Search PubMed⌕ Search

Biomedical subjects

A Gassner

Publications and source records attributed to A Gassner.

At least 19 recordsLinked to original sources

Correlation of atrial natriuretic peptide and cyclic guanosine monophosphate plasma concentrations in patients with heart disorders during rest and exercise.

The concentration of atrial natriuretic peptide was measured in order to evaluate its importance in patients suffering from a variety of cardiac diseases. There was a correlation between plasma concentrations of atrial natriuretic peptide and its "second messenger" cyclic guanosine monophosphate (cGMP) in all of the cases examined. We investigated the relationship between atrial natriuretic peptide and cGMP plasma concentrations during rest and exercise in comparison with the scintigraphically assessed left- and right-ventricular ejection fraction in patients with chronic heart disease (n = 20), and after orthotopic heart transplantation (n = 16); plasma concentrations were also measured in healthy controls (n = 14). Atrial natriuretic peptide and cGMP concentrations showed a similar correlation during rest and exercise with r = 0.74 and r = 0.81, respectively. With the exception of patients after heart transplantation, a significant negative correlation was seen between the left ventricular ejection fraction and atrial natriuretic peptide or cGMP plasma concentrations during rest conditions (r = 0.76 or 0.58, respectively). No correlation was apparent between plasma concentrations of atrial natriuretic peptide or cGMP and the left- or right ventricular ejection fraction during exercise. The concentrations of atrial natriuretic peptide and cGMP in plasma differed significantly between healthy controls and patients during rest and exercise. It is noteworthy that atrial natriuretic peptide and cGMP concentrations were markedly higher in patients after heart transplantation than in patients suffering from chronic heart disease. Our results indicate that plasma atrial natriuretic peptide and cGMP concentrations are sensitive markers of cardiac impairment.

Atrial Natriuretic Factor↗

Lack of negative inotropic effects of the new calcium antagonist Ro 40-5967 in patients with stable angina pectoris.

We screened the antiischemic, hemodynamic, and inotropic effects of different dosages of the new calcium channel blocker Ro 40-5967 in 65 patients with stable effort-induced angina pectoris. In a double-blind way, patients were randomized to recieve a single oral dose of 50, 100, or 200 mg Ro 40-5967 or placebo, given as a drinking solution. Left ventricular ejection fraction (LVEF), blood pressure (BP), and heart rate (HR) were measured at rest and during a supine bicycle exercise test on day 0 (baseline) and 2 h after drug intake on day 1. Twenty-four hours later, the bicycle exercise test was repeated. Ro 40-5967 improved exercise duration and resting LVEF. After 200 mg, exercise time increased significantly from 8.4 +/- 0.8 min (mean +/- SEM) to 9.6 +/- 0.7 min (p = 0.018), and LVEF at rest increased from 54.5 +/- 2.2 to 58.1 +/- 2.6% (p = 0.045). Time to 0.1 mV ST-segment depression increased significantly from 4.3 +/- 0.8 to 5.5 +/- 0.9 min in the 100-mg group (p = 0.013) and from 4.3 +/- 1.3 to 5.4 +/- 1.5 min in the 200-mg group (p = 0.027). Maximum ST-segment depression decreased significantly at all dose levels (p = 0.01), with the maximum decrease noted in the 200-mg group (from 0.21 +/- 0.03 to 0.15 +/- 0.02 mV, p = 0.004). BP, HR, and rate-pressure product did not change significantly at rest or at maximum exercise. A single dose of Ro 40-5967 has antiischemic properties in patients with stable angina pectoris, with maximum effects obtained after 200 mg. No signs of negative inotropy were noted, and the drug was well tolerated.

Adult↗

Differential therapy with calcium antagonists in pulmonary hypertension secondary to COPD. Hemodynamic effects of nifedipine, diltiazem, and verapamil.

In 53 patients with COPD and precapillary pulmonary hypertension, we investigated the effect of three typical calcium antagonists on hemodynamics at rest and during bicycle ergometer exercise. In the responders, the decrease in pulmonary vascular resistance following nifedipine was 23 percent at rest (p less than 0.0005) and 35 percent during exercise (p less than 0.0005); following diltiazem, it was 10 percent at rest (p less than 0.05) and 23 percent during exercise (p less than 0.025); following verapamil, it was 22 percent at rest (p less than 0.005) and 11 percent during exercise (p less than 0.025). The cardiac index rose significantly at rest and under exercise only after the administration of nifedipine (+16 percent and +8 percent, resp). Nifedipine caused the most distinctive peripheral vasodilation. The heart rate increased slightly following nifedipine and decreased slightly following diltiazem and verapamil. After long-term therapy with nifedipine (13 +/- 5 months), the decrease in pulmonary artery pressure and pulmonary vascular resistance was no longer significant. In our opinion, the different hemodynamic action profiles will have consequences for the differential therapy in patients with COPD and pulmonary hypertension.

