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Biomedical subjects

C C Jaffe

Publications and source records attributed to C C Jaffe.

At least 19 recordsLinked to original sources
PubMed1992

Multimedia for clinical education in myocardial perfusion imaging.

Interactive multimedia has many advantages as a presentation medium for diagnostic imaging case studies, particularly for teaching digital imaging techniques such as myocardial perfusion imaging. Multimedia documents may incorporate interactive audiovisual presentations, sophisticated diagnostic images, anatomical illustrations, and text in medical instructional materials. The article describes a multimedia teaching atlas of SPECT and planar myocardial perfusion imaging delivered on Apple Macintosh II microcomputers, and discusses some of the advantages of delivering medical educational materials with interactive multimedia techniques.

Computer-Assisted Instruction↗
PubMed1992

Echocardiography of the right side of the heart.

Echocardiography has not only revealed the morphologic aspects of the right-sided cardiac structure but has, through the use of pulsed and color Doppler imaging, provided a whole new level of certainty in the diagnosis of cardiac disease. The structure and function of the right-sided chambers are now far better appreciated since this technique has become more widely used for early clinical diagnosis of right-sided cardiac disease.

Atrial Function, Right↗
PubMed1990

Reduction of myocardial ischemia during percutaneous transluminal coronary angioplasty with oxygenated Fluosol.

The effects of perfusion of an oxygen-carrying perfluorochemical emulsion (Fluosol) in alleviating symptoms of myocardial ischemia during balloon occlusion were examined in a multicenter trial of 245 patients. Severe anginal pain occurred less frequently in patients receiving Fluosol perfusion (21%) than in those receiving routine angioplasty (34%) (p less than 0.05). ST-segment changes at balloon deflation in routine angioplasty patients were significantly greater than in patients who received oxygenated Fluosol perfusion (2.2 +/- 1.2 vs 1.7 +/- 0.9 mm; p less than 0.03). Profound regional wall dysfunction (-561 +/- 224 U) was observed in routine angioplasty patients by 2-dimensional echocardiography. Patients receiving oxygenated Fluosol perfusion, however, maintained near baseline levels of ventricular function (-61 +/- 335 U) during occlusion (p less than 0.0001). Mean global left ventricular ejection fraction was preserved at baseline levels during balloon inflation in patients perfused with oxygenated Fluosol but decreased significantly (p less than 0.001) during occlusion in routine angioplasty patients. A total of 26 complications (19 routine group; 7 perfusion group) was reported. Adverse responses to the perfusate were infrequent, occurring in 1.6 and 2.0% of patients after the test dose and during perfusion, respectively. Thus, transcatheter perfusion with an oxygen-carrying perfluorochemical emulsion is effective in alleviating myocardial ischemia during angioplasty and can be safely administered in this patient population.

Aged↗
PubMed1990

Metabolic and functional effects of perfluorocarbon distal perfusion during coronary angioplasty.

Myocardial lactate metabolism and left ventricular function were studied in 12 patients during angioplasty of the left anterior descending artery performed with distal coronary perfusion (oxygenated and nonoxygenated Fluosol) and by conventional technique without distal perfusion. Before balloon inflation there was net lactate extraction by the heart (31 +/- 6%). During balloon inflations performed with distal perfusion there was net lactate release into the great cardiac vein while the balloon was inflated; the great cardiac vein lactate concentration was approximately 25% lower during perfusion with oxygenated versus nonoxygenated Fluosol (p less than 0.02) indicating less myocardial lactate release. After balloon deflation washout of lactate into the great cardiac vein (net myocardial release) was observed in all 3 protocols. Left ventricular ejection fraction measured by echocardiography decreased markedly during nonperfused (53 +/- 3 to 36 +/- 3%, p less than 0.001) and nonoxygenated Fluosol (52 +/- 2 to 30 +/- 3%, p less than 0.001) inflations. This dysfunction was largely prevented by oxygenated Fluosol where only a minimal decrease in ejection fraction (51 +/- 2 vs 48 +/- 2%, p less than 0.02) occurred. Analysis of regional contractile function yielded similar results. Although oxygenated perfluorocarbons decrease cardiac lactate release during angioplasty, this study provides evidence for the onset of lactate production even when ventricular function is preserved.

Aged↗
PubMed1990

An introduction to interactive hypermedia.

Current computers can create and display documents that incorporate a variety of audiovisual media, and can be organized to allow the user, guided by curiosity and not by a fixed path through the material, to move through the information in non-linear pathways. These hypermedia documents and the concept of hypertext offer significant new possibilities for the creation of educational materials for the biomedical sciences. If the full capabilities of the computer are to be used to enhance the educational experience for learners, computer professionals need to collaborate with publishing and teaching professionals. Biomedical communications professionals can and should play a role in establishing and evaluating hypermedia documents for medical education.

Audiovisual Aids↗
PubMed1990

Myocardial dysfunction during percutaneous transluminal coronary angioplasty.

