P Gaudron

University of Wuerzburg, Würzburg, Bavaria, Germany

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Publications (58)336.21 Total impact

  • European Heart Journal 10/2013; · 14.72 Impact Factor
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    ABSTRACT: -Differentiation of cardiac amyloidosis (CA) from other causes of concentric left ventricular (LV) hypertrophy remains a clinical challenge, especially in patients with preserved ejection fraction at the early disease stages. -Consecutive hypertrophic patients with CA, isolated arterial hypertension (HP), Fabry disease (FD), and Friedreich's ataxia (FA) (n=25 per group) were investigated; 25 healthy volunteers served as a control group. Standard echocardiography was performed and segmental longitudinal peak systolic strain (LSsys) in the septum was assessed by two-dimensional speckle tracking imaging. Indices of LV hypertrophy and ejection fraction were similar among all patient groups. Deceleration time of early filling (DT) was significantly lower in CA (147±46 ms) compared with HP, FD or controls (all P<0.0125). Septal basal LSsys (-6±2%) was significantly lower in CA than in HP (-14±6%), FD (-12±5%), FA (-16±2%), or controls (-17±3%; all P<0.001), whereas septal apical LSsys was similar amongst all patient groups and controls (all P>0.05). A data-driven cut-off value for the ratio of septal apical to basal LSsys ratio (LSsysapi/bas) >2.1 differentiated CA from other causes of LV hypertrophy (sensitivity 88%, specificity 85%, positive predictive value 67%, negative predictive value 96%). The prevalence of LSsysapi/bas >2.1 plus DT <200 ms was 88% in CA, but 0% in all other groups. -A systolic septal longitudinal base-to-apex strain gradient (LSsysapi/bas >2.1) in combination with a shortened diastolic deceleration time of early filling (DT <200 ms) aids in differentiating CA from other causes of concentric LV hypertrophy.
    Circulation Cardiovascular Imaging 10/2013; · 5.80 Impact Factor
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    ABSTRACT: The visual echocardiographic evaluation of left ventricular (LV) systolic function can be cumbersome, especially in patients with poor image quality. This review describes several alternative echocardiographic methods to determine LV systolic function: endocardial border delineation by contrast agents, mitral annular plane systolic excursion, mitral annular velocity derived from tissue Doppler, myocardial performance index, mitral regurgitation derived LV dP/dtMax and estimation of cardiac output by Doppler echocardiography. The review introduces the respective methods along with the presentation of suitable measurements, clinical implications and methodological limitations.
    Herz 08/2013; · 0.78 Impact Factor
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    ABSTRACT: The aim of this study was to explore the left ventricular (LV) deformation changes and the potential impact of deformation on outcome in patients with proven light-chain (AL) amyloidosis and LV hypertrophy. Cardiac involvement in AL amyloidosis patients is associated with poor outcome. Detecting regional cardiac function by advanced non-invasive techniques might be favorable for predicting outcome. LV longitudinal, circumferential and radial peak systolic strains (Ssys) were assessed by speckle tracking imaging (STI) in 44 biopsy-proven systemic AL amyloidosis patients with LV hypertrophy (CA) and in 30 normal controls. Patients were divided into compensated (n = 18) and decompensated (n = 26) group based on clinical assessment and followed-up for a median period of 345 days. Ejection fraction (EF) was preserved while longitudinal Ssys (LSsys) was significantly reduced in both compensated and decompensated groups. Survival was significantly reduced in decompensated group (35% vs. compensated 78%, P = 0.001). LSsys were similar in apical segments and significantly reduced in basal segments between two patient groups. LSsys at mid-segments were significantly reduced in all LV walls of decompensated group. Patients were further divided into 4 subgroups according to the presence or absence of reduced LSsys in no (normal), only basal (mild), basal and mid (intermediate) and all segments of the septum (severe). This staging revealed continuously worse prognosis in proportion to increasing number of segments with reduced LSsys (mortality: normal 14%, mild 27%, intermediate 67%, and severe 64%). Mid-septum LSsys<11% suggested a 4.8-fold mortality risk than mid-septum LSsys≥11%. Multivariate regression analysis showed NYHA class and mid-septum LSsys were independent predictors for survival. Reduced deformation at mid-septum is associated with worse prognosis in systemic amyloidosis patients with LV hypertrophy.
