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Biomedical subjects

M Kaltenbach

Publications and source records attributed to M Kaltenbach.

At least 199 records · Page 11Linked to original sources
PubMed1987

10-year results and survival of patients with hypertrophic cardiomyopathy treated with calcium antagonists.

Hypertrophic cardiomyopathy is characterized by progredient myocardial hypertrophy causing ventricular systolic and diastolic dysfunction. Long-term results of beta-blocker therapy have been disappointing. Neither the impaired ventricular filling or the prognosis are improved. In contrast, calcium antagonists mainly influence diastolic ventricular dynamics, but also have beneficial effects on systolic function. The results of long-term therapy with calcium antagonists, including patients treated for more than 10 years, are presented here. A total of 84 consecutive patients (mean age 43 years; 20 female and 64 male) with confirmed hypertrophic cardiomyopathy were treated with high doses of calcium antagonists (mean doses of 515 mg verapamil or 158 mg gallopamil per day). In the course of therapy with a mean duration of 52 months, heart size--assessed by X-ray technique--and Sokolow-index in the ECG decreased significantly (heart volume: from 947 to 885 ml/1.73 m2 body surface; Sokolow-index: from 5.0 to 4.5 mV). The echocardiogram showed a significant decrease in left atrial diameter, whereas wall thickness only tended to decrease. Hemodynamic control investigations confirmed an improvement in systolic as well as in diastolic ventricular function (mean follow-up period was 31 months). According to these findings the condition and stress tolerance improved in 84% of the patients. Therapy with calcium antagonists also improved prognosis: without treatment or following treatment with beta-blocking agents, annual mortality is approximately 3.5%, whereas in the described patient population mortality dropped to less than 2%. Thus, a calcium antagonist is the medication of first choice for patients with hypertrophic cardiomyopathy.

Adolescent↗
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

Systolic anterior movement of the mitral valve and the Venturi effect: an in vitro study.

We constructed two different "mitral valve" models in order to investigate the influence of the Venturi effect on SAM. According to our results, SAM can be caused as a result of a subvalvular obstruction. In this case, the valve itself does not contribute to the degree of outflow tract obstruction (first model). In the second model, the valve itself contributes to the degree of outflow tract obstruction. In both models only the Venturi effect is the cause of SAM. We conclude that different anatomic abnormalities causing a Venturi effect can induce SAM.

Cardiomyopathy, Hypertrophic↗
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↗
PubMed1987

[Treatment of hypertrophic cardiomyopathy with nifedipine and propranolol in combination].

Fifteen patients (14 males and 1 female) with hypertrophic cardiomyopathy, ranging from 22 to 67 years of age (mean: 45.5 years) 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 to 93 (mean 78.5) months, showing slight subjective and objective improvement. Treatment with nifedipine and propranolol was terminated in five cases, due to deterioration or side effects after 6 and 12 months, respectively. During combined therapy, two patients reported improvement, whereas in five cases there was no change and eight patients reported deterioration. There was no change in the Sokolow index. The radiologically determined heart volume increased in 10 out of 15 patients and in the total group from 887 +/- 214 to 938 +/- 248 ml/1.73 m2. Echocardiographic measurements showed a significant increase in left atrial diameter from 40.0 +/- 9 to 44.0 +/- 11 mm, whereas ventricular wall thickness remained unchanged. Thus, high-dose verapamil therapy seems superior to nifedipine-propranolol therapy in patients with hypertrophic cardiomyopathy.

Adult↗
PubMed1987

[Muscular obstruction of the right ventricular outflow tract. Subvalvular pulmonary stenosis or hypertrophic cardiomyopathy?].

A case is reported of right ventricular outflow obstruction caused by hypertrophic cardiomyopathy. The pressure gradient between the inflow tract and the outflow tract of the right ventricle was 84 mm Hg. Resection of the hypertrophic muscle bundles practically eliminated the obstruction leaving only an insignificant subvalvular gradient of 2 mm Hg. Histologic examination revealed cardiac muscle cell hypertrophy and disorganization.

Adult↗
PubMed1986

[Successful angioplasty of a coronary stenosis followed angiographically for 9 years].

