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Biomedical subjects

M Kaltenbach

Publications and source records attributed to M Kaltenbach.

At least 253 records · Page 14Linked to original sources
PubMed1985

[Anti-angina effect of the calcium antagonist bepridil in stable angina pectoris].

Twelve patients with angiographically proven coronary artery disease and stable, exercise-induced angina pectoris were treated in a randomized sequence with placebo (PL) and bepridil tablets in maintenance doses of 200 mg, 400 mg and 600 mg per day for one week each, according to a double blind-protocol with intra-individual cross-over. The four treatment phases were separated by 2-week wash-out periods (placebo). On day 7 of each treatment phase and at the end of each wash-out period heart rate and blood pressure were measured 2 and 5 hours after drug intake and exercise stress testing was performed. The mean plasma concentrations at the end of the 1-week treatment periods 2 hours after drug intake were: 375 +/- 202 ng/ml (200 mg/day), 844 +/- 273 ng/ml (400 ng/day) and 1378 +/- 538 ng/ml (600 mg/day). Systolic blood pressure was not influenced by either bepridil dose. Diastolic blood pressure was slightly reduced (-6%) after 600 mg bepridil/day (p less than 0.05). While heart rate at rest in the upright position tended to lower values with regard to bepridil dosages, it was significantly lowered at the end of stress testing (2 hours/5 hours):400 mg: -7% (p less than 0.05)/-15% (p less than 0.05); 600 mg: -11% (p less than 0.001)/-10% (p less than 0.05). Myocardial ischemia (sum of ST-segment depressions) was improved in a dose-dependent manner (2 hours/5 hours):200 mg: -21% (p less than 0.05)/-31% (n.s.); 400 mg: -27% (n.s.)/-31% (p less than 0.01); 600 mg: -56% (p les than 0.001)/-55% (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

[Lack of symptomatic and long-term hemodynamic effects of prazosin in chronic heart failure. Double-blind, randomized study over one year].

Long-term treatment of congestive heart failure with prazosin is disputed. Only few controlled trials have been reported so far. Our study is the first randomized double-blind placebo controlled trial over several months that also takes haemodynamic measurements into account. 25 patients with congestive heart failure classes III and IV (NYHA) received either prazosin 20 mg/d orally (n = 12) or placebo (n = 13) and were followed up closely. Before treatment, after 6 and after 12 months we performed echocardiography, heart volume (estimated by chest X-ray) and right heart catheterization at rest and during exercise. No significant differences could be noticed during follow-up concerning the following parameters: symptoms (NYHA), left ventricular end-diastolic diameter, shortening fraction, heart volume and systemic vascular resistance. While diuretics could be reduced in 3 patients with placebo an increasing dose was necessary in 6 out of 12 patients of the prazosin group. Long-term treatment of congestive heart failure with prazosin may be valuable only in exceptional cases.

Adult↗
PubMed1985

[In vitro study of transvenous commissurotomy in severe mitral valve stenoses using the balloon catheter].

To answer the question whether mitral commissurotomy with a balloon catheter is possible, the following in vitro study was performed. In 12 patients who were operated due to severe mitral stenosis the fibrotic (n = 8) or calcified (n = 4) valves were excised and mounted in a glass cylinder. In a first step a valvuloplasty was performed with a balloon catheter (size 20 mm). Mitral valve area increased by about 40%. With simultaneous inflation of a second balloon catheter (size 15 mm) valve area increased more than 100% and reached 1.63 cm2 in the mean. Valvuloplasty was successful (increase of at least 0.5 cm2) in 11/12 cases. In 9 valves the rupture occurred within the commissures, twice within the leaflets and once the opening area increased due to dilatation. Commissurotomy with a balloon catheter seems to be possible even in calcified mitral valves although in most cases a mild to moderate stenosis will remain.

Adult↗
PubMed1985

[Follow-up studies in chronic aortic insufficiency].

