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Biomedical subjects

W Rafflenbeul

Publications and source records attributed to W Rafflenbeul.

At least 55 records · Page 3Linked to original sources
PubMed1989

Angiographic assessment of human coronary artery endothelial function by measurement of endothelium-dependent vasodilation.

In isolated atherosclerotic human coronary arteries endothelium-dependent vascular relaxation is abolished with acetylcholine whereas another EDRF-dependent vasodilator, substance P, still produces significant relaxation. To study further these in vitro findings, graded doses of acetylcholine and substance P, which produced no systemic effects, were infused into the left anterior descending artery of patients with angiographically moderate coronary artery disease. The effects of acetylcholine and substance P on LAD diameter were analysed by quantitative angiography. Generally, acetylcholine caused no relaxation but concentration-dependent contraction from 1.67 +/- 0.06 mm to 1.45 +/- 0.09 mm (P less than 0.01), whereas substance P dilated the arteries to 1.89 +/- 0.10 mm (P less than 0.01). In contrast, both drugs caused a marked increase in great cardiac vein oxygen saturation, indicating an increase of coronary flow. The results suggest that the failure of the atherosclerotic epicardial human coronary artery to vasodilate in response to acetylcholine represents a muscarinic endothelial defect. The preserved vasodilation with substance P in the presence of a refractoriness to acetylcholine suggests that atherosclerotic human coronary endothelial cells exposed to appropriate non-muscarinic stimuli are still capable to release EDRF and that atherosclerotic smooth muscle retains a responsive receptor mechanism for EDRF.

Acetylcholine↗
PubMed1989

Influence of ionic and non-ionic radiographic contrast media on the vasomotor tone of epicardial coronary arteries.

The effect of ionic and non-ionic contrast media on the vasomotility of epicardial coronary arteries was investigated in 21 patients during coronary angiography by use of either diatrizoate-76% (10 patients, group A) or iopromide-370 (11 patients, group B). Coronary angiograms were taken in RAO 30 degrees projection before (= reference) and directly after (t0) diagnostic angiography of the left coronary artery (approx. 7 dye injections in approx. 7 min). Additional angiograms in the same projection followed after 1, 3, 6 and 10 min. Mean diameters of angiographically normal coronary segments were analysed with an automatic edge detection system (CAAS). With diatrizoate-76% coronary dilation at t0 averaged 18.9 +/- 6.7% (P less than 0.001); it correlated positively (P less than 0.001) with the number of diagnostic injections performed per min (mean 1.2 +/- 0.3 min-1), and negatively (P less than 0.5) with the time interval between the last diagnostic contrast injection and t0 (mean interval 73 +/- 35 s). Coronary dilation was unchanged 1 min after t0 (18.3 +/- 5.4%, P less than 0.001) and was still present after 6 min (6.2 +/- 4.6%, P less than 0.01). With iopromide-370 coronary dilation at t0 was mild (5.4 +/- 4.3%; P less than 0.05); the subsequent injections led to minimal insignificant dilation. It is concluded that in quantitative angiographic studies on changes in coronary vasomotor tone repeated coronary angiograms should be taken with non-ionic contrast media; furthermore adequate injection intervals of greater than 3 min should be observed.

Adult↗
PubMed1989

Coronary vasodilation with nitrocompounds--is there a maximum?

The maximal extent of the dilation of epicardial coronary arteries attainable with nitro-compounds was investigated in 12 patients with coronary artery disease. Before and 5, 10, 15, 19, 60 and 64 min after onset of a 4-min-intravenous infusion of 0.025 mg SIN-1/kg bodyweight coronary angiograms were performed in identical projection; simultaneously, the mean pulmonary wedge pressure (PWP) was measured. At 15 and 60 min, 0.8 mg nitroglycerin (NTG) were additionally administered as sublingual spray. Mean diameters of angiographically normal coronary segments were analyzed with the computer-assisted contour detection system CAAS; they increased by an average maximum of 29 +/- 5% prior to NTG (p less than 0.001). PWP decreased from 9.2 +/- 3.1 mmHg to an average minimum of 4.3 +/- 1.6 mmHg (p less than 0.01) prior to NTG. Neither of these SIN-1-effects was significantly augmented by additional NTG: at 19 min coronary dilation amounted to 28 +/- 7% (p less than 0.001), PWP to 3.9 +/- 1.0 mmHg (p less than 0.01). At 60 min coronary dilation still amounted to 24 +/- 8% (p less than 0.001), PWP to 6.2 +/- 2.5 mmHg (p less than 0.05). By the second administration of NTG the maximal effects attained before could be reproduced: coronary dilation 28 +/- 8% (p less than 0.001), PWP 4.6 +/- 2.2 mmHg (p less than 0.01). Thus, the dilation reserve of epicardial coronary arteries for nitrocompounds is approximately 30% on average. These results suggest the possibility of a reproducible maximal activation of the enzyme guanylate cyclase which seems to be the mediator of the nitro-compound-induced vasodilation.