    PLoS ONE 01/2013; 8(3):e56923. · 3.53 Impact Factor
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    ABSTRACT: The assessment of left ventricular (LV) systolic function is often the most important information obtained during clinical echocardiography. Although LV systolic function may be visually estimated in many patients with or without contrast opacification, technically difficult patients may require alternative methods for evaluating LV systolic function. In this review, the authors describe several surrogate echocardiographic methods that might be helpful for the evaluation of LV systolic function in patients with poor image quality, including endocardial border delineation by contrast agents, mitral annular plane systolic excursion, mitral annular velocity derived from tissue Doppler, systolic time intervals, mitral regurgitation-derived LV dP/dt, and estimation of cardiac output by Doppler echocardiography. After a short introduction to the various issues involved, the authors propose a method for suitable measurement. In addition, indications and clinical implications, as well as limitations, of the different methods are discussed.
    Journal of the American Society of Echocardiography: official publication of the American Society of Echocardiography 12/2012; · 2.98 Impact Factor
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    ABSTRACT: Mitral annular plane systolic excursion (MAPSE) has been suggested as a parameter for left ventricular (LV) function. This review describes the current clinical application and potential implications of routinely using MAPSE in patients with various cardiovascular diseases. Reduced MAPSE reflects impaired longitudinal function and thus provides complementary information to ejection fraction (EF), which represents the global result of both longitudinal and circumferential contraction. Reduced long-axis deformation results from dysfunctional or stressed longitudinal myofibres due to endo- (and potentially epi-) cardial ischaemia, fibrosis, or increased wall stress. In patients with aortic stenosis, reduced MAPSE is suggestive of subendocardial fibrosis. Moreover, reduced MAPSE could be used as a sensitive early marker of LV systolic dysfunction in hypertensive patients with normal EF, where compensatory increased circumferential deformation might mask the reduced longitudinal deformation. In addition, reduced MAPSE was associated with poor prognosis in patients with heart failure, atrial fibrillation and post-myocardial infarction as well as in patients with severe aortic stenosis undergoing aortic valve replacement. Despite of the routine use of newer and more refined echocardiographic technologies nowadays, such as strain-rate imaging, speckle-tracking imaging, and 3D echocardiography, the use of MAPSE measurement is still especially helpful to evaluate LV systolic function in case of poor sonographic windows, since good imaging quality is required for most of the modern echocardiographic techniques with the exception of tissue Doppler imaging.
    European heart journal cardiovascular Imaging. 11/2012;
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    ABSTRACT: Background- Noninvasive echocardiographic differentiation between old and fresh left ventricular thrombi after myocardial infarction would be of clinical importance to estimate the risk for embolization and the necessity of anticoagulation. Methods and Results- Fifty-two patients, aged 41 to 87 years, with a thrombus after myocardial infarction were included in this 2-part study: In substudy-I, 20 patients, 10 each with a definite diagnosis of fresh or old thrombus, were included. In the subsequent prospective substudy-II, 32 consecutive patients with an incident thrombus after myocardial infarction but unknown thrombus age were started on phenprocoumon and followed for 6 months. Data on medical history, standard echocardiography, strain-rate (SR) imaging and magnetic resonance tomography were analyzed. In substudy-I, analysis of thrombus deformation revealed the most rapid change in SR during the isovolumetric relaxation period when cavity pressure decreases rapidly. Fresh (range: 5-27 days) and old thrombi (4-26 months) could be discriminated without overlap by peak SR during the isovolumetric relaxation period, using a cutoff value of 1 s(-1). Applying this threshold value in substudy-II, 17 thrombi were echocardiographically classified as fresh (=SR ≥1 s(-1)) and 15 as old. After 6 months in the fresh thrombus group, 16 of 17 thrombi had disappeared (94%), and in 1 patient the thrombus size was diminished by >50% (now presenting an old thrombus SR pattern). In contrast, 14 of the 15 old thrombi remained unchanged in size and deformation (1 thrombus disappeared). Conclusions- Fresh and old intracavitary thrombi can be reliably differentiated by deformation imaging. In fresh thrombi, anticoagulation with phenprocoumon results in thrombus resolution in most patients.
