Search PubMed⌕ Search

Biomedical subjects

M Haude

Publications and source records attributed to M Haude.

At least 145 records · Page 8Linked to original sources
PubMed1991

Results of intracoronary stents for management of coronary dissection after balloon angioplasty.

Dissections after coronary balloon angioplasty are risk factors for acute or subacute vessel closures. Intracoronary stenting was developed to avoid these complications by pressing the intimal and medial flaps against the vessel wall, thus reducing the risk of acute thrombosis. A total of 22 stents were implanted into the coronary arteries of 15 patients with dissections after balloon angioplasty causing angina pectoris or ischemic electrocardiographic changes. Stent delivery was successful in all cases. In 1 patient acute stent thrombosis was documented and treated successfully by thrombolytic therapy. Another patient underwent coronary artery bypass surgery 24 hours later because of persisting angina. Angiograms after 24 hours documented vessel patency in the remaining 14 patients. Late control angiograms after 4 to 6 months were obtained in 12 of 14 patients. Vessel patency without significant restenosis was observed in 8 patients, restenosis in 3 and reocclusion in 1 patient. All 3 patients with multiple stent implantation had restenosis (n = 2) or reocclusion (n = 1), compared with 1 patient with single stent implantation. Thus, intracoronary stenting appears to be a secure and effective method of handling bailout situations caused by dissection after balloon angioplasty, with good long-term results when only a single stent is implanted.

Aged↗
PubMed1991

Sublingual administration of captopril in patients with acute myocardial ischemia.

To investigate the anti-ischemic capability of the angiotensin-converting enzyme inhibitor captopril, 10 patients with acute myocardial ischemia (angina pectoris less than 1 h, ST-segment depression greater than or equal to 0.1 mV, no rise in creatine phosphokinase) received 25 mg captopril sublingually after being treated with an intravenous infusion of nitroglycerin (3 mg/h) and heparin (1200 IU/h) for 1 hour. A control group of 10 patients received placebo instead of captopril. Results showed a decrease of the initial ST-segment depression from 0.25 +/- 0.04 to 0.2 +/- 0.03 mV (p less than 0.01) with nitroglycerin for the captopril group and from 0.26 +/- 0.05 to 0.21 +/- 0.05 mV (p less than 0.01) for the control group. An additional decrease to 0.13 +/- 0.03 mV (p less than 0.001) was measured after sublingual captopril, while no significant change was found in the placebo group (0.19 +/- 0.04 mV). In both groups, 3 patients had no incidents of angina after 1-h nitroglycerin infusion. An additional 6 patients resolved their complaints after captopril administration in contrast to only 1 after placebo. Two patients in the placebo group required increased doses of nitroglycerin because of impairment of anginal complaints. Hemodynamic measurements documented a significant drop of pulmonary vascular resistance after a 1-h infusion of nitroglycerin (-12.9% and -13.1%, respectively, p less than 0.05), while all other parameters remained unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1991

Short and long term results after intracoronary stenting in human coronary arteries: monocentre experience with the balloon-expandable Palmaz-Schatz stent.

OBJECTIVE: Intracoronary stenting was designed to overcome acute complications after percutaneous transluminal coronary angioplasty and to achieve a reduced rate of restenosis, both of which are major limitations of this well accepted method for treating coronary heart disease. This report describes the experience at one centre with the implantation of balloon-expandable Palmaz-Schatz stents and focuses on device related complications and the short and long term angiographic outcome. DESIGN: A retrospective data analysis. PATIENTS: Stenting was attempted in 50 patients. Restenosis after an initially successful angioplasty procedure, inadequate postangioplasty results, saphenous coronary bypass stenoses, and bail-out situations were regarded as indications. MAIN OUTCOME MEASURES AND RESULTS: In 49 of 50 attempted patients 61 stents (1-4 per patient) were implanted. Delivery problems occurred in three patients and were successfully overcome in two patients. Bail-out situations were successfully managed in 16 patients. Complications included acute thrombus formation within the stent immediately after implantation in one patient, which was successfully treated by thrombolysis. One patient was sent for bypass surgery the day after implantation; another died 10 days after implantation for unknown reasons. Subacute stent thrombosis occurred in seven patients 5-9 days after implantation and was successfully treated by thrombolysis or balloon angioplasty in five patients. Bleeding complications occurred in nine patients, five of whom required blood transfusions. Angiography showed long term vessel patency after 4-6 months in 31 (76%) of the 41 patients who were followed up, restenosis in six (14%), and reocclusion in four (10%). Late restenosis or reocclusion was found in five (15%) of 33 patients with a single stent in contrast to five (63%) of eight patients with multiple stents. CONCLUSIONS: Balloon-expandable intracoronary stenting is a feasible method for treating the acute complications of balloon angioplasty. It reduced the rate of restenosis for single stent implantation. Subacute thrombotic events must be regarded as previously unknown and serious complications.

