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D Baumgart

Publications and source records attributed to D Baumgart.

At least 37 records · Page 2Linked to original sources
PubMed2001

Early clinical experience with the 6 French Angio-Seal device: immediate closure of femoral puncture sites after diagnostic and interventional coronary procedures.

The objective of this study was to assess the early safety and efficacy of the novel 6 Fr Angio-Seal device for routine clinical use after diagnostic cardiac catheterization and coronary angioplasty. In a prospective study, we used the 6 Fr Angio-Seal device in 180 consecutive patients (131 male, 49 female, mean age 60.7 years) for closure of femoral arterial puncture sites immediately after diagnostic (n = 108) or interventional (n = 72) coronary procedures independent of the coagulation status. All patients were monitored for 24 hr after the procedure and followed for 30 days. The closure device was successfully deployed in 95.4% after diagnostic catheterization versus 98.6% after coronary angioplasty (P = 0.963). Immediate hemostasis was achieved in 91.5% versus 90.1% of the patients (P = 0.993). Major complications were observed 1.9% versus 2.8% of the patients (P = 0.885). During 30-day follow-up, no late events or complications were reported. The 6 Fr Angio-Seal device is a safe and effective device that allows for immediate closure of femoral puncture sites after both diagnostic and interventional procedures with a low rate of major complications.

Adult↗
PubMed2001

Assessment of coronary morphology and flow in a patient with Guillain-Barré syndrome and ST-segment elevation.

Patients with Guillain-Barré syndrome often have cardiac disturbances as a manifestation of autonomic dysfunction. Such abnormalities consist of arrhythmias and disturbances of heart rate and blood pressure. We report a case of a patient with Guillain-Barré syndrome who developed ST-segment elevation in the inferolateral leads, suggestive of an acute coronary syndrome. Cardiac catheterization revealed angiographically normal coronary arteries. Intracoronary ultrasound was also normal. Intracoronary Doppler flow measurements revealed an elevated baseline coronary flow velocity of up to 41 cm/s and decreased coronary flow reserve, particularly in the left circumflex artery. Myopericarditis as cause of the electrocardiographic changes could be ruled out by echocardiography and endomyocardial biopsy. We postulate that the intracoronary Doppler findings are caused by autonomic dysfunction with decrease of coronary resistance and redistribution of the transmural myocardial blood flow.

Autonomic Nervous System Diseases↗
PubMed2001

[Late stent thrombosis after intracoronary brachytherapy. A case report and review of the literature].

Intracoronary irradiation is currently the most promising approach to reduce restenosis after percutaneous transluminal coronary angioplasty. Meanwhile numerous data are available concerning efficacy and safety of this novel method. These data confirm the results of preclinical studies that reported a dramatic reduction of neo-intima proliferation and negative remodeling. However, the number of reports on an elevated incidence of late stent thrombosis (> 30 days post intervention) are increasing. It is commonly suggested that the delayed neo-intima formation within vascular stents is responsible for this new phenomenon. We report the case of a 48-year-old man who underwent coronary irradiation therapy after stent placement in a de-novo/restenotic lesion. Despite an explicit recommendation of a combined anti-aggregatory therapy consisting of ticlopidine and acetysalicylic acid for at least 6 months, ticlopidine was withdrawn after 4 weeks. Two weeks later, the patient was readmitted to an external hospital with an acute myocardial infarction and successfully treated with thrombolysis. The angiographic and intravascular control, which was conducted after another two weeks, showed absolutely no neointima formation within the implanted stent. Thus, a late thrombotic occlusion of the implanted stent appears most likely to be the cause underlying the myocardial infarction. This case underlines, together with other existing reports, the importance of a prolonged, combined anti-aggregatory therapy after stent placement and subsequent intracoronary irradiation.

Angina Pectoris↗
PubMed2001

Reproducibility of two coronary calcium quantification algorithms in patients with different degrees of calcification.