    Circulation Cardiovascular Imaging 07/2012; 5(5):667-75. · 5.80 Impact Factor
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    ABSTRACT: Pronounced trabeculation is presented in both left ventricular non-compaction (LVNC) and dilated cardiomyopathy (DCM), which sometimes makes the differentiation difficult. We hypothesized that echocardiographic deformation analysis would help to differentiate these two cardiomyopathies. We investigated 15 patients with LVNC (9 males; 42 ± 9 years), 15 age- and gender-matched DCM patients, and 15 healthy controls. The echocardiographic diagnosis of LVNC was confirmed by magnetic resonance imaging. In all subjects standard echocardiography and tissue Doppler imaging (TDI) to study regional LV deformation were carried out. No statistical difference was observed in standard echocardiographic parameters between LVNC and DCM patients. Compared with controls, both patient groups showed significantly reduced annular displacements (septal: controls 14 ± 2 mm vs. DCM 6 ± 3 mm vs. LVNC 7 ± 3 mm) and reduced strain values of the LV segments. A characteristic deformation pattern with significantly higher values in the LV base compared with the apex was observed in patients with LVNC by deformation measurements with TDI. This gradient was found particularly in the lateral and inferior wall but spared the anteroseptal wall; non-compaction was not found in basal segments throughout the ventricle and also spared the anteroseptal midventricular wall. In DCM the strain and strain rate values were homogeneously reduced in all LV segments. A special regional deformation pattern (preserved deformation in basal segments of LVNC) seems to be of major diagnostic help for the definite differential diagnosis of LVNC and DCM.
    European Journal of Heart Failure 01/2012; 14(2):155-61. · 5.25 Impact Factor
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    ABSTRACT: We prospectively studied the relationship between left ventricular (LV) dilation, dysfunction, electrical instability and death in patients after a first myocardial infarction (MI) without symptoms of heart failure and ischemia. Mechanisms linking LV dysfunction and sudden death in patients after MI remained controversial. Left ventricular volumes, hemodynamics, electrocardiogram and 24-h Holter recordings were sequentially obtained between two days and seven years after MI. Left ventricular catheterization and coronary angiography were performed, and revascularization was performed if appropriate. Death occurred in 16 (12%) of the 134 patients included; it was of cardiac origin in 14 (88%) and sudden in origin in 12 (75%) patients. Of 37 (28%) patients with LV dilation, 12 died (32%); four patients (5.8%) died in the group without dilation. Left ventricular dilation was closely related to signs of electrical instability, as indicated by a significant correlation between end-diastolic LV volume index, Lown score (r = 0.98, p < 0.0001) and QTc prolongation (r = 0.998, p < 0.01), respectively. Patients with progressive remodeling are at increased risk of sudden death in chronic MI. Cardiac electrical instability is closely related to progressive LV dilation. Parameters of electrical instability and remodeling are predictors of sudden death. The findings suggest that remodeling might serve as a link between dysfunction, electrical instability of the heart and sudden death after MI.
    Journal of the American College of Cardiology 08/2001; 38(1):33-40. · 14.09 Impact Factor
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    ABSTRACT: Alterations of the central nervous system may be important for imbalance of cardiovascular and fluid regulation in heart failure. The central renin-angiotensin and atrial natriuretic peptide (ANP) systems act as mutual antagonists. The effects of angiotensin converting enzyme (ACE) inhibition (quinapril, 6 mg/kg/day) and angiotensin II type 1 (AT1) receptor blockade (losartan, 10 mg/kg/day) on ANP levels in 18 selected, microdissected brain nuclei were determined in sham-operated rats and rats with left ventricular dysfunction 8 weeks after myocardial infarction (MI). Plasma ANP tended to increase in MI rats and was further increased by quinapril. ANP was decreased in 12 brain areas of MI rats. ANP concentration was also significantly decreased by quinapril in six brain nuclei including subfornical organ and organum vasculosum laminae terminalis (areas lacking blood-brain barrier), and by losartan in 16 brain nuclei outside and within the blood-brain barrier in sham operated rats. However, both quinapril and losartan prevented a further reduction of central ANP as a result of myocardial infarction. These data suggest that there are effects on central ANP that result from chronic left ventricular dysfunction as well as an ACE-inhibitor and AT1-antagonist. Mechanisms and consequences of central ANP depression remain unclear. They could, however, support systemic vasoconstriction and sodium and fluid retention.
