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[Cardiologic application of a clinical database with graphic extension and its utilization in inter-hospital teleconsultation].

A local area network of personal computers has been operative in our Cardiology Department for seven years, to collect and retrieve on-line character-based data. At present, the network is based on 2 servers and 21 workstations. DBF and DOS files are used by a Clipper 5.2d compiled program to handle demographic data, clinical reports (32,000/year) and diagnostic codes of more than 52,000 patients. In the last two years, we started entring ECG tracings using: RS232 connection, floppy disk transfer, and modem connection with commercially available machines as well as by image scanner. We integrated our clinical database with three dedicated subsystems, written in Assembly and C languages, to manage drawings, digital ECGs and complete reports. Mass storage is provided by a 10 Gbyte magneto-optical disk autochanger physically connected to a dedicated server running an original software manager to optimize routine access to the optical disks. Interhospital network connections were established with two different institutions to allow clinical information sharing, long distance consultation and ECG transfer. The system has been found to be fast, user-friendly and suitable for daily operation of a large cardiological database. Standardized versions of the system are running in seven other cardiology institutions in Italy.

Cardiology

Transtelephonic electrocardiographic monitoring: reliability in detecting the ischemic ST segment response during exercise.

The ECG detection of ST segment depression during maximal treadmill exercise has diagnostic and prognostic significance in coronary artery disease. This study of 200 consecutive patients undergoing Bruce exercise testing for chest pain documents the ability of a transtelephonic ECG system, capable of storing segments of ECG memory during exercise, to reliably record ST segment depression detected during simultaneous exercise testing (sensitivity 79%; specificity 99.6%). Of the three transtelephonic ECG systems tested, the modified precordial V5 snap-on lead most accurately reflected ST segment amplitude and morphology with no "false positives" (specificity 100%) and few "false negatives" (sensitivity 78%). Therefore, this system is a potentially important clinical tool for accurately and conveniently monitoring coronary patients during exercise outside the hospital (e.g., following myocardial infarction) as well as for providing useful clinical information for ambulatory patients with undiagnosed sporadic chest pain.

Adult

Clinical application of a second generation electrocardiographic computer program.

An electrocardiographic computer program based on multivariate analysis of orthogonal leads (Frank) was applied to records transmitted daily by telephone from the Veterans Administration Hospital, West Roxbury, Mass., to the Veterans Administration Hospital, Washington, D. C. A Bayesian classification procedure was used to compute probabilities for all diagnostic categories that might be encountered in a given record. Computer results were compared with interpretations of conventional 12 lead tracings. Of 1,663 records transmitted, 1,192 were selected for the study because the clinical diagnosis in these cases could be firmly established on the basis of independent, nonelectrocardiographic information. Twenty-one percent of the records were obtained from patients without evidence of cardiac disease and 79 percent from patients with various cardiovascular illnesses. Diagnostic electrocardiographic classifications were considered correct when in agreement with documented clinical diagnoses. Of the total sample of 1,192 recordings, 86 percent were classified correctly by computer as compared with 68 percent by conventional 12 lead electrocardiographic analysis. Improvement in diagnostic recognition by computer was most striking in patients with hypertensive cardiovascular disease or chronic obstructive lung disease. The multivariate classification scheme functioned most efficiently when a problem-oriented approach to diagnosis was simulated. This was accomplished by a simple method of adjusting prior probabilities according to the diagnostic problem under consideration.

Analysis of Variance

Simple method for computer-aided analysis of echocardiograms.

The use of echocardiography in the diagnosis and assessment of heart disease is increasing as greater familiarity is obtained with this noninvasive procedure. Quantitative evaluation of echocardiographic studies has heretofore required time-consuming manipulation of mathematical formulas. A simple method utilizing a sonic digitizing tablet has been developed for computer-aided analysis of M-mode echocardiograms. This device can convert a point located manually with a digitizing pen into X and Y coordinates and with use of the standard telephone network can communicate on a time-shared basis with a DECSYSTEM-10 computer. A program has been written to compute and type the results of standard calculations involving mitral valve motion and left ventricular function. The information can also be stored on disk by the computer for future use. This simple, relatively inexpensive system is valuable because of the ease with which it permits usually laboriously obtained information to be extracted from the standard echocardiogram.

