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Biomedical subjects

C B Higgins

Publications and source records attributed to C B Higgins.

At least 469 records · Page 26Linked to original sources
PubMed1981

Acquired coronary-to-bronchial artery communication: a possible cause of coronary steal.

An unusual case of an acquired coronary-to-bronchial artery communication is presented. Collateral flow to the lung was provided by the right coronary circulation following obstruction of pulmonary blood flow by chronic pulmonary emboli. A coronary steal phenomenon may have caused an exacerbation of cardiac symptoms by further reducing already compromised coronary blood flow in a patient with atherosclerotic coronary artery disease.

Bronchial Arteries↗
PubMed1981

Effects of intracoronary administration of contrast materials on left ventricular function in the presence of severe coronary artery stenosis.

The effects of intracoronary administration of contrast materials on regional and global left ventricular (LV) function were assessed in anesthetized dogs with segmental myocardial ischemia produced by critical stenosis of the circumflex coronary artery. Effects caused by sodium meglumine diatrizoate (R76), sodium meglumine calcium metrizoate (ISO), and metrizamide were evaluated. In the nonischemic state R76 produced an early (0-10 seconds) decrease in LV contractility followed by a late (10-20 seconds) positive inotropic effect. In the presence of regional ischemia there was prolongation of the negative inotropic effect. ISO produced only positive inotropic effects without significant differences between responses in the nonischemic and ischemic states. Metrizamide produced almost no alterations in LV function.

Animals↗
PubMed1981

The cardiothoracic ratio in newborn infants.

In order to provide improved techniques and standards for measuring radiographic heart size in infants, cardiothoracic ratios (C/T) using four different thoracic measures were calculated from anteroposterior supine chest radiographs of 175 normal infants who were a week or less in age, with gestational ages of 26.5-44 weeks, and birthweights of 765-4540 g. The lowest variation in C/T was observed when the thoracic measurement was either the chest width at the inner margins of the eighth ribs (normal range, 43.2%-56.5%) or the maximum internal chest width (normal range, 42.7%-56.4%); by these methods, a value of 57% or greater may be considered enlarged. Average C/T was above normal in 131 infants with respiratory distress syndrome and in 105 infants with various other parenchymal abnormalities. The presence of assisted ventilation did not significantly affect C/T measured as described above. In evaluating level of inspiration by the position of the right hemidiaphragm, posterior rib count proved more predictive of heart size than anterior rib count; the normal inspiratory range was 6.6-9.4 posterior ribs.

Birth Weight↗
PubMed1981

Computerized tomographic diagnosis of paracardiac masses.

Paracardiac masses may alter the cardiac contour seen on roentgenograms of the chest so as to mimic configurations associated with cardiac disease. Recently, the use of computerized transmission tomography has proved valuable as a noninvasive method of distinguishing between intrinsic cardiac disease and paracardiac masses. In some cases, the procedure obviates the need for preoperative cardiac catheterization.

Adolescent↗
PubMed1980

Axial left ventriculography in discrete subaortic stenosis.

Left ventricular angiograms of six children were reviewed, and it was found that those obtained in axial (long axial oblique and hepatoclavicular) projections enhanced precision in the diagnosis of subvalvular aortic stenosis. The methods for obtaining these views are described, and the results presented. Axial views are never inferior to standard (posteroanterior, lateral, and right anterior oblique) projections, and are usually superior to them, especially when there are associated lesions, such as ventricular septal defects, left-sided obstructive lesions, and patent ductus arteriosus.

Angiography↗
PubMed1980

Assessment of patent ductus arteriosus in preterm infants by single lateral film aortography.

Differentiation of a hemodynamically significant cardiovascular abnormality from lung disease in the newborn infant may remain problematic after clinical, radiographic, and echocardiographic evaluation. Single-view aortography was performed in 38 preterm and one full term infant in the neonatal special care nursery. Special lateral views were obtained consisting of either a horizontal x-ray beam with oblique angulation of the supine patient or a vertical bean with 30 degree head-up angulation of the patient. These views projected the ductus caudal to the aortic arch and enabled visualization of the entire length of the ductus and focal constrictions of the ductus. The severity of patent ductus arteriosus was judged by anatomic (diameter of the ductus compared to the descending aorta) and physiologic (preferential opacification of the aortic arch or pulmonary circulation) criteria.

Aortography↗
PubMed1980

Heart failure in the neonate due to extreme abnormalities of heart rate: clinical and radiographic features.

Extreme variations of heart rate caused clinical and radiographic findings of heart failure in six neonates in the absence of structural heart disease. Two infants had heart block with heart rates below 50/min and four had paroxysmal atrial tachycardia with rates approaching 300/min. Each infant had interstitial or alveolar pulmonary edema and most had cardiomegaly. After restoration of a normal heart rate, there was rapid and dramatic resolution of pulmonary edema and reduction in cardiac size.

Arrhythmias, Cardiac↗
PubMed1980

Radiography of acute myocardial infarction.

In conclusion, the plain radiograph provides an insight into the hemodynamic severity of myocardial infarctions and the effected patient's ultimate prognosis. It may also be the initial indicator of one of the several complications that may accompany the evolution of an acute myocardial infarction.

Arrhythmias, Cardiac↗
PubMed1980

Radiology of neonatal heart disease.

The diagnosis of heart disease in newborn infants presents numerous radiologic difficulties because of a variety of factors, including the frequent absence of specific radiographic signs, the confusing effects of parenchymal disease, and the difficulties encountered in identifying specific locations of chamber enlargement and even in distinguishing between arterial and venous plethora. Definitive anatomic diagnoses can only rarely be made from plain chest films. Nevertheless, with adequate clinical information, lesions can be assigned to pathophysiologic categories, permitting intelligent planning of subsequent diagnostic maneuvers. Echocardiographic evaluation permits investigation on internal cardiac architecture and motion, which is very useful in diagnosing not only congenital cardiac malformations but also extracardiac lesions such as patent ductus arteriosus and persistent neonatal pulmonary hypertension.