    Archiv für Kreislaufforschung 01/2001; 96(3):258-66. · 5.90 Impact Factor
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    ABSTRACT: Approximately 20% of patients with healed myocardial infarction develop asymptomatic progressive left ventricular (LV) dilation and remodeling and are at increased risk for progression to symptomatic congestive heart failure and premature death. It was the goal of this study to test whether quinapril may interrupt this process and to analyze potential mechanisms. Of 138 patients with an average infarct age of 56 months, 25 had asymptomatic progressive LV dilation and were randomized in a prospective, double-blind study to placebo or quinapril. At baseline (mean +/- SEM) ejection fraction was reduced (35 +/- 3% and 39 +/- 3%) and end-diastolic volume (gated single-photon emission computed tomography) increased (104 +/- 9 and 117 +/- 12 ml/m(2)) with placebo (n = 13) and quinapril (n = 12), respectively. Progressive dilation continued in patients taking placebo (6 months: 9.4 +/- 5.2 ml/m(2), 12 months 24.6 +/- 5. 4 ml/m(2); change from baseline: p <0.05 vs baseline; p <0.05 vs 6 months), but not with quinapril (6 months: -0.9 +/- 4.0 ml/m(2); 12 months: 4.1 +/- 5.2 ml/m(2) [p <0.05] vs placebo). Wedge pressure during bicycle exercise was similar at baseline, but at 12 months tended to be lower with quinapril (17 +/- 1 mm Hg) than with placebo (24 +/- 4 mm Hg, p = 0.1673). Thus, quinapril prevented further progression of asymptomatic LV dilation and remodeling after remote myocardial infarction, possibly due to attenuation of an exercise-induced increase in LV filling pressure.
    The American Journal of Cardiology 08/2000; 86(2):139-44. · 3.21 Impact Factor
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    ABSTRACT: The plasma membrane calmodulin-dependent calcium ATPase (PMCA) is a calcium-extruding enzyme controlling Ca2+ homeostasis in nonexcitable cells. However, its function in the myocardium is unclear because of the presence of the Na+/Ca2+ exchanger. We approached the question of the physiological function of the calcium pump using a transgenic "gain of function" model. Transgenic rat lines carrying the human PMCA 4 cDNA under control of the ventricle-specific myosin light chain-2 promoter were established, and expression in the myocardium was ascertained at the mRNA, protein, and functional levels. In vivo hemodynamic measurements in adult homozygous animals showed no differences in baseline and increased cardiac performance recruited by volume overload compared with controls. No differences between transgenic and control cardiomyocytes were found in patch clamp voltage dependence, activation/inactivation behavior of the L-type Ca2+ current, or fast [Ca2+]i transients (assessed by the Fura-2 method). To test whether the PMCA might be involved in processes other than beat-to-beat regulation of contraction/relaxation, we compared growth processes of neonatal transgenic and control cardiomyocytes. A 1.6- and 2.3-fold higher synthesis rate of total protein was seen in cells from transgenic animals compared with controls on incubation with 2% FCS for 24 hours and 36 hours, respectively. An effect of similar magnitude was observed using 20 micromol/L phenylephrine. A 1.4-fold- and 2.0-fold-higher protein synthesis peak was seen in PMCA-overexpressing cardiomyocytes after stimulation with isoproterenol for 12 hours and 24 hours, respectively. Because pivotal parts of the alpha- and beta-adrenergic signal transduction pathways recently have been localized to caveolae, we tested the hypothesis that the PMCA might alter the amplitude of alpha- and beta-adrenergic growth signals by virtue of its localization in caveolae. Biochemical as well as immunocytochemical studies suggested that the PMCA in large part was colocalized with caveolin 3 in caveolae of cardiomyocytes. These results indicate that the sarcolemmal Ca2+-pump has little relevance for beat-to-beat regulation of contraction/relaxation in adult animals but likely plays a role in regulating myocardial growth, possibly through modulation of caveolar signal transduction.
