Search PubMed⌕ Search

Biomedical subjects

G C Friesinger

Publications and source records attributed to G C Friesinger.

At least 73 records · Page 4Linked to original sources
PubMed1980

Platelet aggregates in peripheral and coronary-sinus blood in patients with spontaneous coronary-artery spasm.

Five out of twenty patients with vasotonic angina had frequent spontaneous attacks with dramatic ST-segment alterations. These attacks were consistently associated with an increase in platelet aggregates in coronary-sinus blood but not arterial blood. This increase in platelet aggregates during coronary-artery spasm suggests a potential causal role for the platelet in this subset of patients with ischaemic heart-disease. However, the increase in platelet aggregates could be secondary to reduced coronary blood-flow.

Adult↗
PubMed1980

Bacterial endocarditis with aortic regurgitation: implications of embolism.

We studied 16 patients with 18 episodes of bacterial endocarditis and aortic regurgitation to learn the frequency and characteristics of systemic embolism. Seven patients had eight episodes of clinically apparent emboli, with a mortality of 43%; in those without emboli there was no mortality. The influences of congestive heart failure, type of infection, and echocardiographic findings on the embolic complications are discussed. The close association among embolism, congestive heart failure, and echocardiographic vegetation suggests that early operation is warranted in patients with any of these features in order to prevent emboli.

Adolescent↗
PubMed1979

Variant angina pectoris: investigation of indexes of sympathetic nervous system function.

One thousand forty-five spontaneous episodes of S-T segment elevation were observed in three patients over a total of 72 days of continuous electrocardiographic monitoring. Eighty-nine percent of episodes were asymptomatic; chest pain tended to occur with episodes longer than 3 minutes, and ventricular ectopy occurred almost exclusively with symptomatic episodes. Nitroglycerin regularly relieved angina or S-T elevation, or both. Plasma and urinary catecholamines and their metabolites were normal. Episodes of variant angina were not associated with a generalized increase in sympathetic outflow because serum catecholamine levels at the onset and termination of the S-T abnormalities were not elevated. Controlled trials of propranolol showed no significant beneficial effect. Propranolol significantly increased the length of episodes of S-T elevation in one patient, increasing ventricular irritability. The overall course of variant angina was quite variable, with spontaneous and long-lasting remissions, necessitating cautions interpretation of clinical trials.

Angina Pectoris↗
PubMed1979

Scintigraphic characteristics of experimental myocardial infarct extension.

Technetium-99m-stannous pyrophosphate scintiphotos were evaluated for diagnosing and quantitating myocardial infarct (MI) extension in sedated dogs. Infarction and extension were produced by serial left anterior descending coronary artery ligations at 0 and 48 hours. We compared serial scintiphoto data with regional myocardial blood flow (MBF) (microsphere technique) and infarct histopathology. In eight control dogs, the scintigraphic MI area was stable at 24, 48, and 72 hours. In each of 11 dogs undergoing extension, the MI area increased after the 48-hour occlusion, averaging a 48.9% increase (p less than 0.001). Grossly, most extensions were mixtures of confluent necrosis and moderate (patchy) necrosis. MBF to confluent infarct tissue decreased significantly, allowing the documentation of extension by totaling the grams of newly flow-deprived tissue, but patchy infarct tissue had little flow deprivation, making it difficult to quantitate this type of extension accurately by flow criteria alone. Rarely, extension could be diagnosed using conventional histologic criteria. We concluded that the scintiphoto MI area was related quantitatively to infarct weight in both control and extension. However, it was not possible to determine that an increase in the MI scintiphoto area was an accurate predictor of the degree of extension using independent flow or pathologic criteria.

Acute Disease↗
PubMed1978

Prognostic and therapeutic considerations in ischemic heart disease.

