Publications by authors named "Cees A Visser"

Aims: We sought to evaluate the relation between long-term functional outcome after revascularization in patients with chronic ischaemic left ventricular (LV) dysfunction and baseline extent of myocardial fibrosis.

Methods And Results: Thirty-five patients underwent cine and delayed contrast-enhanced cardiovascular magnetic resonance (deCMR) for the quantitative assessment of regional and global LV functions and segmental extent of hyperenhancement (SEH). Function was assessed 1 month before and 3, 6, and 24 +/- 12 months after revascularization, and temporal changes were related to baseline extent of hyperenhancement.

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Ultrasound (US) contrast agents have gained wide interest in gene therapy as many researchers reported increased membrane permeability and transfection efficiency by sonoporation in the presence of US contrast agents. We recently demonstrated an increase in cell membrane permeability for Ca2+ in rat cardiomyoblast (H9c2) cells insonified in the presence of microbubbles. In the present study, we specifically investigated whether US-exposed microbubbles have an effect on the cell membrane potential and whether Ca2+-dependent potassium (BK(Ca)) channels are involved.

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In patients with chronic ischemic myocardial dysfunction, late gadolinium enhancement CMR (LGE-CMR) accurately depicts the regional extent of fibrosis and predicts functional recovery after revascularization. We hypothesized that the predictive accuracy of LGE-CMR could be optimized by not only taking into account the transmural extent of hyperenhancement but also the amount of residual, non-enhanced viable myocardium, and procedure related necrosis. We studied 45 patients with chronic ischemic left ventricular dysfunction, who underwent cine and LGE-CMR 1 month before and 3 months after surgical or percutaneous revascularization.

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Purpose: Cardiovascular magnetic resonance (CMR) is considered the standard imaging modality in clinical trials to monitor patients after acute myocardial infarction (AMI). However, limited data is available with respect to infarct size, presence, and extent of microvascular injury (MVO), and changes over time, in relation to cardiac function in these optimally treated patients. In this study, we prospectively investigate the change of infarct size over time, and the incidence and significance of MVO in a uniform, optimally treated patient group after AMI.

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Aims: The present study compared microvascular resistance (MR) of viable myocardium in infarct areas with those in reference areas in patients with chronic myocardial infarction (MI).

Methods And Results: In 27 patients, MR (ratio distal coronary pressure and flow) of reference and viable infarct areas was calculated at baseline and during hyperaemia. H2 15O positron emission tomography (PET) was used to provide myocardial blood flow measurements.

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Left ventricular (LV) filling results from diastolic suction of the left ventricle and passive left atrial (LA) emptying at early diastole and LA contraction at end-diastole. Effects of aging on LA and LV geometric characteristics and function and its consequences for LV filling are incompletely understood. Insight into these effects may increase the understanding of diastolic function.

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Background: A left bundle branch block (LBBB) affects both global left ventricular (LV) function and mechanical dyssynchrony. The aim was to evaluate global LV function and mechanical dyssynchrony with real-time 3D echocardiography (RT3DE), in asymptomatic LBBB patients, healthy volunteers and patients with symptomatic heart failure (HF) and a LBBB. Furthermore, the relation between presence or absence of symptoms of HF and mechanical dyssynchrony was investigated.

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Background: We studied the value of quantitative three-dimensional echocardiography (3DE) in the evaluation of mitral valve stenosis using the measurement of the mitral valve area (MVA) with two new indices: the doming volume and mitral valve volume.

Methods And Results: A total of 45 consecutive patients with mitral valve stenosis were studied. MVA was measured using Doppler with the pressure half-time (PHT) method.

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Background: Cardiac resynchronization therapy (CRT) improves left ventricular (LV) systolic function and clinical status, and prolongs survival of patients suffering from heart failure. An optimal LV site selection is key with respect to improvements in systolic function, though whether a site-specific effect on diastolic function exists is unclear. This study compared the effects of CRT on changes in systolic and diastolic function from 2 LV stimulation sites.

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Intravenous myocardial contrast echocardiography (MCE) is a recently developed technique for assessment of myocardial perfusion. Up to now, many studies have demonstrated that the sensitivity and specificity of qualitative assessment of myocardial perfusion by MCE in patients with acute and chronic ischemic heart disease are comparable with other techniques such as cardiac scintigraphy and dobutamine stress echocardiography. Furthermore, quantitative parameters of myocardial perfusion derived from MCE correlate well with the current clinical standard for this purpose, positron emission tomography.

