PubMed Health⌕ Search

Biomedical subjects

H Sievert

Publications and source records attributed to H Sievert.

At least 109 records · Page 6Linked to original sources
PubMed1987

[Repeated recurrences after balloon dilatation--dilate or operate?].

In a total of 333 patients who had undergone a first successful transluminal coronary angioplasty (TCA) of a single stenosis in a native coronary vessel, restenosis occurred in 15% (follow-up angiography was performed in 94% of these patients). The restenosis rate was higher in bypass stenoses (45%) and in reopened vessels (54%). Repeat dilatation of restenoses showed a high primary success rate (93%) and only a few complications (2%). In this group, recurrent restenosis was observed in 33% of patients. Thirteen patients with recurrent restenoses (11 patients with two recidivations and two patients with three) underwent a total of 41 dilatation attempts. The degree of the recurrent stenosis (prior to the first TCA: 89%; prior to the second: 82%; prior to the third: 74%), the number of eccentric stenoses (8; 7; 5, respectively) and the length of the stenotic obstruction (5.2 mm; 4.7 mm; 4.3 mm, respectively) decreased. Accordingly, exercise tolerance was improved (99 W, 133 W, 146 W). To date, follow-up angiography and functional investigations have been performed in 11 out of 13 patients. Good long-term results have been observed in eight patients and another restenosis in three. It is concluded that repeat angioplasty is a reasonable therapeutic approach also in patients with recurrent restenosis.

Angioplasty, Balloon↗
PubMed1987

[Coronary-dilating effect of minimal doses of nitroglycerin].

A previous study verified the antianginal efficacy of 0.025 mg nitroglycerin without it having any effect on heart rate and blood pressure. In a randomized double-blind study, 40 patients with coronary heart disease received intravenously either 0.025 mg nitroglycerin or placebo. Before and 1-2 min after injection, the aortic and left ventricular (n = 20) pressures were recorded and coronary angiography performed. Mean heart rate, systolic and diastolic aortic pressure, left ventricular filling pressure and the pre- and poststenotic diameter of the coronary arteries, as well as the diameter of a distal coronary artery segment, showed no significant changes (p greater than 0.05). The stenotic segment diameter of the coronary artery remained unchanged after placebo administration (1.01 +/- 0.5 to 1.13 +/- 0.49 mm; p greater than 0.05) but increased significantly after the injection of nitroglycerin (from 1.15 +/- 0.68 to 1.32 +/- 0.73 mm; p less than 0.01). These results support the hypothesis that dilatation of coronary stenoses is an important aspect of the antianginal action of nitroglycerin. This may have practical consequences in the treatment of patients with angina and low blood pressure or severe headaches after the administration of conventional doses of nitroglycerin.

Angina Pectoris↗
PubMed1987

[Imaging of aortocoronary bypasses with intravenous digital subtraction angiography].

We examined 24 patients with 52 coronary bypass grafts, an average of 18 months after their respective operations. During the course of 1 week, a coronary angiography and a digital subtraction angiography (DSA) incorporating an intravenous injection of contrast medium were performed. Conventional coronary angiograms showed 40 bypasses as being open, ten as being occluded, and two could not be displayed at all. With the aid of digital angiography, 50 out of 52 bypasses could be classified as either open or occluded. In 44 out of 52 bypasses, DSA and coronary angiogram results were identical. Using DSA, three out of ten angiographically occluded bypasses were falsely diagnosed as being open and three out of 40 open bypasses as occluded. Two bypasses could not be interpreted due to poor picture quality. In the diagnosis "open bypass" the degree of both sensitivity and specificity subsequently amounted to 92.5%, and 70% in the diagnosis "occluded bypass". The distal part of the bypasses, as well as the proximal and distal part of the anastomoses, could not be evaluated for the most part. Furthermore, on account of the comparatively inferior quality of the pictures, detection of bypass stenosis is not reliable using digital subtraction angiography. Intravenous digital subtraction angiography may therefore serve as a screening method in the evaluation of coronary bypass grafts.

Coronary Angiography↗
PubMed1987

Long-term observations in mild forms of cardiomyopathy.