Adult↗
PubMed1991

[Collaterals do not prevent infarcts in subacute vascular stenosis following initially successful vascular stent implantation].

UNLABELLED: Sufficient collateralization may prevent acute myocardial infarction despite complete obstruction of a coronary artery. Nevertheless, it is unclear if collaterals which regressed after restoration of antegrade flow may be recruited fast enough to prevent myocardial infarction in case of subacute coronary artery thrombosis. In 50 patients (pts) (48 males, two females, age 60 +/- 7.6 years) with high-grade coronary artery stenosis and collaterals from the contralateral non-diseased coronary artery, stenting devices (Palmaz-Schatz) were implanted. In seven patients subacute thrombosis of the stent occurred. Six patients developed myocardial infarcts with a CKmax greater than 100 U/l (mean 943 +/- 635 U/l). One patient was treated by intravenous thrombolysis, three pts with acute PTCA, one patient with both, and one patient had CABG after unsuccessful PTCA; no patient died. There was no statistical correlation to the degree of collateralization and time after, or location of stent implantation, most likely because of the small number of cases. CONCLUSION: This retrospective study shows that collaterals in humans with a high-grade coronary artery stenosis which has regressed after restoration of sufficient antegrade blood-flow cannot be recruited fast enough to prevent myocardial necrosis in case of subacute coronary artery occlusion. This is in contrast to earlier results obtained in animal studies.

Aged↗
PubMed1991

[Angiographic and histologic findings in high frequency rotational ablation in coronary arteries in vitro].

High-frequency rotational angioplasty is a recently developed method for coronary angioplasty in the catheter laboratory. An elliptical burr tip (phi 1.25-2.0 mm) with embedded diamant chips (phi 40-50 microns) is rotated by a helical drive shaft at 150,000-180,000 rpm. The burr is advanced over a 0.009-inch coaxial guide wire. To show the effects of this approach in diseased and healthy vessels, which may be present before and behind a stenosis, 17 atherosclerotic coronary arteries of nine human hearts, and 18 normal coronary arteries of nine pig hearts were treated by this method in vitro. Standardized coronary angiography was performed before and after Rotablator treatment, followed by histological examination. From these data the burr-to-vessel-diameter ratio was calculated for each vessel segment and compared with the angiographical and histological outcome. Partial or complete removal of the circumference of the innermost vessel wall layers was observed regularly. The average removal of tissue in human coronary arteries was limited to the intimal layer and in the pig coronary arteries to the internal elastic membrane. In the pig coronary arteries no intimal tears or dissections occurred, in human coronary arteries tears could be seen frequently (13 of 17 vessels (76%)). Media tears were observed in 3 of 17 vessels; one (2%) media dissection could be demonstrated; no perforation occurred. Thus, the in vitro studies suggest that coronary rotational angioplasty has only a slight effect on the vessel segment next to a stenosis, regardless of the burr-to-vessel-diameter ratio.(ABSTRACT TRUNCATED AT 250 WORDS)

Angioplasty, Balloon, Coronary↗
PubMed1990

Coronary stent implantation in acute vessel closure 48 hours after an unsatisfactory coronary angioplasty.

We report the implantation of a balloon-expandable stent in a patient with acute vessel closure in the state of evolving myocardial infarction following 48 hr after unsatisfactory coronary angioplasty. The stent was implanted after successful recanalization of an occluded left anterior descending artery, with repeated unsatisfactory results of balloon angioplasty. Adjunct thrombolytic therapy was contraindicated. No residual stenosis was documented in immediate control angiograms, or after 24 hr, 3 weeks, and 4 months.