Animals↗
PubMed1980

Evaluation of ischemic heart disease by computerized transmission tomography.

As the technology of CTT advances in speed and resolution, a new clinical applications of this modality for noninvasive evaluation of ischemic heart disease should emerge. This modality has already advanced to the stage at which it can compete with echocardiography in producing static images of cardiac structures. The ability of CTT to quantitate regional blood flow using dynamic densitometry is a unique capability of this modality. Although cardiac scintigraphy provides excellent density sensitivity using small amounts of radioactive tracers, it currently lacks the spatial fidelity needed to differentiate many anatomic structures in the heart. Thus, CTT will likely complement the capabilities of other noninvasive imaging modalities. In the future, ultra high-speed CTT scanners will be developed that should provide a multi-section capacity for true three-dimensional imaging. Such scanners will enable many of the cardiac CTT techniques described in this article to advance from the experimental laboratory stage into the mainstream of clinical practice.

Aortic Dissection↗
PubMed1980

Uptake of iodinated contrast material in ischemic myocardium as an indicator of loss of cellular membrane integrity.

Differential uptake of iodine containing radiographic contrast medium (I) in myocardial infarcts compared with normal mycardium has been detected by computerized transmission tomography (CTT). In this study the histologic and cellular distribution of I in ischemically damaged canine myocardium after intravenous administration of contrast material was examined by the use of scanning electron microscopy and energy dispersive X-ray microanalysis of fresh frozen cryosections. Analysis of individual cells in 6-mu thick sections mounted on carbon substrates showed that I was detectable in the ischemically damaged but not the normal myocardial cells. A decline in the potassium-to-sodium ratio confirmed the loss of membrane integrity in the ischemically damaged cells that accumulated I. These results indicate that I enters ischemically damaged but not normal myocardial cells suggesting that CTT scans after intravenous administration of contrast material may be capable of defining the area of the myocardium in which cells have lost membrane integrity after an ischemic injury.

Animals↗
PubMed1979

Differential accumulation of radiopaque contrast material in acute myocardial infarction.

The differential accumulation of radiographic contrast materials in ischemically damaged and normal myocardium was assessed with direct measurement (fluorescent excitation analysis) of the iodine content of tissue samples from dogs with 48 hour old myocardial infarctions. Tissue samples were obtained 10, 30, 60 and 180 minutes after the intravenous administration of 2 ml/kg body weight of diatrizoate meglumine and sodium (Renografin-76). At all time intervals, the iodine concentration of infarcted tissue was at least threefold greater than that of normal myocardium. At 180 minutes the ratio between iodine concentration in infarcted myocardium and that in normal myocardium was 8.5 and between that in infarcted myocardium and that in blood was 2.6. The iodine concentration in the liver was similar to or greater than that in the infarcted area at time intervals after 10 minutes. These results suggest that the intravenous administration of contrast material may facilitate the identification of acutely infarcted myocardium with computerized X-ray transmission tomography.

Animals↗
PubMed1979

Control of hemorrhage from a common carotid arterial-cutaneous fistula by temporary implantation of a balloon catheter.

Hemorrhage from an infected carotid arterial-cutaneous fistula was treated by occlusion of the common carotid artery with a 6-French (Swan-Ganz) balloon catheter. After nine months, there was no recurrence of bleeding or neurological sequelae. Temporary balloon occlusion to induce thrombosis of a major artery is an alternative to transcatheter embolization of small particulate material and larger foreign bodies.

Adult↗
PubMed1979

The hemodynamic significance of massive pneumopericardium in preterm infants with respiratory distress syndrome. Clinical and experimental observations.

Radiographic and clinical data were evaluated in 12 preterm infants with pneumopericardium complicating ventilator therapy of respiratory distress syndrome. Eight infants had massive or tension pneumopericardium, reflected by bradycardia, hypotension, and cyanosis of abrupt onset; cardiac size decreased dramatically but returned to approximately the former size after aspiration of the pneumopericardium. In puppies, pneumopericardium large enought to reduce heart size by 32 +/- 3% caused decreased mean arterial pressure (-22 +/- 7%) and right ventricular peak systolic pressure (-11 +/- 2%) and increased right ventricular diastolic and intrapericardial pressures. These findings suggest that pneumopericardium per se causes severe hemodynamic compromise. When it is large enought to reduce heart size, drastic circulatory impairment is produced and pericardiocentesis should be performed immediately.

Animals↗
PubMed1979

Evaluation of myocardial ischemic damage of various ages by computerized transmission tomography. Time-dependent effects of contrast material.

The potential role of computerized transmission tomography (CTT) in the detection and quantitation of acute myocardial ischemic damage was assessed in 42 excised canine hearts at 2 hours, 8 hours, and 48 hours after coronary occlusion. The CTT scan detected by myocardial damage that was 2-48 hours old each time the presence of regional ischemia was confirmed by histochemical straining or epicardial electrocardiographic mapping. Intravenous administration of contrast material enhanced the x-ray attenuation of areas of ischemic damage of 8 and 48 hours duration compared with normal myocardium, but enhanced only normal myocardium in those of 2 hours duration. Volumetric estimation of the extent of damage from the CTT scans in dogs with ischemia of 48 hours duration showed a close linear relationship with the morphometric volume in the absence of contrast material. Quantitation of the area of ischemic damage from the CTT scan after contrast administration resulted in substantial underestimation of the volume of damaged tissue.

Animals↗