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Hausmann M, Behrendt-Körbitz S, Kautz H, Lamm C, Radelt F, Güntürkün O. Sex differences in oral asymmetries during wordrepetition. Neuropsychologia 1998; 36:1397-402. [PMID: 9863693 DOI: 10.1016/s0028-3932(98)00027-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
During speech production the right side of the mouth is opened to a larger degree in most people. This facial asymmetry is thought to be related to a left hemisphere dominance in language processing and/or motor programming. We investigated asymmetrical lip separations during discrete or serial word productions in right handed persons. The results revealed a right sided lip separation bias in both genders during discrete word production in which the words had to be uttered once. As soon as the words had to be produced continuously, however, a clear sex difference appeared with males having the usual right bias but females now showing no clear asymmetry, with a tendency for larger lip separations on the left side. These results suggest the existence of two separate neural systems from which one controls the discrete task and which is left hemisphere dominant in both genders. The other is probably involved in serial word productions and shows a sex difference with regard to its asymmetry pattern.
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202
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Bauer H, Lamm C, Adelbauer G, Leodolter M, Leodolter U, Guttmann G. 548 Slow potential topographic activities with stereoscopic versus monoscopic stimulus presentation. Int J Psychophysiol 1998. [DOI: 10.1016/s0167-8760(98)90547-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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203
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Vitouch O, Lamm C, Bauer H, Vanecek E. 484 Functional mapping in time and space: A SPT investigation of piano playing. Int J Psychophysiol 1998. [DOI: 10.1016/s0167-8760(98)90483-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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204
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Fitzgerald O, Lamm C, Leodolter M, Bauer H, Hartmann G. 714 Sensory evoked dc-potential changes companying anesthesia. Int J Psychophysiol 1998. [DOI: 10.1016/s0167-8760(98)90713-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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205
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Lamm C, Bauer H, Vitouch O, Gstättner R, Durec S, Gronister R. 549 Slow potential topographic activities with spatial cognition under speed and power conditions. Int J Psychophysiol 1998. [DOI: 10.1016/s0167-8760(98)90548-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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206
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Lamm C, Bauer H, Leithner D, Kastner-Koller U, Leodolter M. 658 Slow potential topographic activities accompanying reading aloud in adult dyslexic and control subjects. Int J Psychophysiol 1998. [DOI: 10.1016/s0167-8760(98)90657-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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207
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Hadimeri H, Lamm C, Nyberg G. Coronary aneurysms in patients with autosomal dominant polycystic kidney disease. J Am Soc Nephrol 1998; 9:837-41. [PMID: 9596081 DOI: 10.1681/asn.v95837] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Patients with autosomal dominant polycystic kidney disease (ADPKD) have an increased risk of intracranial aneurysms. Reports on arterial aneurysms in other locations have not been conclusive. The present study was initiated to investigate the prevalence of coronary aneurysms. Thirty ADPKD patients who had undergone coronary angiography on clinical indication were identified, 15 after renal transplantation. For each ADPKD patient, a control patient was identified with end-stage renal disease, investigated by coronary angiography, and matched for age, sex, and time relation to transplantation. All angiograms were retrieved and reevaluated with respect to aneurysms, defined as an increase in artery diameter by 50% or more, as well as to pathologic ectasias not fulfilling this criterion. Aneurysms were detected in four ADPKD patients and two control subjects. Five more ADPKD patients, but none of the control subjects, had minor ectasias. One ADPKD patient had a dissecting aortic aneurysm, and another died of aortic dissection during bypass surgery. This study adds to the evidence of an increased risk of extracranial aneurysms in ADPKD patients.
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208
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Lamm K, Lamm C, Arnold W. Effect of isobaric oxygen versus hyperbaric oxygen on the normal and noise-damaged hypoxic and ischemic guinea pig inner ear. Adv Otorhinolaryngol 1998; 54:59-85. [PMID: 9547878 DOI: 10.1159/000059054] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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209
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Sembrano E, Barthlen GM, Wallace S, Lamm C. Polysomnographic findings in a patient with the mitochondrial encephalomyopathy NARP. Neurology 1997; 49:1714-7. [PMID: 9409376 DOI: 10.1212/wnl.49.6.1714] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
A 23-year-old woman with the mitochondrial encephalomyopathy NARP (neurogenic muscle weakness, ataxia, and retinitis pigmentosa) presented with symptoms of obstructive sleep apnea (OSA). An overnight polysomnogram (PSG) showed apnea, EEG slowing, and a paucity of sleep spindles. The patient had a tracheostomy for OSA, and 5 months later she had normal EEG patterns and marked clinical improvement. We propose that patients with mitochondrial encephalomyopathies should have sleep evaluations if the history suggests OSA.
