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Biomedical subjects

S E Warren

Publications and source records attributed to S E Warren.

At least 37 records · Page 2Linked to original sources
PubMed1986

Assessment of the end-systolic pressure-volume relationship in human beings with the use of a time-varying elastance model.

The analysis of left ventricular end-systolic pressure-volume relationships in human beings has been hindered by the lack of a practical method of serial volume assessment and by an imprecise definition of end-systole. Modifications of the end-systolic relationship that have been used to circumvent these problems have included the use of single-point end-systolic pressure-volume ratios, the use of peak systolic pressure/minimum ventricular volume points for end-systolic points, and the use of end-ejection as a marker for end-systole. To assess the correlation between the parameters generated by these modifications with the slope (Emax) and volume intercept (VO) of the end-systolic line as defined by Sagawa's model of time-varying elastance, simultaneous measurement of left ventricular pressure and gated radionuclide volume was made in 26 patients under various loading conditions and pressure-volume diagrams were constructed for each loading condition from 32 simultaneous pressure-volume coordinates. Two pressure-volume diagrams were recorded in 14 patients and three pressure-volume diagrams were recorded in 12 patients. Emax and VO were determined in all patients from the slope and volume intercept of the isochronic pressure-volume line with the maximum time-varying elastance as described by Sagawa's model and were designated true Emax and true VO, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Pressure↗
PubMed1986

Complex wound closure, excisional biopsy, and use of simple flaps.

The primary care physician can utilize the various techniques discussed in this article to close complex lacerations, modify scars, and perform excisional biopsies. Various methods for closure of square, triangular, semicircular, circular, and rectangular defects were described. The principle of flap advancement and Z-plasties was explained, and the method for performing excisional biopsies was detailed. These techniques can be mastered by the primary care practitioner and can lead to improved patient satisfaction. These techniques can be practiced using pig's feet. These minor plastic surgery techniques are an important component in a primary care practice.

Biopsy↗
PubMed1986

A comparison of family practice clinics and free-standing emergency centers: organizational characteristics, process of care, and patient satisfaction.

Because of the increasing popularity of free-standing emergency care centers as a source of primary care services, this cross-sectional study was conducted to compare four of them with two family practice centers that provided extended hours. A total of 2,339 patient encounters were examined with data obtained from both physicians and patients. The factors that were found to be a basis for discrimination between the two types of practice were the cost of care and the patient's satisfaction with convenience and personal attention from the physicians. The overall average costs were significantly higher for the free-standing centers ($45) as compared with the family practice clinics ($27). Convenience and time factors, including waiting time, time spent with the physician, time to get an appointment, clinic location, and out-of-pocket cost, all produced a higher level of satisfaction for the free-standing clinic patients. Conversely, the personal concern of the physician and the ability to see the same physician brought higher levels of satisfaction for the family practice clinic patients. The free-standing emergency center is clearly becoming a significant factor in the delivery of primary care with evidence to suggest that patients are willing to pay a premium for convenience.

Ambulatory Care Facilities↗
PubMed1984

Occult pulmonary malignancy in syndrome of inappropriate ADH secretion with normal ADH levels.

Although the syndrome of inappropriate ADH secretion (SIADH) has many causes, principally pulmonary, central nervous system or neoplastic disease, and drugs, patients may present with SIADH in whom the etiology is not readily evident. We measured serum ADH levels in such an individual in both the eunatremic and water-loaded states and found levels to be undetectable despite failure to dilute the urine. A small oat cell pulmonary carcinoma was ultimately diagnosed with lung tomograms and cytology. Following a partial response to water restriction, demeclocycline was effective in producing a water diuresis that restored the serum sodium concentration to normal. Patients with clinical SIADH but low serum ADH levels can harbor a malignant or benign process that, notwithstanding the low ADH levels, may still remain responsive to demeclocycline, suggesting either neoplastic production of a biologically-active, immunologically-inactive ADH-like peptide, or increased renal tubular sensitivity to ADH.

Carcinoma, Small Cell↗
PubMed1983

M-mode and two-dimensional echocardiographic correlation with findings at catheterization and surgery in patients with mitral stenosis.

