[Anti-ischemic effect of verapamil within the scope of interventional recanalization].

We report on a 46-year-old male with unstable angina pectoris due to a total proximal occlusion of the left circumflex artery. At the side of a plaque rupture there was a thrombotic occlusion. With PTCA recanalization was possible, but a dissection occurred, therefore coronary stents were implanted.

Skin microcirculation in healthy subjects and patients with arteriosclerosis.

The concept to use the human skin microcirculation as a pharmacological in-vivo test system is old; however, methods developed in the 50s have been abandoned because of side effects and/or use of radioactive substances. We describe a newly developed minimally invasive method that allows in-vivo pharmacology in the human skin microcirculation injecting very low doses of a substance of drug without any systemic effects. The double injection technique (DIT) bears the potential to predict the effects of a drug and/or the vascular reactivity or dysfunction of other less accessible areas of the circulation (e.

Prevalence of microvascular disease in patients with significant coronary artery disease.

Coronary flow velocity reserve (CFVR) measurement using intracoronary Doppler techniques has been increasing accepted for the assessment of physiological significance of epicardial stenosis and the functional changes after coronary interventions. However, large discrepancy exists concerning the acute changes of CFVR immediately after intervention. The purpose of this study was to investigate the prevalence of microvascular dysfunction in patients with significant coronary artery disease.

Intravascular ultrasound classification of atherosclerotic lesions according to American Heart Association recommendation.

Background: Intravascular ultrasound (IVUS) offers a new modality by which to image the vessel wall in high resolution. The aim of the study was to classify atherosclerotic lesions using IVUS according to American Heart Association (AHA) recommendation.

Methods: IVUS was performed using a 20 or 30 MHz mechanically rotated catheter in 190 patients (aged from 35 to 75 years, mean 59 +/- 9 years) who presented with suspicion of coronary artery disease based on clinical examination.

New signs characteristic of myocardial bridging demonstrated by intracoronary ultrasound and Doppler.

Background: Large discrepancies exist concerning the incidence of myocardial bridging. This has been reported to be 0.5%-2.

G protein beta3 subunit 825T allele and enhanced coronary vasoconstriction on alpha(2)-adrenoceptor activation.

Recently, alpha(2)-adrenoceptor activation was shown to play an important role in the vasoconstriction of normal coronary arteries, whereas in the presence of atherosclerosis, the activation of both alpha(1)- and alpha(2)-adrenoceptors reduces coronary blood flow in humans. alpha(2)-Adrenoceptors activate pertussis toxin (PTX)-sensitive G proteins, whereas alpha(1)-adrenoceptors couple to PTX-insensitive G proteins. Thus, the 825T allele of the beta3 subunit of heterotrimeric G proteins, associated with enhanced PTX-sensitive G protein signaling, was expected to determine the alpha(2)-adrenoceptor-, but not the alpha(1)-adrenoceptor-, mediated reduction in coronary blood flow (CBF).

Does remodeling occur in the diseased human saphenous vein bypass grafts? An intravascular ultrasound study.

Background: Coronary artery remodeling is a common phenomenon in human atherosclerotic arteries. Controversies exist concerning the presence of absence of the remodeling process in diseased human coronary saphenous vein bypass grafts. The purpose of the study was to observe the vessel and lumen dimensions in patients who had undergone saphenous vein grafting with intravascular ultrasound to find out whether the remodeling process exists in the diseased human saphenous vein bypass grafts.

Early clinical experience with the implantation of a novel synthetic coronary stent graft.

Coating stents with autologous venous grafts has been suggested to prevent problems associated with conventional stenting, but the need for surgical vessel harvest hampered broad application. A novel synthetic coronary stent graft (CSG) overcomes this limitation by a synthetic membrane, fixed between two thin metallic stents. We successfully implanted 21 CSGs in 18 patients for treatment of acute coronary rupture, thrombus-containing lesions, and lesions with plaque rupture or adjacent pseudoaneurysm.

Minimally invasive evaluation of coronary stents with electron beam computed tomography: In vivo and in vitro experience.

