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Biomedical subjects

M Kaltenbach

Publications and source records attributed to M Kaltenbach.

At least 217 records · Page 12Linked to original sources
PubMed1986

Left predominant coronary circulation in patients with valvular aortic stenoses.

This study was conducted to examine whether a correlation exists between the incidence of aortic stenosis and predominant left coronary perfusion. Therefore, coronary angiograms of 77 patients with mitral stenosis (Group 1), 50 patients with combined mitral valve disease and pure mitral insufficiency (Group 2), 61 patients with aortic insufficiency with or without mitral valve disease (Group 3), 49 patients with pure aortic stenosis (Group 4), and 69 patients with combined aortic valve disease and aortic stenosis with concomitant mitral valve disease (Group 5) were reviewed. Group 6 consisted of 20 patients with coronary heart disease. A statistically significant accumulation of left coronary circulation was found in patients with pure aortic stenosis (Group 4) (33%) as well as in patients with combined aortic valve disease (19%). The frequency of predominant left coronary circulation was comparable in all other patients (Group 1: 8%; Group 2: 10%; Group 3: 8%; Group 6: 7.5%). Thus, the presence of left predominance in a diagnostic coronary arteriogram performed in a patient with aortic stenosis could be a clue that the aortic stenosis is congenital.

Adult↗
PubMed1986

Coulometric high-performance liquid chromatographic analysis of morphine in biological fluids.

A simple method is described for the determination of morphine in biological fluids (plasma and urine) by high-performance liquid chromatography with coulometric detection. The detector consists of three porous electrodes which are arranged in a way to give maximum selectivity and sensitivity. Quantitation of morphine is performed using naloxone as the internal standard. Sample preparation involves an extraction procedure from plasma and urine. The limit of quantification of the method is 1 ng/mL plasma. The methodology was applied to measure blood levels in rats after subcutaneous administration of a slow-release morphine pellet.

Animals↗
PubMed1986

[Indications in angina pectoris: balloon dilatation].

Nine years after the introduction of transluminal coronary angioplasty by Andreas Grüntzig, large medical centers all over the world report on an acute success rate between 85 and 90%. Complications leading to an emergency bypass operation are observed in 3-7%. The mortality rate is less than 1%. The technical progress with the development of new guiding catheters and steerable balloon systems led to an extension of indications. Probably prognostical aspects of indication may become more important in the future.

Angina Pectoris↗
PubMed1986

[Direct myocardial anti-ischemic effect of diltiazem in the human].

In a randomized double blind placebo-controlled study in 20 patients the influence of the calcium antagonist diltiazem (1.0 mg administered intracoronarily, distal from the stenosis) on the severity of myocardial ischemia during therapeutic coronary occlusion (transluminal coronary angioplasty) of the left anterior descending coronary artery was investigated. The severity and time of onset of ischemic ST and T wave changes as well as anginal pain were significantly reduced 3 and 8 minutes after diltiazem, whereas there was no definite change in the controls. Heart rate and blood pressure were not influenced by diltiazem or placebo. The results indicate a direct antiischemic effect of diltiazem on myocardial cells. The findings can neither be explained by an influence on cardiac afterload nor by coronary vessel reactions, nor a reduction of myocardial contractility. The findings do not permit conclusions in terms of the duration of this direct antiischemic mode of action.

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↗
PubMed1986

[Dose-response relationship of nitrate therapy of angina pectoris].

The treatment of 15 patients with coronary heart disease and exertion-related angina pectoris with isosorbide dinitrate (ISDN) tablets in 4 doses (6 X 5 mg, 6 X 20 mg, 6 X 40 mg, 6 X 80 mg) in a randomized sequence for 1 week each resulted in a dose-related improvement of ischemia (ST-segment depression during stress testing) as compared to placebo: 5 mg (30 mg/day): 24% (p less than 0.05); 20 mg (120 mg/day): 40% (p less than 0.05); 40 mg (240 mg/day): 60% (p less than 0.01); 80 mg (480 mg/day): 74% (p less than 0.01). Continuation of treatment for another 4 weeks with 480 mg/day led to a slight decrease in antianginal activity, with a 55% improvement of ST-depression. The frequency of angina pectoris was also lowered in a dose-related manner. For nitroglycerin in oral sustained release form (matrix system) a dose-related antianginal efficacy could be demonstrated in 12 patients enrolled in a double-blind cross-over trial: 2.6 mg (single dose): 23% (n.s.); 6.5 mg: 38% (p less than 0.01); 10 mg: 55% (p less than 0.001); 20 mg: 74% (p less than 0.0001). The duration of action of 20 mg was 4 hours. Transdermal nitroglycerin also proved to be effective in a dose related fashion. In 12 patients undergoing 1-week treatment periods with 5 cm2, 10 cm2 and 20 cm2-patches ST-depression was favourably influenced by 15% (n.s.), 22% (p less than 0.05) and 46% (p less than 0.001) 3 hours after administration. No antiischemic efficacy was demonstrable 24 hours after medication.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Cutaneous↗
PubMed1986

