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Biomedical subjects

A C Otto

Publications and source records attributed to A C Otto.

At least 37 records · Page 2Linked to original sources
PubMed1988

Investigation into the effect of Fenoterol on mucociliary clearance in patients with chronic bronchitis.

We investigated the effect of Fenoterol, a selective beta 2 adrenoceptor stimulant, on mucociliary clearance in 12 patients with chronic bronchitis. Mucociliary clearance was measured with a scintillation camera after inhalation of a 99mTc labelled aerosol. Fenoterol was administered one h after acquisition commenced and imaging was maintained for a further two h. Three regions of interest (ROI) were selected over each lung to generate time activity curves. Corrections for decay, alveolar deposition (using 24 h image), cough and movement of activity through each ROI were carried out. An exponential function was fitted to the clearance curves to determine clearance rates. The increase in percentage clearance after Fenoterol administration for the left and right whole lung ROI was 35% and 36% per h respectively (P = 0.006 and 0.020). Fenoterol enhances cilial clearance in chronic bronchitis patients.

Adult↗
PubMed1988

The effects of nisoldipine on left ventricular filling rate in patients with ischemic heart disease measured with radionuclide gated blood pool scintigraphy.

Nisoldipine is a newly developed calcium channel blocker with outstanding vasodilatory properties especially with regard to the coronary arteries. Thus it may find wide-spread application as a therapeutic agent in various ischemic heart disease syndromes. The purpose of this study was to evaluate the effect of nisoldipine on the diastolic function of the left ventricle (LV) in the clinical situation. A patient group on nisoldipine treatment was compared to a control group. In the nisoldipine group a maximum decrease of 17 mmHg in the mean systolic blood pressure with an increase in the mean peak ejection rate (0.78 EDV/s) and peak filling rate (0.52 EDV/s) were observed. Mean LV ejection fraction increased by 6.4% and the time to peak filling rate decreased by 36.5 ms. After eight weeks of treatment the acute effects of nisoldipine were similar to the previous study. Nisoldipine therefore tends to improve both the diastolic and systolic function of the left ventricle.

Adult↗
PubMed1987

Absolute left ventricular volume changes after sublingual nitroglycerine and nifedipine intervention.

The haemodynamic effects of two vasodilators, sublingual nitroglycerine and nifedipine, on absolute end-diastolic volume, end-systolic volume, stroke volume (SV), heart rate, systolic blood pressure (SBP), cardiac output (CO) and corresponding cardiac indices were measured in two different groups, each consisting of 20 ischaemic heart disease patients, with gated blood pool scintigraphy. A control study was done in 5 ischaemic heart disease patients without intervention. Direct measurement of left ventricular (LV) volume was done by correcting LV activity for tissue attenuation utilising a geometric method. With nifedipine intervention only SBP (125.25 +/- 19.8 mmHg) showed a significant mean decrease (11 mmHg). The other measured parameters did not change significantly. With nitroglycerine all the parameters except LV ejection fraction showed significant changes. Mean CO decreased by 8% while mean SV decreased by 16%. The results in the control group showed excellent repeatability. The absolute haemodynamic changes of future cardiac drugs might easily be measured in vivo by this non-invasive technique.

Administration, Oral↗
PubMed1987

A comparison of the acute hemodynamic effects of nifedipine and nisoldipine in patients with ischemic reduced left ventricular function.

Nisoldipine (BAY k 5552) like nifedipine, is a dihidropyridine compound with strong calcium blocking activity. The purpose of this study was to measure and compare the absolute hemodynamic effects of these two drugs before and at 30 min, 60 min and 120 min after oral intake in 20 ischemic heart disease patients with radionuclide gated cardiac scintigraphy. No significant change was seen in end diastolic volume index with either of the drugs. With nifedipine the stroke volume index (SVI) increased significantly from the basal value at 30 min (P = 0.004) and 60 min (P = 0.034) yet not significantly at 120 min. The same trend was seen in left ventricular ejection fraction (LVEF) with significant increases at 30 min (P = 0.02) and 60 min (P = 0.025) yet not at 120 min. The cardiac index increased significantly at 30 min (P = 0.001), 60 min (P = 0.002) and 120 min (P = 0.025) but the latter value was significantly lower than the 30 min value indicating the maximal effect had already passed. With nisoldipine the SVI increased significantly at 60 min (P = 0.004) and 120 min (P = 0.001) but not at 30 min. These changes were again reflected by a significant increase in LVEF at 60 min (P = 0.021) and 120 min (P = 0.002) without significant increase at 30 min. The increase in CI was highly significant at 60 min (P = 0.003) and 120 min (P = 0.001) without significant change at 30 min. Nisoldipine proved to be a potent calcium antagonist with slower onset and longer duration of action than nifedipine.

Aged↗
PubMed1986

Radionuclide evaluation of left ventricular function in a distantly located intensive coronary care unit.