In order to study the course of chronic aortic regurgitation 17 patients with various degrees of aortic valve incompetence were investigated twice with a time interval of 1.5 +/- 0.4 years. The following parameters were evaluated: NYHA class; electrocardiographic sum of the largest R-wave in V4-V6 plus the largest S-wave in V1-V3 (RS index); echocardiographic left ventricular end-diastolic diameter (EDD); roentgenographic heart volume (HV); scintigraphic left ventricular end-diastolic volume (EDV), regurgitated blood volume (RBV) and ejection fraction (EF). During the period of observation functional deterioration occurred in 5 cases, all suffering from moderate to severe aortic regurgitation. While EF did not change significantly (55 +/- 12% vs. 55 +/- 11%), all other parameters showed a significant increase: RS index 5.4 +/- 1.4 mVolt to 6.0 +/- 1.7 mVolt (p less than 0.01); EDD 6.3 +/- 0.7 to 6.8 +/- 0.9 cm (p less than 0.001); HV 1017 +/- 151 ml to 1099 +/- 261 ml (p less than 0.01); EDV 371 +/- 131 ml to 441 +/- 175 ml (p less than 0.001); RBV 117 +/- 57 ml to 151 +/- 77 ml (p less than 0.001). Cases with functional deterioration showed a higher initial EDV and EDD (487 +/- 143 vs. 322 +/- 93 ml, p less than 0.05; 7.1 +/- 0.7 vs. 6.1 +/- 0.5 cm, p less than 0.01). The increase of HV, EDV and RBV during the time of observation was higher than in the remaining patients (166 +/- 137 vs. 39 +/- 95 ml, p less than 0.05; 133 +/- 75 vs. 44 +/- 29 ml, p less than 0.01; 66 +/- 22 vs. 22 +/- 31 ml, p less than 0.01). On average it was less pronounced in cases with mild initial left ventricular dilation than in those with marked dilation.(ABSTRACT TRUNCATED AT 250 WORDS)

Angina Pectoris↗
PubMed1984

[Aortocoronary bypass operation in considerably reduced left-ventricular function caused by chronic ischemia].

Among a group of 18 patients with severe angina and an ejection fraction of less than 46%, cine-angiography was performed on 18, 2-D echocardiography on 18, radionuclide ventriculography on 13 and 201Thallium myocardial scintigraphy on 13 at rest, both pre-operatively and six months after an aortocoronary bypass operation. In nine patients there was a significant increase postoperatively in the ejection fraction (P less than 0.001) (group I), while it remained practically unchanged in the remainder (group II). Similar results were obtained with radionuclide ventriculography and echocardiography. Ischaemia at rest was demonstrated by myocardial scintigraphy preoperatively in an average of 10 out of 27 sectors in group I patients, but within six months postoperatively decreased to 3.1 (P less than 0.01). In group II patients the mean number of sectors with ischaemia at rest was pre-operatively 2.5, postoperatively 6.0. With one exception there was an improvement in left-ventricular function at rest in all patients with pre-operatively 7 or more sectors showing ischaemia at rest. These results suggest that myocardial scintigraphy makes it possible to identify those patients with severe ischaemic myocardial damage who would profit from revascularization.

Angina Pectoris↗
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↗
PubMed1984

[Anti-anginal efficacy of oral nitroglycerin. A clinical double-blind study with dose-effect relationships].

Nitroglycerin, bound to polymerized cellulose (Nitroglin) was administered orally in single doses of 2.6 mg, 6.5 mg, 10 mg and 20 mg (randomized sequence) on four different days to 12 patients with angina due to coronary heart disease. This was done within the framework of a placebo-controlled double-blind study with intra-individual cross-over to assess dose-related reduction of the ischaemia reaction in the exercise ECG. The ischaemia reaction (sum of ST segment depressions) 30 min after a placebo was 10.4 +/- 4.6 mm; after 2.6 mg nitroglycerin it was 8.0 +/- 4.3 mm (-23%, not significant); after 6.5 mg it was 6.4 +/- 3.4 mm (-38%, P less than 0.01), after 10 mg it was 4.7 +/- 2.9 mm (-55%, P less than 0.001), and after 20 mg 2.7 +/- 1.9 mm (-74%, P less than 0.0001). The dose-related effect of nitroglycerin was still demonstrable to the same extent three hours after intake. After 20 mg a reduction in ischaemia reaction by 55% compared with the placebo effect was still present 6 hours later (P less than 0.01). The arterial blood pressure on lying and standing as well as the heart rate on lying, standing and on exercise did not change significantly, regardless of dose. Taken by mouth nitroglycerin was well tolerated and had a dose-related anti-anginal effect. After single doses of 10-20 mg the anti-ischaemic effect was shown to persist for several hours.

Administration, Oral↗
PubMed1984

Percutaneous angioplasty of stenoses of bypass grafts or of bypass graft anastomotic sites.

