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Biomedical subjects

S D Clements

Publications and source records attributed to S D Clements.

At least 19 recordsLinked to original sources
PubMed1994

Recruitment and retention of the older adult into research studies.

Recruitment and retention of the older adult participant presents challenges. Unless the researcher is attuned to the physical, mental and psychosocial characteristics and issues unique to the older adult population, major problems may occur. When working with an older adult population, the researcher must be aware of the changes consistent with normal aging often complicated by chronic disease states, as well as the special concerns of respondent burden, informed consent, transportation, negotiations with gatekeepers, physician involvement and common recruitment issues. Recruitment and retention must be addressed by researchers in the proposal stage of the research protocol. Techniques are available to overcome the barriers.

Accidental Falls↗
PubMed1991

Outpatient cardiac catheterization: a report of 3,000 cases.

A total of 3000 patients have had cardiac catheterization in the Andreas Gruentzig Cardiovascular Laboratory of the Emory Clinic. The purpose of this presentation is to describe the patient population selected for this procedure and our experience with this group. The concept of catheterization as an outpatient is attractive from the standpoint of cost savings and time conservation. Safety has been questioned. We have found that this technique can be performed safely in carefully selected outpatients. Careful selection attempted to eliminate those with unstable symptoms, recent myocardial infarction, severe diabetes, and renal failure. Small catheters were used to minimize the potential for bleeding. Excellent opacification of vessels was obtained with these catheters. Despite careful screening we found 2.2% had significant left main obstruction, 10.8% had triple-vessel disease, 16.0% had double-vessel disease, and 23.5% had single-vessel disease, and a similar percentage had normal coronary arteriograms. Our patients experienced ventricular fibrillation on five occasions, there were two small cerebral emboli with reversible neurologic defects, two episodes of pulmonary edema, and two episodes of severe allergic reactions. Only three patients had significant groin bleeding at home that required compression of the site. We subsequently did angioplasty on 323 patients, performed cardiac surgery (mostly coronary bypass) on 187 patients, and admitted 18.2% of the entire group. We conclude that this procedure can be done safely in this carefully designed setting and it saves time and offers cost savings. Patient selection is very important to minimize potential emergency situations and complications. The laboratory must be carefully set up and provide a close relationship with a hospital capable of attending to any unexpected emergency.

Ambulatory Care↗
PubMed1991

Lack of association between keratoconus, mitral valve prolapse, and joint hypermobility.

The authors enrolled 95 patients with keratoconus and 96 matched controls in a cross-sectional study to determine if mitral valve prolapse and hypermobile joints occur with greater frequency in individuals with keratoconus than in individuals without keratoconus. The hypothesis that keratoconus may not be a distinct eye disease, but a nonspecific sign representing a more generalized systemic disorder, possibly a mild collagen tissue abnormality, was considered. M-mode and two dimensional echocardiography and cardiac auscultation detected no statistically significant difference in the prevalence of mitral valve prolapse in patients with keratoconus compared with controls. Formal, systematic examination of five joints also failed to detect a statistically significant difference in the prevalence of hypermobile joints in keratoconus patients and controls. However, as an ancillary finding, a significantly higher proportion of patients with keratoconus was found to have a history of hay fever than was the case with controls.

Adult↗
PubMed1989

Left ventricular aneurysm: a review.

The vast majority of left ventricular aneurysms (LVA) are secondary to coronary artery disease. The natural history of LVA is now better understood. The increasing use of noninvasive techniques has allowed earlier recognition and better appreciation of LVA genesis and pathophysiology. Improvements in surgical anesthesia and techniques have resulted in more successful LVA surgery. This article reviews the pathogenesis, natural history, and complications of LVA. Surgical indications and available treatment options in the management of patients with LVA and severe symptoms are presented. Left ventricular pseudoaneurysm (false aneurysm) will also be discussed.