Coronary arteriography and coronary artery bypass surgery have provided a tremendous stimulus to learn more about the natural history of ischemic heart disease. It has become apparent that the most important approach to understanding prognosis involves placing patients into subsets. Clinical presentation is an entry into subsets but is an inadequate way to assess the problem. Anatomical information in the form of coronary arteriographic abnormalities and left ventricular functional abnormalities are powerful prognostic determinants. It remains important to consider matters such as increased blood pressure, cardiomegaly, and perhaps other factors such as cigarette smoking as additive to any anatomical information which can be obtained for any given subset. Premature ventricular contractions, particularly of the complicated type, may be a very powerful and important additive prognostic consideration in all patients with ischemic heart disease but especially those prone to sudden cardiac death. Coronary bypass, surgery now widely practiced in Western Europe and the United States, is an established, integral part of therapy for certain subsets of patients. It clearly cannot resolve the total issue of therapy and must be utilized selectively and critically along with other intensive medical measures to hope to control risk factors and progression of the coronary arteriosclerotic process.

Coronary Angiography↗
PubMed1978

Echocardiographic evaluation of porcine heterograft valves in the mitral and aortic positions.

We evaluated 15 porcine heterograft valves in the mitral position and seven in the aortic position by echocardiography. Combining our quantitative description of valve stent and leaflet motion with 31 previously reported cases, we suggest echocardiographic criteria for the range of normal porcine heterograft valve motion in the mitral position. Quantitative evaluation of valve leaflet and stent motion for valves in the aortic position is described for the first time. Correlative hemodynamic and echocardiographic data is provided for three patients who underwent postoperative catheterization. The use of echocardiography in following the function of porcine heterograft valves is discussed.

Adult↗
PubMed1978

Prostaglandin D2, another renal prostaglandin?

Prostaglandin (PG) D2 was biosynthesized by rabbit renal papillae incubates in vitro. Quantification of the renal prostaglandins by gas chromatography-mass spectroscopy demonstrated that the concentration of PGD2 generated by renal papillae was 1/6 to 1/10 the amount of PGE2 or about 1microgram/g tissue/30 min. Infusion of the sodium salt of PGD2 into the renal artery of the dog produced a dose related increase in renal blood flow and urine flow, free water clearance, sodium excretion and potassium excretion without changes in systemic hemodynamics. At low doses PGD2 increased renal blood flow to all cortical zones. Higher concentrations of PGD2 produced a shift in the intrarenal distribution of blood flow toward the juxtamedullary nephrons.

Animals↗
PubMed1978

The effect of PGI2 on canine renal function and hemodynamics.

The effect of prostaglandin I2 (prostacyclin) on renal and intrarenal hemodynamics and function was studied in mongrel dogs to elucidate the role of this novel prostaglandin in renal physiology. Starting at a dose of 10(-8) g/kg/min, PGI2 decreased renal vascular resistance and redistributed the blood flow away from the outer cortex (zone 1) and towards the juxtamedullary cortex (zone 4). At 3 X 10(-8) g/kg/min, the renal vascular resistance decreased even further, but at this dose the mean arterial blood pressure also declined 13% indicating recirculation of this prostaglandin. PGI2 infusion at a vasodilatory dose resulted in natriuresis and kaliuresis. With a decline in filtration fraction, these changes were most likely secondary to the hemodynamic effects of this prostaglandin. Unlike PGE2, PGI2 had no direct effect on free water clearance indicating lack of activity at the collecting duct. PGI2 may be the important renal prostaglandin involved in modulating renal vascular resistance and intrarenal hemodynamics as well as influencing systemic blood pressure.

Animals↗
PubMed1977

The effect of the Valsalva maneuver on echocardiographic dimensions in man.