Calcium Channel Blockers↗

Correlation between heart disorders and concentrations of directly measured atrial natriuretic peptide in plasma.

We used new commercially available direct radioimmunoassay to measure human atrial natriuretic peptide (h-ANP) in plasma from 48 individuals who were being evaluated for left and right ventricular function. For 13 healthy individuals with normal ventricular function these concentrations ranged up to 54 ng/L. Measurements of h-ANP clearly differentiated between normal subjects, patients with coronary artery disease, and patients who had undergone orthotopic heart transplantation (ANOVA P less than 0.0001, significant differences between all groups)--all showing normal ventricular function at rest. There was a strong negative correlation (r = -0.64, P less than 0.001) between left ventricular ejection fraction and h-ANP concentrations in plasma of patients with proven coronary artery disease, patients with cardiomyopathy, and healthy individuals. Results by the present method and methods involving extraction of the sample correlated well. Evidently the direct assay of h-ANP in plasma yields information that could be used to help evaluate heart disorders and other pathophysiological conditions causing increased h-ANP concentrations in plasma.

Adult↗

Prognostic value of supine scintigraphic heart function and simultaneous conventional exercise response in patients after myocardial infarction.

A total of 240 survivors of one or more myocardial infarctions were consecutively admitted to perform supine exercise radionuclide ventriculography. Within 3 years after the test, 22 died; this group was compared to an age-matched control group of 22 survivors for left and right ventricular function during rest, exercise, and simultaneously assessed exercise performance as well as ECG variables. Evaluation of 3-year survival by linear discriminant analysis revealed an accuracy of 82% for discriminant models using ECG and exercise performance variables. Implementation of resting left ventricular ejection fraction and change of right ventricular ejection fraction during exercise, as well as scintigraphic presence or absence of dyskinesia, improved the accuracy of the model to 91% of correctly classified patients.

Adult↗

Radionuclide detection of mild valvular regurgitation: its significance as assessed by Doppler sonography.

Radionuclide ventriculography (RNV) indices of regurgitation, Fourier amplitude ratio (FAR) and additional RNV variables were prospectively compared to Doppler echocardiography (DE) in 108 consecutive patients with no or mild left ventricular regurgitation, to assess RNV accuracy in detecting regurgitation in patients with different cardiac disorders. Exclusion of left ventricular or tricuspid regurgitation allowed investigation of the FAR range at rest and during exercise in a sufficiently large appropriate reference group without regurgitation. FAR, as well as other RNV variables, failed to provide more information for the diagnosis of mild (clinically irrelevant) left ventricular regurgitation than the diagnosis upon admission alone. Despite the superiority of DE as a gold standard in the detection of mild regurgitation, at present evaluation of RNV regurgitation indices might be the only method to discover regurgitation arising during dynamic exercise.

Echocardiography↗

Dynamic 123I-HDA myocardial scintigraphy after aortocoronary bypass grafting.

In an attempt to evaluate the dynamics of fatty acid metabolism after aortocoronary bypass grafting (ACBG), ten patients were investigated after ACBG by 123I-HDA myocardial scintigraphy. Tracer kinetics were followed for 90 min and compared to those of 36 nongrafted patients with different underlying heart diseases, including healthy volunteers. Regional analysis and monoexponential curve fitting were used to evaluate t1/2 (half-life of the early period of tracer elimination); biexponential curve analysis was used to calculate Ca/Cb, the ratio of a fast and a slow component of tracer elimination. Rest and stress MUGA-RNV served as discriminating parameters to discern between patient groups with normal and abnormal ventricular function. Group I (normal controls) encompassed ten patients with normal ventricular function, including three after ACBG, and group II seven patients after ACBG and with abnormal ventricular function. Group III had coronary artery disease (CAD) documented by angiography, and group IV by prior myocardial infarction (MI). Group V included patients with cardiomyopathy (CMP). Regional analysis of group II revealed no significant differences to control regions (Gr I) for t1/2 or Ca/Cb, but showed for Ca/Cb a nonsignificant shift toward group III values. However, group II differed significantly from group III and V. Three patients with normal ventricular function after ACBG showed elimination values that were all well within the range of completely normal individuals. Thus our data support the assumption that a normal function is indicative of a normal metabolism. Following myocardial fatty acid metabolism during rest might be a helpful noninvasive tool for etiologic differentiation of disturbed ventricular function.

