Richard D. Judge

Takayasu's arteritis and the aortic arch syndrome

Abstract From the many confusing terms currently employed to describe occlusive aortic arch disease, two are selected: aortic arch syndrome to describe the general clinical entity regardless of etiology; and Takayasus arteritis to describe the idiopathic aortitis usually affecting young women. All others would best be discarded, particularly that of pulseless disease. It is suggested that Takayasus arteritis is a connective tissue disease which like lupus erythematosus is sex limited; that two factors may be important in its localization: an autoimmunopathy affecting vascular elastin, and hemodynamic stress. The clinical diagnosis of Takayasus arteritis can be made with certainty only by exclusion or pathologic study. Factors of helpful diagnostic value include: abnormal serum electrophoretic pattern, persistent elevation of the erythrocyte sedimentation rate and angiocardiographic changes.

Changes in myocardial threshold. Physiologic and pharmacologic factors in patients with implanted pacemakers

Abstract Seventy-one controlled threshold studies were performed on 14 patients with implanted cardiac pacemakers. Eating and sleeping raised myocardial threshold significantly, whereas exercise had a reverse effect. A solution of insulin and potassium in dextrose, 3 per cent NaCl, and aldosterone also increased threshold. Epinephrine, methylprednisolone, and potassium chloride in Ringers solution lowered threshold. Isoproterenol caused an initial fall in threshold, followed by a marked rise. No significant changes were demonstrated with 10 per cent dextrose, normal saline, calcium gluconate, lanatoside C, procaine amide, atropine, or morphine at those dosages that were arbitrarily chosen for this study. The results demonstrate that myocardial threshold in man is labile, and that it can be manipulated by physiologic activities and pharmacologic agents.

Myocardial threshold in patients with artificial pacemakers

Abstract A method for estimating myocardial threshold in patients with implanted artificial pacemakers has been described. By the external application of a calibrated suppression signal, the output of the implanted unit can be gradually reduced until the myocardial response ceases. The threshold level thus determined can be expressed as a per cent of available pulse energy by a simple calculation. This method promises to have clinical application because it is relatively simple and entirely external. It has been demonstrated to be safe, no sequelae having occurred during over 700 human studies. In combination with our previously reported method of estimating interelectrode impedance, it should provide a rational means of serially evaluating pacemaker function following implantation. It is applicable to both direct myocardial and transvenous modes of pacing, but its most important limitation at the present time is that it can be used with only one of the commercially available pacemakers. By application of quantitative threshold measurements, we have been able to confirm our clinical observations of exit block as a significant cause of pacemaker failure. This complication comprised the second most common cause of failure to pace, 14 per cent in a series of 128 implantations. It has also been possible by this means to verify the effectiveness of glucocorticoid and sympathomimetic drugs in lowering the myocardial threshold level. The implications of these observations have been briefly discussed. Threshold analysis may prove to be an important means of investigating the myocardial effects of other pharmacologic preparations in the future.

Using a Multimedia Tool to Improve Cardiac Auscultation Knowledge and Skills

AbstractOBJECTIVE: Today’s medical school graduates have significant deficits in physical examination skills. Medical educators have been searching for methods to effectively teach and maintain these skills in students. The objective of this study was to determine if an auscultation curriculum centered on a portable multimedia CD-ROM was effective in producing and maintaining significant gains in cardiac auscultatory skills. DESIGN: Controlled cohort study PARTICIPANTS: All 168 third-year medical students at 1 medical school in an academic medical center. INTERVENTIONS: Students were tested before and after exposure to 1 or more elements of the auscultation curriculum: teaching on ward/clinic rotations, CD-ROM comprehensive cases with follow-up seminars, and a CD-ROM 20-case miniseries. The primary outcome measures were student performance on a 10-item test of auscultation skill (listening and identifying heart sound characteristics) and a 30-item test of auscultation knowledge (factual questions about auscultation). A subset of students was tested for attenuation effects 9 or 12 months after the intervention. RESULTS: Compared with the control group (1 month clinical rotation alone), students who were also exposed to the CD-ROM 20-case miniseries had significant improvements in auscultation skills scores (P<.05), but not knowledge. Additional months of clerkship, comprehensive CD-ROM cases, and follow-up seminars increased auscultation knowledge beyond the miniseries alone (P<.05), but did not further improve auscultation skills. Students’ auscultation knowledge diminished one year after the intervention, but auscultation skills did not. CONCLUSION: In addition to the standard curriculum of ward and conference teaching, portable multimedia tools may help improve quality of physical examination skills.