Thirty-two consecutive patients referred to our institution for evaluation of rheumatic mitral stenosis were studied with M-mode echocardiography (M-mode E), two dimensional echocardiography (2DE), and cardiac catheterization. Twenty-three of these patients underwent mitral valve surgery, 11 requiring mitral valve replacement, and 12 requiring open mitral commissurotomy. Clinical and noninvasive parameters were assessed in order to predict catheterization-determined mitral valve areas as calculated by the Gorlin formula, and to predict the choice of operation in patients selected for surgery. For the prediction of valvular area, 2DE planimetry correlated highly (r = 0.89, p less than 0.01) with Gorlin formula results. The presence or absence of pericardial effusion, the anterior-posterior valve leaflet separation (M-mode E), and the left atrium-aortic index (2DE) correlated poorly with the degree of mitral stenosis as determined by the Gorlin formula. The most useful predictors of type of mitral surgery were age over 50 years, 2DE valve classification, the presence or absence of calcium at fluoroscopy, and degree of anterior leaflet-septal separation (M-mode E).

Age Factors↗
PubMed1983

Autonomic and baroreflex function after captopril in hypertension.

Absent reflex tachycardia with captopril therapy suggests blunting of circulatory reflexes, perhaps contributing to antihypertensive efficacy, and angiotensin converting enzyme inhibition may alter sympathetic function. Captopril effects on autonomic function were investigated in five severe hypertensive patients. Mean blood pressure fell in all patients (from 141 +/- 6 to 119 +/- 7 mm Hg, p less than 0.02) without orthostatic blood pressure fall or increase in heart rate (both p greater than 0.1) on captopril. Captopril did not alter baroreflex sensitivity as tested by amyl nitrile hypotension or phenylephrine hypertension (both p greater than 0.1). Comparison of these severely hypertensive patients to age matched normotensive control subjects did reveal markedly blunted baroreflex sensitivity in both the amyl nitrite test (by 89%, p less than 0.01) and the phenylephrine test (by 83%, p less than 0.01), suggesting that baseline blunting of baroreflex function may in part account for absence of reflex tachycardia. Captopril diminished the cardioacceleration after cold stress (from 61 +/- 38 to 23 +/- 43 msec, p less than 0.05) as well as the blood pressure fall after alpha-adrenergic blockade (from 46 +/- 13 to 24 +/- 9 mm Hg, p less than 0.05), suggesting diminished sympathetic stimulation of resistance vessels and decreased sympathetic participation in blood pressure maintenance, possibly at the prejunctional synaptic level. Four biochemical indices of sympathetic activity did not change. Thus captopril-treated patients had blunted reflex tachycardia, commensurate with blunted baroreflex function at baseline, and physiologic and pharmacologic evidence of diminished sympathetic activity was obtained with captopril therapy. Whether diminished sympathetic activity is involved in captopril's antihypertensive effect has not been determined.

Aged↗
PubMed1982

Myocardial infarction before age 36: risk factor and arteriographic analysis.

One-hundred consecutive patients who were 35 years of age of younger underwent coronary arteriography after clinical myocardial infarction. Ninety-two percent were men. Four distinct subgroups were identified: Ninety-four patients (78 percent) had significant coronary artery disease (greater than 50 percent diameter narrowing of at least one major coronary artery), 20 (17 percent) had normal coronary arteries, 5 (4 percent) had major coronary arterial anomalies and 1 patient had coronary arteritis. Of the patients with obstructive coronary disease, risk factors were smoking in 89 percent, positive family history of coronary artery disease in 48 percent, hypertension in 21 percent and a history of lipid abnormality in 20 percent. Risk factors were distinctly less frequent in the groups without coronary atherosclerosis. In the group with coronary artery disease, the prevalence rate of one, two and three vessel disease was 32, 26 and 42 percent, respectively. Coronary arterial anomalies included anomalous origin of the left coronary artery from the pulmonary artery (three patients) and single right and single left coronary artery (one patient each). It is concluded that myocardial infarction before age 36 is a disease of men who smoke and who often have a family history of premature coronary artery disease. Twenty-two percent of patients will have normal coronary arteries, coronary arterial anomalies or coronary vasculitis. Coronary arteriography should be considered for patients who sustain a myocardial infarction before age 36 for purposes of diagnosis, management and prognosis.

Adult↗
PubMed1982

Two-dimensional echocardiography in predicting left ventricular wall motion abnormalities and left ventricular function.