24 patients suffering from a mild cardiomyopathy with normal or nearly normal ejection fraction and histologic evidence of cardiac fiber hypertrophy were followed-up over 5.5 +/- 1.9 years. Patients presented predominantly with dyspnea, angina and palpitations. During the observation period, the severity of symptoms increased only slightly. The ECG showed atrial arrhythmias in 34% and premature ventricular beats or conduction disturbances in the majority. During the 5.5 year follow-up period four patients had developed an intermittent III AV-block and two patients a bundle branch block. The heart volume determined by X-ray increased insignificantly (893 +/- 224 to 933 +/- 245 ml/1.73 m2; n.s.), while left ventricle end-diastolic (5.5 +/- 1.1 to 5.6 +/- 0.6 cm) and end-systolic (3.9 +/- 1.2 to 3.7 +/- 0.7 cm) diameter remained nearly constant. Pulmonary artery pressure at rest (18 +/- 5.9 to 17.8 +/- 4 mm Hg) and during exercise (40.5 +/- 9.5 to 37.4 +/- 7.8 mm Hg) showed no significant change. However, cardiac output decreased significantly at rest from 5.6 +/- 1.6 l/min/1.73 m2 to 4.5 +/- 0.7 l/min/1.73 m2 (p less than 0.01) and during exercise from 13 +/- 4.1 l/min/1.73 m2 to 10.4 +/- 2.3 l/min/1.73 m2 (p less than 0.05). It is concluded that patients with this mild cardiomyopathy show only minor changes over a period of 5.5 years. The prognosis seems to be promising in most cases.

Adult↗
PubMed1987

Calcium antagonist treatment in mild forms of cardiomyopathy.

Twenty-one patients with a mild form of cardiomyopathy (with normal ejection fraction but histologically-confirmed hypertrophy of myocardial cells and/or elevated diastolic pulmonary artery pressure during exercise) received 120 mg verapamil t.i.d. or no therapy at all for a period of 2 months in an open randomized cross-over study. Out of the 21 patients, 14 improved clinically, one patient's condition deteriorated and six remained unchanged (p less than 0.05). The mean diastolic pulmonary artery pressure during exercise decreased (25.3 +/- 7.6 to 20.1 +/- 6.6 mm Hg, n = 21, p less than 0.05). At rest, the decrease was only significant in the subgroup with pressures above 12 mm Hg (15.4 +/- 2.7 to 11.1 +/- 4.1 mm Hg, n = 9, p less than 0.05). All other hemodynamic data displayed no significant change. The benefits of verapamil therapy may be attributed to an improvement in diastolic ventricular function. The disturbance in diastolic relaxation might be of greater importance than the disturbance in systolic function in patients with mild forms of cardiomyopathy.

Adult↗
PubMed1987

Transfemoral plug closure of patent ductus arteriosus.

A patent ductus arteriosus should be closed because of its hemodynamic significance and/or the risk of infective endocarditis. Mortality of surgery is low. In adults, however, technical problems can arise due to calcification of the ductus walls. Using the transfemoral plug technique, developed by Porstmann, we attempted a ductus closure without surgery on 35 patients. The youngest was an 11-year-old girl, the oldest a 63-year-old woman (mean age of all patients: 37 years). The pressure in the pulmonary artery ranged from 15/5 to 70/27 mmHg, the diameter of the ductus from 2 to 9 mm (mean: 4.4 mm). According to the size and shape of the ductus, a plug of polyvinyl alcohol (Ivalon) with an inner steel wire frame was prepared. Threaded over a long arterio-transductal venous track wire, the plug was introduced into the femoral artery and advanced into the ductus by a pushing catheter. After removal of the track wire the plug remained wedged in the ductus. In all 35 patients, transfemoral ductus closure was possible. Patients with complaints improved remarkably within some days. Heart size and pulmonary congestion decreased considerably. All patients were followed for a period of 1-46 months. In two of them, the ivalon plug embolized into a side branch of the left pulmonary artery 7 and 2 weeks after the procedure, but without serious consequences.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1987

[Nuclear medicine in determining the shunt in ductus arteriosus Botalli].