PURPOSE: To evaluate the reproducibility of coronary calcium quantification algorithms by electron beam CT (EBT) in patients with different amounts of calcified plaque using the conventional (Agatston) score and an area score and to demonstrate a potential application of these results for evaluation of follow-up scans. METHODS: In 50 consecutive patients. the conventional calcium score (CCS = Agatston score) and the area score (AS) were summed for each artery and patient. Data were analyzed in four groups according to degrees of calcification: 0 (absent-minimal): CCS 0-9, I (mild): CCS 10-99, II (moderate): CCS 100-399, III (severe): CCS > or = 400. We determined and compared the reproducibility for each algorithm within and among groups. RESULTS: Median percent reproducibility improved with increasing amounts of calcified plaque for the CCS and the AS (p = 0.002 and p = 0.004, respectively). We demonstrate how these reproducibility values can be used to evaluate long-term follow-up studies. The reduction of median reproducibility per patient using the AS vs. the CCS was 32% (13 vs. 19%, respectively). On a vessel-by-vessel basis, the reduction of median reproducibility was 7% (24.3 vs. 22.6%, CCS vs. AS, p < 0.02), which was attributable to a 45% reduction in reproducibility in arteries with mild scores (46.1 vs. 25.5%, CCS vs. AS, p < 0.005). CONCLUSION: The AS has an improved reproducibility compared with the CCS, especially in patients with small amounts of coronary calcifications which may prove clinically useful. Different reproducibility values in different degrees of calcification can be used for an individual assessment of changes in amounts of coronary calcification.

Adult↗
PubMed2001

Myocardial lactate release after intracoronary verapamil application in humans: acute effects of intracoronary verapamil on systemic and coronary hemodynamics, myocardial metabolism, and norepinephrine levels.

Coronary and systemic hemodynamic effects of verapamil have been investigated previously in detail. The acute impact of intracoronary verapamil on coronary hemodynamics has, however, not been correlated to simultaneously changes in myocardial metabolism or norepinephrine levels in humans. After bolus application of 1 mg verapamil into the left coronary artery of 52 patients scheduled for routine coronary angiography, heart rate (HR) remained unchanged, whereas mean arterial blood pressure (MAP) decreased (93.8 +/- 14.9 mmHg to 85.1 +/- 13.7 mmHg, p = 0.001). Coronary blood flow (CBF), calculated from intracoronary Doppler measurements and quantitative coronary angiography, increased after verapamil administration (28.5 +/- 16.7 ml/min to 66.2 +/- 41.8 ml/min, p < 0.001), whereas coronary vascular resistance index (CVRI) decreased (1.43 +/- 0.92 to 0.46 +/- 0.23, p < 0.001). Blood samples, taken simultaneously from the aorta (Ao) and coronary sinus (CS) at baseline and at maximal flow velocity, showed an increase in norepinephrine concentrations in Ao (209 +/- 151 ng/l to 283 +/- 195 ng/l, p < 0.001) and CS (233 +/- 162 ng/l to 323 +/- 248 ng/l, p = 0.004). Myocardial metabolism of pyruvate and free fatty acids were not affected. Glucose release was augmented and initial lactate consumption changed to a net lactate release into the CS (Ao to CS differences: glucose: -1.92 +/- 9.9 mg/dl to -12.8 +/- 22.8 mg/dl, p < 0.001; lactate: 0.07 +/- 0.2 mmol/l to -0.08 +/- 0.3 mmol/l, p = 0.001). Similar results were obtained for the extraction ratios and flux of these metabolites. There was a weak correlation between the increase in CBF and lactate release into the CS. This is the first report of unexpected myocardial lactate release following intracoronary verapamil administration in humans. This lactate release was paralleled by an increased glucose release into the CS at an unchanged metabolism of free fatty acids and pyruvate. One explanation for this unexplained lactate release during increased coronary blood flow might be a wash out phenomenon of lactate from previous ischemic areas, other explanations might be the induction of paradox myocardial ischemia and/or a steal effect. Further studies are necessary to explain these unexpected findings of increased coronary flow and myocardial lactate release. Until reliable explanations are pending, studies using only lactate release as a marker of myocardial ischemia, without taken coronary and systemic hemodynamic parameters into account, should be interpreted with caution.

Adult↗
PubMed2001

Echocardiographic detection of coronary artery fistula into the pulmonary artery.