Regular evaluation of left ventricular (LV) function is important in assessing patients in an intensive coronary care unit (ICCU). An adapted first-transit (FT) technique was applied to 21 patients for calculation of LV ejection fraction (LVEF). In this method the radionuclide is administered directly into the right pulmonary artery through a Swan-Ganz catheter. High-quality LV images are obtained because of minimal activity in the right ventricle and left lung. Data were acquired on a distantly located on-line computer system to restrict equipment in the ICCU. LVEF from FT compared well with LVEF from gated blood pool studies (r = 0.91) but gave consistently lower values. The adapted FT method ensures improved counting statistics during LVEF determination and facilitates evaluation of LV wall motion in the ICCU patient.

Adult↗
PubMed1986

Radionuclide cholescintigraphic imaging: an evaluation of several 99mTc labelled hepatobiliary radiopharmaceuticals.

Recently, much interest has been shown in the development of 99mTc labelled cholescintigraphic agents for imaging the hepatobiliary tract. In this study six cholescintigraphic agents were compared in rabbits with respect to transit efficiency through the liver and the halftime on the washout portion of the liver time-activity curve. The agents compared were p-butyl-IDA (PBIDA), diisopropyl-IDA (DISIDA), two mebrofenin (MBF) agents and two pyridoxylaminates (PDA). Best transit efficiencies were obtained with MBF (34.1 and 31.2%) followed by PDA (27.7 and 24.9%) while DISIDA (23%) and PBIDA (19.3%) were the lowest. The same phenomenon was observed regarding the washout halftime, with MBF the most rapid (6.3 and 5.9 min), PDA more prolonged (10.1 and 12.0 min) and DISIDA and PBIDA the slowest (23.0 and 23.2 min). This study confirms the difference in physiological behaviour of the various cholescintigraphic agents and shows identical flow patterns for locally produced and imported compounds.

Aniline Compounds↗
PubMed1986

Radionuclide determination of absolute LV volumes: interstudy, interobserver and intraobserver variances.

The results of 22 absolute left ventricular volume (LVV) determinations by a radionuclide (RN) method are compared to the results obtained by contrast ventriculography (CV). Another 10 patients were analysed in order to evaluate the interstudy, interobserver and intraobserver variances. Good correlation was shown between the RN and CV measurements of the end diastolic volume (EDV), end systolic volume (ESV), stroke volume (SV) and ejection fraction (EF), but the RN method overestimates the EDV and ESV. The EF was underestimated, but no difference could be shown for the SV. On the inter- and intraobserver levels, regression analysis yielded excellent correlation (r greater than 0.99 in all cases) with no statistically significant difference (P less than 0.05). The interstudy variance was minimal as indicated by regression analysis (r greater than 0.87) and no statistically significant difference (P less than 0.05) could be shown between studies. The results indicate that the RN method of LVV determination can be used in intervention studies over a limited period.

Adult↗
PubMed1986

Left ventricular function evaluation using radionuclide methods in the intensive coronary care unit.

We describe an adapted first-transit (FT) technique to perform left ventricular ejection fraction (LVEF) measurements on patients with Swan-Ganz catheters in the intensive cardiac care unit (ICCU). The radionuclide is introduced directly into the right pulmonary artery through the catheter. High-quality images of the left ventricle are obtained owing to minimal activity in the right ventricle and left lung. LVEF measurements obtained by FT compared well with measurements obtained from gated blood pool studies (r = 0.91) but gave consistently lower values. The adapted FT method improves LVEF determination and left-ventricular wall motion evaluation in the ICCU patient.

Cardiac Catheterization↗
PubMed1985

Lysis of a coronary embolus by intracoronary streptokinase. A case report.

A patient presenting with an acute myocardial infarction, probably caused by a coronary artery embolus after aortic valve replacement, was treated by intracoronary thrombolysis with streptokinase. Restoration of antegrade flow in the previously totally occluded vessel was followed by an uncomplicated recovery and evidence of good preservation of left ventricular function.

Adult↗
PubMed1985

Evaluation of (o)-[77Br]bromohippuran as renal tubular function agent.

(o)-[77Br]bromohippuran (BHIP) was developed as renal tubular function agent due to its favourable chemical and physical properties and compared to (o)-[131I]iodohippuran (IHIP). Renograms obtained from baboons were compared and absorbed radiation dose calculations performed. Although BHIP showed a delayed kidney uptake and washout pattern, good kidney clearance of the radionuclide was obtained after 30 min. Radiation dose values for BHIP were markedly lower than for IHIP indicating that larger activities of BHIP could be administered to increase counting statistics. BHIP imaging in normal volunteers did however not substantiate the favourable behaviour obtained in the primate.

Animals↗
PubMed1985

Persistent left superior vena cava detected with radionuclide angiocardiography.

A 28-year-old man presented with paresthesias, fatigue, central cyanosis, and erythrocytosis. A first pass flow study with Tc-99m as free pertechnetate was done, among other tests, to exclude a central shunt when a persistent left superior vena cava was incidentally detected. The value of radionuclide angiocardiography to examine the central circulation noninvasively was again illustrated in this case.