Diagnosis, Computer-Assisted

Impact of field-transmitted electrocardiography on time to in-hospital thrombolytic therapy in acute myocardial infarction.

To assess the impact of a field-transmitted electrocardiogram (ECG) on patients with possible acute myocardial infarction, randomized and open trials were performed with a portable electrocardiographic system coupled with a cellular phone programmed to automatically transmit ECGs to the base hospital. Consecutive patients served by the 6 units of the Salt Lake City Emergency Rescue System were studied; 71 patients were randomized to in-field ECG (n = 34) versus no ECG (n = 37). Time on scene was 16.4 +/- 9.7 minutes for the ECG group versus 16.1 +/- 7.0 minutes for the non ECG group (difference not significant). Time of transport averaged 18.2 +/- 9.9 and 17.6 +/- 13.1 minutes, respectively (difference not significant). Six of 34 patients with in-field ECG showed acute myocardial infarction, qualified for and received thrombolytic therapy at 48 +/- 12 minutes after hospital arrival (range 30 to 60) compared with 103 +/- 44 minutes (p less than 0.01) for 51 historical control patients and 68 +/- 29 minutes for 6 concurrent control patients without in-field ECG. Thus, in-field ECG causes negligible delays in paramedic time, leads to significant decreases in time to in-hospital thrombolysis and may make in-field therapy feasible. In-field ECG may be an important addition to reperfusion strategies.

Allied Health Personnel

Detection of preterm labor by ambulatory monitoring of uterine activity for the management of oral tocolysis.

A study to evaluate whether ambulatory tocodynamometry at home could enhance the management of oral tocolysis was performed. On discharge from the hospital, after completing parenteral tocolysis, 60 patients received a lightweight tocodynamometer, designed for storage and transmission of uterine activity data. Sixty additional contemporary patients, who were matched for maternal age, parity, and risk factors, served as a control group. In addition to instructions regarding self-detection of recurrent preterm labor, monitored patients recorded uterine activity for greater than or equal to 200 min/day and then transmitted the data to the study center. Tocolytic dosage was adjusted to maintain mean uterine contraction frequency of less than 4/hr. Persistent uterine contractions of greater than or equal to 4/hr lead to in-hospital evaluation for recurrent preterm labor. The results indicate that the monitored group had a lower incidence of preterm births mostly because of a decrease in the proportion of patients with failed tocolysis. It is suggested that surveillance of uterine activity at home during oral treatment for preterm labor may be instrumental in improving perinatal outcome in high-risk patients.

Adult

Using JPEG image compression to facilitate telemedicine.

Economical applications of teleradiology and telemedicine are limited to the existing telephone network infrastructure, which greatly limits the speed of digital information transfer. Telephone lines are inherently slow, requiring image transmission times to be unacceptably long for large, complex, or numerous images. JPEG (Joint Photographic Experts Group) image transmission has been shown to compress images to 10% of the original file size without a noticeable change in the quality of the image. This study was carried out to assess the quality of medical diagnostic images after JPEG compression and decompression. X-rays, computed tomography scans, and ultrasound samples were compressed and decompressed using JPEG. The compressed JPEG images were indistinguishable from the original images. The JPEG images were approximately 10% of the original file size. This would reduce image transmission times by 90% (eg, an unacceptable time of 50 minutes would be reduced to an acceptable time of 5 minutes). JPEG can be used to optimize teleradiology and telemedicine.

Humans

Systems analysis of computerized EKG processing center.

A functional description of a computerized system for analysis of electrocardiograms (EKGs) is presented. Although it is recognized that the diagnostic accuracy of the program is the critical parameter in determining system acceptance, other system features such as quality control, turn around time and cost are shown to be of high importance. A digital simulation of alternative configurations for on-line data acquisition is presented. The simulation predicts the system throughout and wait times in different phases of a telephone EKG transmission for combinations of interfaces, telephone lines and acquisition procedures. These results should be helpful in selecting the appropriate configuration for each special situation.

Computers

Advances in the management of cardiac arrhythmias in children.

The authors discuss several recent developments in the diagnosis and management of cardiac arrhythmias in the young, focusing on areas in which the greatest progress has been made so that the pediatrician can incorporate these developments into his practice and participate more fully in the management of the patient requiring tertiary care.

Adolescent