Balloon inflation during percutaneous transluminal coronary angioplasty (PTCA) transiently occludes the coronary artery, causing temporary ischemia. In patients without collaterals, regional hypokinesis of the ventricular myocardium at risk occurs within the first 20 seconds and persists throughout balloon inflation. Early PTCA procedures were performed with brief balloon inflations, but the desire to improve procedural results has led many operators to extend balloon inflation times to 45 seconds or longer. Although the ischemic indicators of pain and electrocardiographic changes are commonly noted with these longer inflations, actual hemodynamic consequences are often obscured by physiological compensation. The PTCA-induced ischemic period is often too short to measure changes in cardiac output by conventional methods, but it is increasingly evident that profound regional myocardial dysfunction, in fact, occurs. Continuous two-dimensional echocardiography with quantitative assessment of regional wall motion and ejection fraction is particularly effective in detecting the location, extent, and temporal change of ischemic regional contractile dysfunction. Echocardiographic recordings during baseline, ischemia, and post-balloon-deflation periods permit examination of PTCA-caused alterations in ejection fraction and ventricular volumes and allow the use of testing techniques aimed at mitigation of ischemia.

Adult↗
PubMed1989

Fetal cardiac output in the isoimmunized pregnancy: a pulsed Doppler-echocardiographic study of patients undergoing intravascular intrauterine transfusion.

The mechanism of development of hydrops fetalis in severe isoimmunization has been subject to speculation. We performed pulsed Doppler assessment of cardiac output in 13 severely isoimmunized fetuses before and after intravascular transfusion and compared the results with 37 control fetuses between 20 and 34 weeks' gestation. The cardiac index of the anemic fetuses was significantly greater than that of the control group. A significant (right ventricle, p less than 0.01; left ventricle, p less than 0.02) increase in indexed output was noted from both ventricles and in the combined ventricular output (mean +/- SEM 644 +/- 35.3 ml/kg/min in control fetuses versus 879 +/- 86.0 ml/kg/min in anemic fetuses, p less than 0.006). An increase in cardiac output was also noted when anemic fetuses were compared with gestational age-specific norms. We conclude that severely anemic fetuses of isoimmunized pregnancies tend to have significantly higher cardiac output than do unaffected fetuses and that this high output state may play a part in the development of hydrops fetalis.

Blood Transfusion, Intrauterine↗
PubMed1989

Hypermedia techniques for diagnostic imaging instruction: videodisk echocardiography encyclopedia.

Because of the visual complexity of medical images and the intensive tutorial experience required to develop image recognition expertise, professional training programs have concentrated on educating limited numbers of experts. Videodisk and CD-ROM (compact disk read only memory) image storage media now make it possible for a microcomputer workstation to provide a learning environment substantially equivalent to that of conventional time-consuming tutorial methods. A demonstration hypermedia program on echocardiography was constructed that provides a user-controlled learning environment with instant access to 54,000 video frames encompassing 1,200 clinical items. The instructional module is controlled by a microcomputer, which provides electronic linkage to relevant graphics, animations, text, categorized data bases, and digitized sound. The system has been successfully used in a residency program as the primary instructional tool for achieving an intermediate level of clinical expertise. Hypermedia offer substantial advantages over conventional books as a clinical reference source.

Computer-Assisted Instruction↗
PubMed1988

Dynamics of early and late left ventricular filling determined by Doppler two-dimensional echocardiography during percutaneous transluminal coronary angioplasty.

To study the influence of ischemia on both early and late left ventricular filling, Doppler 2-dimensional echocardiography was used to measure filling parameters during percutaneous transluminal coronary angioplasty (PTCA) in 26 patients. Doppler recordings were taken immediately before balloon inflation and continuously during balloon inflation and deflation until 60 seconds into the recovery period. During PTCA of the left anterior descending artery (16 patients) there was a 35% decrease in early peak filling rate from 269 +/- 88 to 169 +/- 55 ml/s (p less than 0.0005) by 60 seconds of balloon inflation. In patients undergoing PTCA of the left circumflex (4 patients) or dominant right coronary artery (6 patients), the early peak filling rate decreased 15% from 325 +/- 126 to 284 +/- 137 ml/s (p less than 0.005). The decrease in early peak filling rate became evident at approximately 15 seconds after balloon inflation and fully recovered 20 seconds after balloon deflation. Rather than an expected increase in atrial stroke volume and a decrease in early to late filling ratio during coronary occlusion, there was a 28% decrease in atrial stroke volume during left anterior descending coronary artery PTCA and a 6% decrease during right coronary and circumflex PTCA. Because of the simultaneous decrease in both early and late ventricular filling, peak early to late filling ratio was only slightly altered during PTCA. There was an 83% increase in mean pulmonary artery wedge pressure during balloon inflation from 12 +/- 5 to 20 +/- 4 mm Hg. In 11 of these patients global systolic function was measured on subsequent inflations during PTCA using 2-dimensional echocardiography.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Preservation of left ventricular ejection fraction during percutaneous transluminal coronary angioplasty by distal transcatheter coronary perfusion of oxygenated Fluosol DA 20%.