Adult↗
PubMed1984

Thrombolysis by intracoronary streptokinase infusion in patients with acute ischaemic syndromes.

Intracoronary streptokinase was administered to 40 patients with acute myocardial ischaemic syndromes in an effort to restore antegrade flow in the affected vessel by thrombolysis. This was successful, with total occlusion of the vessel, in 66% of cases. Restoration of antegrade flow by the intracoronary administration of nitroglycerin was successful in only 1 case (2%). Subsequent study showed that re-occlusion of an initially patent vessel had occurred in 43% of cases and that recanalization had occurred in 62% of cases in which the vessel had initially remained occluded. Complications comprised reperfusion arrhythmias (55%), serious haemorrhage (8%) and reinfarction (8%). Intracoronary thrombolysis with restoration of antegrade flow was safely achieved in the majority of cases.

Adult↗
PubMed1983

Variation in left ventricular ejection fraction determination at rest and during exercise.

The results of multi-gated blood pool imaging (MBPI) for determination of left ventricular ejection fraction (LVEF) in 48 patients at rest and during exercise were analysed in order to evaluate observer variance and interstudy variance. Twenty-three MBPI studies carried out with the patient at rest and 37 studies carried out during graded ergometer exercise were analysed by two independent observers in order to determine intra- and inter-observer variance. On the intra-observer level regression analysis yielded excellent correlation between rest and exercise studies (r = 0,998 at rest, r = 0,964 during exercise), and showed no statistically significant difference (P less than 0,01); this was also true of the inter-observer measurements (r = 0,999 at rest, r = 0,988 during exercise). In order to evaluate interstudy variance, MBPI was repeated in 15 patients at rest. Interstudy variation of the LVEF was minimal as indicated by regression analysis (r = 0,98), and showed no statistically significant difference (P less than 0,01). During the repeat study a mean increase in the LVEF of 2,1% was obtained, but this difference was not statistically significant.

Adolescent↗
PubMed1983

Determination of right ventricular ejection fraction utilising a radionuclide washout technique.

A radionuclide washout technique (WO), for calculation of the right ventricular ejection fraction (RVEF) which is independent of the exact position of the right ventricular region of interest was evaluated and results compared with first pass (FP) and equilibrium gated blood pool (GBP) values. Regression analysis between RVEF values of 24 patients obtained from FP and WO yielded a correlation coefficient (r) of 0.89, while a slightly poorer correlation coefficient was obtained when FP and GBP were compared (r = 0.79) and between WO and GBP (r = 0.71). No significant difference between RVEF values calculated from the three techniques was found (P less than 0.05) on inter- and intraobserver level. The radionuclide washout technique yields an accurate determination of RVEF without the necessity of outlining the RV accurately.

Adult↗
PubMed1981

[Radionuclide exercise gated studies in female patients with positive exercise electrocardiogram].

Radionuclide left ventricular ejection fraction (LVEF) has been determined in a group of 14 female patients at rest and during graded supine bicycle exercise. One group consisted of 9 patients complaining of chest pain and demonstrating positive exercise electrocardiography (EECG), but with normal contrast angiographic results. The second group of 5 patients had a normal response to EECG and was used as a control group. LVEF increased markedly in both groups during exercise. This study confirms the known fact of high false-positive EECG in female patients and that exercise radionuclide LVEF response can be used as a final screening test for cardiac catheterization in female patients demonstrating positive EECG.

Adult↗
PubMed1977

Unreliable drug histories, analgesics, and changes in renal function.

One hundred and nine outpatients were questioned on their use of analgesics and asked to provide urine and blood samples. Forty-one per cent said they used analgesics daily and 54% said they had ingested analgesics during the 3 days before questioning. The analgesics used were mainly aspirin or paracetamol, alone or in combination. Five (42%) of the patients who denied the use of analgesics, and 10 (29%) of those who denied intake during the preceding week, had detectable amounts of paracetamol or aspirin in their urine. Mean serum urea, although still within the normal range, increased with increasing use of analgesics. The mean serum urea of patients who used aspirin and paracetamol in combination was significantly higher than that of those who used either of the drugs alone. The findings suggest that one should not rely heavily on the history of analgesic use, and that by replacing phenacetin with paracetamol one might not have achieved much as far as renal function is concerned.

Acetaminophen↗
PubMed1976

[Cycling, fitness and the prevention of ischemic heart disease].

A short review of the prevalence of ischaemic heart disease in South African Whites is given, and primary prevention, which entails an alteration in life style, is emphasised. The role of increased physical activity in primary prevention is discussed. Any programme to increase the fitness status of a population based on activities that must be performed outside the daily routine, willhave limited impact. The possible role of cycling is discussed and it is shown that ordinary cycling to work probably causes sufficient stimulation of the cardiovascular system to produce an acceptable standard of physical fitness.

Activities of Daily Living↗