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210
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Sjöland H, Herlitz J, Lamm C, Hartford M, Caidahl K. Prediction of left ventricular dysfunction in coronary artery disease from clinical and exercise test findings. Cardiology 1997; 88:246-53. [PMID: 9129845 DOI: 10.1159/000177338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
We studied the ability to predict depressed left ventricular ejection fraction (LVEF) from clinical and exercise test findings prior to surgery in consecutive patients who underwent coronary artery bypass grafting (CABG) from 1988 to 1991 (n = 663). Multivariate analysis showed a history of myocardial infarction, pathological Q-wave in resting ECG, systolic blood pressure at maximal exercise and the degree of mitral regurgitation as significant independent predictors of impaired LVEF. The relative risk (RR) of depressed LVEF was markedly increased for a previous history of myocardial infarction (RR 3.3, p < 0.0001) and a pathological Q-wave in resting ECG (RR 2.4, p < 0.0001). All associations found between depressed LVEF and exercise test results were poor, and of little value for discriminating patients with depressed LVEF. Thus, clinical data appear to be better markers of low LVEF than the information obtained from the exercise test.
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211
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Albertsson P, Emanuelsson H, Karlsson T, Lamm C, Sandén W, Lagerberg G, Herlitz J. Morbidity and use of medical resources in patients with chest pain and normal or near-normal coronary arteries. Am J Cardiol 1997; 79:299-304. [PMID: 9036748 DOI: 10.1016/s0002-9149(96)00751-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
To evaluate morbidity and use of medical resources in patients with chest pain and normal or near-normal coronary angiograms: 2,639 consecutive patients who underwent coronary angiograms due to chest pain were registered. Two years thereafter all patients who showed normal or near-normal coronary angiograms were approached with a questionnaire regarding hospitalization during the last 4 years (2 years before and 2 years after angiography). All medical files were also examined. Of the patients who underwent angiography, 163 (6%) had no significant stenoses, and of these, 113 showed complete normal angiograms and 50 showed mild (i.e. <50%) stenoses. During the 2 years before diagnostic angiogram, 66% of the patients were hospitalized compared with only 35% during 2 years after angiography (p <0.001). The reduction in hospitalization was due to curtailed utilization of medical resources for cardiac reasons; mean days in hospital was 6.6 days before angiography versus 2.8 days after (p <0.001). There were no significant differences in hospitalization when comparing patients with mild stenoses and completely normal angiograms. There were, furthermore, no differences between patients with positive or negative exercise tests. Thus, the need for hospitalization is significantly reduced after a diagnostic angiogram reveals normal or near-normal coronary arteries.
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212
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Lepore V, Lamm C, Bugge M, Larsson S. Magnetic resonance imaging in the follow-up of patients after aortic root reconstruction. Thorac Cardiovasc Surg 1996; 44:188-92. [PMID: 8896161 DOI: 10.1055/s-2007-1012014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Long-term survival after replacement of the aortic root with a composite graft is improving. Late deaths are in several cases due to complications related to the previous surgery or to pathologies of the remaining aorta. Regular follow-up of these patients is of paramount importance. The purpose of this study is to evaluate the reliability of magnetic resonance imaging (MRI) in such cases. Twenty-seven patients (9 dissections and 18 aneurysms) who had undergone replacement of the aortic root with a composite graft were studied 20 to 167 months after surgery using magnetic resonance imaging with a 1.5 Tesla magnet. The left-ventricular outflow tract, the mechanical valve function, the proximal part of the coronary arteries, the graft, and the remaining aorta could be examined. No aortic insufficiency, ectasy of the proximal part of the coronaries, or pseudoaneurysms were seen. A widening of the remaining ascending aorta was noted in 4 cases. A still open, dissected pipe was visualized in 7 patients. Our conclusions are that MRI provides excellent images of the thoracic and abdominal aorta following surgical repair. The examination is becoming cost-competitive. More import is its very low risk for the patient group considered here: since it is non-invasive and requires no contrast medium or X-ray exposure, examinations can be repeated as required.