Coronary Artery Bypass↗

[Vasodilator therapy in pulmonary hypertension and chronic obstructive lung disease (COPD). Hemodynamic studies exemplified by nifedipine and nitroglycerin].

In 41 patients with chronic obstructive pulmonary disease (COPD) and pulmonary hypertension, the effects of sublingual administration of 20 mg nifedipine and 0.8 mg nitroglycerin on the hemodynamics were assessed at rest and during bicycle ergometry. Additionally, in six patients, the effects of nifedipine during longterm treatment were analyzed. On acute testing, at rest and during exercise nifedipine led to decreases in mean pulmonary artery pressure of 16% and 23% and pulmonary arteriolar resistance of 23 and 35%, respectively, in 81% (17/21) of the patients. The reduction in the pulmonary vascular resistance was greater than that of the systemic resistance. In all patients, cardiac output increased. There was a similar number of responders to nitroglycerin (16/20). The reductions in mean pulmonary artery pressure and pulmonary arteriolar resistance ranging between 20 and 25% at rest and during exercise were comparable to those affected by nifedipine. In addition to the right ventricular afterload reduction, there was a decrease in cardiac output of 17%. During longterm treatment with nifedipine (average 18 months), the reduction in mean pulmonary artery pressure and pulmonary arteriolar resistance was not of the same magnitude as seen on acute testing. This may be due primarily to progression of the underlying disease since pulmonary function studies demonstrated an increase in the obstructive component. With the intention of circumventing or postponing the onset of right ventricular failure, the individual patient should undergo hemodynamic studies to delineate the optimal medication.

Exercise Test↗

[Complete AV block in a heart catheter study using a Swan-Ganz catheter].

A case of complete heart block during right heart Swan-Ganz balloon-tipped flow-directed catheterization in a patient with intermittent left bundle branch block after aortic valve replacement is reported. After entrance into the right ventricle with the catheter tip as well as after insertion of a temporary balloon-floated pacemaker electrode symptomatic complete heart block occurred. This case demonstrates that in a patient with intermittent left bundle branch block a complete AV block may occur and therefore the possibility of cardiopulmonary resuscitation and temporary pacing has to be taken in account.

Aged↗

[Pulmonary hypertension and chronic obstructive ventilatory disorders--correlation between hemodynamic parameters and pulmonary function].

We evaluated 74 patients with pulmonary hypertension secondary to chronic obstructive pulmonary disease and compared pulmonary function tests as well as capillary blood gas values with pulmonary hemodynamic parameters. Thirty-four patients demonstrated pulmonary hypertension only at exercise, fourty patients had pulmonary hypertension at rest (mean pulmonary artery pressure greater than 20 mm Hg). There was a significant correlation between capillary oxygen tension and mean pulmonary artery pressure as well as pulmonary vascular resistance, both at rest and during exercise. The relation between capillary PCO2 and pulmonary hemodynamics were statistically less significant. The correlation between criteria of pulmonary obstruction and/or increased lung volumes and mean pulmonary artery pressure and pulmonary vascular resistance were not as significant. The 34 patients with pulmonary hypertension only at exercise differed significantly from the other groups of patients with pulmonary hypertension at rest as seen in all pulmonary function parameters. Furthermore there was also a difference in the capillary oxygen tension during exercise, but not in the capillary carbon dioxide tension. In conclusion, of all pulmonary function tests the most efficient criteria for pulmonary hypertension are reduced FEV1/VC and low oxygen tension at rest respectively a fall during exercise.

Adult↗

[Pulmonary hypertension in chronic respiratory tract obstruction: a combined study on haemodynamics and radionuclide ventriculography].

In 44 patients with chronic obstruction of the respiratory passages pulmonary artery pressures were measured by Swan-Ganz catheter and right-ventricular ejection fraction by radionuclide ventriculography (equilibrium method). Although there was no linear correlation between the haemodynamic parameters of afterload or preload of the right ventricle and global right-ventricular ejection fractions, sensitivity and specificity of radionuclide ventriculography were very good (87% and 83%, respectively) for the recognition of pulmonary hypertension during exercise tests. Global right-ventricular ejection fraction in patients without pulmonary arterial hypertension had a normal and significant rise from 52% to 58% on exercise. In the group with pulmonary hypertension mean right-ventricular ejection fraction fell during exercise from 47% to 46%. Radionuclide ventriculography in the assessment of right ventricular function, especially during exercise, provides useful pointers to the diagnosis of pulmonary hypertension due to chronic respiratory-tract obstruction.

Adult↗

Tracer elimination in I-123-heptadecanoic acid: half-life, component ratio and circumferential washout profiles in patients with cardiac disease.

