ISSN:0009-7322    

出版商:OVID    

年代:1984

数据来源: OVID

ISSN:0009-7322    

出版商:OVID    

年代:1984

数据来源: OVID

ISSN:0009-7322    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

ABSTRACTProtamine is widely used for reversing systemic heparinization after cardiac catheterization. Although rare, major reactions to protamine that simulate anaphylaxis occasionally occur and have previously been associated only with an allergic reaction to fish. Because neutral protamine Hagedorn (NPH) insulin includes protamine, it might be anticipated that NPH insulin‐dependent diabetic patients would develop sensitivity to protamine. Of 866 consecutive patients undergoing cardiac catheterization over a 20 month period, 651 received protamine for reversal of heparinization. Of these, 8.5% (56/651) were diabetics and 2.3% (15/651) were NPH insulin‐dependent diabetics. During this period seven patients were observed immediately after administration of protamine to have major adverse reactions that required the administration of catecholamines. One death ensued. Of the seven major reactions, four occurred in NPH insulin‐dependent diabetics and one occurred in a patient with an allergy to fish. The incidence of major protamine reactions was 27% (4/15) in the NPH insulin‐dependent diabetics vs 0.5% (3/636) in those with no history of NPH insulin use (p < .001). This represents a 50‐fold increased risk of a major reaction to protamine if the patient was receiving NPH insulin. Accordingly, we recommend that diabetics on NPH insulin and patients with allergies to fish undergo cardiac catheterization without the use of protamine or, when necessary, that protamine be administered cautiously in anticipation of a major adverse reaction.Circulation 70, No. 5, 788‐792, 1984.

ISSN:0009-7322    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

ABSTRACTThe incidence of the coexistence of left ventricular false tendons and premature ventricular contractions (PVCs) was evaluated prospectively. Over 14 months, left ventricular false tendons were found in 71 (6.4%) of 1117 consecutive patients examined echocardiographically. Two types of false tendons were observed: longitudinal, from the ventricular septum to the posteroapical wall (n = 62), and transverse, between the septum and the lateral wall (n = 9). Among 62 patients with PVCs and no underlying heart disease, false tendons were detected in 35 (56%); 28 had unifocal and seven had bifocal PVCs. Episodes of ventricular tachycardia were documented in one of the 28 patients with unifocal PVCs and in one of the seven patients with bifocal PVCs. These PVCs were poorly controlled by antiarrhythmic drugs but easily suppressed by exercise. Left ventricular false tendons were detected in 36 patients on routine echocardiographic examinations performed in the other 1055 subjects, and 10 of these patients were judged to have no underlying heart disease. PVCs were detected in two (20%) of these 10 patients. Although a definite conclusion that left ventricular false tendons are arrhythmogenic cannot be derived from these results, the unexpectedly high incidence of the coexistence suggests that left ventricular false tendons may be an etiologic factor in the development of PVCs, especially the rate‐dependent and medically uncontrollable PVCs seen in apparently healthy individuals.Circulation 70, No. 5, 793‐798, 1984.

ISSN:0009-7322    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

ABSTRACTTwenty‐six adult patients, classified by clinical and catheter criteria into groups of those with normal and abnormal left ventricular function, were studied during cardiac catheterization. Right heart pacing was established, and left ventricular dP/dt was measured with end‐catheter manometers. By varying the interval preceding a test beat after periods of steady pacing it was confirmed that recovery of left ventricular mechanical function (maximum dP/dt) occurs approximately 800 msec (optimum interval) after a beat. The augmentation of maximum dP/dt of the first 2 beats after an extrasystole, each spaced at the optimum interval, was also studied; the amount of potentiation was varied by alterations in extrasystolic interval. Potentiation decayed from the first to the second postextrasystolic beat with a ratio that was fixed in each individual patient. The ratio (recirculation fraction) was higher in patients with normal than in those with abnormal left ventricular function (mean ± SD 0.52 ± 0.10 vs 0.37 ± 0.11, p < .005). There was an inverse relationship between this ratio and the degree of potentiation of the first postextrasystolic beat (r = .80, p < .001). We postulate a disturbance of excitation‐contraction coupling mechanisms to explain these effects.Circulation 70, No. 5, 799‐805, 1984.

ISSN:0009-7322    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

ABSTRACTThe transparent oxygen electrode, recently developed by Huch and his co‐workers, permits monitoring of transcutaneous oxygen tension (tcPo2) at defined sites on the capillaroscopic image obtained by videomicroscopy. This combined system has been applied to study the nutritional skin capillaries of patients with chronic venous incompetence (CVI). The results of 44 studies in 17 patients with CVI demonstrated a direct correlation between tcPo2and density and morphologic characteristics of the superficial capillaries. The mean tcPo2was 47.7 ± 14.4 mm Hg at the site of incompetent perforating veins of the ankle without major trophic changes. There was no statistically significant difference between the mean values obtained in patients and control subjects (56.8 ± 9.9 mm Hg). Videomicroscopic examination revealed dilated and tortuous capillaries surrounded by halo formations. In areas of hyperpigmentation, induration, and hyperkeratosis, significantly decreased mean tcPo2(22.5 ± 7.0 mm Hg; p < .001) corresponded to reduced capillary density (<10 capillaries/mm2). In avascular skin areas (scar tissue, white atrophy) tcPo2was measured at 0 mm Hg. No capillaries, or a greatly reduced number, were visible at such sites, resulting in a distance between capillary and cathode tip of the oxygen sensor of greater than 100 &mgr;m. The combined system of tcPo2measurement and simultaneous videomicroscopy gives new pathophysiologic information on the development of skin ulcers and may be useful for the objective comparison of different therapeutic modalities at the microcirculatory level.Circulation 70, No. 5, 806‐811, 1984.

