Biomedical subjects

M Kaltenbach

Publications and source records attributed to M Kaltenbach.

At least 181 records · Page 10Linked to original sources

PubMed1987

[Transfemoral valvuloplasty in calcified aortic valve stenosis].

In a 55 year old male patient and a 67 year old woman with calcified aortic valve stenosis, a valvuloplasty was performed via the femoral approach using a large-lumen balloon catheter. The 55 year old patient, who had undergone an aortocoronary bypass operation some years ago, displayed the symptoms of a cardiogenic shock. A surgical intervention would have entailed an additional risk. In the second case, there was a raised risk for the operation in view of a coronary two-vessel disease and with regard to the patient's age. By filling the balloon catheter placed in the aortic valve, the pressure gradient could be reduced from 100 mm Hg to 40 mm Hg, and in the second case from 95 mm Hg to 45 mm Hg. The slight aortic insufficiency which had been previously present in the two cases did not increase appreciably. The symptoms of cardiogenic shock disappeared, and there was a distinct clinical improvement. Valvuloplasty is evidently a possible method of treatment (even if it is palliative) in calcified aortic valve stenosis.

Aged↗

PubMed1987

[Can beta-receptor blockers trigger coronary spasm?].

Beta-blockers are frequently administered in therapy of arterial hypertension and coronary heart disease. They mostly lead to an asymptomatic increase of peripheral and coronary resistance. Three patients in whom there were indications of a deterioration of myocardial blood flow under beta-blockade were observed within a few weeks. After discontinuation of the beta-blockers and instituting a therapy with calcium antagonists, both a reduction of ischemia in the exercise ECG and a reduction of symptoms could be observed. The possibility that beta-blockers trigger coronary spasms and thus give rise to unfavorable effects on myocardial blood flow must be considered in the context of therapy monitoring, especially in patients with coronary heart disease.

Cardiac Catheterization↗

PubMed1987

[Treatment of hyperkinetic heart syndrome with alinidine and propranolol].

A hyperkinetic heart syndrome has been diagnosed in 10 patients by clinical investigation and right-heart catheterization at rest and during exercise. Subsequently, the patients received 3 X 40 mg alinidine, and 2 X 40 mg propranolol and placebo, each for 2 weeks in a double-blind crossover study. Heart rate at rest (P less than 0.05) and during exercise (P less than 0.001) decreased significantly under alinidine and propranolol to the same extent (control, 83/170; alinidine, 68/146; propranolol, 73/139; placebo, 83/162 beats per min). Lower limb flow at rest and after exercise, measured by plethysmography, as well as left-ventricular fractional shortening and mean velocity of circumferential fiber shortening, measured by echocardiography, decreased insignificantly. Sedation and a dry mouth occurred in six patients under alinidine, while fatigue and cold hands and/or feet were reported by five patients under propranolol. Thus, alinidine may be used as an alternative to beta-blocking in the treatment of the hyperkinetic heart syndrome.

Adult↗

PubMed1987

Does coronary angioplasty replace, delay, or complement aortocoronary bypass surgery?

In single vessel disease angioplasty can replace surgery in the majority of patients. In cases of recurrence at the site of angioplasty or in the case of progression elsewhere, a second intervention can be performed. Thus, in the majority of patients surgery can be replaced; in the minority it can be delayed. In patients with localized multivessel disease consisting of several localized, short stenoses the situation is similar. If coronary atherosclerosis involves long segments of one or more coronary arteries and in patients with vessel occlusions primary surgery is still the first choice of therapy. In some patients angioplasty can complement surgery. After surgery, angioplasty can be carried out in vessels not bypassed or after early bypass occlusion. Stenoses suitable for angioplasty can be treated with lower risk after surgery if collateral providing vessels are bypassed. Angioplasty can also complement surgery if bypass stenosis occurs in aortocoronary venous or in mammary artery bypasses.