Administration, Sublingual↗
PubMed1989

Konkurrenz zwischen endothelabhängiger und Nitroglygerin-induzierter koronarer Vasodilatation [Competition between endothelium-dependent and nitroglycerin-induced coronary vasodilation].

UNLABELLED: Intact vascular endothelium can relax the smooth muscle by liberation of EDRF (endothelium-derived relaxing factor) and thus induce vasodilation. We investigated to what extent functional integrity of the endothelium modifies the dilatory capacity of coronary arteries and which influence nitroglycerin exerts on endothelium-dependent relaxation mechanism. In 74 coronary segments from eight patients with coronary artery disease, coronary artery diameters were measured before (C1) and 90 s after intracoronary infusion of the endothelium-dependent vasodilator bradykinin (0.1 mM) by means of a computer-assisted contour assessment system (CAAS). The same segments were then measured before (C2; 10 min after C1) and 90 s after an intracoronary infusion of the endothelium-independent vasodilator nitroglycerin (0.29 mM). By dividing diameter increases after bradykinin in group I less than 0.15 mm, n = 42 segments and group II: greater than 0.45 mm, n = 32 segments, the following diameters were obtained (mean +/- SD): (table; see text) CONCLUSION: In atherosclerotic coronary segments with impaired endothelium and consecutively reduced endothelium-dependent dilation the vasodilatory capacity of nitroglycerin is enhanced. Due to a competitive effect on the final common biochemical pathway, i.e., stimulation of soluble guanylate cyclase and elevation of intracellular levels of cyclic guanosylmonophosphate (cGMP) nitrovasodilators can facilitate insufficient endogenous relaxation of vascular smooth muscle.

Bradykinin↗
PubMed1989

Correlation between isosorbide dinitrate plasma levels and coronary vasodilation after chewing capsules.

In 10 patients with coronary artery disease coronary angiograms were performed in identical projections before and 5, 10 and 15 min after sublingual administration of two chewing capsules with 5 mg of isosorbide dinitrate (ISDN) each. Simultaneously, blood samples were taken for gas-chromatographical determination of nitrate plasma levels. The average ISDN plasma levels amounted to 138 +/- 73 ng/ml, 102 +/- 76 ng/ml and 62 +/- 34 ng/ml in the fifth, tenth and fifteenth min, resp. In the fifteenth min significant isosorbide mononitrate plasma levels (greater than 70 ng/ml) were found only in three patients. Mean diameters of angiographically normal coronary segments were measured with the automatic edge detection system CAAS; they increased by an average of 20 +/- 10%, 26 +/- 11%, and 27 +/- 13% (p less than 0.001) in the fifth, tenth and fifteenth min, resp. Due to hysteresis of the coronary dilation in relation to ISDN plasma levels no significant correlation was found between these parameters. The minimal diameters of seven of 10 coronary stenoses analyzed in seven patients reacted with a maximal increase of 23%-98%. Thus, ISDN chewing capsules may be preferable for rapid and prolonged relief of anginal attacks as well as for potent dilation of epicardial coronary arteries as desired during angiography.

Administration, Sublingual↗
PubMed1989

Drug plasma levels and coronary vasodilation after isosorbide dinitrate chewing capsules.