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213
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Lamm C, Albertsson P, Dohnal M, Tylén U, Emanuelsson H. Assessment of coronary artery stenosis during PTCA by measurement of the trans-stenotic pressure gradient. Comparison with quantitative coronary angiography. Eur Heart J 1995; 16:1367-74. [PMID: 8746905 DOI: 10.1093/oxfordjournals.eurheartj.a060744] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
A fibreoptic pressure sensor mounted on an 0.018 inch guidewire (Pressure Guide, RadiMedical Systems, Uppsala, Sweden) was used to measure the trans-stenotic pressure gradient in 20 patients admitted for percutaneous transluminal coronary angioplasty (PTCA) of a single, discrete stenosis. Pressure measurements were made both at rest and during maximal vasodilatation induced by intracoronary injection of papaverine. From the ratio of distal coronary pressure divided by the proximal pressure, the relative coronary flow reserve was calculated. The aim of the study was to compare the different pressure-derived parameters by correlating them to stenosis geometry estimated by quantitative coronary angiography. There was a moderate correlation between baseline pressure gradient and percent area stenosis; r = 0.64, P < 0.001 and minimal cross-sectional area; r = 0.45, P < 0.005. A higher correlation was found between hyperaemic pressure gradient and area stenosis (r = 0.80, P < 0.001) and minimal cross-sectional areas, respectively (r = 0.55, P < 0.005). The best correlation was found between relative coronary flow reserve and area stenosis (r = 0.86, P < 0.001) and minimal cross-sectional area (r = 0.70, P < 0.001). In conclusion, pressure measurement using a pressure guidewire is useful as a complement to angiography in evaluation of coronary stenoses during PTCA. Pressures should be measured during maximal vasodilatation. Relative coronary flow reserve calculated from the pressure measurements provides additional information about the fraction of normal maximal flow possible in the presence of a stenosis.
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214
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Selin K, Johansson SR, Lamm C, Emanuelsson H. [Intracoronary diagnosis in coronary angioplasty. Extended information with new techniques]. LAKARTIDNINGEN 1995; 92:1583-6. [PMID: 7715282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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215
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Lamm C. Sleep-disordered breathing in children. THE MOUNT SINAI JOURNAL OF MEDICINE, NEW YORK 1994; 61:131-8. [PMID: 8022425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The recent better recognition of children with sleep-disordered breathing has led to the evaluation of more patients in the sleep laboratory and thence to the definition of sleep problems among children in a variety of clinical situations. Further investigation of these abnormalities is necessary to ascertain the clinical significance of these disorders.
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216
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Lamm C, Dohnal M, Serruys PW, Emanuelsson H. High-fidelity translesional pressure gradients during percutaneous transluminal coronary angioplasty: correlation with quantitative coronary angiography. Am Heart J 1993; 126:66-75. [PMID: 8322693 DOI: 10.1016/s0002-8703(07)80011-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
A fiberoptic pressure sensor mounted on an 0.018-inch guidewire (Pressure Guide) was used to measure the transstenotic pressure gradient in 30 patients undergoing percutaneous transluminal coronary angioplasty (PTCA) with lesions considered suitable for quantitative coronary angiographic (QCA) assessment. The aim of the study was to correlate pressure gradients with parameters obtained with QCA. After intracoronary injection of 125 micrograms of nitroglycerin, multiple angiographic views were taken of the lesion. The Pressure Guide fiberoptic sensor was then positioned distal to the stenosis and the pressure gradients were recorded before and after PTCA. There was a significant correlation between mean pressure gradients (delta P) and percent diameter stenosis (r = 0.73; p < 0.001) and absolute stenosis diameter (r = -0.67; p < 0.001) and with percent area stenosis (r = 0.69; p < 0.001) and absolute stenosis area (r = -0.63; p < 0.001). The closest relationship, though, was found with stenotic flow reserve (SFR), which is an integrated parameter calculated from QCA. This relationship can be described by the equation: delta P = 65.2 - 12.6.SFR (r = -0.79; p < 0.001). With a measured gradient of > 15 mm Hg, the sensitivity was 94% and the specificity 96% to predict an SFR < 3.5. In conclusion, a statistically significant relationship could be found between stenosis pressure gradients and angiographic parameters in this study with lesions without complicated morphology. The independent information obtained by pressure gradient measurement may be of particular value in intermediately severe lesions or in stenoses where the angiographic assessment otherwise is difficult.