In an attempt to formulate a reliable noninvasive method of detecting segmental wall motion disturbances, we examined 25 patients with coronary artery disease by two-dimensional echocardiography (2-DE), standard 12-lead electrocardiography (ECG), and biplane left ventriculography. The 2-DE technic predicted qualitative wall motion abnormalities as defined by ventriculography with a sensitivity of 88% and a specificity of 86%. The ECG (Q waves) predicted segmental wall motion disturbances with only 50% and 51% sensitivity and specificity, respectively. Extrapolating the advantages of 2-DE to the assessment of global myocardial function, left ventricular wall motion index (LVWMI) and E-point septal separation (EPSS) by 2-DE were correlated with left ventriculographic ejection fractions; r values were high (.73 and -.76, respectively) in both instances. Thus, 2-DE provides a reliable noninvasive technic by which both regional and global myocardial wall motion disturbances can be assessed. Unlike previous noninvasive methods, the 2-DE results compared very favorably with those of biplane left ventriculography.

Cineangiography↗
PubMed1981

Comparison of coronary arteriographic and left ventriculographic findings in patients with single, double, and triple vessel disease and angina pectoris.

The distribution and severity of coronary artery disease and degree of left ventricular dysfunction are described in 500 patients with single (103), double (119), and triple (278) vessel disease and angina pectoris. The coronary arterial patterns were divided into right (360), mixed (89), and left (51) systems, depending upon the blood supply to the inferior surface of the left ventricle. The following relationships were noted: 1) Coronary arterial patterns of right, mixed, and left systems do not influence the presence, distribution, or severity of coronary arterial lesions among patients with single, double, and triple vessel disease and angina pectoris. 2) Analysis of the distribution of lesions among patients with single and double vessel disease reveals that the circumflex/obtuse marginal arteries contribute least of the three major coronary arteries to angina pectoris. 3) Lesions of 70-90% reduction in coronary arterial luminal diameter are the most common, and 90-99% lesions are the least common. The latter are least stable among patients with both coronary artery disease and angina pectoris. 4) Quantitatively there is progression of both coronary artery disease and left ventricular dysfunction as one moves from single to double and then to triple vessel disease. However, the pattern of coronary arterial lesions (50-70%, 70-90%, 90-99%, and 100% reduction of luminal diameter) and the pattern of left ventricular dyssynergy (hypokinesis, akinesis, and dyskinesis) are similar among the patients with single, double, and triple vessel disease and angina pectoris.

Angina Pectoris↗
PubMed1981

M-mode and cross-sectional echocardiographic diagnosis of right ventricular cavity masses.

Two patients with metastatic carcinoma (one cervical and one testicular) in whom echocardiography was instrumental in diagnosing a right ventricular cavity mass are presented. In first case the M-mode echocardiogram revealed dense echoes in the right ventricle and right ventricular outflow tract during systole and diastole. Surgical confirmation of the mass lesion was obtained. The second case also revealed abnormal echoes in the right ventricle and right ventricular outflow tract, but they were less dense and distinct. Two-dimensional echocardiography clearly delineated a highly mobile mass of tissue in the right ventricle which corresponded to the necropsy findings.

Adult↗
PubMed1981

Clinical correlates in hypertensive patients with left ventricular hypertrophy diagnosed with echocardiography.

Seventy-three hypertensive patients were evaluated with M mode and two dimensional echocardiography. Left ventricular hypertrophy was found in 37 patients (51 percent); 29 had concentric hypertrophy and the remaining 8 had disproportionate septal thickening. Factors that did not influence the distribution of patients in the group with left ventricular hypertrophy and normal subjects included (1) duration of hypertension, (2) level of blood pressure, (3) age, (4) body surface area, and (5) race. More of the patients who had a normal left ventricular mass (32 or 89 percent) than of those who had hypertrophy (22 or 59 percent) were receiving two or more antihypertensive drugs. Electrocardiography was very insensitive in identifying left ventricular hypertrophy in these patients. The presence of increased left ventricular mass was associated with a greater incidence of other target organ disease.

Adrenergic beta-Antagonists↗
PubMed1981

Renal hemodynamic changes during long-term antihypertensive therapy.

Studies of renal hemodynamics were carried out in 84 patients with essential hypertension during long-term antihypertensive therapy with a number of drugs. Renal perfusion was maintained or enhanced despite a fall in mean arterial pressure during therapy with hydrochlorothiazide, furosemide, clonidine, prazosin, and the combination of guanabenz and hydrochlorothiazide. Renal perfusion deteriorated during long-term treatment with propranolol. Renal hemodynamics may be enhanced, maintained, or adversely influenced depending on the choice of antihypertensive agent.

Antihypertensive Agents↗