Angina, Unstable↗
PubMed1990

Parametric assessment of myocardial perfusion during interventional cardiac catheterization by means of X-ray densitometry-short-and long-term results.

X-ray densitometric evaluation of digital subtraction angiocardiograms allows an assessment of myocardial perfusion by means of the parameter 'MEAN RISE TIME' (MRT), defined as the time from the onset of local myocardial contrast medium opacification to the point of maximum opacification. Best results are obtained when the response of that parameter is compared before and after stimulation of coronary flow by papaverine. A prolongation of this parameter, especially after papaverine, was indicative of an impairment of myocardial perfusion, when compared to the results of TL-201 scintigraphy. In 50 patients with single vessel coronary artery disease the results of MRT pre and post papaverine before and after coronary angioplasty, as well as after 6 months were evaluated for 204 post-stenotic regions-of-interest. Before angioplasty papaverine induced a significant prolongation of post-stenotic MRT was measured 2.3 s +/- 0.9 s vs 3.1s +/- 0.8s; p less than 0.01), while after successful angioplasty post-stenotic MRT was measured significantly shorter after stimulation of coronary flow (2.6s +/- 1.0s vs. 1.9s +/- 0.9s; p less than 0.01). This indicated an improvement in myocardial perfusion. Nevertheless, 16/50 patients still presented pathological results of post-stenotic MRT after papaverine, although angioplasty was regarded successful. These patients presented a markedly higher rate of restenosis (14/16 patients after 6 months), a higher rate of dissections at the dilation site and a higher rate of dilated vessels, supplying myocardial areas after a Q-wave myocardial infarction. Thus, these results demonstrate the additional information about the short-and long-term outcome of an angioplasty procedure by densitometric myocardial perfusion analysis.

Absorptiometry, Photon↗
PubMed1990

Sublingual administration of captopril versus nitroglycerin in patients with severe congestive heart failure.

Angiotensin-converting enzyme inhibition has proven to be a successful approach for the long-term treatment of patients with congestive heart failure. This investigation compared the acute hemodynamic changes after sublingual administration of the angiotensin-converting enzyme inhibitor captopril with those after nitroglycerin. A total of 24 patients with severe left heart failure (New York Heart Association classes III and IV) were given 25 mg captopril and 0.8 mg nitroglycerin sublingually in this randomized, cross-over study. Hemodynamic monitoring revealed a clear improvement in pre- and afterload parameters for both drugs (P less than 0.01 and P less than 0.001), while captopril induced a higher increase in cardiac index (+49.2% vs. +25%), stroke volume index (+53.5% vs. +25.7%), and stroke work index (+55% vs. +28%) than nitroglycerin (P less than 0.001). Although not statistically significant, the onset of change for most hemodynamic parameters was measured earlier after nitroglycerin (after 12-19 vs. 16-22 minutes). Captopril revealed later peak effects (after 47-84 vs. 25-55 minutes, P less than 0.001) and a longer sustained improvement in hemodynamic values (return to baseline values after 117-162 vs. 68-120 minutes, P less than 0.001). No side effects occurred after either captopril or nitroglycerin in this study. Thus, these results indicate there is an early improvement in hemodynamic parameters after the sublingual administration of both drugs in patients with severe congestive heart failure, and that captopril induces a more pronounced and prolonged improvement than nitroglycerin.

Administration, Sublingual↗
PubMed1990

[Coronary vessel stent implantation in patients with symptomatic dissections following balloon dilatation].