[Effect of captopril in chronic aortic insufficiency].

In 16 patients with chronic aortic regurgitation, we studied the acute hormonal and hemodynamic effects of 12.5 to 25 mg captopril; in 12 patients the changes after a 4 to 8 week treatment period (mean 6.3 +/- 2 weeks; doses: 3 times 12.5 to 3 times 25 mg/day) were investigated. The following baseline variables were evaluated: the radionuclide left ventricular ejection fraction (EF) at rest and during exercise, left ventricular end-diastolic volume (EDV), regurgitant blood volume (RBV); and plasma renin activity (PRA). Repeated determinations of EF, EDV and RPA were carried out 90 minutes after application of the drug. In patients with chronic therapy, EF at rest and during exercise, EDV, RBV and PRA were reinvestigated at the end of the study. Acute administration of captopril was followed by an increase of EF (from 49 +/- 12 to 55 +/- 12%, p less than 0.001) and a slight decrease of EDV (from 389 +/- 160 to 376 +/- 146 ml, p less than 0.05). PRA significantly increased (from 1.6 to 3.1 ng/ml/h, p less than 0.05). Chronic therapy resulted in a moderate decrease of systolic and diastolic blood pressure (from 156/70 +/- 31/15 to 140/63 +/- 23/15 mm Hg, p less than 0.01). However, no significant changes were observed in EF at rest and during exercise (51 +/- 9 vs. 53 +/- 10% and 45 +/- 14 vs. 47 +/- 14%), EDV (433 +/- 179 vs. 422 +/- 179 ml) and RBV (136 +/- 81 vs. 129 +/- 77 ml). PRA was significantly increased (6.3 ng/ml/h, p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Aortic Valve Insufficiency↗
PubMed1986

[The diameter of arterial and venous abdominal vessels during acute and chronic administration of nitrates. A sonographic study].

Fourteen male patients with coronary heart disease were randomly assigned to treatment periods with isosorbide dinitrate (ISDN) 120 mg/day (6 X 20 mg) and placebo for 4 weeks each, according to a double-blind protocol with intraindividual cross-over. The luminal diameters of the superior mesenteric artery, the hepatic artery, the superior mesenteric vein and the portal vein were determined sonographically in the supine position on days 1, 14 and 28 of both treatment periods 90 min after drug intake. The measurements were repeated after 1.6 mg sublingual nitroglycerin. On day 1 of drug intake the vessel diameters increased significantly after ISDN as compared to placebo: superior mesenteric artery: +11%; hepatic artery: +26%; superior mesenteric vein: +17%; portal vein: +11% (p less than 0.05). No differences in luminal diameters between both drug regimens were found on days 14 and 28. Additional nitroglycerin caused a marked diameter increase during the placebo period (14-21%; p less than 0.001) and on days 14 and 28 of ISDN therapy, while the drug effects were absent after maximal ISDN-induced vasodilatation on day 1. Thus, nitroglycerin and isosorbide dinitrate administered acutely caused a comparable vasodilatation of arterial and venous vessels in the splanchnic region. During sustained therapy with isosorbide dinitrate the vasodilatory effects of the drug were lost. It is supposed that a decrease of blood pooling in the splanchnic region occurs during sustained ISDN therapy. Despite this tolerance development to the circulatory effects of isosorbide dinitrate, nitroglycerin remained effective with regard to arterial and venous vasodilatation.

Adult↗
PubMed1986

[Persisting volume overload of the left ventricle following surgical correction of chronic aortic insufficiency].