Five, ten and fifteen min after sublingual administration of 10mg isosorbide dinitrate (ISDN) in chewing capsules, in 10 patients with coronary artery disease, ISDN plasma levels were correlated with the dilation of epicardial coronary arteries as well as with changes in aortic blood pressure and heart rate. Due to the rapid and extensive drug absorption, maximal ISDN plasma levels averaged 138 +/- 73 ng ml-1 and were already obtained after 5 min; they declined to 102 +/- 76 and 62 +/- 34 ng ml-1 in the 10th and 15th min respectively. In 7 patients isosorbide mononitrate plasma levels were still negligibly low (less than 30 ng ml-1). Mean diameters of 'normal' coronary segments increased by an average of 20 +/- 10%, 26 +/- 11% and 27 +/- 13% (P less than 0.001) at 5, 10 and 15 min respectively compared to control. The maximal drop in systolic aortic pressure (147 +/- 19 to 115 +/- 15 mmHg; P less than 0.01) as well as the maximal increase in heart rate (66 +/- 4 to 80 +/- 11 beats min-1; P less than 0.01) were observed in the 15th min; diastolic aortic pressure and double product remained constant. Due to the long persistence of coronary dilation and haemodynamic changes, none of these drug effects correlated significantly with the ISDN plasma levels. In addition, the minimal diameters of 10 coronary stenoses were measured in 7 patients; with ISDN 7 stenoses showed dilation ranging from 23% to 98%.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Sublingual↗
PubMed1989

[Effect of calcium antagonists and beta receptor blockers on coronary vessel diameter].

32 patients in an early state of coronary sclerosis were investigated in connection with diagnostic angiography. 8 patients received 2 mg gallopamil (G) and for every 12 patients 0.1 mg/kg propranolol (P), respectively, 0.12 mg/kg Atenolol (A). All medications were injected intravenously over 4 min. The angiograms were repeated in identical projections before (control) as well as 5, 10, 15, and 20 min after G and 2, 4, 6...up to 20 min after P and A. All angiograms were analyzed using a quantitative computerized contour detection system. 10 min after infusion of G 34 measured coronary segments showed a significant (p less than 0.05) medium dilation of 21 +/- 4.3% and after a further 10 min an insignificant increase in coronary diameter was observed up to 25 +/- 4%. After infusion of P and A a distinct vasoconstriction could be seen. Especially P showed a decrease in diameter of almost 25% in small coronary segments (less than 2.0 mm diameter). The dilatative effect of G i.v. seems to be important in the therapy of acute ischemic situations, for instance, for unstable angina, acute myocardial infarction, or during PTCA. The acute coronary vasoconstriction after infusion of P and A should be considered when used in acute ischemic events.

Angina Pectoris↗
PubMed1989

[Computer-assisted geometric measuring technic in coronary angiography interval studies: results of initial angiograms of the International Nifedipine Trial of Anti-atherosclerotic Therapy (INTACT) study].

In 396 of 423 (93.6%) patients with mild to moderate coronary artery disease participating in a coronary angiographic follow-up trial, diameters of the epicardial coronary arteries were measured with an automatic contour detection system (CAAS). The underlying INTACT study (International Nifedipine Trial on Antiatherosclerotic Therapy), a prospective, placebo-controlled, randomized, double-blind multicenter trial, investigates the influence of the calcium antagonist nifedipine (80 mg/day) on the progression of coronary atherosclerosis over a three-year interval. The study is based on coronary angiograms repeated in identical projections after premedication with 10 mg isosorbide dinitrate sublingually. For quantitative analysis the coronary artery system was, in consideration of all anatomical variations, subdivided into 25 segments. In the first angiograms of the 396 patients evaluated up to April 1, 1988, altogether 5,425 different coronary segments could be analyzed over their entire length in one or more angiographic projections--on the average 13.7 +/- 2.8 segments per patient. Analysis parameters were the mean diameters of the entire segments and of the individual subsegments (about 5 mm in length). The 10 major proximal segments could be evaluated in 76-94% of patients respectively in more than two different angiographic projections on the average; in 0-13% of patients the respective segments were occluded. In 1-4% of patients the evaluation of these segments was prevented by poor film quality and in 1-16% of patients prevented by anatomical abnormalities (e.g., segment too short or too small). 184 segments were found occluded (RCA 42%, LAD 30%, CX 28%) and 909 mostly low-grade to moderate stenoses (RCA 34%, CX 32%, LAD 30%, left main 4%) were analyzed with a special algorithm. The following obstruction parameters were derived: minimal diameter, percentage severity, length, and plaque area. The present data demonstrate that in an angiographical multicenter follow-up study such as INTACT a nearly complete quantitative morphometric analysis of the visualized coronary artery system can indeed be obtained in virtually all angiograms when a computer-assisted contour detection system is applied.

Clinical Trials as Topic↗
PubMed1989

Assessment of the vasomotility of epicardial coronary arteries with quantitative coronary angiography.