Sixty patients with different cardiac diseases and healthy volunteers were given omega-I-123-heptadecanoic acid (HDA) intravenously. Tracer kinetics were followed for 90 min, and tracer elimination curves were obtained regionally. In addition, circumferential washout profiles were evaluated for 26 patients and interpolative as well as constant background subtraction was performed for comparison in selected patients. Rest and stress radionuclide ventriculography allowed formation of a group with normal ventricular function (control group); the remaining patients had an abnormal ventricular function at rest or under stress. Regions of patients in the control group were significantly different (P less than 0.005) from regions of patients with CHD or CMP with regard to the initial half-life or the component ratio between a fast and a slow component (Ca/Cb). Regions of patients after MI without exercise-induced angina did not differ strikingly from control regions. Circumferential washout analysis showed homogeneous tracer kinetics in healthy subjects, bus some individuals showed increasing regional activity, mainly by late activity uptake of the stomach. Dynamic heart scintigraphy with HDA is an additional nuclear cardiologic tool that makes possible the classification of patients with myocardial disease and abnormal ventricular function already under resting conditions. Initial half-life allows reasonable discrimination between different severely diseased patient groups; expansion of acquisition time to 90 min refines biexponential tracer analysis which, by means of an altered component ratio Ca/Cb, may allow better clinical judgement of the individual patient. Circumferential washout analysis and interpolative background correction lead to a better specificity of examination.

Adult↗

[Favorable response of pulmonary hypertension in patients with chronic obstructive airway disease treated with diltiazem].

The hemodynamic response to 20 mg diltiazem i.v. was assessed at rest and during bicycle exercise in the supine position in 32 patients with pulmonary hypertension due to chronic obstructive pulmonary disease. The mean arterial pressure decreased significantly at rest by some 8% and by 2% during exercise. The heart rate fell by some 4% at rest, but remained unchanged during exercise. The cardiac index, stroke volume index and pulmonary capillary wedge pressure did not differ significantly at rest, but during exercise the cardiac index increased by 5% and the stroke volume index by 8%; pulmonary wedge pressure was not influenced by diltiazem. The systolic pulmonary artery pressure fell significantly by some 9% at rest and by 10% on maximum exercise; mean pulmonary arterial pressure decreased significantly by some 10% both at rest and during exercise. Right atrial mean pressure rose significantly on average from 4 to 6 mm Hg, while remaining unchanged during exercise. After diltiazem the total body vascular resistance fell by 8% at rest and by 6% during exercise, while pulmonary arteriolar resistance was lowered by 13% (significant) at rest and by 11% (also significant) during exercise. Decrease in pulmonary afterload was more significant in our patients than decrease in peripheral afterload. In 6 of 32 patients there was no improvement in hemodynamic data after administration of diltiazem. These results support the inclusion of calcium channel blockers in the therapeutic regimen of pulmonary hypertension due to chronic lung disease.

Adult↗

Scintigraphic left ventricular function during exercise in elderly patients with coronary artery disease.

Left ventricular performance at rest and during supine symptom-limited exercise was determined by radionuclide ventriculography (RNV) in 65 subjects of the age of 65 years or older. Eleven subjects had no evidence of coronary artery disease (CAD) by history or submaximal stress ECG. In this control group left ventricular ejection fraction (LV-EF) increased from 0.62 +/- 0.09 (mean +/- SD) to 0.69 +/- 0.08 with a further increase in regional wall motion. There were 10 patients with a history of hypertension or atypical angina without infarction. Left ventricular ejection fraction (LVEF) at rest was 0.65 +/- 0.11 and showed no significant increase during exercise (mean exercise tolerance: 73 +/- 33W). Nineteen patients had an anterior infarction. LVEF at rest was 0.44 +/- 0.16 and as a group showed no change during exercise (mean exercise tolerance: 70 +/- 23W). Only two of 19 patients showed an increase of LVEF greater than 0.10. There were 19 patients with inferior infarction. LVEF at rest was 0.49 +/- 0.08 and showed also no significant change during exercise (mean exercise tolerance: 80 +/- 25W). Four of 19 patients showed an increase of LVEF in response to exercise. The five patients with two or more infarctions showed a markedly decreased resting LVEF of 0.28 +/- 0.11 with a further decline (0.22 +/- 0.09) during exercise (mean exercise tolerance: 45 +/- 32W). Therefore, age by itself does not significantly impair left ventricular ejection fraction at rest and during exercise. RNV appears as a valuable method in evaluating left ventricular performance of older patients with a similar response to exercise as in younger persons without or with comparable disease.

Aged↗