    Circulation Research 12/1998; 83(9):877-88. · 11.86 Impact Factor
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    ABSTRACT: The plasma membrane calmodulin-dependent calcium ATPase (PMCA) is a calcium-extruding enzyme controlling Ca2+ homeostasis in nonexcitable cells. However, its function in the myocardium is unclear because of the presence of the Na+/Ca2+ exchanger. We approached the question of the physiological function of the calcium pump using a transgenic "gain of function" model. Transgenic rat lines carrying the human PMCA 4 cDNA under control of the ventricle-specific myosin light chain-2 promoter were established, and expression in the myocardium was ascertained at the mRNA, protein, and functional levels. In vivo hemodynamic measurements in adult homozygous animals showed no differences in baseline and increased cardiac performance recruited by volume overload compared with controls. No differences between transgenic and control cardiomyocytes were found in patch clamp voltage dependence, activation/inactivation behavior of the L-type Ca2+ current, or fast [Ca2+]i transients (assessed by the Fura-2 method). To test whether the PMCA might be involved in processes other than beat-to-beat regulation of contraction/relaxation, we compared growth processes of neonatal transgenic and control cardiomyocytes. A 1.6- and 2.3-fold higher synthesis rate of total protein was seen in cells from transgenic animals compared with controls on incubation with 2% FCS for 24 hours and 36 hours, respectively. An effect of similar magnitude was observed using 20 micromol/L phenylephrine. A 1.4-fold- and 2.0-fold-higher protein synthesis peak was seen in PMCA-overexpressing cardiomyocytes after stimulation with isoproterenol for 12 hours and 24 hours, respectively. Because pivotal parts of the alpha- and beta-adrenergic signal transduction pathways recently have been localized to caveolae, we tested the hypothesis that the PMCA might alter the amplitude of alpha- and beta-adrenergic growth signals by virtue of its localization in caveolae. Biochemical as well as immunocytochemical studies suggested that the PMCA in large part was colocalized with caveolin 3 in caveolae of cardiomyocytes. These results indicate that the sarcolemmal Ca2+-pump has little relevance for beat-to-beat regulation of contraction/relaxation in adult animals but likely plays a role in regulating myocardial growth, possibly through modulation of caveolar signal transduction.
    Circulation Research 11/1998; 83(9):877-88. · 11.86 Impact Factor
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    ABSTRACT: Myocardial ischemia results in myocardial dysfunction. Recovery may be delayed ("stunning"), or persistent if perfusion remains reduced ("hibernation") and ischemia may go on to necrosis, thus, contributing to chronic heart failure. In addition, myocardium not directly affected by ischemia may undergo adaptive processes like hypertrophy and dilatation, which may result in chronic left heart failure. This process is characterized by hemodynamic, neurohumoral, and progressive morphologic changes of the heart which are closely interrelated. Hemodynamic changes basically consist of an increase in left ventricular filling pressure and a decrease in global ejection fraction, and, in most cases years after myocardial infarction, in an increase in systemic vascular resistance and right atrial pressure. Neurohumoral changes consist of an increase in plasma catecholamines, atrial natriuretic factor and vasopressin, and in an activation of the renin-angiotensin-system. Plasma endothelin-1 was recently reported to be increased in patients with heart failure, and prognosis was related to endothelin levels. Diminished response of vessels to endothelium (EDRF/NO) dependent vasodilatation suggests impairment of vascular endothelium in heart failure. Local changes of cardiac neurohumoral systems could contribute to structural changes of the heart, e.g., systemic activation to hemodynamic changes. Structural changes of the heart are characterized by an increase in volume and thickness of surviving myocardium and an expansion of ischemic and necrotic myocardium. Molecular control of these processes which include various cell types, such as cardiomyocytes and cardiofibroblasts, are currently an issue of intense research and could result in specific therapeutic importance.