Quantitative in vivo analysis of the vasomotility of epicardial coronary arteries is based on the measurement of changes of the vessel diameters. Vessel contours can be determined with the help of a precision caliper by the investigator or with computer-assisted geometrical analysis systems applying a contour detection algorithm; the variability of the results from repeated coronary diameter measurements in the identical film frame is comparably low with all systems (less than or equal to 0.12 mm standard deviation). When investigating the influence of an intervention on coronary vasomotility the variability of the measurements can only be kept low by careful standardization of the entire method. Repeated coronary angiograms are performed in identical angiographic projections (mono- or biplane) with standardization of the inspiratory status of the patient and of the rate of contrast material injection (automatic injection pump). For quantitative analysis all coronary segments with a diameter greater than 1 mm which are clearly outlined, free from overlaps, and mainly run parallel to the image plane, are selected by the investigator in preferably end-diastolic cineframes. Whereas with a caliper and with most of the semi-automatic edge detection systems the segment diameter can only be measured at particular sites defined by the investigator, few systems are able to analyze and average the diameter over the entire segment length. The variability of measurements of the minimal diameters of coronary stenoses in different cine frames is particularly high; therefore, only distinct changes of this parameter (e.g. with the CAAS-system greater than 0.24 mm) may be considered significant.(ABSTRACT TRUNCATED AT 250 WORDS)

Cineangiography↗
PubMed1988

Clinical application of quantitative coronary angiography using the CAAS system: preliminary results of the INTACT study (International Nifedipine Trial on Antiatherosclerotic Therapy).

It is the objective of the INTACT-study to test in man, whether a significant retardation of the progression of coronary artery disease is attainable with the Ca-antagonist nifedipine; this may be possible on the basis of numerous animal experiments. INTACT is a prospective, randomized, double blind, placebo controlled investigation in 423 patients with preferably early stages of coronary sclerosis in whom a progression of the disease seems likely. A proper coronary angiogram led to inclusion of the patients in the study (October 1983-June 1985). Over the following 3-years-period patients received either nifedipine 80 mg/day or placebo. The study is concluded by a control coronary angiogram with angiographic projections which are identical to those of the first coronary angiography. The extent of coronary sclerosis is objectivated by computer-assisted quantitative measurement of the entire coronary arterial system with the CAAS-system (Rotterdam). For definition purposes the coronary artery system subdivided into 25 segments. Parameters for progression assessment will be mean segment diameter, minimal obstruction diameter, percentage severity of obstruction, length of obstruction and plaque area. So far 4826 coronary segments have been analyzed from the first angiograms of 383 patients. Per patient an average of 12.6 different segments could be evaluated in at least one angiographic projection. The major coronary segments could be measured in 72-93% of the patients in one or more angiographic projections (at the average about 2 different projections). Five hundred and forty-six coronary obstructions were analyzed; 131 of these were total occlusions. Only 9% of the length of the vessel contours detected by the computer algorithm required manual correction by the operators, suggesting a high reliability of the system. It can be concluded that quantitative measurement of the complete coronary artery system can indeed be obtained in a large angiographical multicenter study such as INTACT.

Angiography↗
PubMed1988

Effects of nifedipine and nitrates on coronary vasomotion.

The diameter changes of angiographically normal coronary arteries following vasodilator drugs were studied in 41 patients. In group 1 (22 patients) angiograms and plasma levels were obtained before as well as 10, 20 and 30 minutes after 20 mg nifedipine s.l. (15 patients) or placebo (7 patients). A cluster analysis allowed a classification of patients into group A (N = 4) and B (N = 11) according to the slope of plasma level increase. Plasma levels A versus B were 27.8 +/- 9.8/13.5 +/- 4.5 ng ml-1; P less than 0.05; 54.0 +/- 11.7/21.7 +/- 6.6 ng ml-1; P less than 0.001; 79.1 +/- 9.3/28 +/- 9.8 ng ml-1; P less than 0.001. Corresponding diameter changes A versus B were: 7.3 +/- 5.1%/-5.6 +/- 9.0%; P less than 0.01; 11.4 +/- 4.1%/-4.5 +/- 11.3%; P less than 0.01; 14.5 +/- 5.9%/0.5 +/- 13.6%; P less than 0.05. In group 2 (N = 19) angiograms were obtained before as well as 2, 4, 7 and 15 minutes after administration of 10 mg isosorbide dinitrate (N = 9) or placebo (N = 10). Coronary dilation ISDN versus placebo was: 2.4 +/- 3.6%/0.9 +/- 4.0%; NS; 10.6 +/- 5.1%/3.1 +/- 3.8%; P less than 0.001; 12.3 +/- 5.9%/-0.3 +/- 6.4%; P less than 0.005; 10.5 +/- 6.5%/-4.0 +/- 7.7%; P less than 0.005. These data indicate that the interindividual variations of changes in coronary lumen size are due to different slopes of plasma level increase, most likely due to different rates of drug absorption after sublingual administration of nifedipine.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Sublingual↗
PubMed1988

[Comparison of high and low osmolar roentgen contrast media in quantitative coronary angiography].