ISSN:0009-7322    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

ABSTRACTAn eight‐electrode conductance catheter previously developed by us and used to determine stroke volume in dogs was applied in human beings and dogs to measure absolute left ventricular volume quantitatively. For calibration we developed the formula V(t) = (1/&agr;)(L2/&sgr;b)G(t) ‐ Vc, where V(t) is time‐varying left ventricular volume, &agr; is a dimensionless constant, L is the electrode separation, &sgr;bis the conductivity of blood obtained by a sampling cuvette, and G(t) is the measured conductance within the left ventricular cavity. Vcis a correction term caused by the parallel conductance of structures surrounding the cavity and is measured in two ways. The first method, applicable in the anesthetized animal, consists of temporary reduction of volume to zero by suction. The second method uses a transient change in &sgr;bby injection f a small bolus of hypertonic saline (dogs) or 10 ml of cold glucose (humans) into the pulmonary artery. The validity of the formula was previously established for the isolated postmortem canine heart. The predicted linearity, slope constant &agr;, and accuracy of Vcfor the left ventricle in vivo were investigated by comparing the conductance volume data with results from independent methods: electromagnetic blood flow measurement for stroke volume and indicator dilution technique for ejection fraction (dogs), thermal dilution for cardiac output (12 patients), and single‐plane cineventriculography for V(t) (five patients). In all comparisons, linear regression showed high correlation (from r = .82 [n = 46] to r = .988 [n = 20]) while &agr;, with one exception, ranged from 0.75 to 1.07 and the error in Vcranged from 0.5% to 16.5% (mean 7%). After positioning of the catheter, no arrhythmias were observed. It is concluded that the conductance catheter provides a reliable and simple method to measure left ventricular volume, giving an on‐line, time‐varying signal that is easily calibrated. Together with left ventricular pressure obtained through the catheter lumen, the instrument may be used for instantaneous display of pressure‐volume loops to facilitate assessment of left ventricular pump performance.Circulation 70, No. 5, 812‐823, 1984.

ISSN:0009-7322    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

ABSTRACTEnzymatic estimates of myocardial infarct size based on plasma levels of MB creatine kinase (MB‐CK) were compared with anatomic infarct size in 49 human hearts obtained at autopsy. The patients studied had been enrolled in the Multicenter Investigation of Limitation of Infarct Size (MILIS) study program within 18 hr of the onset of acute infarction and were treated at one of five participating hospitals. Infarct size was estimated from serial measurements of plasma MB‐CK made at the core laboratory for CK analysis. Hearts obtained at autopsy were studied independently by the core pathology laboratory without knowledge of the MB‐CK levels or clinical results. Data from the two laboratories were compared at the data coordinating center. Of 49 hearts, 12 were excluded either because anatomic infarct size could not be established or because the infarct occurring at the time of enrollment in the MILIS study could not be distinguished with certainty from other infarcts. Of the remaining 37 hearts, peak MB‐CK level was available in 36, but samples sufficient for estimation of infarct size were available in only 25. The overall correlation coefficient (Spearman) was .87 for these 25 hearts, indicating that enzymatic estimates of infarct size correlate closely with anatomic measurements. The results indicate that CK estimates of myocardial infarct size represent a valid clinical end point for assessing myocardial infarct size, and the effect of therapy thereon, in groups of treated and control patients.Circulation 70, No. 5, 824‐835, 1984.

ISSN:0009-7322    

出版商:OVID    

年代:1984

数据来源: OVID

摘要:

ABSTRACTThe accuracy of two‐dimensional echocardiography in the recognition of aberrant ventricular bands and pathologic trabeculations (hypertrophic, fibrotic, or both) was assessed in 35 patients who underwent cardiac transplantation and pathologic examination. At pathologic study the prevalence of specific intracavitary structures ranged from 28% to 43%. Left ventricular thrombi were found in 12 patients (34%) and right ventricular thrombi in three (9%). Echocardiography accurately defined left ventricular aberrant bands and left ventricular thickened or fibrotic trabeculations. Bands, trabeculations, and thrombi each showed characteristic echocardiographic patterns. In the right ventricle, these structures were recognized, but accurate discrimination among them was not possible by echocardiography. Aberrant bands and pathologic trabeculations mimicked or obscured fresh or organized thrombi in three patients on two‐dimensional echocardiography. Left ventricular longitudinal bands and pathologic right ventricular trabeculations obscured the interventricular septal border in four patients; the presence of these abnormalities could lead to the erroneous diagnosis of asymmetric septal hypertrophy on M mode echocardiography. By expressing the accuracy of two‐dimensional echocardiography in the recognition of left ventricular anomalous bands, our results support the feasibility of prospective studies to clarify their clinical significance.Circulation 70, No. 5, 836‐842, 1984.

ISSN:0009-7322    

出版商:OVID    

年代:1984

数据来源: OVID