A rare case of left coronary artery--pulmonary artery fistula is reported. Transoesophageal echocardiography was capable of precisely demonstrating the origin, the course and the drainage site of the fistula. In contrast, transthoracic echocardiography could visualise a drainage flow in the pulmonary artery only. In conclusion, transoesophageal echocardiography may be helpful in the diagnosis or exclusion of the form of coronary artery fistula.

Arterio-Arterial Fistula↗
PubMed2001

Increased heterogeneity of coronary perfusion in patients with early coronary atherosclerosis.

BACKGROUND: In patients with typical angina but angiographically normal coronary arteries, abnormal vasomotor function is assumed to be a major underlying cause. However, data on this issue are conflicting, and recent studies suggest that fluid dynamic abnormalities exist in these patients. The aim of the study was to evaluate whether early stages of atherosclerosis are characterized by alterations of baseline coronary hemodynamics and endothelium-independent vasomotion. Besides established intracoronary Doppler parameters, heterogeneity of perfusion was assessed and related to early signs of atherosclerosis as determined by electron-beam computed tomography (EBCT). METHODS: In 59 patients with typical angina and angiographically normal or near-normal coronary arteries, intracoronary Doppler measurements were performed in all 3 major coronary arteries. Baseline average peak velocity (bAPV) and hyperemic average peak velocity (hAPV) in response to intracoronary injection of adenosine were measured, and coronary flow velocity reserve (CFVR) was calculated. Heterogeneity was assessed as variability of bAPV, hAPV, and CFVR and was calculated as (STD/MEAN). 100. Doppler data were analyzed according to tertiles of the EBCT-derived Agatston calcium score (ie, score 0-1 [lowest tertile], 2-28 [medium tertile], and >28 [highest tertile]). RESULTS: The mean EBCT-derived Agatston calcium score was 49 +/- 107. No coronary calcium was observed in 17 (29%) patients. The mean values of bAPV, hAPV, and CFVR were not different between the calcium score tertiles. However, patients in the highest tertile had a significantly increased variability index of bAPV (29.6% +/- 11.6%) compared with patients in the lowest tertile (13.4% +/- 7.3%, P <.0001). Variability of CFVR was also increased in these patients (15.5% +/- 11.7% vs 10.5% +/- 4.0%, P =.03). CONCLUSION: These results indicate that early stages of atherosclerosis are characterized by microvascular abnormalities that do not uniformly affect the myocardium but are heterogeneous. The high variability of baseline coronary flow velocity with increasing coronary calcium suggests that in patients with early stages of atherosclerosis fluid dynamic effects may play a crucial role even in the absence of angiographically appreciable epicardial stenoses.

Adenosine↗
PubMed2001

eNOS 894T allele and coronary blood flow at rest and during adenosine-induced hyperemia.

The 894T allele of a G894T polymorphism in the endothelial nitric oxide synthase (eNOS) gene is associated with decreased eNOS activity, cleavage of the protein, and endothelial dysfunction. The present study evaluated the association with coronary blood flow (CBF) at rest and during adenosine (ADO)-induced hyperemia. CBF was determined by Doppler flow wire and angiography in 97 left anterior descending arteries of individuals without coronary artery disease. At rest, average peak velocity (APV) was lower and coronary vascular resistance (CVR) was higher in homozygous carriers of the 894T allele than in heterozygotes and individuals without the 894T allele. CBF tended to be lower in eNOS 894T allele carriers. During ADO-induced hyperemia (18 microg ic), APV, CVR, and CBF were not statistically different between the genotypes. The reduced APV at rest in conjunction with an increased CVR indicates a vasomotor dysfunction related to an increased microvascular resting tone in eNOS 894T allele carriers.

Adenosine↗
PubMed2001

Natural history and topographic pattern of progression of coronary calcification in symptomatic patients: An electron-beam CT study.

