Biomedical subjects

F Mannting

Publications and source records attributed to F Mannting.

27 records · Page 2Linked to original sources

PubMed1991

Mucociliary transport with and without the use of a heat and moisture exchanger. An animal study.

The importance to mucociliary transport (MCT) and the condition of the mucus of using a heat and moisture exchanger (HME) was investigated. A high tracheotomy was performed on 10 young pigs. The animals were ventilated using a non-breathing system. In five animals an HME was used; the other five were connected directly to the ventilator circuit. After 6 h the trachea was inspected via a flexible bronchoscope. Mucociliary transport velocity was measured using Tc-99-marked macrospheres and a gamma camera. In the control group the tracheal mucus membrane was desiccated at half the distance from the tube tip to the bifurcation. In the HME group the entire trachea was well moistened, but two cases showed large amounts of abnormally thin and foamy secretion. Mucus quality differed significantly between the two groups. Maximum MCT velocities were 8.3 +/- 4.6 and 4.9 +/- 3.0 mm/min for the HME- and the control groups, respectively. The marker had moved 49 +/- 32 and 35 +/- 21 mm during 24 min. Neither of these differences was statistically significant. In the control group there was no transport over desiccated areas. We conclude: 1) the quality of tracheal secretion differed significantly between the two groups, and 2) a heat and moisture exchanger may retain too much water in the airway.

Animals↗

PubMed1991

Revascularization of infarcted vs. viable myocardium. Effects on symptoms, physical performance and global/regional left ventricular function.

Symptoms, physical performance and global vs. regional left ventricular (LV) function were reviewed in 25 patients with postinfarction anterior-apical akinesia and minor dyskinesia who subsequently underwent revascularization of all graftable stenotic vessels. The observed postoperative improvement in functional NYHA capacity and physical performance was not related to significant change in any systolic or diastolic variable of global LV function. 'Nonspecific postoperative septal hypokinesia' developed in most cases. The regional ejection fraction showed slight (nonsignificant) mean increase in the infarcted apex and low anterior wall supplied by the left anterior descending artery, but marked increase in the noninfarcted lateral wall supplied by the left circumflex branch. Hearts with grafted left circumflex artery showed on average lower preoperative and postoperative ejection fraction in the lateral wall than did hearts without such grafting, but the rise in regional ejection fraction was significant only after left circumflex grafting. The clinical response to coronary artery surgery is attributed mainly to functional improvement of non-infarcted myocardium. Revascularization of viable myocardium occurs directly via bypass grafts, but collateral vessels may also contribute.

Adult↗

PubMed1991

Revascularization of infarcted myocardium. Effect on myocardial perfusion assessed with quantified Tl-201 SPECT technique.

Myocardial perfusion was studied in 21 patients before and after revascularization of all graftable stenotic vessels following post-infarction anteroapical akinesia and minor dyskinesia. At preoperative and late postoperative evaluation, perfusion abnormalities in identified sectors were quantified with two methods, one (Q1) assessing the extent and the other (Q3) the severity of abnormal perfusion. The preoperative scores with both methods indicated permanent myocardial perfusion defects in all 21 patients and reversible defects, indicating myocardial ischemia, in 16 with Q1 and 14 with Q3. After bypass grafting there was overall reduction of myocardial perfusion defect and of abnormality scores: Notably, 13/21 patients (62%) had decreased permanent myocardial defect score, reflecting reactivation of 'hibernating myocardium'. The findings indicated that obstructed but graftable vessels supplying myocardium with loss of contractile function should be bypassed, since flow contribution to distant, viable myocardium is probable via preserved collateral circulation. This should be particularly relevant for the LAD, because of that artery's septal branches.

Adult↗

PubMed1990

A new method for quantification of pulmonary thallium uptake in myocardial SPECT studies.

Quantified pulmonary thallium 201 (Tl) uptake was assessed in 32 normal subjects and 66 patients with suspected coronary artery disease (CAD) by a new method utilizing SPECT acquisition data. In 26 subjects pulmonary uptake was assessed with both SPECT and planar techniques. Pulmonary/myocardial (PM) ratios for the whole right lung (PM1) and for the upper left lung (PM2) were computed and compared with stress test, coronary angiography, radionuclide angiography (ERNA), and quantified Tl single photon emission computed tomography (SPECT) results. Excellent correlation between pulmonary uptake assessed by planar and SPECT technique was disclosed (r = 0.92). The PM ratios (PM1/PM2) sensitivity and specificity in patients with CAD were 88%/92% and 60%/70%, for predicting perfusion abnormalities 90%/87% and 88%/88%, and an inverse correlation to left ventricular ejection fraction (LVEF) was found (r = -0.40/r = -0.37, P less than 0.01). Significant correlations to coronary angiography findings (r = 0.54/r = 0.49, P less than 0.001) and to number of vessel territories with abnormal perfusion (r = 0.70/r = 0.69, P less than 0.001) were seen. Thus, pulmonary Tl uptake can be assessed in SPECT studies. The new method's discriminative ability seems higher than that of the standard planar techniques currently employed. Positive correlations to coronary angiography findings and even stronger ones to perfusion abnormalities were observed.

Adult↗

PubMed1990

Spatial distribution and temporal changes of pulmonary thallium uptake in myocardial perfusion studies.