    Zeitschrift für Kardiologie 10/1998; 87(9):667-75. · 0.97 Impact Factor
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    ABSTRACT: The long-term effects and mechanisms of early started angiotensin converting enzyme (ACE) inhibition post myocardial infarction (MI) are not well understood. Chronic effects of early ACE inhibition on hemodynamics, left ventricular diastolic wall stress and remodeling were, therefore, compared to that of angiotensin AT1-receptor subtype blockade in rats with experimental myocardial infarction. The contribution of bradykinin potentiation to both ACE inhibitor and angiotensin AT1-receptor subtype blockade was assessed by cotreatment of rats with a bradykinin B2-receptor antagonist. MI was produced by coronary artery ligation in adult male Wistar rats. The ACE inhibitor, quinapril (6 mg/kg per day), or the angiotensin AT1-receptor subtype blocker, losartan (10 mg/kg per day), administered by gavage, and the bradykinin B2-receptor antagonist, Hoe-140 (500 micrograms/kg per day s.c.), administered either alone or in combination with quinapril or losartan, were started 30 min after MI and continued for eight weeks. Quinapril and losartan reduced left ventricular end-diastolic pressure and global left ventricular diastolic wall stress only in rats with large MI. Pressure volume curves showed a rightward shift in proportion to MI size that was not prevented by quinapril or losartan treatment. Only the ACE inhibitor reduced left ventricular weight and this effect was prevented by cotreatment with the bradykinin antagonist. Baseline and peak cardiac index and stroke volume index, as determined using an electromagnetic flowmeter before and after an acute intravenous volume load, were restored by quinapril, whereas losartan had no effects. Treatments starting 30 min after coronary artery ligation, with either quinapril or losartan, reduced preload only in rats with large MI. Despite this unloading of the heart, structural dilatation was not prevented by this early treatment. Only quinapril improved cardiac performance and reduced left ventricular weight and this effect was abolished by cotreatment with Hoe-140, suggesting an angiotensin II blockade-independent, but bradykinin potentiation-dependent, mechanism.
    Cardiovascular Research 09/1998; 39(2):401-12. · 5.81 Impact Factor
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    ABSTRACT: An endothelin (ET(A)) antagonist reduced mortality and an ET(A) + ET(B) antagonist prevented left ventricular dilatation in rats with large myocardial infarction. This study tested the hypothesis that long-term blockade of the ET(A) receptor would have beneficial effects on left ventricular function and remodeling. Three hours after coronary artery ligation or sham operation in rats, EMD94246 (100 mg/kg/day, n=62) or placebo (n=62) was given by gavage. Eight weeks later, left ventricular hemodynamic measurements were performed and left ventricular volume determined with a double-lumen catheter after KCl-induced cardiac arrest. EMD94246 treatment had no effects on mortality or hemodynamic parameters. In rats with large infarcts, EMD94246 significantly increased left ventricular volume (2.5+/-0.1 vs. 2.2+/-0.1 ml/kg; p < 0.05). The nonpeptide ET(A)-selective antagonist EMD94246 promoted chronic left ventricular dilatation in rats with large myocardial infarction.
