A transthoracic devascularization procedure for control of bleeding esophageal varices: preliminary report.

A procedure for control of variceal bleeding has been described which involves "devascularization" of the distal one third of the esophagus and upper one half of the stomach combined with a Nissen fundoplication performed through a left lateral thoracotomy and an incision in the left diaphragm. Transection of the truncal vagi is required to effectively de vascularize the distal esophagus and, thus, pyloromyotomy or pyloroplasty is added. Six patients who were moderately high risk candidates underwent this procedure for control for persistent hemorrhage; five of these patients were operated on within 48 hours of admission. There was one postoperative mortality. The five survivors have not rebled, and there has been no evidence of encephalopathy or progressive liver deterioration over a mean follow-up of thirteen months.     

Running as fast as they can: organizational changes in home health care

During the 1980s, as the health care industry experienced what observers have dubbed a revolution, the home health industry also experienced its own transformation. Utilizing three organizational theories (neoinstitutional, resource dependency and population ecology), the authors report on a study of a probability sample of 163 home health agencies (HHAs) that were interviewed in 1986 and again in 1987 on the effects of Medicare policy changes including prospective payment (DRGs). This study tests hypotheses concerning the influence of environmental factors (e.g., state policy and characteristics of the local market) and organizational characteristics of the HHA (e.g., tax status and Medicare reliance) in explaining the propensity of HHAs to be (or become) parts of chains and/or multi-facility systems; and to develop particular types of interorganizational relations. The paper discusses the results in the context of public policy changes and the implications for future research and practice.     

Electrocardiographic diagnosis of left ventricular hypertrophy: depolarization changes

Electrocardiographic signs of left ventricular hypertrophy (LVH) are on one hand accepted as independent cardiovascular risk factors and indicators of target organ damage in hypertensive patients, but, on the other hand they are strongly criticized for their low sensitivity. In this paper, a historic perspective on the ECG dignosis of LVH is presented, showing the development of current views on the role of ECG in LVH detection. Based on the fact that ECG provides information on the electrical properties of myocardium and on new knowledge about electrical remodeling in LVH, a shift of paradigm in our consideration of the diagnosis of left ventricular hypertrophy is proposed, based on changes in the electrical properties of hypertrophied myocardium. This new paradigm could explain the broad spectrum of QRS patterns seen in LVH, including increased QRS voltage, prolonged duration of QRS complex, left axis deviation, prolonged intrinsicoid deflection, LBBB and LAFB patterns, as well as pseudo-normal ECG findings.     

Testing of a New T‐Wave Subtraction Algorithm as an Aid to Localizing Ectopic Atrial Beats

Background: Identifying the timing and morphology of an ectopic P wave from the surface electrogram can aid in the diagnosis and localization of atrial arrhythmias. Given the relatively short coupling interval of atrial ectopic beats, the P wave is often obscured by the larger amplitude QRS‐T wave complex. A method to uncover such “buried” P waves using a standard 12‐lead surface ECG would be clinically useful and could potentially be a noninvasive guide to catheter ablation of focal atrial tachycardia. Methods: We developed an automated computerized program (BARD DUO LAB SYSTEM?) designed to subtract the QRS‐T wave complex from the surface electrogram and uncover a previously obscured P wave. The purpose of the present study was to validate this program. The surface ECG from 21 patients undergoing atrial pacing during electrophysiologic study (group I) and 10 patients with atrial tachycardia (group II) were analyzed and the derived P‐wave morphology assessed using correlation waveform analysis (CWA) and visual grading by three reviewers. Results: The algorithm successfully uncovered the P wave in each surface ECG. For the 21 patients in group I, average CWA comparing the derived P wave with the previous paced P wave was 83%. Average CWA for group II was 82%. Visual grading of the match between derived P waves and paced P waves revealed a 21/21 match in group I patients and a 12/12 match in 9/10 of group II patients. Conclusions: An ectopic atrial P wave obscured by a coincident QRS‐T wave complex can be accurately uncovered using this new algorithm. Addition of this technique to existing methods may improve the diagnosis of atrial arrhythmias and aid in the localization and ablation of ectopic atrial foci.     

Extraction of Buried P Waves from Printed Electrocardiograms

Background: Morphologic identification of ectopic P‐waves from surface ECGs can be challenging, particularly when the P‐wave is buried in the QRST wave complex. Because ECGs are often available on paper and not digitally, we developed a method of subtracting the T‐wave from the buried P‐wave complex on paper ECGs. Methods: To validate our system, an atrial extrastimulus was introduced during and following the T‐wave. The ECGs were scanned and then transformed from an image format to a digital format. A computer algorithm digitally subtracted a QRST with no buried P‐wave from one with a buried P‐wave, thus resulting in an extracted P‐wave. The extracted P‐waves were compared to the nonburied P‐wave by determining correlation coefficients and by visual grading by two independent reviewers. Results: Visual grading comparing the buried P‐wave with the exposed paced P‐wave was 94%. The median correlation coefficient was 85%. Conclusions: An ectopic atrial P‐wave obscured by a coincident QRST wave complex can be accurately derived from printed ECG using this PC‐based system. Addition of this technique to the existing methods may aid in the localization and ablation of ectopic atrial foci.