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217
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Houltz E, Gustavsson T, Caidahl K, Kirnö K, Lamm C, Milocco I, Ricksten SE. Effects of surgical stress and volatile anesthetics on left ventricular global and regional function in patients with coronary artery disease. Evaluation by computer-assisted two-dimensional quantitative transesophageal echocardiography. Anesth Analg 1992; 75:679-87. [PMID: 1416118 DOI: 10.1213/00000539-199211000-00005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
We investigated the effects of halothane, enflurane, and isoflurane on central hemodynamics and left ventricular global and regional function when used to control intraoperative hypertension in 39 patients with coronary artery disease. Left ventricular short-axis, midpapillary images were obtained by transesophageal echocardiography. Using a centerline algorithm, we analyzed left ventricular images for global area ejection fraction (GAEF) and segmental area ejection fraction (SAEF). The SAEF/GAEF ratio was calculated for each of eight segments. Measurements were performed after induction of anesthesia but before skin incision; 1 min after sternotomy; and during administration of the inhaled anesthetic. The increase in arterial blood pressure during sternotomy was due to an increase in vascular resistance accompanied by increases in heart rate and filling pressures while GAEF decreased. No changes in the SAEF/GAEF ratio appeared during sternotomy. The inhaled anesthetics restored arterial blood pressure by a similar decrease in vascular resistance. Isoflurane caused an increase in cardiac index that was not seen with halothane or enflurane (halothane vs isoflurane, P < 0.05). The GAEF was decreased by halothane but unaffected by isoflurane and enflurane (halothane vs enflurane; P < 0.05). Isoflurane induced a decrease in the SAEF/GAEF ratios of two segments corresponding to the inferolateral wall of the left ventricle that was, in one of these segments, significantly more pronounced compared with both halothane and enflurane. Halothane or enflurane did not cause any change in regional wall motion. We conclude that isoflurane is more likely to cause regional wall motion changes than halothane or enflurane in patients with coronary artery disease.
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218
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Dernevik L, Houltz E, Lamm C, Wallentin I. [Superior vena cava syndrome. Surgery of thrombosis of the right atrium immediately after intravenous fluid therapy is preferable]. LAKARTIDNINGEN 1992; 89:1083-4. [PMID: 1552814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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219
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Emanuelsson H, Dohnal M, Lamm C, Tenerz L. Initial experiences with a miniaturized pressure transducer during coronary angioplasty. CATHETERIZATION AND CARDIOVASCULAR DIAGNOSIS 1991; 24:137-43. [PMID: 1742783 DOI: 10.1002/ccd.1810240213] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
A newly constructed pressure sensor with a diameter of 0.45 mm was evaluated in 15 patients undergoing balloon coronary angioplasty (PTCA). The sensor and an optic fiber were mounted on a 0.018" guide wire, which was used in the balloon catheter. Pressure gradients were recorded before and after PTCA, respectively. The pressure tracings were of satisfactory quality in all cases. The mean systolic and diastolic gradients before PTCA were 32 +/- 20mm Hg and 44 +/- 26mm Hg, respectively. Pressure gradients were also obtained with the balloon placed in the lesion in order to simulate the conventional way of pressure measurement through the balloon catheter. In this setting, the systolic and diastolic gradients were 77 +/- 32mm Hg and 59 +/- 25mm Hg, respectively. Following balloon dilatation, the systolic pressure gradient decreased to 14 +/- 12mm Hg, and the diastolic gradient to 13 +/- 11mm Hg. In conclusion, this new pressure sensor delivers recordings of good quality and may be especially of interest during angioplasty due to its small diameter.