Angioplasty, Balloon↗

PubMed1987

The haemodynamic side-effects of ionic and non-ionic contrast media in the presence of pulmonary hypertension: experimental and clinical investigation.

The haemodynamic side-effects of ionic (amidotrizoate) and non-ionic (iopamidol) contrast media after injection into the right atrium were compared in experimental and clinical studies. Pulmonary hypertension was induced in 10 dogs by embolization of the pulmonary vascular bed with agar-agar solution (mean pulmonary artery pressure = 44.2 mmHg). Iopamidol (1.5 ml kg-1) caused a moderate decrease in pulmonary and systemic vascular resistance, slight increases in right ventricular end-diastolic pressure and a marked rise in right ventricular contractility (dP/dtmax). Amidotrizoate (1.5 ml kg-1) caused considerable systemic vasodilation and initial increases in pulmonary vascular resistance and pressure followed by a substantial increase in right ventricular end-diastolic pressure and a decrease in contractility. Central and peripheral haemodynamics were measured in 20 patients with pulmonary hypertension (mean pulmonary artery pressure = 38.1 mmHg) due to valvular heart disease before and following injections with 40 ml of both types of contrast medium in randomized order. Heart rate, cardiac output and right atrial pressure rose significantly more after amidotrizoate and this contrast medium caused more extensive systemic vasodilation and a larger decrease in aortic pressure as compared to iopamidol. Pulmonary artery pressure went up moderately with both contrast media. It is concluded that non-ionic low-osmolality contrast media like iopamidol induce less pronounced haemodynamic alterations, in particular less increase in right ventricular filling pressure. This may be beneficial to patients with pulmonary hypertension undergoing angiocardiography or digital subtraction angiography.

Adult↗

PubMed1987

Long-term treatment of severe chronic heart failure with captopril: a double-blind, randomized, placebo-controlled, long-term study.

Twenty-three patients with severe heart failure (NYHA classes III and IV) on treatment with digitalis and diuretics were additionally treated in a randomized double-blind study over a 6-month period with captopril (n = 12; mean daily dose 84 mg) or a placebo (n = 11) and were then reexamined. In the captopril group, the left-ventricular filling pressure decreased by 9 mm Hg (from 23 to 14) at rest and 6 mm Hg (from 35 to 29) during exercise. In the placebo group, there was an increase of 4 mm Hg (from 25 to 29) at rest and 7 mm Hg (from 33 to 40) during exercise; p less than 0.01 (p less than 0.01). In the captopril group, the cardiac index at rest increased 0.7 1/min/m2 (from 2.1 to 2.8) and during exercise 1.2 1/min/m2 (from 2.8 to 4.0). In the placebo group, the increase in cardiac index was considerably less pronounced at rest (= 0.2 1/min/m2; from 1.9 to 2.1) and during exercise (= 0.1 1/min/m2; from 2.7 to 2.8); p less than 0.02 (p less than 0.01). The improved cardiac output had a beneficial effect on the renal blood flow. Hippuran clearance increased by 46 ml/min (from 271 to 318), whereas in the control group it decreased 25 ml/min (from 259 to 234) (p less than 1.02). Both the heart rate and the arterial blood pressure remained constant, whereas the decrease in peripheral vascular resistance was definitely more pronounced in the captopril group (= 562 dyne X s X cm-5, from 1,841 to 1,279) than in the placebo group (= 123 dyne X s X cm-5, from 1,834 to 1,710; p less than 0.02). The heart volume, assessed radiographically, increased slightly in the placebo group, and the left-ventricular end-diastolic diameter remained constant in both groups. In the course of the study, two patients died in the captopril group and three in the placebo group. After six months, eight patients in the captopril group and three in the placebo group had improved by at least one NYHA category. The beneficial effects of captopril are due to its inhibitory effect on the renin-angiotensin system as well as to the inhibition of sympathetic stimulation. Consequently, in the captopril group the quantity of plasma norepinephrine decreased by 188 ng/ml (from 430 to 618); p less than 0.03. The indirect vasodilation caused by this mechanism leads to persistent unloading of the myocardium and an improvement in heart failure without loss of action by counterregulatory mechanisms.