    Journal of Cardiovascular Pharmacology 09/1998; 32(3):505-8. · 2.38 Impact Factor
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    ABSTRACT: It has been speculated that high pressure implantation may improve the results of coronary stenting. However, this method bears the risk of persistent dissection and may increase late lumen loss. Presently, there is no consensus about the optimal stent implantation technique with the regard to balloon size and pressure. To elucidate this question an experimental study was performed in a coronary stenosis model. 3.5 mm Multi-Link (ML) stents were implanted in 3.3 mm silicone rubber tubes containing 50% concentric narrowings. Three implantation techniques were applied: 1. The standard technique using the conventional ML delivery system with a compliant balloon (ML-ST). 2. A new deployment method with a high pressure delivery system (ML-HP). 3. "Focal postdilation" using the ARC catheter, which has a special balloon with an inner compliant and an outer non-compliant section (ML-ARC). For comparison, the Palmaz-Schatz stent was implanted by using a high pressure balloon. Stent expansion was imaged by magnification radiography. Minimal lumen diameter within the stent (MLD) and the lumen diameter outside the stent (BD) were measured after dilations with 6, 9, 12, 15, 18, and 21 atm. The relation of the BD to the MLD was used as an index of vessel trauma. The results lead to the following conclusions: 1. A complete apposition to the vessel wall for a balloon/vessel relation of 1.1:1 could not be reached with pressures below 9-15 atm. The increase of the pressure beyond 15 atm resulted only in a minimal additional lumen. 2. Compared to the Palmaz-Schatz stent the recoil of the ML stent was significantly lower. 3. For all three implantation techniques the ML-ARC showed the best results with the maximal dilation of the stenotic vessel-area and the minimal expansion of the vessel outside the stent.
    Zeitschrift für Kardiologie 06/1998; 87(5):344-52. · 0.97 Impact Factor
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    K Hu, P Gaudron, G Ertl
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    ABSTRACT: This study was designed to assess the long-term effects of a beta1-selective beta-adrenergic blocking agent on mortality, in vivo hemodynamic function, left ventricular volume and wall stress in post-myocardial infarction (MI) rats. Beta-blockers have shown beneficial results in clinical studies after MI. However, the underlying mechanism is not yet understood, and experimental studies have shown conflicting results. Bisoprolol (60 mg/kg body weight per day) was given 30 min or 14 days after MI or sham operation. The mortality rate was reduced only in early bisoprolol-treated rats (29% vs. 46% in untreated rats, p < 0.05). Heart rate was equally reduced in all treatment groups, and the maximal rate of rise of left ventricular systolic pressure (dP/dt(max)) decreased in sham rats and in rats with a small to moderate infarct size. Stroke volume index was unchanged in sham rats and in rats with a small to moderate infarct with early or late bisoprolol treatment and increased in rats with a large infarct in the late bisoprolol group. Left ventricular volume was increased by bisoprolol in sham rats and rats with a small infarct but not in rats with a large infarct. Treatments starting early (30 min) or late (14 days) after coronary artery ligation with bisoprolol increased left ventricular volume in sham rats and in rats with a small infarct but not in rats with a large infarct. Late bisoprolol treatment improved stroke volume index, and early bisoprolol treatment reduced diastolic wall stress, in rats with a large myocardial infarct. Thus, bisoprolol effects on remodeling and cardiac performance after myocardial infarction strongly depend on infarct size and timing of treatment. This finding may explain previous controversial results that did not consider infarct size and timing of treatment.
    Journal of the American College of Cardiology 03/1998; 31(3):692-700. · 14.09 Impact Factor
