperfused MI. However, evidence is still limited, and earlier reports have produced conflicting results regarding the significance of contrast patterns after infarction. METHODS: Thirty patients (mean age 59 +/- 11 years, 27 males) underwent cine MRI and DCE-MRI 7 +/- 3 days after a first reperfused acute MI and follow-up cine MRI at 13 +/- 3 weeks. Segmental wall thickening and segmental extent of hyperenhancement were scored in 1,689 segments. RESULTS: Of 500 dysfunctional segments, 273 (55%) improved at follow-up. There was no difference in likelihood of improvement or complete functional recovery between segments with 0% and 1% to 25% hyperenhancement. The likelihood of improvement of segments without hyperenhancement was 2.9, 14.3, and 20 times higher than that of segments with 26% to 50%, 51% to 75%, and >75% hyperenhancement, respectively (p < 0.001). The likelihood of complete functional recovery of segments without hyperenhancement was 3.8, 11.1, and 50 times higher than that of segments with 26% to 50%, 51% to 75%, and >75% hyperenhancement, respectively (p < 0.001). CONCLUSIONS: In patients with recent reperfused MI, functional improvement of stunned myocardium is predicted by DCE-MRI.

Aged↗
PubMed2003

Myocardial viability in chronic ischemic heart disease: comparison of contrast-enhanced magnetic resonance imaging with (18)F-fluorodeoxyglucose positron emission tomography.

OBJECTIVES: We sought to compare contrast-enhanced magnetic resonance imaging (ceMRI) with nuclear metabolic imaging for the assessment of myocardial viability in patients with chronic ischemic heart disease and left ventricular (LV) dysfunction. BACKGROUND: Contrast-enhanced MRI has been shown to identify scar tissue in ischemically damaged myocardium. METHODS: Twenty-six patients with chronic coronary artery disease and LV dysfunction (mean ejection fraction 31 +/- 11%) underwent (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET), technetium-99m tetrofosmin single-photon emission computed tomography (SPECT), and ceMRI. In a 17-segment model, the segmental extent of hyperenhancement (SEH) by ceMRI, defined as the relative amount of contrast-enhanced tissue per myocardial segment, was compared with segmental FDG and tetrofosmin uptake by PET and SPECT. RESULTS: In severely dysfunctional segments (n = 165), SEH was 9 +/- 14%, 33 +/- 25% (p < 0.05), and 80 +/- 23% (p < 0.05) in segments with normal metabolism/perfusion, metabolism/perfusion mismatch, and matched defects, respectively. Segmental glucose uptake by PET was inversely correlated to SEH (r = -0.86, p < 0.001). By receiver operator characteristic curve analysis, the area under the curve was 0.95 for the differentiation between viable and non-viable segments. At a cutoff value of 37%, SEH optimally differentiated viable from non-viable segments defined by PET. Using this threshold, the sensitivity and specificity of ceMRI to detect non-viable myocardium as defined by PET were 96% and 84%, respectively. CONCLUSIONS: Contrast-enhanced MRI allows assessment of myocardial viability with a high accuracy, compared with FDG-PET, in patients with chronic ischemic heart disease and LV dysfunction.

Adult↗
PubMedDate not supplied

Impact of scar on water-perfusable tissue index in chronic ischemic heart disease: Evaluation with PET and contrast-enhanced MRI.

BACKGROUND: The water-perfusable tissue index (PTI) is assumed to differentiate viable myocardium from scar tissue, but histological comparisons in humans are lacking. The present study compares PTI with delayed contrast-enhanced magnetic resonance imaging (DCE-MRI), a validated marker of fibrotic tissue, in patients with ischemic left ventricular (LV) dysfunction. In addition, the optimal PTI threshold for detection of myocardial viability was defined when DCE-MRI was taken as a reference. MATERIALS: Twenty patients with ischemic LV dysfunction were studied with positron emission tomography, using oxygen-15-labeled water and carbon monoxide as tracers, and DCE-MRI. RESULTS: Of the 200 analyzed segments, 112 demonstrated DCE and were subsequently divided in three subgroups according to the severity of enhancement. PTI was 1.04 +/- 0.21 in control segments and gradually decreased with increasing extent of DCE to 0.77 +/- 0.31 for segments with transmural enhancement (p < 0.001). However, PTI progressively underestimated infarct size with increasing quantities of scar tissue (r = 0.61, p < 0.01). A PTI cutoff value of 0.89 yielded the best diagnostic accuracy for detection of myocardial viability with sensitivity and specificity values of 75 and 77%, respectively. CONCLUSIONS: PTI is inversely related to the extent of scar tissue estimated by DCE-MRI in patients with chronic ischemic heart disease and LV dysfunction. However, with increasing quantities of scar tissue, PTI overestimates the extent of residual viable tissue. A PTI threshold of 0.89 yields the best diagnostic accuracy for viability detection.

Aged↗
PubMedDate not supplied

Pericardial cyst.

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Aged↗