Electron-beam CT may assess the progression of coronary atherosclerosis by visualizing changes in calcification. The present investigation analyzes (1) the rate of progression of calcification in symptomatic patients, (2) the topographic pattern, and (3) the influence of baseline plaque burden and risk factors. Progression of calcification during a mean (median) interval of 18 (15) months was measured in 102 symptomatic outpatients (aged 59+/-9 years, 80% male) with calcification. In 4 patient groups with a baseline total score (Agatston criteria) of 1 to 30, >30 to 100, >100 to 400, and >400, the median was 3.1, 26.1, 58.9, and 109.7, respectively, for absolute annual progression of the score (P<0.05) and 57%, 49%, 32%, and 15%, respectively, for relative progression (P<0.05). On the coronary segmental level, changes were largely restricted to typical predilection sites of coronary atherosclerosis. The presence of angiographically defined coronary narrowing influenced absolute, but not relative, progression. Of the risk factors, only low density lipoprotein cholesterol levels showed a trend, although not significant, for predicting progression. These data indicate that baseline plaque burden determines the rate of progression of calcification. This appears to be a coronary systemic process, reflecting the natural history of coronary atherosclerosis.

Aged↗
PubMed2000

Usefulness of topography of coronary calcium by electron-beam computed tomography in predicting the natural history of coronary atherosclerosis.

Electron-beam computed tomography (EBCT) allows for accurate noninvasive detection and quantification of coronary calcium that is representative of underlying atherosclerotic disease. The present study quantitatively analyzes the topography and establishes the natural history of coronary calcium in patients with variable degrees of coronary atherosclerosis. EBCT was performed in 330 consecutive patients aged 56 +/- 12 years (70% men) with recent (<3 months) onset of signs or symptoms of coronary artery disease (CAD) or who were evaluated because of a presumed high risk. Total calcium scores, computed by the Agatston method, were positive in 269 patients (82%) (mean age 58 +/- 11 years, 73% men). These patients were classified into 4 groups, with total calcium scores ranging between 1 and 30, >30 and 100, >100 and 400, and >400, respectively. The presence and amount of calcium was additionally assessed in 10 major segments of the coronary arterial tree, including the major coronary arteries. Of the 72 patients with calcium of only 1 of the major coronary arteries, the left anterior descending coronary artery was involved in 39 patients (54%) and the right coronary artery in 18 patients (25%). Left main stem calcium was observed in only 10 of 139 patients (7%) with 1- or 2-vessel calcium and in 17 of 77 patients (23%) with 3-vessel calcium. Calcium was consistent most frequently in the proximal left anterior descending coronary artery, followed by the proximal left circumflex and right coronary artery segments. A significant decrease of frequency and amount of calcium from the proximal to distal segments was observed in the left coronary system but not in the right coronary artery, where the distribution was more even. With increasing total calcium scores, segmental scores in the more distal segments were enhanced, but the increase was most pronounced in the proximal segments and particularly in the proximal left anterior descending coronary artery. EBCT-derived coronary calcium shows an axial distribution that appears comparable to that of atherosclerotic lesions observed in pathologic and angiographic studies, highlighting the potential role of EBCT for studying the natural history of CAD.

Aged↗
PubMed2000

alpha-adrenergic coronary vasoconstriction and myocardial ischemia in humans.

The use of quantitative coronary angiography, combined with Doppler and PET, has recently been directed at the study of alpha-adrenergic coronary vasomotion in humans. Confirming prior animal experiments, there is no evidence of alpha-adrenergic coronary constrictor tone at rest. Again confirming prior experiments, responses to alpha-adrenoceptor activation are augmented in the presence of coronary endothelial dysfunction and atherosclerosis, involving both alpha(1)- and alpha(2)-adrenoceptors in epicardial conduit arteries and microvessels. Such augmented alpha-adrenergic coronary constriction is observed during exercise and coronary interventions, and it is powerful enough to induce myocardial ischemia and limit myocardial function. Recent studies indicate a genetic determination of alpha(2)-adrenergic coronary constriction.

Coronary Vessels↗
PubMed2000

Potential embolization by atherosclerotic debris dislodged from aortic wall during cardiac catheterization:: histological and clinical findings in 7,621 patients.