Heart Aneurysm↗
PubMed1988

Alterations in myocardial thallium-201 distribution in patients with chronic systemic hypertension undergoing single-photon emission computed tomography.

To characterize thallium-201 distribution in single-photon emission computed tomography (SPECT) cardiac images and polar bullseye maps, 100 patients with chronic systemic hypertension due to end-stage renal disease were studied and the results compared with those in 35 normotensive control subjects. Thallium-201 SPECT was performed after exercise in all control subjects and 70 hypertensive patients, and after intravenous dipyridamole in 30 patients. A frequent finding in hypertensive patients was a fixed decrease in the normal lateral-to-septal count density ratio in immediate thallium-201 SPECT images (1.02 +/- 0.10 vs 1.17 +/- 0.08 in control subjects, p less than 0.00001) and in 3-hour delayed images (1.02 +/- 0.11 vs 1.11 +/- 0.08 in control subjects, p less than 0.00001). No significant difference in count density ratio was present in patients undergoing treadmill versus diypridamole intervention. In 35 patients the count density ratio was greater than 2.0 standard deviations below the normal mean, creating the false impression of a fixed lateral defect (i.e., myocardial infarction). In 12 patients, myocardial wall thickness was measured at end-diastole by 2-dimensional echocardiography. Wall thickness was increased (greater than 11 mm) in all patients. The mean lateral-to-septal wall thickness ratio was 1.08 +/- 1.11; in no patient was the ratio less than 0.76 to indicate selective septal hypertrophy. The lateral-to-septal wall thickness and lateral-to-septal thallium-201 count density ratios correlated poorly (r = 0.43).(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiomegaly↗
PubMed1987

Tissue plasminogen activator: an evaluation of clinical efficacy in acute myocardial infarction.

Recombinant tissue plasminogen activator (t-PA) is a synthetic fibrinolytic protein which activates plasminogen or converts plasminogen to plasmin specifically in the presence of fibrin. With its "clot-selectivity", t-PA is capable of lysing clots without having a significant effect on circulating plasminogen. In contrast, activation by streptokinase and urokinase is non-specific and affects circulating as well as thrombus plasminogen. These agents, therefore, have a greater potential to induce bleeding than does t-PA. Plasma levels of t-PA following intravenous administration are generally proportional to the dose, but there can be significant interpatient variation. The drug is eliminated primarily by hepatic metabolism and is then excreted in the urine. Half-life of circulating t-PA ranges from 2-8 minutes. Most clinical trials of t-PA have evaluated its use in acute myocardial infarction. Indeed, its current indication is for thrombolysis in evolving MI. Short-term benefits of t-PA administration include a prompt reperfusion and restoration of coronary artery patency in patients with total coronary artery occlusion. The degree to which the heart benefits from thrombolysis is unknown, but electrocardiographic changes, changes in cardiac enzymes and alterations in the pattern of chest pain indicate that rapid reperfusion may limit the size of the infarct. Overall, t-PA appears to be a relatively safe thrombolytic agent. Bleeding is the most significant adverse effect reported with t-PA administration. In most cases, however, bleeding has been minor. Other reported adverse effects include reperfusion arrhythmias, bradycardia, and chest pain. Allergic reactions were not observed in clinical trials.

Animals↗
PubMed1985

Ruptured papillary muscle, a complication of myocardial infarction: clinical presentation, diagnosis, and treatment.