In 48 patients undergoing diagnostic coronary angiography changes of mean diameters of angiographically "normal" coronary segments after intracoronary injections of diatrizoate 76% or iopromide 370 performed in different intervals, were analyzed with a computer-assisted contour detection system (CAAS). Four study protocols were applied, differing in respect to the type of contrast medium administered and/or to the timing of the reference- and control-angiograms in the course of diagnostic coronary angiography. Coronary angiograms in identical projections were performed before (= reference) and directly after (1. control = C1) diagnostic angiography of the left coronary artery by injection of either diatrizoate 76% (group 1, 10 patients) or iopromide 370 (group II, 11 patients). Additional coronary angiograms were performed 1, 3, 6, and 10 min after C1. During diagnostic angiography in either group about eight dye injections were performed in about seven min. With diatrizoate 76% a significant coronary dilation averaging 18.9 +/- 6.7% (p less than 0.001) was observed at C1, depending on the number of diagnostic dye injections performed per min (mean 1.2 +/- 0.3) and on the interval between the last diagnostic injection and C1 (mean 73 +/- 35 s). Coronary dilation persisted up to the sixth minute (6.2 +/- 4.6%, p less than 0.01). With iopromide 370 a small but significant coronary dilation was observed merely at C1 (5.8 +/- 4.3%, p less than 0.05). In two other studies coronary angiograms were performed in identical projections immediately following complete diagnostic coronary angiography (reference) and in addition after 3, 4, 5, 6, 10, and 20 min (group III, 18 patients) and after 10, 20, and 30 min, respectively (group IV, 9 patients) by administration of diatrizoate 76% as the only contrast medium. Short injection intervals (1 min) resulted in a mild coronary dilation (mean up to 2.4 +/- 4.1% compared to reference; p less than 0.05), longer intervals (3-10 min) resulted in a marked diameter reduction (averaging up to -9.7 +/- 9%; p less than 0.05), probably a consequence of the return of coronary vasomotor tone to baseline levels. These results suggest that in quantitative coronary angiographic studies (e.g., testing coronary vasomotility) non-ionic contrast media should preferably be applied, and adequate injection intervals (greater than 2 min) are mandatory. In intervention- and follow-up studies based on repeated coronary angiograms dye-induced changes of coronary vasomotor tone can be avoided by premedication with vasodilating drugs, e.g. nitrates, and/or calcium antagonists.

Adult↗
PubMed1987

International nifedipine trial on antiatherosclerotic therapy (INTACT).

A number of animal studies revealed an inhibition or retardation of the progression of atherosclerosis by calcium-antagonists. Encouraged by these studies, a multicenter trial on the progression of coronary artery disease (CAD) in man was initiated testing the antisclerotic effect of nifedipine against placebo in 426 patients with mild to moderate coronary disease over 3 years. All patients underwent coronary angiography before entering the trial and will be restudied after 3 years; changes of the coronary artery lumen size are quantitatively assessed by a computer-assisted system (CAAS). INTACT (International Trial on Antiatherosclerotic Coronary Therapy) is therefore the first randomized prospective study on the progression of CAD based on a quantitated anigraphic control of the coronary system. This report presents the design of this still-ongoing study as well as inclusion and exclusion criteria. The quantitative evaluation of the coronary angiograms and the mode of compliance test are described in detail. A number of baseline data as well as the preliminary results of the quantitative evaluation of the first coronary angiograms are presented. Beside the results on the effect of the calcium-antagonist nifedipine on the progression of CAD, INTACT might also supply information on the antiatherosclerotic potency of other drugs administered additionally (beta-blockers and nitrates) and of HDL-cholesterol.

Adult↗
PubMed1987

Monophasic action potential mapping in human subjects with normal electrocardiograms: direct evidence for the genesis of the T wave.