Captopril↗

PubMed1987

[Measuring the intracoronary pressure gradient--value and methodologic limitations].

Measurements of pressure gradients were performed in a fluid-filled model. The hydrostatically regulated perfusion pressure, as well as the diameter of the tube segments and the regulation of the flow by peripheral resistance, were comparable to conditions in human coronary arteries. Pressure gradients above 20 mm Hg were only measured with a reduction in cross-sectional area of more than 90%. Even after increasing the flow four-fold, which corresponds to the human coronary flow reserve, as well as after probing the stenosis with different catheters (2F-5F), gradients greater than 20 mm Hg were only recorded with high-grade stenoses (more than 80% reduction in cross-sectional area). The findings in this model demonstrate that measurement of pressure gradients allows only a quantitative differentiation between high-grade (greater than 80%) and low-grade (less than 80%) stenoses. The catheter itself can substantially contribute to the gradient by vessel obstruction, depending on the diameter of the catheter and of the coronary vessel. A quantitative assessment of the stenosis therefore requires knowledge of the pre- and post-stenotic vessel diameter as well as of the catheter diameter. However, pressure measurements during transluminal coronary angioplasty should not be abandoned. They can be useful to aid catheter positioning and to estimate dilatation efficacy. Moreover, measurement of coronary capillary wedge pressure during balloon expansion provides valuable information about the extent of collateralisation.

Angioplasty, Balloon↗

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

[Rotation angioplasty--a new procedure for reopening and dilating blood vessels. Experimental findings].

16 fresh postmortem specimens of human femoral and popliteal arteries with severe atherosclerosis were removed and angiography was performed. Eight vessels were completely occluded and eight showed stenoses of up to 60%. All occluded vessels were heavily calcified. The duration of occlusion, estimated according to the patient's history, ranged from 1 to 2 years. In one case, a duration of 18 months was documented by angiography. The lengths of the occlusions were between 5 and 12 cm. A rotating catheter was introduced through a 9F guiding catheter. All stenosed vessels were passed and seven out of eight occluded vessels, in which passage was not possible using conventional wires, were successfully reopened at low speed rotation of 200 rpm. Angiography, as well as histology, showed no perforation, and angioscopy revealed a smooth surface of the new channel. In three vessels this new channel was dilated with a balloon catheter and in one with an elastic element under rotation. It is concluded that with the new technique it is possible to reopen totally occluded human arteries which cannot be passed by conventional methods.

Angioplasty, Balloon↗

PubMed1987

[Angiographic and functional long-term results 2 to 8 years following coronary angioplasty].

Functional and angiographic follow-up was performed in 61 patients 3.9 months (range 2-8 months) and 3.7 years (range 2-8 years) after successful transluminal coronary angioplasty. The mean degree of stenosis prior to angioplasty was 78.7% and after the procedure, 36%. After 3.9 months there was a slight increase to 39% because of 12 recurrences. In three of these patients a second angioplasty was performed; nine were continued on medical treatment because of sustained clinical benefit. After 3.7 years, the mean degree of stenosis was 29%. No patient with persistent vessel patency after 3.9 months showed an increase of the dilated stenosis of more than 15% after 3.7 years. Prior to angioplasty, 41 patients (75%) had one-vessel disease; 19 (18%) two- and 4 (7%) three-vessel disease. 2-8 years after successful angioplasty, 48% of patients showed no stenosis of greater than or equal to 50% narrowing. Progression of coronary artery disease was found in 29/61 patients at the late follow-up. Of these 29 patients, 11 underwent another angioplasty because of a new stenosis in another vessel or segment; 18 were treated medically. There was no need for bypass surgery. It is concluded that a sustained success 3.9 months after angioplasty predicts excellent long-term vessel patency.

