Search PubMed⌕ Search

Biomedical subjects

S B Schmidt

Publications and source records attributed to S B Schmidt.

15 recordsLinked to original sources
PubMed1992

Radiofrequency catheter ablation of cardiac arrhythmias: initial WVU experience.

Radiofrequency catheter ablation is a method of selectively destroying cardiac tissue to treat various arrhythmias. In a relatively short time, it has evolved from an investigational tool to a widely applied clinical technique (1). This article reviews the current status of radiofrequency catheter ablation and reports on the results of its initial clinical use in 14 patients at West Virginia University Hospital.

Aged↗
PubMed1990

The prehospital phase of acute myocardial infarction in the era of thrombolysis.

To evaluate the factors affecting the time between symptom onset and hospital arrival in patients with acute myocardial infarction (AMI), we gave a detailed questionnaire to all who were admitted or transferred with AMI from January 1988 to February 1989. In these 126 patients (94 men, 32 women) the mean prehospital time was 5.9 +/- 11.0 hours (median 2.0, range 0.4 to 69.0). The time between symptom onset and reaching a decision that medical care should be sought was 62% of the mean prehospital time. In 100 (79%) patients, the prehospital time was less than or equal to 6 hours; of these, 61 (61%) were retrospectively judged to have been optimal candidates for lytic therapy. Stepwise multiple regression selected the following 4 variables as independent predictors of prehospital time: slow symptom progression; low income; female gender; and advanced age. All of these variables are predictive (p less than 0.03) of increased prehospital time; absence of prior AMI was of borderline additional significance (p = 0.053). Similarly, logistic regression analysis selected slow symptom progression, female gender and low income as significant (p less than or equal to 0.02) independent predictors of prehospital time greater than 6 hours. The logistic regression model incorporating these 3 variables had a sensitivity of 54%, a specificity of 95% and a positive predictive value of 72% in identifying patients with prehospital time greater than 6 hours. Thus, these data indicate it is possible to characterize patients likely to experience undue prehospital delay during AMI, which may be of importance to future public education efforts.

Female↗
PubMed1990

What are the facts on cholesterol? Questions physicians often ask about screening and treatment.

In spite of, or possibly because of, the many studies about cholesterol in the literature, some physicians remain confused or skeptical about the issues and conclusions. Reasonably clear evidence indicates that lowering the total serum cholesterol level can lessen the likelihood of primary coronary artery disease. There is no reason to believe that this benefit would not be conferred on women and the elderly, even though specific studies have not been done in these populations. Also, lowered cholesterol levels have been shown to correlate with regression of established atherosclerotic lesions. Moderate dietary changes can have significant impact on serum lipid levels in many patients, and a trial of low-dose drug therapy can usually identify those who may benefit from combination therapy.

Cholesterol↗
PubMed1990

Survey of physician practices in managing patients with chronic ventricular arrhythmias.

To better understand how physicians manage patients with chronic ventricular arrhythmias, questionnaires were mailed in July, 1989, to 680 internists, family physicians and cardiologists in West Virginia. Responses were returned by 35 per cent; those from 33 physicians who seldom prescribed drugs to treat arrhythmias were excluded from analysis. Quinidine and procainamide were the preferred first-line antiarrhythmics for 53.3 per cent and 24.3 per cent of physicians, respectively. Control of symptoms was listed as the usual indication for therapy by 32.2 per cent, and improvement in prognosis by 20.1 per cent. Physicians perceived a high prognostic benefit to antiarrhythmic treatment in patients with sustained ventricular tachycardia or history of cardiac arrest, and a generally low prognostic benefit in those with mitral valve prolapse. Opinion was divided on the prognostic benefit in other patient groups including those with frequent ventricular premature beats following myocardial infarction. These results help quantify current physician practices in managing patients with chronic ventricular arrhythmias.

Arrhythmias, Cardiac↗
PubMed1990

Wolff-Parkinson-White syndrome.

This article discusses a patient with Wolff-Parkinson-White syndrome who recently underwent surgical ablation of her accessory pathway at West Virginia University Health Sciences Center. Surgical cure of this arrhythmia is possible in a high percentage of cases and should be strongly considered for those with life-threatening arrhythmias or poorly controlled symptoms.

Adult↗
PubMed1989

Sudden cardiac death.

This article reviews the epidemiology of sudden cardiac death, and outlines suggested management of patients who are successfully resuscitated from cardiac arrest. Emphasis is placed on the favorable impact of newer means of therapy on the very high recurrence rate using empiric antiarrhythmic treatment.

Death, Sudden↗
PubMed1989

Mitral valve prolapse syndrome revisited.

Mitral valve prolapse is a relatively common cardiac finding which, unfortunately, is often overdiagnosed and overtreated. For most patients, it can be regarded as an incidental observation without significance in terms of symptoms or prognosis. This article reviews our current understanding of what has been aptly called "the mitral prolapse fiasco".

Humans↗
PubMed1988

Mitral valve prolapse. Practical aspects of diagnosis and management.

Because auscultatory findings may vary greatly among patients with suspected mitral valve prolapse, careful examination is essential to avoid diagnostic misinterpretation. The presence of mitral valve prolapse can be confirmed by echocardiography. Clinicians should be reluctant to attribute symptoms to the echo or physical finding of prolapse. Prognosis in the vast majority of patients is excellent, and reassurance is a critical element of successful patient management. Endocarditis prophylaxis and periodic follow-up examinations are appropriate for patients with mitral regurgitation.