Forty patients who had stenoses of coronary artery bypass grafts or stenoses of the proximal or distal coronary insertion sites were treated with percutaneous transluminal angioplasty (PTA). PTA was successful in 78% of the patients. Mean stenoses were diminished from 86% to 34% in luminal diameter. One patient needed emergency coronary artery bypass grafting. There were no deaths associated with PTA. Follow-up angiography showed continued patency in asymptomatic patients, whereas in all but 1 patient with recurrent symptoms restenosis had developed at the PTA site. In 38% of patients restenosis developed after successful PTA; the highest restenosis rate was after PTA of aorta/graft anastomoses or proximal graft stenoses. In conclusion, PTA is a successful, low risk alternative to repeat coronary artery bypass grafting, although the restenosis rates at some PTA sites are high.

Adult↗
PubMed1984

Dose-response relation of antianginal activity of isosorbide dinitrate.

Eleven men with angiographic evidence of coronary heart disease and stable, exercise-induced angina pectoris were given placebo (P) or isosorbide dinitrate (ISDN) in a daily dose of 30, 120, 240 or 480 mg, in a randomized single-blind trial. The daily doses were administered 6 times a day as single oral doses of 5, 20, 40 and 80 mg. Each dose or placebo was given for 7 days. Before therapy was begun, and on the seventh day of each treatment period, an exercise ECG with standardized level and duration of exercise was recorded. Subsequently, a 4-week treatment period with 480 mg/day was carried out at the end of which another stress test was performed. The was followed by a final 2-week placebo period. The frequency of anginal attacks per week tended to decrease with increasing nitrate doses, but decreased significantly only after the highest dose (480 mg/day) compared with placebo. Continuation of therapy with 480 mg/day maintained the reduced rate of anginal attacks. The ischemic response, expressed as the sum of ST-segment depressions in the exercise ECG, revealed a dose-dependent reduction of 26% (30 mg/day), 39% (120 mg/day) (p less than 0.01), 63% (240 mg/day) (p less than 0.01) and 72% (480 mg/day) (p less than 0.01), respectively. At the end of the 4-week treatment period with 480 mg/day, antianginal efficacy was found to be moderately reduced, showing a 56% reduction of ischemic response compared to the placebo trial. The time of onset of angina during exercise testing was also delayed in relation to the dosage given.(ABSTRACT TRUNCATED AT 250 WORDS)

Angina Pectoris↗
PubMed1984

[Life-threatening complications in 1741106 cases of ergometry].

No life-threatening complications occurred in exercise-testing in 384 938 athletes. Among 1 356 168 patients the most frequent complication was ventricular fibrillation (1:15 000). The step test was associated with a two-fold diminution of fibrillations when compared to bicycle ergometry in the supine position and with a four-fold decrease when compared to conventional bicycle ergometry. Pulmonary oedema, a typical complication, occurred once in 29 000 bicycle ergometries in supine position. Infarctions were seen 3.5 times more frequently between 1950 and 1977 (1:26 000) than in the following four years (1:92 000). Fatal cardiac infarction occurred in 1:42 000 before 1978 and in 1:644 000 thereafter. It was the sole cause of death. Present data show a potentially life-threatening risk of 1:9000 ergometries in patients. Considering the favourable trend at present, a risk of 1:12 000 can be expected in conditions of an experienced investigator. Defibrillation facilities ready for use must be available in any ergometry.

Adult↗
PubMed1984

Prolonged application of pressure in transluminal coronary angioplasty.

We investigated the morphologic structure and fluid content of atherosclerotic specimens of fresh human postmortem artery segments before and after application of a pressure of 5 atmospheres simulated by a weight of 5 kg per 1 cm2. After applying pressure in nonorganized atheromata, we noticed a marked reduction in thickness while in fibrotic atheromata we observed only smaller differences in thickness. Reduction in fluid content was significantly more pronounced in nonorganized atheromatous tissue. Reduction in thickness was closely related to reduction in weight (i e, fluid content). The time of pressure application necessary to achieve the optimal result averaged 60 sec. The conclusions drawn from these experiments were incorporated into clinical application of coronary angioplasty. Prolonged balloon inflation was applied to the last 400 out of a total of 600 coronary angioplasty procedures, performed between October 1977 and October 1983. Stenoses not sufficiently responsive to balloon inflation periods of 5-10 sec were exposed to periods of 60 sec (30-120 sec). The number of "non dilatable" stenoses was 15% with the standard short pressure procedure, but only 5% with the prolonged pressure application. No serious complications related to prolonged pressure application were observed. Thus, from experimental data and clinical experience the application of longer pressure periods appears justified and beneficial.