Spatial distribution and temporal changes in pulmonary thallium uptake were assessed in 24 normal subjects and 35 patients with coronary artery disease (CAD). In studies carried out directly after stress and 3 h later, pulmonary Tl uptake was assessed as body surface area corrected absolute pulmonary uptake in the upper, middle and lower right lung regions, and in the total right lung and upper left lung. Pulmonary/myocardial (PM) uptake ratios for these 5 regions were calculated as mean pulmonary/mean background-corrected myocardial uptake. Additionally, wash-out was assessed for each region and for the myocardium. In normal subjects, the initial pulmonary Tl uptake, the PM ratios and Tl wash-out were greater in the lower lung regions than in the upper. In the late studies, no significant differences in Tl content or PM ratios were found among the regions. In patients with CAD, initial pulmonary Tl uptake and PM ratios were greater in the lower than in the upper regions, and higher than for the normal subjects in all pulmonary regions (P less than 0.001). Tl wash-out was significantly higher in the low and middle regions versus the upper region (P less than 0.001) and higher in all regions than in normal subjects (P less than 0.001). In the late studies no significant differences in Tl content or PM ratios were found between any pulmonary regions. Pulmonary Tl content was, in all regions, higher in CAD than in normal subjects (P less than 0.01), as were the PM ratios (P less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary Disease↗

PubMed1990

Pulmonary thallium uptake: correlation with systolic and diastolic left ventricular function at rest and during exercise.

Quantified pulmonary 201-thallium uptake, assessed as pulmonary/myocardial ratios (PM) and body surface area-corrected absolute pulmonary uptake (Pc), was determined from single photon emission computed tomography studies in 22 normal subjects and 46 consecutive patients with coronary artery disease (CAD). By means of equilibrium radionuclide angiography (ERNA), ejection fraction (EF), peak ejection rate (PER) in end-diastolic volume (EDV/sec) and peak filling rate (PFR) in EDV/sec and stroke volume (SV/sec) units, PFR/PER ratio, and time to peak filling rate (TPFR) in milliseconds were computed at rest and during exercise (n = 35). Left ventricular response to exercise was assessed as delta EF, relative delta EF, delta EDV, and delta ESV. In normal subjects the PM ratios showed significant inverse correlation with PER at rest and with EF, PER, and PFRedv during exercise. For the left ventricular response to exercise, delta ESV showed significant correlation with the PM ratios. The body surface area-corrected pulmonary uptake values showed no correlation with any of the variables. In patients with CAD the PM ratios and Pc uptake showed significant inverse correlation with EF, PER, PFRedv and to exercise EF, exercise PER, and exercise PFRedv. For the left ventricular response to exercise, delta EF showed significant inverse correlation with the PM ratios but not with the Pc uptake. Neither in normal subjects nor in patients with CAD did any of the independent diastolic variables show significant correlation with the PM ratios or Pc values. Thus pulmonary thallium uptake is correlated with systolic left ventricular function at rest and during exercise in normal subjects and in patients with CAD but not with diastolic function. In normal subjects delta ESV and in patients with CAD, delta EF showed correlation with pulmonary thallium uptake.

Adult↗

PubMed1989

Cold-induced reversible myocardial ischaemia in systemic sclerosis.

The effect of cold provocation on myocardial perfusion was studied in 21 patients with systemic sclerosis and 8 healthy controls. The cold provocation was designed not to cause a pain reaction, and no rise in heart rate/blood pressure product occurred during provocation. Myocardial perfusion was assessed by measurement of thallium uptake by imaged single photon emission computed tomography. No patient had clinical evidence of cardiac involvement, but abnormal electrocardiographic (ECG) findings were found in 5. In 12 patients cold-induced reversible perfusion defects were found; 9 of these also had permanent defects. A further 3 patients had permanent perfusion defects but no reversible defects. The permanent and/or reversible perfusion defects were not related to age among the patients and were not seen in any of the healthy controls, whose age distribution was similar. The reversible and permanent defects were not related to other features of systemic sclerosis, nor to the ECG findings. It is concluded that abnormalities in myocardial perfusion are common in systemic sclerosis and may be present without apparent clinical myocardial involvement. A cold-induced vasopastic process in the myocardial circulation might contribute to the development of the patchy myocardial fibrosis seen in patients with systemic sclerosis.

Adult↗

PubMed1984

Does iron deficiency in treated polycythemia vera affect whole blood viscosity?

The relation between whole blood viscosity and iron status was studied in 11 patients with polycythemia vera (PV) who were treated with venesection without iron supplementation. Six were already iron deficient at the start of the study, five were followed from normal iron status to deficiency. Iron status was investigated with serum ferritin, erythrocyte protoporphyrin, mean cell volume and mean cell hemoglobin. There was no correlation between whole blood viscosity at a fixed erythrocyte volume fraction of 44% and any of these variables. The mean whole blood viscosity during iron deficiency and during normal iron state did not differ. Even after several months of iron deficiency there was no increase in whole blood viscosity. It is concluded that iron deficiency in treated PV does not give increased whole blood viscosity.

Anemia, Hypochromic↗

PubMedDate not supplied

Pre- and postoperative CT and MR in pseudoaneurysms of the heart.

Pseudoaneurysms of the heart have a propensity to rupture and surgery is indicated. Usually in these cases diagnostic imaging is based on angiographic and/or echocardiographic studies. We have attempted to determine in pre- and postoperative studies the value of CT and ECG-gated MRI in patients with pseudoaneurysm. Seven patients with a pseudoaneurysm and/or dyskinesia of the posterolateral or diaphragmatic wall of the left ventricle were investigated with CT and/or ECG-gated MR studies, in addition to angiography, echocardiography, and radionuclide studies, prior to cardiac surgery. Postoperative follow-up studies with CT in six and MR in five patients were also carried out. Both CT and ECG-gated MRI allowed us to visualize the neck and CT also confirmed the communication between the cavities with or without demonstrating the conduit. In addition, disruption of the epicardial fat layer by the pseudoaneurysm was seen on both CT and MR, and the presence of intrapericardial adhesions was visualized on MR. Finally, CT and MRI, in postoperative follow-up studies, may indicate a myocardial discontinuity adjacent to the surgical patch.

Aged↗