Abstract Left ventricular ejection fraction is frequently quantitated by M‐mode echocardiography despite limitations, including 1) the ability to measure an accurate left ventricular short axis, 2) the mathematic and geometric assumptions used to derive the volumes from which the ejection fraction is calculated, and 3) the lack of applicability to asynergic ventricles. Nevertheless, using a cubed function or correction formula, ejection fraction can be calculated for symmetrically contracting, normally sized, and enlarged left ventricles. A table and accompanying comments are presented.
The most common anomaly of the coronary arteries is the origin of the left circumflex artery from the right sinus of Valsalva or the right coronary artery proper. This anomaly is rarely clinically significant. A patient is reported here who has such an anomaly which did become clinically significant after a bioprosthetic aortic valve replacement. The circumflex artery described here became compressed between the Hancock aortic valvular ring and the mitral valvular apparatus. This case is the first antemortem report of such a compression to be demonstrated angiographically and the first case to be the results of an aortic bioprosthetic ring alone. Special surgical considerations must be made when performing valvular replacements on patients with this coronary artery anomaly.
Four computer programs which provide computational assistance in the analysis of man/machine systems are reported. The programs are: (1) Modified Transfer Function Program (TF); (2) Time Varying Response Program (TVSR); (3) Optimal Simulation Program (TVOPT); and (4) Linear Identification Program (SCIDNT). The TV program converts the time domain state variable system representative to frequency domain transfer function system representation. The TVSR program computes time histories of the input/output responses of the human operator model. The TVOPT program is an optimal simulation program and is similar to TVSR in that it produces time histories of system states associated with an operator in the loop system. The differences between the two programs are presented. The SCIDNT program is an open loop identification code which operates on the simulated data from TVOPT (or TVSR) or real operator data from motion simulators.
Letters and Corrections1 November 1989Medical Therapy for Chronic Congestive Heart FailureKenneth M. Kessler, MDKenneth M. Kessler, MDSearch for more papers by this authorAuthor, Article, and Disclosure Informationhttps://doi.org/10.7326/0003-4819-111-9-768 SectionsAboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinkedInRedditEmail ExcerptTo the Editor:The editorial by Drs. Jaeschke and Guyatt (1) on the medical therapy for chronic congestive heart failure was concise, timely, and well focused; however, the treatment subgroup was assumed and not defined. Currently, there are four studies (2-4) demonstrating that approximately 30% of patients with congestive heart failure have normal left ventricular ejection fractions. Such patients cannot be clinically discerned from those with abnormal ejection fractions, rarely have marked hypertrophy or hypertrophic cardiomyopathy, but frequently have hypertensive or ischemic heart disease with accompanying diastolic left ventricular dysfunction. Pertinent to medical therapy, patients with normal ejection fractions do...References1. JaeschkeGuyatt RG. Medical therapy in chronic congestive heart failure [Editorial]. Ann Intern Med. 1989;110:758-60. LinkGoogle Scholar2. EcheverriaBilskerMyerburgKessler HMRK. Congestive heart failure: echocardiographic insights. Am J Med. 1983;75:750-5. CrossrefMedlineGoogle Scholar3. SouferWohlgelernterVita RDN. Intact systolic left ventricular function in clinical congestive heart failure. Am J Cardiol. 1985;55:1032-6. CrossrefMedlineGoogle Scholar4. AguirrePearsonLewen FAM. Usefulness of doppler echocardiography in the diagnosis of congestive heart failure. Am J Cardiol. 1989;63:1098-102. CrossrefMedlineGoogle Scholar5. Kessler K. Heart failure with normal systolic function. Arch Intern Med. 1988;148:2109-11. CrossrefMedlineGoogle Scholar1. JaeschkeGuyatt RG. Medical therapy for congestive heart failure. [Editorial]. Ann Intern Med. 1989;110:758-60. LinkGoogle Scholar This content is PDF only. To continue reading please click on the PDF icon. Author, Article, and Disclosure InformationAffiliations: University of Miami Veterans Administration Medical Center Miami, FL 33125 PreviousarticleNextarticle Advertisement FiguresReferencesRelatedDetails Metrics Cited byCongestive heart failure in coronary artery diseaseCardiac failure in coronary heart disease 1 November 1989Volume 111, Issue 9Page: 768-769KeywordsCardiomyopathiesCardiovascular therapyEjection fractionHeart failureLeft ventricular ejection fractionLongitudinal studies Issue Published: 1 November 1989 PDF downloadLoading ...