Harvey: the impact of a cardiovascular teaching simulator on student skill acquisition

Harvey, a life-sized cardiovascular patient simulator which depicts the auscultatory, tactile and visual findings for a broad range of cardiac problems was used as an adjunct to a standard sophomore physical skills course. Significant gains, as measured by a pre-posttest, were found in overall scores as well as in assessment and interpretation of carotid pulses and precordial auscultation. There were no significant changes in jugular venous pulse or precordial motion assessment. There were no significant correlations between student perceptions of skills gained and objective test measurements.This study underscores the need for cardiovascular examination skills training and confirms the utility of a simulator such as Harvey in developing these abilities. The lack of correlation between perceived improvements and actual changes highlights the need for objective evaluations of educational endeavours. Use of a simulator such as Harvey presents the student with the opportunity to compare and contrast cardiova...

Permanent Ventricular Pacing: Effect on Long-Term Survival, Congestive Heart Failure, and Subsequent Myocardial Infarction and Stroke

Abstract One hundred and fifty patients with permanent ventricular pacemakers were followed to determine long-term survival statistics, the effect of pacing on congestive heart failure, and the inc...

Acquired Pulmonic Stenosis Report of a Case Caused by Mediastinal Neoplasm

Acquired pulmonic stenosis is rare. A well-documented case of pulmonary infundibular stenosis due to mediastinal lymphoma has been described. Complete disappearance of the heart murmur followed therapy with nitrogen mustard. Other causes of acquired pulmonic stenosis have been discussed.

Measurement of pacemaker performance

Abstract Entirely satisfactory treatment of complete heart block has been prevented by an inability to measure pacemaker function after implantation. Two major problems can be identified in the long-term management of pacemaker patients: first, adequate prediction of when a pacemaker will fail; and second, accurate diagnosis of the type of pacemaker failure if it occurs. Observations on dogs gave precise measurements of interelectrode impedances. A method is described of externally measuring the interelectrode resistance and capacitance of implanted pacemakers. In studies on both dogs and human beings it was found that all changes in interelectrode impedance could be identified by changes in pacemaker rate and pulse width. Serial measurements of these two parameters allowed accurate diagnosis of the different types of “pacemaker failures.” The method also enabled anticipation of failures, other than wire breakage, before they were clinically evident. We think that pacemaker performance can be adequately evaluated by this method, making unnecessary prophylactic replacement of the unit.

Committee report on economic, administrative and legal factors influencing the insurability and employability of patients with ischemic heart disease

This report reviews how government agencies and private industry use medical information related to ischemic heart disease. The key premises of this conference include the following: ??Ischemic heart disease exerts a significant economic impact on government and industry. ??Advances in medicine are only slowly translated into changes in administrative and legal guidelines. ??Failure of physicians to communicate pertinent information adversely affects the assessment of employability and insurability. ??Many practicing physicians need a better understanding of the administrative and legal guidelines affecting insurability and employability of patients with ischemic heart disease. As many as 5.4 million Americans exhibit coronary artery disease, manifestations of chronic angina or healed myocardial infarction (1). Treatment of myocardial infarction accounts for the largest component of all hospitalization costs and foregone earnings due to cardiac disease (2).

An Appraisal of the Double Indicator-Dilution Method for the Estimation of Mitral Regurgitation in Human Subjects

The amount of mitral regurgitation was estimated in 50 patients by an indicator-dilution technic and by the usual clinical, catheterization, operative, and autopsy criteria. There was a good correlation between the two estimates. Patients with significant mitral regurgitation (grade 2 or grade 3) had, with one exception, QR/QF ratios above 0.41. There were at least two instances where the calculated QR/QF was almost certainly falsely high. It seems likely that these discrepancies are related to the presence of an unusually large volume between the pulmonary artery and the femoral artery.