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    ABSTRACT: Die Hochdruckdilatationstechnik scheint geeignet, die Ergebnisse der Stentimplantation in Koronargefäßen zu verbessern. Trotzdem birgt diese Methode das Risiko einer Gefäßdissektion im Stentbereich und eines Anstiegs der Restenoserate. Gegenwärtig besteht kein Konsensus zur optimierten Stentimplantation hinsichtlich Ballongröße und -druck. Um diese Frage zu untersuchen, wurde eine experimentelle Studie anhand eines Koronarstenose-Modells durchgeführt. 3,5-mm-Multi-Link-(ML-)Stents wurden in 3,3 mm weite Silikon-Gummischläuche mit einer 50%igen konzentrischen Enge implantiert. Drei Implantationstechniken wurden verwendet: 1. Die Standardtechnik mit konventionellem ML-Träger-System und zugehörigem Ballon (ML-ST). 2. Ein neu entwickeltes Hochdruck-System (ML-HP). 3. Die “fokale” Implantationstechnik unter Verwendung des ARC-Katheters, dessen Ballon in der Mitte compliant und außen nichtcompliant ist (ML-ARC). Zu Vergleichszwecken wurde der Palmaz-Schatz-Stent untersucht. Die Stentexpansion wurde mit der hochauflösenden Vergrößerungsradiographie wiedergegeben. Der minimale Diameter innerhalb des Stents (MLD), am Randbereich des Stents (BRD) und der Ballondiameter außerhalb des Stents (BD) wurden nach Aufdehnung bei 6, 9, 12, 15, 18 und 21 atm gemessen. Das Verhältnis BD zu MLD diente als “Traumatisierungsindex” für das angrenzende Gerfäß. Zusammenfassend läßt sich sagen: 1. Eine komplette Apposition des Multi-Link-Stents wurde auch bei adäquater Größenwahl des Ballons (Ballon-Gefäß-Verhältnis 1,1:1) bei allen Systemen erst bei Drücken zwischen 9 und 15 atm erzielt. Eine Hochdruckdilatation mit Drücken oberhalb von 15 atm brachte nur einen geringen Lumengewinn und erscheint nur in Einzelfällen, insbesondere bei nicht komplett vordilatierten Stenosen, sinnvoll. 2. Der Multi-Link-Stent wies aufgrund seiner größeren radialen Kraft einen geringeren Recoil als der Palmaz-Schatz-Stent auf. 3. Unter den verglichenen Implantationstechniken zeigte das ML-ARC-System die besten Resultate mit maximal hoher Aufdehnung des stenotischen Bereiches (MLD) bei geringster Aufdehnung des angrenzenden Gefäßabschnitts (BD). It has been speculated that high pressure implantation may improve the results of coronary stenting. However, this method bears the risk of peristent dissection and may increase late lumen loss. Presently, there is no consensus about the optimal stent implantation technique with the regard to balloon size and pressure. To elucidate this question an experimental study was performed in a coronary stenosis model. 3.5 mm Multi-Link (ML) stents were implanted in 3.3 mm silicone rubber tubes containing 50% concentric narrowings. Three implantation techniques were applied: 1. The standard technique using the conventional ML delivery system with a compliant balloon (ML-ST). 2. A new deployment method with a high pressure delivery system (ML-HP). 3. “Focal postdilation” using the ARC catheter, which has a special balloon with an inner compliant and an outer non-compliant section (ML-ARC). For comparison, the Palmaz-Schatz stent was implanted by using a high pressure balloon. Stent expansion was imaged by magnification radiography. Minimal lumen diameter within the stent (MLD) and the lumen diameter outside the stent (BD) were measured after dilations with 6, 9, 12, 15, 18, and 21 atm. The relation of the BD to the MLD was used as an index of vessel trauma. The results lead to following conclusions: 1. A complete apposition to the vessel wall for a balloon/vessel relation of 1.1:1 could not be reached with pressures below 9–15 atm. The increase of the pressure beyond 15 atm resulted only in a minimal additional lumen. 2. Compared to the Palmaz-Schatz stent the recoil of the ML stent was significant lower. 3. For all three implantation techniques the ML-ARC showed the best results with the maximal dilatation of the stenotic vesselarea and the minimal expansion of the vessel outside the stent. Schlüsselwörter Multi-Link-Stent – Hochdruckdilatation – In-vitro-Gefäßmodell – Vergrößerungsradiographie – StentappositionKey words Multi-Link stent – high pressure dilatation – in vitro vessel model – magnification radiography – stent apposition
    Zeitschrift für Kardiologie 01/1998; 87(5):344-352. · 0.97 Impact Factor
  • Journal of The American College of Cardiology - J AMER COLL CARDIOL. 01/1998; 31:311-311.

Publication Stats

825 Citations
336.21 Total Impact Points

Institutions

  • 1989–2013
    • University of Wuerzburg
      • • Department of Internal Medicine I
      • • Department of Internal Medicine II
      Würzburg, Bavaria, Germany
  • 1997–2001
    • Universität Heidelberg
      • • Medical University Clinic and Polyclinic
      • • II. Medical Clinic
      Heidelberg, Baden-Wuerttemberg, Germany