Ruptured papillary muscle due to myocardial infarction was encountered in 14 patients during the period 1975-1983. Five of the 14 patients had a history of angina pectoris and two had a history of prior myocardial infarction. Eleven patients with myocardial infarction developed additional pain due to myocardial ischemia and/or a murmur of mitral regurgitation and pulmonary edema within a week, 3 others had a prolonged course with intermittent pain due to myocardial ischemia and breathlessness for longer periods and then deteriorated. Thirteen of our 14 patients developed a murmur and all but one had pulmonary edema on the chest x-ray. Five patients had infarction patterns on the electrocardiogram, the remainder of the patients had only ST- and T-wave changes. Echocardiograms showed fine flutter and notching of the anterior mitral leaflets and vigorous contractions of the left ventricle. Only one patient was demonstrated to have a papillary muscle tip prolapsing into the left atrium on two-dimensional echocardiography. Twelve patients underwent surgery and 8 survived. Seven patients had single-vessel coronary disease, 4 involving the circumflex system and 3 involving the right coronary system. Four of the 7 patients with single-vessel coronary disease survived surgery. Five patients went to surgery with the intra-aortic balloon pump in place and only 3 survived. Three others had the pump inserted intraoperatively and 2 of these survived. Six of 9 patients who had mitral valve replacement and coronary bypass survived. Ejection fraction ranged from 40 to 79%. Surgical survival did seem to be related to the extent of papillary muscle rupture, with the best results occurring in the group with a small portion of the tip ruptured. Seven patients had a stormy clinical course and required surgery within 10 days of rupture. Four of these 7 survived. It seems reasonable to believe that these patients who often have small infarction and limited coronary disease have good potential for survival. Our approach has been to move toward surgery once the diagnosis is made to avoid the sudden deterioration that frequently occurs. The surgical mortality in this group remains in the 30 to 40% range.

Aged↗
PubMed1983

The cost effectiveness of selected optometric procedures.

As funding of optometric care by the government and third parties increases, more regulation of vision care is anticipated. Utilization of cost effectiveness studies may largely determine the level of optometric care acceptable to these providers. Consequently, a method of determining cost effectiveness of optometric procedures has been developed and applied to three models of optometric care. Data taken from a review of patient records are used to develop quantifiable cost criteria for a specified patient group. These criteria include actual cost, patient acceptance (satisfaction), and professional acceptance of prescribed therapy. These criteria are then applied to each model of patient care to determine which is most cost effective.

Cost-Benefit Analysis↗
PubMed1981

Coronary bypass for relief of persistent pain following acute myocardial infarction.

Between January, 1976, and April, 1980, 116 patients had urgent myocardial revascularization for clinical instability within 30 days of acute myocardial infarction (MI). Group 1 (8 patients) had coronary bypass grafting within 24 hours of acute MI; Group 2 (20 patients) had coronary bypass grafting 2 to 7 days after acute MI; and Group 3 (88 patients) had coronary bypass grafting 8 to 30 days after infarction. Indications for operation were persistent or recurrent pain (81%), pain plus ventricular arrhythmias (12%), and pain plus compelling anatomy. The incidence of single-vessel, triple-vessel, and left main coronary artery disease was 28%, 31%, and 12%, respectively. There were no hospital deaths in the series. The incidence of inotropic requirements, postoperative intraaortic balloon pumping, ventricular arrhythmias, and perioperative infarction was higher in patients operated on within 7 days of acute MI than for patients having coronary bypass grafting after this time. There have been 5 late deaths during a mean follow-up of 14 months. Actuarial survival was 97% at 18 months. Seventy-one percent of patients are presently pain free. Graft patency was 84% in 17 patients recatheterized after coronary bypass grafting and in 14 patients, grafts placed into the area of infarction were patent. This study suggests that the frequency of perioperative complications will be increased in patients operated on within one week of MI, but after this period, coronary bypass grafting can be accomplished with the same morbidity as the of elective operation.

Angina Pectoris↗
PubMed1981

The role of the electrocardiogram in the diagnosis of myocardial infarction.

The electrocardiogram is often the key to the diagnosis of myocardial infarction. In order to use it effectively, the clinician must be aware of its limitations. Most importantly, it must be remembered that a single normal electrocardiogram does not exclude myocardial infarction. In addition, certain clinical entities mimic infarction electrocardiographically and others mask electrocardiographic evidence of infarction. These factors must be considered when the electrocardiogram is interpreted in order to provide the clinician with the best possible information about the patient.

Cardiomegaly↗