T wave concordance in the normal human electrocardiogram (ECG) generally is explained by assuming opposite directions of ventricular depolarization and repolarization; however, direct experimental evidence for this hypothesis is lacking. We used a contact electrode catheter to record monophasic action potentials (MAPs) from 54 left ventricular endocardial sites during cardiac catheterization (seven patients) and a new contact electrode probe to record MAPs from 23 epicardial sites during cardiac surgery (three patients). All patients had normal left ventricular function and ECGs with concordant T waves. MAP recordings during constant sinus rhythm or right atrial pacing were analyzed for activation time (AT) = earliest QRS deflection to MAP upstroke, action potential duration (APD) = MAP upstroke to 90% repolarization, and repolarization time (RT) = AT plus APD. AT and APD varied by 32 and 64 msec, respectively, over the left ventricular endocardium and by 55 and 73 msec, respectively, over the left ventricular epicardium. On a regional basis, the diaphragmatic and apicoseptal endocardium had the shortest AT and the longest APD, and the anteroapical and posterolateral endocardium had the longest AT and the shortest APD (p less than .05 to less than .0001). RT was less heterogeneous than APD, and no significant transventricular gradients of RT were found. In percent of the simultaneously recorded QT interval, epicardial RT ranged from 70.8 to 87.4 (mean 80.7 +/- 3.9) and endocardial RT ranged from 80 to 97.8 (mean 87.1 +/- 4.4) (p less than .001).(ABSTRACT TRUNCATED AT 250 WORDS)

Action Potentials↗
PubMed1987

[Change in the diameter of the coronary vessels following sublingual or intravenous nifedipine administration correlated with the plasma level].

UNLABELLED: The diameter changes of angiographically normal epicardial coronary arteries were studied in 25 patients in correlation to nifedipine plasma levels. In group 1 (15 patients) 20 mg of s.l. nifedipine were administered. Measurements of the coronary lumen size (automated contour detection system, accuracy 0.12 mm) and detection of plasma levels (gas-chromatography) were done before and 10, 20 and 30 min after drug administration. According to the slope of nifedipine plasma levels, patients were divided into group 1 A (n = 4) and 1 B (n = 11). Plasma levels in both groups were: at 10 min, 27.8 +/- 9.8 and 13.5 +/- 4.5 ng/ml resp.; P less than 0.05; at 20 min, 54.0 +/- 11.7 and 21.7 +/- 6.6 ng/ml resp.; P less than 0.001; at 30 min, 79.1 +/- 9.3 and 28 +/- 9.8 ng/ml resp.; P less than 0.001. The corresponding diameter changes in A and B were: 7.3 +/- 5.1%/.-5.6 +/- 9.0% resp.; P less than 0.01; 11.4 +/- 4.1% and -4.5 +/- 11.3% resp.; P less than 0.01; 14.5 +/- 5.9% and 0.5 +/- 13.6% resp.; P less than 0.05. In group 2 (10 patients) 1 mg nifedipine was administered intravenously within 4 min. Measurements were done at 1 min intervals during infusion as well as 7 and 15 min after beginning and compared to a placebo group (n = 10). Peak plasma levels amounted to 16.7 +/- 5.7 ng/ml after 7 min. The maximum coronary dilation was reached after 4 min (verum 5.0 +/- 6.8%; placebo 3.2 +/- 3.6%). Significant differences between both groups were observed after 7 min (verum 4.1 +/- 5.3%; placebo -3.1 +/- 5.8%, P less than 0.05) and 15 min (verum 1.2 +/- 3.2%; placebo -6.2 +/- 8.4%; P less than 0.05). CONCLUSION: based on significantly different plasma levels following sublingual application of 20 mg nifedipine a classification of patients into "early-" and "late-coronary-responders" could be established. After intravenous infusion of 1 mg nifedipine peak plasma levels were much lower than after sublingual application of 20 mg and coronary diameters showed only a mild increase.

Administration, Oral↗
PubMed1984

[Calcium antagonists in the treatment of coronary heart disease].

In the treatment of coronary heart disease calcium antagonists unfold a whole spectrum of effects, which favorably influence the clinical picture; dilation of the peripheral vessels, of the coronary arteries and of the particularly eccentric stenoses of the coronary vessels. The myocardial protection and an inhibition of the thrombocyte aggregation in the predamaged vessel area are also discussed as favorable effects of the calcium antagonists. It seems that the prevention of coronary spasms is especially important for patients, who have an angina at rest.

Angina Pectoris↗