Dissections after coronary balloon angioplasty are risk factors for acute or subacute vessel closure. Intracoronary stenting was developed to avoid this complication by wrapping the intimal and medial flaps against the vessel wall, which reduces the risk of acute thrombosis. A total of 17 stents were implanted into the coronary arteries of 10 patients with angiographically documented dissections after balloon angioplasty, who presented angina and ischemic ECG changes. Mean minimal stenosis diameter was 1.11 +/- 0.35 mm (65.1%) before, and 1.48 +/- 0.56 mm (53.9%, n.s.) and 2.45 +/- 0.62 mm (23.5%, p less than 0.005), respectively, after balloon angioplasty with and without taking the dissection membrane into account. All patients reported an immediate recovery of their anginal complaints after stent delivery, and ischemic ECG changes disappeared. The mean residual stenosis after coronary stenting was measured as 3.33 +/- 0.23 mm (0%, p less than 0.001). The immediate control angiograms and these after 24 h depicted smooth vessel walls without any irregulations at the site of implantation, and the mean residual stenosis diameter remained unchanged after 24 h (3.3 +/- 0.23 mm; 1.2%, p less than 0.001). No patient suffered acute myocardial infarction, one patient underwent coronary bypass surgery because of persisting episodes of angina pectoris. Thus, intracoronary stenting seems to be a secure and effective method to handle dissections after balloon angioplasty, and perhaps reduces the rate of acute complications and the need for emergency bypass surgery after coronary balloon angioplasty.

Aged↗
PubMed1990

New mechanical devices for treatment of coronary artery disease.

Percutaneous high-speed coronary rotablation allows to remove arterio-sclerotic material from the vessel wall. A diamond-coated (15-30 microns) brass burr drill fastened to a flexible drive shaft rotating and tracking along a drill coaxial guide wire is used. The turbine rotates the drive shaft at 150,000-190,000 rpm. High-frequency rotational angioplasty was successful in 27 of 28 patients, but in about 34% additional PTCA was necessary. Only one patient went to bypass surgery, and myocardial infarction (CK less than 150 u/l) occurred in only one of 28 patients. No vessel perforation was observed. All vessels were open at 24 h control. The restenosis rate was not increased. The main indication for high-speed rotational angioplasty seems to be rigid sclerotic lesions that cannot be passed by a conventional balloon catheter. Whether restenosis rate can be reduced by this method will be judged in future studies. In order to avoid acute complications of PTCA and to reduce restenosis rate, coronary stents were developed. Self-expandable and balloon-expandable stents are available. It could be demonstrated that these stents can be used as a bail-out system and can block elastic recoil of coronary arteries. The major remaining problem is that of subacute closure of coronary vessels. In order to prevent this, treatment with coumarine, acetylsalicylic acid, and dipyridamol is necessary. Coronary stents can be successfully delivered in more than 90% of the patients, as demonstrated by a cooperative study. In a highly selective patient group using single stents, restenosis rate measured 15%, but was higher in patients with multiple stents.

Angioplasty, Balloon, Coronary↗
PubMed1989

[Hemodynamics after sublingual administration of captopril in severe heart failure. A pilot study].

In a preliminary trial, 23 patients in severe left-heart failure and, in some instances, also right-heart failure (NYHA classes III and IV) received a single sublingual dose of 25 mg captopril. Invasive measurement of various haemodynamic parameters indicated (1) an increase in cardiac index and stroke-volume index of 34% and 38%, respectively (P less than 0.001 for each); (2) decrease in pulmonary artery and systemic pressures by an average of 7% and 11.4% (P less than 0.01 and less than 0.001, respectively); (3) no significant change in heart rate and mean right atrial pressure; (4) decrease in systemic and pulmonary artery resistance by 33% and 29% (P less than 0.001 for both); (5) an increase in left ventricular stroke work index by 18% (P less than 0.001); and (6) a fall in heart rate x pressure product by 10% (P less than 0.005). These haemodynamic changes started within 12 to 23 minutes after captopril administration, the peak effect occurring between 40 and 90 minutes. Baseline values were reached after three hours. Reproducibility measurements revealed a close quantitative and temporal correlation (r for all greater than 0.8). To obtain similar changes of cardiac function 1.65 micrograms/min.kg sodium nitroprusside were needed. The results indicate that sublingual administration of captopril in severe heart failure will achieve early and significant improvement in cardiac function.

Administration, Sublingual↗
PubMed1989

[Balloon dilatation and coronary vascular stent implantation].