Embolic events during cardiac catheterization have been attributed to atherosclerotic aortic debris dislodged by catheter manipulation. We evaluated the frequency and the histologic morphology of atherothrombotic material retrieved during placement of coronary catheters in patients undergoing diagnostic or interventional cardiac procedures. Over a 4-year period, macroscopically visible aortic debris from coronary catheters, if present after advancement to the ascending aorta, was obtained for histologic examination. In 41 of 7,621 patients (0.54%), visible atherothrombotic material was present in the backflow of catheters. Debris occurred most frequently with 8 Fr guiding catheters (98%). Histologic examination showed foam cells, cholesterol crystals, and amorphic lipoid substance as markers of atheromatous material from atherosclerotic plaques in 38/41 patients (93%) with former plaque hemorrhage in 55% of them. In three patients, fresh thrombus material was observed (7%). None of these patients showed in-hospital ischemic complications. Although visible atheromatous material is a rare phenomenon in cardiac catheterization, an increased risk of scraping debris is associated with large-lumen guiding catheters. In order to avoid vascular embolization, the use of smaller guiding catheters and sufficient free backflow of catheters after advancement are recommended.

Adult↗
PubMed2000

Nonsurgical retrieval of embolized coronary stents.

Embolization of coronary stents before deployment is a rare but challenging complication of coronary stenting. Different methods for nonsurgical stent retrieval have been suggested. There were 20 cases (0.90%) of intracoronary stent embolization among 2,211 patients who underwent implantation of 4,066 stents. Twelve of 1,147 manually crimped stents (1.04%) and eight of 2,919 premounted stents were lost (0.27%, P < 0.01) during retraction of the delivery system, because the target lesion could not be either reached or crossed. Percutaneous retrieval was successfully carried out in 10 of 14 patients (71%) in whom retrieval was attempted. In 10 patients, stent retrieval was tried with 1.5-mm low-profile angioplasty balloon catheters (success in 7/10) and in seven cases with myocardial biopsy forceps or a gooseneck snare (success in 3/7). Three patients (15%) underwent urgent coronary artery bypass surgery after failed percutaneous retrieval, but their outcomes were fatal. In two patients, stents were compressed against the vessel wall by another stent, without compromising coronary blood flow. In two patients, a stent was lost to the periphery without clinical side effects; treatment was conservative in these cases. Embolization of stents before deployment is a rare but serious complication of coronary stenting, with hazardous potential for the patient. Manual mounting of stents is associated with a significantly higher risk of stent embolization. Stent retrieval from the coronary circulation with low-profile angioplasty balloon catheters is a readily available and technically familiar approach that has a relatively high success rate.

Aged↗
PubMed2000

Percutaneous transluminal laser guide wire recanalization of chronic subclavian artery occlusion in symptomatic coronary-subclavian steal syndrome.

Treatment of subclavian artery stenosis by percutaneous balloon angioplasty and adjunctive stent placement was shown to be safe and efficacious, but it may be limited in tight stenoses and long occlusions. We describe the case of a patient who experienced progressive angina pectoris associated with signs of cerebrovertebral insufficiency 9 yr after bypass surgery, including left internal mammary artery (LIMA) grafting to the left anterior descending coronary artery. Angiography showed reversed flow through the LIMA graft into the subclavian artery and a 4-cm occlusion beginning at the origin of the left subclavian artery, representing a rare coronary-subclavian steal syndrome. After a conventional approach failed, recanalization was performed successfully using laser guide wire angioplasty with adjunctive stent placement in a combined radial and femoral approach.

Angioplasty, Balloon, Laser-Assisted↗
PubMed2000

[Clinical significance of coronary calcifications in electron beam tomography].

Electron-beam computed tomography (EBCT) permits high-resolution imaging of the beating heart and the coronary arteries and visualization of coronary calcification. For clinical purposes, coronary calcification represents the formation of atherosclerotic plaques. EBCT provides for accurate quantification of calcification, which is itself related to the extent of coronary atherosclerosis in a linear fashion. Accordingly, EBCT has been shown to measure the extent of coronary atherosclerosis. Importantly, an EBCT scan negative for calcification has a high negative predictive value indicating the absence of obstructive coronary artery disease and an excellent short- to midterm prognosis. It appears that, in general, the amounts of calcification detected by EBCT can be used for prospective risk stratification in symptomatic and asymptomatic adults. However, data derived from unbiased populations are not available at present, and the role of calcification in predicting acute coronary syndromes remains debated. Longitudinal EBCT examinations have emerged as another area of substantial clinical interest. The clinical value of this method remains to be defined, in particular, in comparison with competing, established modalities.

Adult↗