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Biomedical subjects

L Crouse

Publications and source records attributed to L Crouse.

9 recordsLinked to original sources
PubMed1998

Safety and efficacy of closed-loop arbutamine stress echocardiography for detection of coronary artery disease. International Arbutamine Study Group.

Closed-loop arbutamine stress echocardiography has been shown to be safe and effective for detecting coronary artery disease (CAD) using a standardized infusion protocol and centralized core laboratory analyses. However, the accuracy of arbutamine stress echocardiography using local test interpretation has not been previously tested in a large population. The present study reports the safety, sensitivity, and specificity of arbutamine stress echocardiography in a multicenter trial allowing user-defined, nonstandardized protocols and local test interpretation. In all, 1,070 patients underwent arbutamine stress testing at 81 sites. Heart rate increased from 73 +/- 13 to 124 +/- 15 beats/min, systolic blood pressure from 144 +/- 24 to 174 +/- 25 mm Hg, and pressure rate product x 10(3) from 10.5 +/- 2.8 to 19.6 +/- 3.9. Among 1,070 patients, there were only 2 (0.2%) significant adverse events related to arbutamine, both of which resolved completely with appropriate therapy. There were no incidents of ventricular fibrillation, sustained ventricular tachycardia, or death related to testing. Among 242 patients who underwent arbutamine stress echocardiography and diagnostic coronary angiography within 12 weeks, sensitivity and specificity for detection of CAD were 71% (95% confidence interval 64% to 77%) and 67% (95% confidence interval 52% to 80%), respectively. Closed-loop arbutamine stress echocardiography is a safe and effective method for evaluating CAD in clinical practice.

Adult↗
PubMed1998

Stress echocardiography: recommendations for performance and interpretation of stress echocardiography. Stress Echocardiography Task Force of the Nomenclature and Standards Committee of the American Society of Echocardiography.

Cardiovascular stress testing remains the mainstay of provocative evaluation for patients with known or suspected coronary artery disease. Stress echocardiography has become a valuable means of cardiovascular stress testing. It plays a crucial role in the initial detection of coronary disease, in determining prognosis, and in therapeutic decision making. The purpose of this document is to outline the recommended methodology for stress echocardiography with respect to personnel and equipment as well as the clinical use of this recently developed technique. Specific limitations will also be discussed.

Cardiovascular Agents↗
PubMed1983

Electrophysiologic effects of theophylline in young patients with recurrent symptomatic bradyarrhythmias.

In this study, both acute electrophysiologic actions of intravenously administered theophylline and clinical effects of chronic oral theophylline therapy were assessed in 10 young patients (aged 9 to 41 years) without clinically significant cardiac disease, in whom recurrent symptoms of syncope and dizziness were attributed to transient bradyarrhythmias (sinus pauses, marked sinus bradycardia or paroxysmal atrioventricular [AV] block). Intravenous theophylline infusion (serum concentration range 9.5 to 12.0 mg/liter) shortened means sinus cycle length (control 973 +/- 285 ms versus theophylline 880 +/- 226 ms, p less than 0.005) and decreased both the estimated sinoatrial conduction time (control 169 +/- 56.0 ms versus theophylline 143 +/- 55.3 ms, p less than 0.05) and the maximum corrected sinus node recovery time (control 442 +/- 251.0 ms versus theophylline 255 +/- 146.2 ms, p less than 0.05). In addition, theophylline infusion shortened the minimum atrial paced cycle length with sustained 1:1 AV conduction (control 414 +/- 86 ms versus theophylline 379 +/- 97 ms, p less than 0.05) and consistently reduced AV node functional refractory periods. Subsequent chronic oral theophylline therapy (serum levels 9 to 12 mg/liter) was tolerated in 8 patients (80%). During a follow-up of 5 to 24 months, suppression of symptoms was achieved in 6 of the 8 patients. Thus, theophylline exhibits positive chronotropic and dromotropic effects in man at serum concentrations in the usual therapeutic range (10 to 15 mg/liter). Furthermore, suppression of symptoms during follow-up suggests that theophylline treatment may be a useful therapeutic consideration in some patients with recurrent symptomatic bradyarrhythmias.

Adolescent↗
PubMed1980

A follow-up study of heroin addicts five years after first admission to a methadone treatment program.

A random sample (n = 260) of the first 799 admissions to the Santa Clara County Methadone Treatment Program was sought for interview five years after the date of their first dose; 80% were successfully located. Data from the year prior to entering methadone treatment were compared to data from the year prior to the follow-up interview. The two specific areas showing the most dramatic improvement were in heroin use and employment. During the year prior to the follow-up interview, 24% of the subjects with known outcome had no heroin use; 19% were abstinent from both heroin and methadone and at risk (not in jail or other treatment) for the entire year. Unemployment dropped from 51% to 19%. Subjects drank significantly more alcohol during the year prior to interview, with a 48% increase in the number of daily drinkers. Little or no change was seen in the use of other drugs, in the percentage of subjects with an arrest or jail time, or in the number living with an addicted person. Time in treatment was not a predictor of successful outcome and subjects who had left methadone treatment were doing at least as well as those continuously in methadone treatment.

Adolescent↗