Physiologic changes in the circulatory system caused by performing the Valsalva maneuver are blunted or absent in patients with congestive heart failure. Previously there has been no noninvasive method for examining cardiac chamber size during this maneuver. M-mode echocardiography was used to evaluate possible changes in cardiac chamber dimensions in 12 normal subjects (group I) and 15 patients with cardiovascular disease (group II). In group I, the left ventricular end-diastolic dimension decreased 11.2% (+/- 1.5%) and the end-systolic dimension 9.5% (+/- 1.32%), with a fall in stroke volume of 29%. The left atrial (LA) dimension decreased 30%. In group II, only the response of the LA dimension is reported. There was a diminished response to Valsalva related to the severity of congestive heart failure. Patients in NYHA classes III and IV decreased LA dimension by only 3.8%, significantly less (P less than 0.001) than those in classes I and II who had essentially normal responses. Echocardiographically-determined changes in left atrial size in response to the Valsalva maneuver may provide an objective, noninvasive means of evaluating and following patients with suspected or proven congestive heart failure. Possible mechanisms for the changes observed are discussed.

Adult↗
PubMed1976

Reactive hyperemia: an index of the significance of coronary stenoses.

Coronary arterial stenosis of varying severity and length were created in open-chest dogs. The reactive hyperemic responses (RHR) to 15 second occlusions were used to produce flow increases and judge the physiological significance of the narrowings. RHR are sensitive indices of functional impairment when resting flow is unchanged. It was demonstrated that the length as well as the severity is important in assessing physiological significance by evaluation of narrowings 3 to 9 mm. long.

Animals↗
PubMed1976

Report of the Inter-Society Commission for Heart Disease Resources. Optimal resources for examination of the chest and cardiovascular system. A hospital planning and resource guideline. Radiologic facilities for conventional x-ray examination of the heart and lungs. Catheterization-angiographic Laboratories. Radiologic resources for cardiovascular surgical operating rooms and intensive care units.

This is an updated and expanded planning and oprimal resource guideline for diagnostic examinations of the cardiovascular system. Catheterization-angiographic laboratories are described and detailed specifications given for radiologic and physiologic equipment. Case loads for maintaining safe and effective performance are recommended and complication rates discussed. An optimal location for the laboratory is defined and the status of affiliated laboratories reviewed. Professional staff qualifications, relationships and requirements are enumerated and recommendations are made for organization and administration of the services. There is a protocol for electrical safety and radiation protection and a data base for assessing case loads in hospitals within a community or region. This statement also defines optimal facility and equipment criteria for conventional chest x-rays and radiologic equipment requirements for cardiovascular surgical operating rooms and intensive care units.

Angiocardiography↗
PubMed1976

Tricuspid regurgitation following inferior myocardial infarction.

Tricuspid regurgitation developed in two patients after inferior wall myocardial infarction. Neither patient had preexisting valvular heart disease or evidence of endocarditis, and neither had suffered chest trauma. Because abnormalities in right ventricular function may occur after inferior infarction, and because other known causes of tricuspid incompetence were not present, we postulate that these patients developed valvular regurgitation from dysfunction of the papillary muscle complex controlling tricuspid valve function, a mechanism similar to that proposed to explain mitral regurgitation seen with inferior wall ischemia.

Aged↗
PubMed1975

Unstable coronary artery disease: comparison of medical and surgical treatment.

In eighty-eight patients with arteriographic findings of obstructive coronary artery disease and the clinical picture of unstable angina pectoris, a decision on operative or nonoperative management was made by the attending physician. Fifty-three of them subsequently underwent aortocoronary saphenous vein bypass grafting and 35 were continued on a program of medical therapy. A marked difference in the course after the first 30 days was noted, with most of the surgically managed patients being either asymptomatic or greatly improved following coronary artery bypass. Two-thirds of the medically treated patients had persistent severe angina pectoris and non was asymptomatic in a follow-up period averaging 20 months. There were 2 late deaths in the medical group and none in the surgical group. These findings indicate that coronary artery bypass operations can be performed with low risk during the unstable phase of coronary artery disease and that relief of angina can be anticipated. In contrast, nonoperative management of unstable coronary artery disease carries an appreciable risk of death or myocardial infarction, and the majority of patients treated nonoperatively continue to experience angina.

Adult↗