Angioplasty, Balloon↗
PubMed1984

Effects of intravenous nitroglycerin on ventricular ectopic beats in acute myocardial infarction.

Ventricular premature beats (VPBs) in 21 consecutive patients with acute myocardial infarction (AMI) were continuously recorded on magnetic tape by means of an automatic arrhythmia monitor and counted manually. The patients were sequentially assigned to either a control (n = 11) or nitroglycerin group (n = 10). Both groups were comparable for age as well as for onset, localization, and extension of infarction. Recording in the control groups was begun at a mean of 9.3 hours following onset of infarction as obtained from patient history. This interval was 12.0 hours in the nitroglycerin group. At the start of therapy, the number of VPBs was identical in both groups. Ten patients received a mean of 2.1 mg of nitroglycerin per hour intravenously for 48 hours, whereas the control group received no specific therapy. The number of VPBs in the control group increased progressively until the sixth hour of registration and reached a maximum of 165% of the baseline value before subsequently declining. Nitroglycerin administration was associated with a significantly more rapid reduction in ventricular arrhythmias: 6 hours after onset of recording, the number of VPBs had declined to 39% of the baseline value (p less than 0.05 compared to control group). This study demonstrates that nitroglycerin reduces ventricular ectopic beats in the acute phase of myocardial infarction.

Arrhythmias, Cardiac↗
PubMed1984

The long wire technique--a new technique for steerable balloon catheter dilatation of coronary artery stenoses.

A new technique for steerable balloon dilatation is described. In contrast to the usual procedure the stenosis is first crossed by a long wire only. To minimize injury of the vessel wall the wire is equipped with a thickened ball-shaped tip. After the stenosis has been crossed and the wire tip has been advanced far enough, the balloon catheter is inserted over the long wire. If necessary, the balloon catheter can be removed and another one can be inserted without repeat crossing. If an occlusion is caused by the process of dilatation a perfusion catheter can be advanced distal to the occlusion. Perfusion can be performed by help of a simple syringe-tap system because the cross sectional area of this catheter is much larger than a single lumen of the double lumen balloon catheter. This procedure even allows the dilatation of branching stenoses through the same guiding catheter whereas for the usually performed 'kissing balloon' technique two guiding catheters are required. Preliminary experience with 80 patients has shown that crossing of stenoses is facilitated by the new technique because steering of the guide wire and display by contrast medium injections are unhindered. If required, the balloon catheter can be changed for another one without difficulty. In case of occlusion, the lesion can be crossed again without any risk and repeat dilatation or coronary perfusion can be performed.

Angioplasty, Balloon↗
PubMed1984

Volumetric evaluation of aortic regurgitation by combined first-pass/equilibrium radionuclide ventriculography.

In 16 men with normal valvular function (group 1) and 23 men and one woman with isolated aortic regurgitation (group 2) effective stroke was determined by first-pass radionuclide ventriculography. Total left ventricular stroke volume was derived from equilibrium radionuclide ventriculography using a geometric approach for the end-diastolic volume multiplied by the ejection fraction. The difference between the two stroke volumes as a fraction of total left ventricular stroke volume was taken as radionuclide regurgitant fraction. Radionuclide lv/rv stroke count ratio was calculated as the ratio of end-diastolic-end-systolic count-rate differences from the left and right ventricles. All patients underwent left heart catheterization. Angiographic regurgitant fraction was evaluated by the method of Sandler and Dodge in 16 patients of group 2. In the others, aortic regurgitation was quantified in 5 grades of severity. Group l was classified correctly by both radionuclide regurgitant fraction and lv/rv stroke count ratio (specificity 100%). In group 2 the radionuclide regurgitant fraction was elevated in all (from + 20% to +88%, sensitivity 100%), radionuclide lv/rv stroke count ratio in 19 of 24 cases (from 0.6 to 5.6, sensitivity 79%). The angiographic regurgitant fraction correlated well with the radionuclide regurgitant fraction (r = 0.78), whereas no significant correlation was found between the angiographic stroke volume ratio (i.e. left ventricular stroke volume/cardiac output per beat) and radionuclide stroke count ratio (r = 0.10) due to the high rate of false-negative results of the latter method.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