In 9 patients with patent ductus arteriosus, quantification of left-to-right shunt was performed with dye dilution curves after peripheral injection and with radionuclide ventriculography. The study was repeated within 7 days after successful transluminal occlusion of the ductus with an Ivalon-plug. Reproducubility of the method could be studied in one patient in whom reopening of the ductus occurred. Dye dilution curves were analyzed using the method of Carter et al. Radionuclide ventriculography was performed as a combined first-pass and equilibrium study: effective stroke volume was derived from the first pass of the tracer through the heart; during the equilibrium phase left ventricular ejection fraction (EF) and left ventricular enddiastolic volume (EDV) were evaluated. The difference between total left ventricular stroke volume (product of EF and EDV) and effective stroke volume was taken as shunt volume. This volume as a fraction of total left ventricular stroke volume resulted in percent left-to-right shunt. The sensitivity of the dye technique was 78%; a quantification of the shunt lesion was possible in 55% of all cases (shunt greater than 35%). The sensitivity of the radionuclide technique was 90%. The severity of the lesion could not be determined in one patient with a minimal shunt. After successful occlusion of the ductus, dye dilution curves normalized in all cases. Radionuclide ventriculography showed normalization in all but one patient. This patient with concomitant mitral regurgitation still showed moderate left ventricular volume overload.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1987

[Radiation burden in heart catheter studies--significance of measures for reducing scatter radiation].

During diagnostic and, more particularly, therapeutic intervention, such as transluminal coronary angioplasty, the operator may be exposed to a considerable degree of scatter radiation. In our study, we measured the level of radiation exposure of the head, unprotected knees and lower legs. A flexible lead screen, attached to the catheterization table (0.5 mm Pb) reduced scatter radiation of the lower legs by 95%. In addition, scatter radiation exposure of the head decreased by 54% by covering the patient with a rubber leaden blanket (0.25 mm Pb). Finally, the use of these supplementary yet simple measures did not hinder or interfere with the examination procedure in any way.

Cardiac Catheterization↗
PubMed1986

[Transluminal angioplasty of stenosis of mammary artery bypass].

Experience with transluminal angioplasty, frequently reported for venous bypass stenosis, has so far been limited for mammary-artery bypasses. In a 53-year-old man with severe triple-vessel coronary disease, two stenoses in the venous bypass with four peripheral anastomoses and one stenosis in the mammary-artery bypass were successfully dilated. Bypass surgery and transluminal coronary angioplasty can, as this case demonstrates, complement one another.

Angiocardiography↗
PubMed1986

[Percutaneous valvuloplasty of the aortic valve in adults].

In a 23-year-old patient with congenital stenosis of the aortic valve the pressure gradient could be reduced from 80 to 35 mm Hg using percutaneous balloon aortic valvuloplasty. The systolic pressure in the left ventricle fell from 200 to 165 mm Hg. A pre-existing mild aortic insufficiency did not worsen. In a 44-year-old female patient retrograde passage of a balloon catheter across the aortic valve failed due to technical reasons. At the present time percutaneous balloon aortic valvuloplasty in adults is more difficult than pulmonary valvuloplasty. It can, however, be considered, prior to surgery, in suitable patients with noncalcified valves.

Adult↗
PubMed1986

[Mechanism of action and long-term results of balloon dilatation of coronary vessel stenoses].

Predominant mechanisms for opening of coronary stenoses by balloon angioplasty are reduction of atheroma by fluid expression and increase in vessel diameter. Coronary dissection is related to complications like abrupt coronary closure but not to acute or long-term success. Local recurrencies after coronary angioplasty occur within the first 4 months. After this period long-term results depend on progression of the disease in other coronary arteries or segments.

Angioplasty, Balloon↗
PubMed1986

[Regional ventricular function before and after sublingual administration of nitroglycerin in patients with recent myocardial infarction in the subacute and chronic stage].