Echocardiography↗
PubMed1988

Diagnostic utility of memory equipped transtelephonic monitors.

The diagnostic utility of memory-equipped transtelephonic electrocardiographic monitors was evaluated in a series of 31 patients referred for evaluation of unexplained syncope (16), presyncope (8), or palpitations (7). Previous nondiagnostic workups included 4 +/- 1 days (mean +/- standard error of the mean) of 24-hour Holter and/or in-hospital telemetric monitoring per patient. The duration of monitoring averaged 31 +/- 2 days per patient. Electrocardiographic recordings were made during a typical symptom episode in 9 of 31 (29%) patients, including 0 of 16 with syncope, 3 of 8 (37%) with presyncope, and 6 of 7 (86%) with palpitations (p less than .001). The probability of recording typical symptoms was strongly influenced by their previous frequency. Potentially causal arrhythmias were documented in 5 of 7 (71%) patients with palpitations, but in none of the other symptom subgroups (p less than .001). Monitoring led to changes in therapy in only two patients. During followup of 9 +/- 1 months, symptoms continued in 4 of 16 (25%) with syncope, 7 of 8 (87%) with presyncope, and 7 of 7 (100%) with palpitations (p = .001). The diagnostic utility of these devices thus appears to be low in patients with previously unexplained syncope or presyncope. The yield was high in those monitored for palpitations, which may be in part attributable to the greater frequency of symptoms observed in this group.

Arrhythmias, Cardiac↗
PubMed1986

The influence of residual coronary stenosis on size of infarction after reperfusion in a canine preparation.

The effect of a residual coronary artery stenosis on size of myocardial infarction was studied in an open-chest canine preparation of coronary occlusion and reperfusion. Eighteen male mongrel dogs (16 to 26 kg) underwent left thoracotomy under general anesthesia; the circumflex artery was instrumented with a hydraulic cuff occluder, a screw clamp, and an electromagnetic flow probe. Animals were randomized to one of three groups: group I (n = 6) had a 6 hr circumflex occlusion, group II (n = 6) had a 2 hr occlusion followed by 4 hr of partial reperfusion through a residual stenosis adjusted to approximately 30% of baseline flow, and group III (n = 6) had full reperfusion for 4 hr after a 2 hr occlusion. Zones of risk, infarction, and no reflow were defined by staining with Evans blue, triphenyl tetrazolium chloride, and fluorescein, respectively. At 6 hr the hearts were excised and areas of risk, infarction, no reflow, and hemorrhage were determined by planimetry of serial transverse heart slices (5 mm thick). Infarction as a percent of the risk area was 96 +/- 1% in group I, 90 +/- 2% in group II, and 79 +/- 4% in group III (p less than .001), and the differences between each of the groups were significant. Gross hemorrhage was seen in none of the six dogs in group I, two of the six in group II, and five of the six in group III, but did not affect infarct size. We conclude that residual stenoses may exert a deleterious effect on the outcome of coronary reperfusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

Lipoprotein and apolipoprotein levels in angiographically defined coronary atherosclerosis.

Recent studies suggest that apolipoproteins and subfractions of high-density lipoprotein (HDL) cholesterol may be better predictors of atherosclerotic coronary artery disease (CAD) than are plasma cholesterol and total HDL cholesterol. To examine this hypothesis, plasma cholesterol and triglyceride, cholesterol of low-density lipoprotein, HDL and its subfractions 2 and 3, apolipoprotein A-I, the apolipoprotein B of low-density lipoprotein, the ratio of apolipoprotein EII to EIII, and ratios of several of these variables were measured in a selected series of 126 patients (83 men and 43 women) who underwent coronary angiography for suspected CAD. Mean values of many of these variables differed significantly between the men with CAD and the men without significant CAD, when controlled for age, use of beta blockers and diuretic drugs. Using multivariate logistic regression analysis, the only variable that made a significant independent contribution in predicting CAD in men was the ratio of HDL cholesterol to total plasma cholesterol (p less than 0.0001). The mean of this ratio was 0.17 +/- 0.01 mg/dl in the men with CAD and 0.23 +/- 0.02 mg/dl in the male controls. All men with ratios of less than 0.15 mg/dl had significant CAD, defined as 50% or greater luminal diameter narrowing of 1 or more of the major coronary arteries. No measurement was a significant univariate or multivariate predictor of CAD in the women, but the power to detect such predictors was reduced because of small group sizes. In conclusion, the ratio of HDL cholesterol to plasma cholesterol may be superior to many of the more recently described lipoprotein and apolipoprotein-derived predictors of CAD.

Apolipoprotein A-I↗
PubMed1985

PVCs in the elderly: when to start worrying.

Recent studies using electrophysiologic testing have established that effective antiarrhythmic therapy does indeed prolong survival in the high-risk group of survivors of out-of-hospital cardiac arrest. Ideally, the initial antiarrhythmic agent is selected on the basis of its efficacy, side effects, ease of administration, cost, and interaction with other medications. To a large extent, however, selection remains empiric. In patients without QT prolongation, long-acting procainamide or quinidine are usually tried first.

Aged↗