To avoid acute complications and restenosis after percutaneous transluminal coronary angioplasty coronary stents were developed. For the first time in 2 patients with severe lesions of the left anterior descending coronary artery 3 Palmaz-Schatz stents were implanted after application and fixation by balloon inflation. The vessels showed larger diameters with smoother surface and smaller gradients compared to balloon angioplasty as related to a blockade of the elastic properties of the vessel and suggested fixation of intima or media dissection. The implantation of the coronary stents was without complications. The control after 24 hours showed an open vessel with unchanged diameter. The patients were without symptoms during control after 4 weeks. Based on this and previous work the implantation of coronary stents seems to open a new dimension for percutaneous transluminal coronary angioplasty because vessel occlusions are prevented and restenosis possibly reduced. The newly designed stents show elementary constructive alternatives to currently used types.

Angioplasty, Balloon↗
PubMed1989

[High-frequency rotational atherectomy in coronary heart disease].

Percutaneous high frequency coronary rotational ablation (PTCR) was used in 10 patients with significant coronary artery disease. PTCR removes arteriosclerotic material from the vessel wall. A diamond-coated (60-80 micron) brass burr-drill, fastened to a flexible drive shaft rotating and tracking along a central coaxial guide wire, was used. The turbine rotates the drive shaft in excess of 150,000-190,000 revolutions per minute. PTCR was successful in all patients, but in three additional percutaneous transluminal coronary angioplasty (PTCA) was then successfully performed. Coronary dissection occurred only once, requiring surgery which was successful. No vessel perforation was observed. All vessels were open on the coronary angiograms performed after 24 hours. The main indication for PTCR seems to be a rigid and longer lesion which can not be dilated with the balloon catheter.

Angioplasty, Balloon↗
PubMed1989

[Balloon dilatation and coronary vascular stent implantation].

To avoid acute complications and restenosis after percutaneous transluminal coronary angioplasty coronary stents were developed. For the first time three flexible Palmaz-Schatz stents were implanted after application and fixation by balloon inflation in two patients with severe lesions of the left anterior descending coronary artery. The vessels showed larger diameters with smoother surface and smaller gradients compared to balloon angioplasty as related to a blockade of the elastic properties of the vessel and suggested fixation of intima or media dissection. The implantation of the coronary stents was without complications. The control after 24 h showed an open vessel with unchanged diameter. The patients with the proximal lesion of the left anterior descending coronary artery six months later showed no restenosis and no luminal narrowing. The recanalized left anterior descending coronary artery, which was dilated, received two stents and was reoccluded after six months. Meanwhile, up to four stents were implanted successfully in an additional four patients with open vessels as the 24-h-control. Based on this and previous work the implantation of coronary stents seems to open a new dimension for percutaneous transluminal coronary angioplasty because vessel occlusions can be prevented. Whether or not the restenosis rate can be reduced has to be demonstrated in additional studies.

Adult↗
PubMed1988

The effect of balloon dilatation on post-stenotic myocardial perfusion before and after stimulation of coronary flow reserve: evaluation by the densitometric parameter 'mean rise time'.

From densitometric evaluation of digital subtraction cineangiocardiograms the parameter 'Mean Rise Time' (MRT), defined as the time from the onset of local myocardial contrast medium opacification to the point of maximal opacification can be derived; this parameter revealed a close correlation with the results on myocardial perfusion obtained by Thallium-201 scintigraphy. A prolonged 'Mean Rise Time' was indicative of an impairment of myocardial perfusion. We have developed a heart-phase gated real-time digitization procedure and computer-supported method for the densitometric estimation of the MRT to obtain information about the effect of coronary balloon dilatation on myocardial perfusion before and after stimulation of coronary flow reserve by Moxaverin. In 22 patients with single vessel coronary artery disease Moxaverin caused a significant prolongation of the post-stenotic MRT (2.3 +/- 1.2s (mean +/- s.d.) vs. 2.9 +/- 1.1s, p less than 0.05), while after successful dilatation of the obstructive lesion a significant shortening of the MRT was found after stimulation of the coronary flow reserve (2.5 +/- 1.2s vs. 1.9 +/- 0.9s, p less than 0.05). A highly significant decrease in MRT after Moxaverin was measured post-dilatation in comparison to the initial pre-dilatation results (2.9 +/- 1.1s vs. 1.9 +/- 0.9s, p less than 0.005); this shows that the effect of successful balloon dilatation on the post-stenotic myocardial perfusion can be described very well by this parameter. These results demonstrate that information about post-stenotic myocardial perfusion during interventional heart catheterization can be obtained from digital densitometry.

Adult↗