Adult↗

PubMed1987

Myocardial biopsy in patients with hypertrophic cardiomyopathy: correlations between morphologic and clinical parameters and development of myocardial hypertrophy under medical therapy.

Left ventricular biopsies from 38 patients with hypertrophic cardiomyopathy (HOCM 28, HNCM 10) were investigated to evaluate possible correlations between morphological and clinical parameters. No correlation was found between the degree of myocardial hypertrophy (muscle cell diameter), nuclear size of the myocytes, fibrous tissue content and various clinical data such as pressure gradient, left ventricular end-diastolic pressure, Sokolow index and heart volume. In 11 patients with HOCM, a second biopsy was performed after medical therapy (verapamil, n = 9; propranolol, n = 2) over 33 +/- 12 months. Increasing myocardial hypertrophy (cell diameter 16.2 +/- 4.4 mu vs. 20.3 +/- 4.2 mu) was observed in all 11 patients. The interstitial fibrous tissue content increased from 5.7 +/- 6.3 to 12.7 +/- 6.8%. The volume fraction of myofibrils decreased (48.8 +/- 2.7 vs. 43.6 +/- 5.3%). The morphological changes were observed regardless of the clinical outcome which was improved in four, unchanged in five and worsened in two cases. The underlying hypertrophic process in HCM seems to be slowly progressive in most patients and cannot be influenced by medical treatment.

Adult↗

PubMed1987

[Transluminal coronary angioplasty: parameters of increased risk of recurrence].

Data about the primary success and complication rates following transluminal coronary angioplasty are comparable worldwide. Reports on the frequency of recurrences, however, differ considerably. Data concerning factors enhancing the risk of restenosis are contradictory. We compared a group of 62 patients with angiographically confirmed restenosis with a group of 62 patients without restenosis. There were no significant differences with regard to age, sex, onset of symptoms and severity of angina pectoris, number of previous infarctions, incidence of multivessel disease, maximum size of the balloon catheters used and primary dilatation results. The following factors were significantly associated with the occurrence of restenosis: high-grade stenoses prior to dilatation, stenoses involving long segments of coronary arteries, eccentric stenoses, the necessity to apply high balloon pressures, long duration of balloon inflation, and also the patient being overweight, a nonsmoker and having undergone an alteration in continuous treatment.

Adult↗

PubMed1987

Long wire technique--experience with 100 procedures.

Derived from more than 1000 procedures the long wire technique has proven to facilitate coronary angioplasty. Maneuvering of the wire is unhindered because the wire is introduced without balloon catheter. Optimal contrast display is possible during crossing of the stenosis. Precision and safety of the procedure is therefore considerably improved. Balloon catheters can be exchanged without recrossing the stenosis including super low profile catheters of small diameter. In case of acute coronary occlusion occurring during angioplasty the long wire allows reintroduction of catheters without danger of via falsa. If necessary a 4.5 f perfusion catheter can be introduced and coronary perfusion with 60-100 ml per minute blood from the femoral artery can be performed by hand. In contrast to the monorail technique the ability to measure pressures through the balloon catheter including intracoronary gradients and coronary capillary pressure is preserved.

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

Long-term treatment of hypertrophic cardiomyopathy with verapamil or propranolol in matched pairs of patients: results of a multicenter study.

The effects of a 2-year treatment with high-dose propranolol (mean, 340 +/- 135 mg/day) and verapamil (mean, 493 +/- 136 mg/day) were compared in two groups of patients with hypertrophic cardiomyopathy. Both groups were broadly identical at the beginning of the trial and were formed of matched pairs. Out of 137 patients entering the study, 37 pairs completed the 2 year follow-up. The mean group symptomatology (NYHA-classification) improved significantly only following verapamil treatment. Individual improvement was seen more often following verapamil (V), but deterioration was almost exclusively seen during propranolol (P) treatment. Reduction of the Sokolow-index was significant in the V group only. Reduction in the resting heart rate and maximum gradient was more pronounced following P. No correlation could be found between the change in clinical symptoms and electrocardiographic, echocardiographic or hemodynamic data, nor to the dosage of V or P administered. From clinical and echocardiographic findings and in respect of side effects, V is advantageous over P in the treatment of hypertrophic cardiomyopathy, although a considerable number of patients improve after P. Objective data do not allow one to anticipate responders or non-responders to either treatment.