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220
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Blomberg S, Emanuelsson H, Kvist H, Lamm C, Pontén J, Waagstein F, Ricksten SE. Effects of thoracic epidural anesthesia on coronary arteries and arterioles in patients with coronary artery disease. Anesthesiology 1990; 73:840-7. [PMID: 2240673 DOI: 10.1097/00000542-199011000-00008] [Citation(s) in RCA: 197] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The effect of cardiac sympathetic blockade by high thoracic epidural anesthesia (TEA) (T1-T6, bupivacaine) on the luminal diameter of normal and diseased portions of epicardial coronary arteries was determined by quantitative coronary angiography in patients (n = 27) with severe coronary artery disease (CAD). In a separate group of patients (n = 9) with severe CAD, the effects of TEA on coronary arterioles (resistance vessels) were studied, by measuring total and regional myocardial blood flow and metabolism with the retrograde coronary sinus thermodilution technique. At the stenotic segments, TEA induced an increase in luminal diameter from 1.34 +/- 0.11 to 1.56 +/- 0.13 mm (P less than 0.002), but did not change the diameter of the nonstenotic segments (3.07 +/- 0.13 to 2.99 +/- 0.13 mm). In the second group of patients, TEA induced no changes in coronary perfusion pressure, total or regional myocardial blood flow, coronary venous oxygen content, coronary blood flow distribution, regional myocardial oxygen consumption, or lactate extraction or uptake. Two patients had chest pain in the control situation and had regional myocardial lactate production that was attenuated by TEA. We conclude that TEA may increase the diameter of stenotic epicardial coronary artery segments in patients with CAD without causing a dilation of coronary arterioles. These effects may be beneficial when high TEA is used to treat severe ischemic chest pain in patients at rest.
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221
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Johansson SR, Lamm C, Bondjers G, Emanuelsson H, Hjalmarson A. Role of beta-adrenergic blockers after percutaneous transluminal coronary angioplasty. Am J Cardiol 1990; 66:915-20. [PMID: 1977297 DOI: 10.1016/0002-9149(90)90925-q] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Restenosis after percutaneous transluminal coronary angioplasty (PTCA) cannot currently be prevented. Different medical regimens have been largely unsuccessful. Experimental studies suggest roles for beta-adrenergic blockers and calcium antagonists. Controlled clinical studies have failed to show any decrease in restenosis rate for calcium antagonists. Corresponding studies for beta blockers are lacking. This study evaluates 541 consecutive PTCA procedures, 455 (86%) in patients treated with beta blockers after PTCA (76% metoprolol, 14% atenolol, 4% sotalol, 6% others) and 86 (14%) in patients without beta blockers. Angiographic success was achieved in 483 of 620 lesions (78%), and was not significantly different with or without beta blockers (79 vs 73%, p greater than 0.05). The procedure success rate and the complication rates (myocardial infarction, emergency coronary artery bypass grafting, death) did not differ with or without beta blockers (p greater than 0.05). Follow-up angiograms for 426 of the 483 successfully dilated lesions (88%) revealed that a total of 155 stenoses had recurred (36%). The restenosis rate was not significantly different with (368) or without (58) beta blockers (36 vs 38%, p greater than 0.05). For beta blockers with calcium antagonists (84% nifedipine, 13% diltiazem, 2% verapamil, 1% others), the restenosis rate was 97 of 250 (39%) vs 36 of 118 (31%) (p greater than 0.05). This retrospective study indicates that treatment with beta-adrenergic blockers after PTCA, alone or in combination with calcium antagonists, does not influence either the success rate or the restenosis rate and can be continued if indicated from an antiischemic viewpoint.