Seven patients with a recent myocardial infarction and mostly normal left ventricular end-diastolic pressure were investigated by radionuclide ventriculography after 3-4 days and three weeks before and after 1.6 mg nitroglycerin. Between day 3-4 and the third week global ejection fraction (EF) rose insignificantly (p greater than 0.05) from 31 +/- 4 to 37 +/- 6 percent. The regional EF in the non infarcted area remained nearly stable (74 +/- 5 to 85 +/- 13 relative percent, p greater than 0.05). However, the EF in the infarcted area rose from 22 +/- 9 to 38 +/- 11 relative percent (p less than 0.05 percent). On day 3-4 nitroglycerin induced a clear increase of the EF in the infarcted area from 22 +/- 9 to 35 +/- 11 relative percent (p less than 0.05). The global EF and the EF in the non infarcted area remained nearly constant (global EF from 31 +/- 4 to 34 +/- 5 percent, EF in the non infarcted area from 74 +/- 5 to 77 +/- 7 relative percent; p greater than 0.05). Three weeks after myocardial infarction 1.6 mg nitroglycerin did not produce a significant alteration of the ejection fraction (slight increase of the global EF from 37 +/- 6 to 40 +/- 6, the regional EF in the infarcted area from 38 +/- 11 to 48 +/- 11 relative percent and from 85 +/- 13 to 90 +/- 11 relative percent in the non infarcted area; p greater than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac Output↗
PubMed1985

[Transfemoral angioplasty in stenosis of the isthmus of aorta].

A 14-year-old patient with severe aortic coarctation was treated by advancing a balloon catheter across the stenosis via the right femoral artery. The 4 cm long balloon, transversal diameter 15 mm, was filled with saline containing contrast media for 10 seconds. The excess pressure in the balloon was 3.5 at. Subsequently the stenosis diameter increased from 3 to 7.3 mm. The systolic pressure gradient decreased from 75 to 35 mm Hg. After the operation the foot-pulse was palpable for the first time. The highly elevated arterial pressure in the upper extremities decreased markedly. Three months after the operation the vessel diameter was 10.2 mm and the pressure gradient only 10 mm Hg.

Adolescent↗
PubMed1985

[Percutaneous pulmonary valvuloplasty].

Five patients (aged between 11 and 59 years) with valvular pulmonary artery stenosis and pressure gradients between 60 and 143 mm Hg underwent percutaneous transluminal balloon valvuloplasty. Selection of the appropriate balloon size was based on the measurement of the dimension of the value anulus as a determinant from the angiogram. Balloon catheters were used with a diameter of 18 to 20 mm. After placement in the stenotic valve the balloon was filled with diluted contrast material for 10-20 s. The balloon indention by the stenotic valve disappeared suddenly during expansion with one to three atmospheres. The pressure gradient in individual patients decreased from 60 to 25, from 143 to 60, 100 to 55, 143 to 60, and 60 to 37 mm Hg, in the mean from 101 to 52 mm Hg. All patients were discharged two to four days after the procedure. During follow-up with recatheterization after three to nine months (four patients) the gradients decreased as compared to the value immediately after valvuloplasty. The exercise capacity increased in all patients. No complications were observed. Balloon valvuloplasty of pulmonary valvular stenosis seems to be an alternative to the operative procedure.

Adolescent↗
PubMed1984

[Transfemoral occlusion of persistent ductus arteriosus].

In six patients aged between 17 and 53 years with persistent ductus arteriosus a non-operative occlusion of the ductus developed by Porstmann was used. The procedure comprises the percutaneous insertion of an Ivalon plug via the femoral artery in local anaesthesia and lodging in the patent ductus. Placement is enabled by pre-placing of an arterio-ductus-venous wire catheter. In all six consecutively treated patients the procedure was successful. Follow-up assessment after three months confirmed positioning of the plug in the ductus. In one female patient with cardiac insufficiency the complaints had completely disappeared and cardiac size had greatly diminished. Thus a comparatively trouble-free catheter technique for occlusion of the ductus is available which may replace surgery.

Adolescent↗
PubMed1984

[Coronary artery aneurysms].

Coronary artery aneurysms are rare and are diagnosed almost exclusively by angiography. Apart from a particular form of coronary artery sclerosis congenital malformations and various inflammatory diseases are to be considered aetiologically. Different opinions exist as to the clinical relevance and prognosis as well as to the necessary treatment of coronary artery aneurysms. Over the last 7 years we have observed 10 patients with in part grotesque dilatations of the coronary arteries. Based on the history and the other findings coronary sclerosis or/and congenital malformations had to be assumed. Follow-up of up to 6 years permits not an unfavourable prognosis which is more determined by the accompanying stenosing coronary sclerosis. Due to the danger of thromboses prophylaxis with platelet aggregation inhibitors is recommended. In dilated vascular disorders only surgery should be considered as the exception.

Adult↗