Cardiomyopathy, Hypertrophic↗

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

[Chronic aortic insufficiency: prediction of postoperative course based on preoperative relations of left ventricular end-diastolic volume to regurgitated blood volume].

The range of appropriate left ventricular dilatation due to volume overload was defined in 21 patients with a stable course of chronic aortic regurgitation, by correlating the scintigraphically determined left ventricular end-diastolic volume with the regurgitated blood volume. 25 other patients with chronic aortic regurgitation, who were scheduled for valve replacement, were within this normal range (group 1); in nine patients, left ventricular end-diastolic volume exceeded the amount expected from the amount of regurgitation (group 2). Patients were followed up between 2 and 62 months postoperatively (average: 26 +/- 13 months). No patients from group 1, but four out of nine patients from group 2 (45%) died postoperatively from congestive heart failure. In 23 out of 24 patients from group 1, left ventricular ejection fraction was postoperatively within the normal range, although preoperative values had been severely depressed in three cases (lower than 40%). Ejection fraction remained depressed in one patient with persistent mitral regurgitation and in all patients from group 2. Global heart volume significantly decreased by 20% in group 1, whereas only minor changes (-15%) were observed in group 2 (group 1: from 1184 +/- 186 to 954 +/- 120 ml, 2p less than 0.001; group 2: from 1402 +/- 300 to 1185 +/- 294 ml). This was compared to the course of left ventricular end-diastolic diameter (group 1: from 7.1 +/- 0.9 to 5.5 +/- 0.7 cm (-23%), 2p less than 0.001; group 2: from 7.6 +/- 0.7 to 6.9 +/- 1.3 cm (-9%). In group 1, left ventricular ejection fraction significantly increased, whereas no significant changes were observed in group 2 (group 1: from 53 +/- 13 to 64 +/- 13% (+21%), 2p less than 0.001; group 2: from 29 +/- 7 to 32 +/- 14% (+10%]. It is concluded that the scintigraphically determined ratio of left ventricular end-diastolic volume to regurgitated blood volume provides important prognostic and functional information regarding the postoperative course of chronic aortic regurgitation. This ratio is more reliable than single radionuclide, electrocardiographic, roentgenographic or echocardiographic parameters.

Adult↗

PubMed1987

Effects of nifedipine and propranolol combined therapy in patients with hypertrophic cardiomyopathy.

Fifteen (14 male and one female) patients with hypertrophic cardiomyopathy, ranging from 22 to 67 (mean: 45.5) years of age were treated with oral nifedipine and propranolol for 6 to 24 (mean:18) months. Twelve of the patients had been pretreated with a mean oral dose of 560 mg verapamil for 60 up to 93 (mean: 78.5) months, showing slight subjective and objective improvement. Treatment with nifedipine-propranolol was terminated in five cases due to deterioration or side effects after 6 and 12 months, respectively. During combined therapy, two patients reported subjective improvement, but in five cases there was no change and eight patients reported deterioration. The mean Sokolow-index showed no change. The radiologically determined heart volume increased in 11/15 patients and significantly in the mean of all patients from 887 +/- 239 to 947 +/- 246 ml/m2. In addition, echocardiographic measurements showed a significant increase in left atrial diameter from 40.0 +/- 9 to 42.1 +/- 9 mm, whereas ventricular wall thickness remained unchanged. Thus, high dose verapamil therapy seems superior to nifedipine-propranolol therapy in most patients with hypertrophic cardiomyopathy.

Adult↗