We sought to describe the value of electron beam computed tomography (EBCT) to detect stent restenoses at follow-up and to identify characteristic EBCT features of coronary stents. Six coronary stents (GRII, Jostent, NIR, PS, Micro, Wiktor) were scanned in vitro (10 1. 5-mm-thick slices, 15-cm FoV, 100-ms AT) before and after inflation with 3.

Chest pain after coronary interventional procedures. Incidence and pathophysiology.

Chest pain following successful percutaneous coronary interventions is a common problem. Although the development of chest pain after coronary interventions may be of benign character, it is disturbing to patients, relatives and hospital staff. Such pain may be indicative of acute coronary artery closure, coronary artery spasm or myocardial infarction, but may also simply reflect local coronary artery trauma.

Screening of ruptured plaques in patients with coronary artery disease by intravascular ultrasound.

Aim: To visualise the characteristics of ruptured plaques by intravascular ultrasound (IVUS) and to correlate plaque characteristics with clinical symptoms to establish a quantitative index of plaque vulnerability.

Methods: 144 consecutive patients with angina were examined using IVUS. Ruptured plaques, characterised by a plaque cavity and a tear on the thin fibrous cap, were identified in 31 patients (group A), of whom 23 (74%) presented with unstable angina.

Augmented alpha-adrenergic constriction of atherosclerotic human coronary arteries.

Background: Although adrenergic activation plays a major role in the initiation of experimental myocardial ischemia, the significance of alpha-adrenergic coronary constriction in humans has been questioned. The present study assessed the impact of selective alpha-adrenergic receptor activation in patients with normal or atherosclerotic coronary arteries.

Methods And Results: In 39 patients, coronary blood flow (CBF, mL/min) was determined from combined angiography and Doppler measurements.

Improved high-frequency transthoracic flow velocity measurement in the left anterior descending coronary artery after intravenous peripheral injection of levovist.

New ultrasonic technology allows noninvasive measurement of the flow in the distal left anterior descending coronary artery. The goal of this study was to validate transthoracic determination of coronary flow velocity with the intracoronary Doppler flow wire technique. In 20 patients with normal coronary arteries, 2 intracoronary and 2 comparative transthoracic Doppler measurements (TTDMs) of the average peak velocity (APV) and the mean systolic and diastolic velocities were performed.

Role of intravascular ultrasound imaging in identifying vulnerable plaques.

Unlabelled: A plaque that has a large lipid core and a thin fibrous cap may undergo rupture. Once it ruptures, it may lead to thrombus formation and subsequent vessel occlusion. To identify unstable plaques before they rupture is essential for clinical management and patient's prognosis.

Mechanisms of immune cell-mediated tissue injury in inflammatory bowel disease (Review).

This review discusses the mechanisms and pathways of immune cell-mediated intestinal inflammation and tissue injury in inflammatory bowel disease (IBD). Our lack of understanding of how the mucosal immune system normally functions to maintain the balance between tolerance and immunity to innumerable dietary and bacterial constituents of the gut is perhaps the biggest obstacle to understanding the cause(s) of IBD, and to developing more effective treatments for these debilitating disorders. Evidence that abnormalities or disruptions in the interaction of immune cells and gut bacteria can trigger or contribute to changes in the composition, regulation and activity of the mucosal immune system that result in inflammatory immune responses and tissue injury are discussed.

[New imaging methods for visualizing coronary arteries].

Techniques in the field of coronary artery imaging can be divided into two groups: invasive and non-invasive methods. Apart from the conventional coronary artery angiography, invasive methods include intracoronary ultrasound, intracoronary angioscopy, and optical coherence tomography. Non-invasive methods include magnetic resonance tomography, synchrotron-coronary angiography, and electron beam computed tomography.

[Arguments against conventional balloon dilatation of recurrences within the stent].

Today, stent restenosis is the major limitation of coronary stent implantation. Despite several prospective randomized trials, which documented significantly lower restenosis rates after stenting compared to conventional balloon angioplasty for the treatment of de-novo stenoses, restenotic lesions, bypass graft stenoses and symptomatic dissections, in daily clinical practice restenosis rates after coronary stenting are reported between 18% and 78% depending on the lesions treated. Interventional treatment options for symptomatic stent restenosis include repeat balloon angioplasty, a combination of ablative approaches (rotablation, laser angioplasty, directional atherectomy) with balloon angioplasty, and stent-in-stent (sandwich technique) placement.