A short 80% peripheral stenosis of the anterior interventricular branch which remained unchanged for nine years was successfully dilated by transluminal balloon coronary angioplasty using long-wire technique with angiographically demonstrated reduction of the stenosis to 30%. The patient has since been without symptoms, even on severe physical exertion. It has previously been thought that increasing hardening of the atheroma of a long-standing stenosis prevented successful lasting dilatation.

Angiography↗
PubMed1986

Effects of bepridil on regional myocardial ischemia and comparison with verapamil.

This study was designed to assess the efficacy of bepridil in reducing regional myocardial ischemia and to compare its efficacy with that of verapamil. Forty-five anesthetized, open-chest dogs were subjected to three 5-minute occlusions of the left anterior descending coronary artery (LAD), each followed by 45 minutes of reperfusion. Eleven dogs (group 1) served as controls. In 10 dogs, bepridil, 5 mg/kg, was administered before the third occlusion (group 2). In 11 dogs, verapamil was administered before the third occlusion (group 3). In each dog, on-line intramyocardial hydrogen ion concentration and carbon dioxide tension were measured in the myocardial segment supplied by the LAD. Regional myocardial contractility was assessed in this area with 2 pairs of ultrasonic crystals inserted to determine percent segmental shortening. Regional myocardial blood flow was determined during each occlusion by washout of xenon-127. The increase in hydrogen ion concentration and carbon dioxide tension did not change from occlusion 2 to occlusion 3 in the control group. Both bepridil and verapamil elicited a significant reduction in the extent of regional ischemia, evidenced by a reduction in the accumulation of hydrogen ions, in occlusion 3 vs occlusion 2. Systolic bulging occurred during all occlusions and the periods of reperfusion were not sufficient to allow complete recovery of regional function. Bepridil and verapamil each caused a significant increase in percent segmental shortening (both p less than 0.025), and verapamil effected a significant improvement of function during occlusion 3 compared with occlusion 2.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
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

[Aortocoronary bypass operation as an emergency intervention after transluminal coronary angioplasty. Which factors prevent the incidence of a major infarct?].

Among 830 patients in whom transluminal coronary angioplasty (TCA) was undertaken there were 41 (4.9%) who required an aortocoronary bypass operation for acute complications (vessel dissection with markedly reduced flow; complete occlusion or contrast-medium extravasation). The group of 41 was divided into two, based on angiography (25) or ECG (16) criteria. Group 1 comprised 30 patients, who developed no or only a small infarct peri-operatively; group 2 had eleven patients with large infarcts. The patients of group 1 had a greater exercise tolerance pre-operatively than those of group 2 (118 +/- 28 vs 91 +/- 45 Watt; P less than 0.05) and had a higher revascularization time (interval between end of the cardiac catheterization and onset of reperfusion: 154 +/- 58 vs 264 +/- 173 min; P less than 0.05). Collaterals to the area supplied by the treated vessel were observed only in group 1 patients (10), but not of those in group 2. Age, history of previous infarction, number of diseased coronary arteries, ischaemic reaction during ergometry, initial left-ventricular ejection fraction and symptoms after onset of complications were without significance. It is concluded that an aortocoronary bypass operation should be performed as early as possible after post-TCA vascular complication in order to prevent the development of larger infarcts.

Angioplasty, Balloon↗
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

[Continuing anti-anginal effectiveness during chronic nitrate therapy in spite of the cessation of hemodynamic partial effects].

A decrease or actual cessation of some of the haemodynamic effects of nitrate, such as fall in blood pressure and rise in heart rate on standing upright, was observed in ten patients with coronary heart disease during a four-week period of treatment with nonretard isosorbide dinitrate, 20 and 40 mg six times daily. Disappearance of the nitrate effect was also observed by ultrasound over arterial and central venous vessels. At the same time, a crossover double-blind randomized study demonstrated that the anti-anginal action persisted. This effect is thus to be taken as preventing anginal attacks. It is concluded that chronic nitrate administration maintains its full anti-anginal action, even though haemodynamic effects are diminished or even cease completely.

Angina Pectoris↗