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222
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Lamm K, Lamm C, Lamm H, Schumann K. [Simultaneous determination of oxygen partial pressure in the scala tympani, electrocochleography and blood pressure values in the guinea pig]. HNO 1989; 37:48-55. [PMID: 2703372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Nineteen guinea pigs were exposed to impulse noise from gunfire (G3 of the Federal German Army, 156 dB peak SPL), 6+6 shots or 12+6 shots, with a 3-s pulse interval. For simultaneous measurements of pO2, cochlea microphonics (CM) and compound action potentials of the auditory nerve (CAP), we used the thin 0.5 microns microcoaxial needle electrode described by Baumgaertl and Luebbers, which was placed through the roundwindow membrane into the scala tympani to a depth of 1000 microns. After exposure to the first 6 or 12 gunshots, the pO2 increased by about 20% of the original values in 12 guinea pigs (63%). In the following 30 min of recovery time the pO2 decreased, stabilized or showed a further decline. There were only 3 animals with a pO2 loss of 70% of the original values. Most animals showed a decline of 25% at the end of the recovery period. In all animals after 6 additional shots, the pO2 only decreased by another 5% of the original values. Amplitudes of CM and CAP were reduced by about 40% of the original values after 6 or 12 shots and by another 20%-24% (CM) and 5%-15% (CAP) after 6 additional shots. The intra-arterial blood pressure in the common carotid artery remained constant. The results are discussed with respect to the well-known morphological damage, subsequent ion imbalance and hypoxia within the cortilymph after exposure to gunfire. These changes are reflected in the loss of CMs and CAPs.
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223
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Lamm K, Lamm C, Lamm H, Schumann K. [Simultaneous determinations of oxygen partial pressure in the scala tympani, electrocochleography and blood pressure measurements in noise stress in guinea pigs]. HNO 1988; 36:367-72. [PMID: 3170282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
In 14 guinea pigs the pO2 in the perilymph of the scala tympani fell to 50%-80% of the original value during exposure to noise consisting of 4,000 Hz clicks with a repetition rate of 20/s, 100 dB CHL = 120 dB SPL p.e., repeated twice over a period of 24 minutes each time. For the measurements of the pO2 we used the thin 0.5 micron micro-coaxial needle electrode described by Baumgärtl and Luebbers, which was placed through the round-window membrane in the scala tympani to a depth of 600 micron. The simultaneously recorded CAP latency times were prolonged by 0.8 ms at a test loudness of 60 and 80 dB CHL. The amplitudes of the CM had declined by 60%-70% of the original values at a test loudness of 80 dB SPL p.e. The intra-arterial blood pressure in the common carotid artery of all animals remained constant. As the cortilymph spaces communicate with the perilymph of the scala tympani, our measured decline of pO2 in the perilymph could indicate a cortilymph hypoxia. During exposure to noise the oxygen-dependent Na+ and K+ pumps, which maintain the ion balance and function of the organ of Corti, can decompensate due to lack of oxygen. That would lead to a K+ contamination of the cortilymph and to an intracellular Na+ accumulation, which can cause microstructural damage (hair cell-cilia fusion, hair cell, synaptic and dendritic swelling, hair cell contraction and sustained depolarization), which would be reflected in the CMs and CAPs.
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224
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Lamm C, Walliser U, Schumann K, Lamm K. [Oxygen partial pressure measurements in the perilymph and scala tympani in normo- and hyperbaric conditions. An animal experiment study]. HNO 1988; 36:363-6. [PMID: 3170281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The purpose of this study was to examine the influence of hyperbaric oxygen on the oxygen tension (pO2) in the normal inner ear. We examined 16 anaesthetised guinea pigs by means of an oxygen-sensitive micro-coaxial needle electrode, using the method described by Baumgaertl and Luebbers. In all animals the pO2 in the perilymph of the scala tympani fell by 34% of the original value during insertion of the sensor into the scala tympani. After we had flooded the hyperbaric chamber with pure oxygen under normobaric conditions the pO2 increased by 244.3% of the original values. Furthermore the pO2 increased by 9.4 times the original values during hyperbaric oxygen at 1.6 bar.
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225
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Boijsen M, Goss F, Jacobsson L, Lamm C, Schlossman D, Björneld L, Tylén U. Cardiac output determination during intravenous cardioangiography using x-ray fluorescence analysis. Acta Radiol 1988; 29:419-22. [PMID: 3408602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Cardiac output was determined with an indicator dilution technique during digital venous angiography of the left ventricle in 11 patients. The contrast medium injected into the right atrium was used as indicator. During and after the injection of contrast medium one blood sample per second was obtained through a catheter placed in the descending aorta. The samples were analyzed for iodine content with x-ray fluorescence analysis and cardiac output determined ad modum Stewart-Hamilton. Thermodilution was used as a reference method. The results indicate that the indicator dilution method with the use of contrast medium might be used for calibration of videodensitometric methods for blood flow measurements.
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