In vivo tomographic assessment of the heart and blood vessels with intravascular ultrasound.

Intravascular ultrasound (IVUS) has emerged from being a research tool to becoming an intrinsic part of modern invasive cardiology mainly due to imaging micro anatomy in vivo. For the first time, it is possible to base therapeutic decisions not only on lumenograms but also on vessel wall assessment. IVUS has both diagnostic and intervention associated potential.

Mechanisms of intestinal epithelial cell injury and colitis in interleukin 2 (IL2)-deficient mice.

Epithelial cell (EC) injury is a feature of all inflammatory bowel disorders (IBD). Although the mechanisms of EC injury are incompletely understood, it has been proposed that T-cell-mediated cytotoxicity and production of inflammatory cytokines are involved. This hypothesis was tested using the interleukin 2-deficient (IL2-/-) mouse model of IBD and cultures of primary colonic EC to determine if abnormal cytokine production or cytotoxicity by colonic T cells cause EC injury.

Current concepts of coronary flow reserve for clinical decision making during cardiac catheterization.

Measurements of coronary flow reserve, once used only for research, have gained wide acceptance as an additional diagnostic approach in the decision-making process of diagnostic cardiac catheterization and coronary interventions. Apart from the noninvasive determination of coronary flow reserve, intracoronary Doppler flow wires have facilitated decision making in the catheterization laboratory. Different techniques, unstandardized procedures, and data from uncomparable patient populations have remained a confounding factor.

Improved assessment of coronary stenosis severity using the relative flow velocity reserve.

Background: Myocardial fractional flow reserve (FFR) is based on pressure measurements. We have now sought to establish a Doppler-based concept of relative flow velocity reserve (RFVR) for the functional assessment of stenosis severity in epicardial coronary arteries. A clear threshold value to discriminate the functional severity of a coronary stenosis does not exist for coronary flow velocity reserve (CVR) based on intracoronary Doppler measurements.

[18-year-old patient with hypercalcemia, hypophosphatemia, nephrocalcinosis and normal iPTH values. Primary hyperparathyroidism].

We report an 18-year old woman with surgically proven primary hyperparathyroidism (pHPT) and normal intact parathyroid hormone (iPTH) serum levels. The reason for this rare biochemical presentation are possible biologically active amino-terminal parathyroid hormone polypeptide fragments not detected by the widely used two-site immunoradiometric parathyroid hormone assay (PTH IRMA). Diagnosis and therapy of primary hyperparathyroidism therefore should not exclusively rest on the finding of hypercalcemia coupled with an elevated iPTH level.

Comparison of electron-beam computed tomography and intracoronary ultrasound in detecting calcified and noncalcified plaques in patients with acute coronary syndromes and no or minimal to moderate angiographic coronary artery disease.

We compared intracoronary ultrasound (ICUS) and electron-beam computed tomography (EBCT) on a coronary segmental basis in 40 consecutive patients with acute coronary syndromes and no or minimal to moderate angiographic disease (53+/-10 years; 34 men, 6 women). ICUS was used to define plaques, and EBCT was used to quantify coronary calcium (using a threshold of a CT density > 130 Hounsfield units in an area > 1.03 mm2).

Measuring the effect of risk factors on coronary atherosclerosis: coronary calcium score versus angiographic disease severity.

Objectives: This study sought to determine whether noninvasive quantification of coronary calcium is comparable to selective coronary angiography in measuring the effect of cardiovascular risk factors on coronary atherosclerosis.

Background: Electron beam computed tomography (EBCT) allows the delineation of anatomic coronary atherosclerotic disease and may be useful for noninvasively defining the role of established and new cardiovascular risk factors in selected patient groups.

Methods: A total of 211 consecutive patients, 26 to 79 years old, referred for evaluation of suspected or recently diagnosed coronary artery disease were examined.