After aortic valve replacement for chronic aortic regurgitation, complete normalization of the left ventricular end-diastolic volume can rarely be observed. We therefore investigated the role of continual volume overload caused by persisting concomitant mitral regurgitation. 20 patients who received an aortic valve for chronic aortic regurgitation (group 1), 5 patients after operation for aortic stenosis (group 2) and 6 patients with double valve replacement because of aortic and mitral valve lesions were included in the study 1 to 108 months after operation. All patients were examined clinically and by combined first pass/equilibrium radionuclide ventriculography. In the case of significant regurgitation (greater than 20%) 2-dimensional colour-coded Doppler-echocardiography was performed in patients of group 1 to localize the regurgitant lesion. 15 patients of group 1 had a typical systolic murmur indicating mitral regurgitation. 14 of these patients had significant scintigraphic left-sided heart regurgitation: 7 patients had regurgitant fractions between 21 and 40%; 6 patients between 41 and 60%; in 1 patient RF was 64%. Echocardiography confirmed mitral regurgitation in 9 of 11 of these cases. No significant regurgitation was observed in patients of group 2; mild regurgitation was measured in 5 of 6 patients of group 3 (26 to 31%). We conclude that in patients with chronic aortic regurgitation complete normalization of the left ventricular end-diastolic volume after valve replacement may not occur in some patients because of persisting mitral regurgitation.

Aortic Valve Insufficiency↗
PubMed1986

[Regional myocardial ischemia in the conscious dog under echocardiography control].

Regional myocardial dysfunction is a very sensitive and early parameter of myocardial ischemia. One minute occlusion of the left anterior descending (LAD (n = 8) and circumflex coronary artery (CCA) (n = 8) by means of hydraulic occluders was performed in 10 chronically instrumented conscious dogs. In a left ventricular cross-section diastolic and systolic area (DA, SA) and area shortening (AS) as well as regional function of 6 radial sectors were evaluated with 2D echocardiography. After occlusion of the LAD, SA increased by 33% (p less than 0.05), AS decreased by 22% (p less than 0.05) while the DA remained unchanged. In 2 of 6 radial sectors (anteroseptal) shortening decreased by 41% (p less than 0.01) and 54% (p less than 0.001) respectively. Occlusion of the circumflex coronary artery CCA caused an increase in DA (18%) and SA (33%) and a reduction of AS by 24% (p less than 0.01). Contraction of the anterior wall (sectors 2 and 3) was reduced by 61% and 57% (p less than 0.001). In the same animal 10 one minute occlusions of the LAD with 5 min intervals of reperfusion caused a reproducible depression of sector 6 (septal) from 63.2 +/- 5.4% to 16.3 +/- 3.4%. In another animal 11 one minute CCA occlusions with 5 min intervals of reperfusion reproducibly decreased the contraction of sector 3 (anterior) from 85.2 +/- 6.7% to 21.4 +/- 17.0%. 2D-E allows a reproducible estimation of regional left ventricular dysfunction during ischemia. Our model has the advantage that numerous studies can be performed in the same animal, so that the results can be compared intraindividually.

Animals↗
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

[Anti-angina effectiveness of isosorbide dinitrate in an acute trial and following continuous 4-week therapy with 40 mg 6 times a day].

Ten patients with angiographically proven coronary heart disease, stable exercise-induced angina pectoris, and reproducible ST-segment depression were treated with isosorbide dinitrate (ISDN) tablets in daily doses of 240 mg (6 X 40 mg) and placebo (PL) for 28 days each on the basis of a randomized double-blind protocol with intraindividual cross-over. ISDN treatment resulted in a sustained reduction of anginal attacks with a weekly mean rate ranging from 1.4 (3rd week) to 3.9 (4th week) as compared to 10.2 (2nd week) to 11.7 (4th week) during placebo treatment (P less than 0.001). Ischemic response during stress testing (sum of ST-segment depressions) was significantly improved during ISDN treatment as compared to placebo. Day 1: 56% (P less than 0.01); day 7: 30% (P less than 0.01); day 28: 49% (P less than 0.001). Heart rate and arterial blood pressure in the upright position were different between ISDN and placebo on day 1 and day 7 of the treatment phases (P less than 0.02), but not on day 28. Nitrate responsiveness with regard to blood pressure and heart rate was restored after a drug-free interval of 2 days. The plasma concentrations for ISDN and the mononitrate metabolites exhibited a constant ratio during the treatment period. Thus, therapy with 6 X 40 mg ISDN per day resulted in a sustained reduction of anginal attacks and preserved improvement of ischemic ST-segment depression during exercise in upright position.

Adult↗