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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.

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Purpose: Although resynchronisation therapy (CRT) is a promising addition to heart failure therapy, a substantial number of patients do not respond to CRT. As FDG PET has routinely been used for prediction of improvement after revascularisation in ischaemic cardiomyopathy, it was hypothesised that there is also a relationship between the extent of viable tissue and improvement as a result of CRT.

Methods: Thirty-nine patients with ischaemic cardiomyopathy (ejection fraction 27 +/- 9%) and a wide QRS complex underwent temporary pacing to determine the optimal pacing combination, i.

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To evaluate the hemodynamic impact of coronary stenoses, the fractional (FFR) or coronary flow velocity reserve (CFVR) usually is measured. The combined measurement of instantaneous flow velocity and pressure gradient (v-dp relation) is rarely used in humans. We derived from the v-dp relation a new index, dp(v50) (pressure gradient at flow velocity of 50 cm/s), and compared the diagnostic performance of dp(v50), CFVR, and FFR.

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Purpose: To prospectively evaluate, by using positron emission tomography (PET) and magnetic resonance (MR) imaging, the interrelationships between regional myocardial fibrosis, perfusion, and contractile function in patients with idiopathic dilated cardiomyopathy (DCM).

Materials And Methods: The study protocol was approved by the hospital ethics committee, and all subjects gave written informed consent. Sixteen patients with idiopathic DCM (mean age, 54 years +/- 11 [standard deviation]; nine men) and six healthy control subjects (mean age, 28 years +/- 2; five men) were examined with PET and MR tissue tagging.

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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.

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Reperfusion of ischemic myocardium after acute myocardial infarction (AMI) induces a local activation of inflammatory reactions that results in ischemia/reperfusion (I/R)-injury. I/R-injury contributes considerably to the total cell damage in the heart after AMI. Secretory phospolipase A2-IIA (sPLA2-IIA), C-reactive protein (CRP) and complement are inflammatory mediators that have been demonstrated to play key roles in I/R injury.

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Previous studies showed that glucose-insulin-potassium (GIK) increases cardiac output in patients after cardiac surgery and improves segmental myocardial wall motion. We hypothesized that GIK improves regional wall motion, detects contractile reserve, and predicts functional recovery at follow-up to a similar extent as low-dose dobutamine (LDD) in patients with recent myocardial infarction. Forty-one patients underwent LDD and GIK echocardiography.

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Background: Intravenous myocardial contrast echocardiography (ivMCE) has the potential to evaluate myocardial contraction and perfusion simultaneously. The purpose of this study was to assess quantification of myocardial blood flow (MBF) using ivMCE and to compare this with MBF as measured with positron emission tomography (PET).

Methods: A total of 16 healthy volunteers underwent ivMCE using power pulse inversion and contrast agent microbubbles at rest and during pharmacologically induced vasodilation.

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Background: Positron emission tomography (PET) with inhaled oxygen 15-labeled carbon monoxide (CO) is used as a marker of myocardial blood pool. Only a limited number of studies with small numbers of patients have reported on the assessment of left ventricular (LV) volumes by use of O-15-labeled CO. The aim of this study was to compare LV volumes and function as measured by routinely acquired blood pool images by use of gated O-15-labeled CO PET with the reference technique, cardiovascular magnetic resonance imaging (MRI).

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Paradoxical embolism is a rare cause of myocardial infarction. We present a case of a young man who was admitted to our hospital with an inferior myocardial infarction. Coronary arteriography showed a total distal occlusion of a posterolateral branch of the circumflex artery.

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Three-dimensional echocardiography offers great promise for improving the understanding of the mitral valve anatomy, function, and pathology. It may have important implications for medical or surgical management of different mitral valve disease. In this article we provide an overview of the three-dimensional anatomy of the mitral valve.

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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.

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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.

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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).

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Studies in patients without coronary artery disease have shown the restoration of glucose metabolism by cardiac resynchronization therapy (CRT) without changes in myocardial perfusion. We report on the long-term outcome of CRT in 24 patients with severe heart failure (HF) and advanced coronary artery disease not amenable for revascularization. All patients had documented myocardial ischemia on stress (99)Tc-sestamibi single-photon emission computed tomography, and all underwent successful implantations of CRT systems.

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