The cardioprotective efficacy of coronary perfusion during angioplasty was evaluated. Forty-two patients underwent transcatheter infusion of oxygenated Fluosol DA, 20% emulsion (FDA-20), a perfluorocarbon oxygen transport fluid, into the distal coronary artery during balloon inflations. Left ventricular function was continuously monitored by two-dimensional echocardiography, and left ventricular ejection fraction was quantitatively analyzed from the video record by an area-length method with a validated computer algorithm. Each patient had multiple nonperfused and perfused balloon inflations lasting more than 45 seconds. Nineteen of the 42 patients also received control solutions of oxygenated Ringer's lactate and nonoxygenated FDA-20. The ejection fraction of nonperfused sequences fell from a baseline value of 57 +/- 15% to 36 +/- 14% at 45 seconds of inflation time (p less than 0.0005). Falls of similar magnitude were seen in the lactated Ringer's and nonoxygenated FDA-20 perfused balloon inflations. The ejection fraction fall was associated with a 54% rise in end-systolic volume (p less than 0.0005) and a 4% rise in end-diastolic volume (p = ns) compared to baseline. Inflations perfused with oxygenated FDA-20 showed a 45-second, left ventricular ejection fraction of 53 +/- 13% (p = ns compared to baseline), which was significantly greater (p less than 0.0001) than the 45-second ejection fraction of the nonperfused, or control solution perfused sequences. Results indicate that the profound fall in ejection fraction occurring during percutaneous transluminal coronary angioplasty can be ameliorated by distal coronary perfusion with an oxygenated perfluorocarbon emulsion.

Adult↗
PubMed1988

Peak filling rate normalized to mitral stroke volume: a new Doppler echocardiographic filling index validated by radionuclide angiographic techniques.

The noninvasive measurement of left ventricular filling has relied predominantly on radionuclide-derived peak filling rate normalized to end-diastolic volume. Doppler echocardiography also has the ability to measure peak filling rate, but wide application of this technique has been limited by technical errors involved in quantitative echocardiographic determination of mitral anulus cross-sectional area and ventricular volumes. For Doppler echocardiography, normalization of peak filling rate to mitral stroke volume rather than end-diastolic volume permits the derivation of a diastolic filling index that is relatively free of errors caused by geometric assumptions, diameter measurements and sample volume positioning. This normalization process can be achieved by simply dividing early peak filling velocity by the time velocity integral of mitral inflow. To validate this new Doppler echocardiographic filling index, Doppler echocardiographic and radionuclide-derived peak filling rate, both normalized to mitral stroke volume, were compared in 30 patients; there was an excellent correlation (r = 0.91, SEE = 0.88). This variable was not influenced by the position of the sample volume in relation to the mitral apparatus in contrast to early filling velocity, which increased 37%, and early/late filling (E/A) ratio, which increased 43% as the sample volume was moved from the anulus to the tips of the mitral leaflets. In a cohort of 22 normal patients, the mean peak filling rate normalized to mitral stroke volume (SV) was 5.25 +/- 1.47 SV/s. The mean peak filling rate for a subgroup of eight normal patients aged 57 to 89 years (mean 71 +/- 9) was 3.9 +/- 1 SV/s.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1987

Silent ischemia during coronary occlusion produced by balloon inflation: relation to regional myocardial dysfunction.

Thirty patients with stable exertional angina undergoing percutaneous transluminal coronary angioplasty of an isolated obstructive lesion of the proximal left anterior descending artery were prospectively evaluated to investigate the relation between angina induced by balloon inflation and the quantity and severity of myocardial ischemia as determined by electrocardiographic (ECG) monitoring and by echocardiographic assessment of regional and global left ventricular wall motion. Anginal pain interviews, continuous two-dimensional echocardiographic recordings and 12 lead ECG recordings at 10 second intervals were obtained for the first two inflation sequences. Seventeen patients had angina with both inflations (symptomatic group), seven patients had no angina or related symptoms during either inflation (asymptomatic group) and six patients had both painful and painless inflations (mixed response group). Comparison of the three groups revealed that they did not differ in mean age, sex distribution, prior history of angina or the incidence of comorbid conditions. Echocardiographic measurements of global and regional left ventricular dysfunction during balloon inflation were comparable in the symptomatic and asymptomatic groups. Similarly, there were no significant differences in the time to onset or magnitude of ST segment changes. The results of the wall motion and ECG studies in the mixed response group paralleled the results in the symptomatic and asymptomatic groups, with no significant differences in any of the variables measured between the painful and painless inflations. These data demonstrate that silent myocardial ischemia occurs in an appreciable proportion of patients during coronary angioplasty and the absence of angina does not imply that a lesser amount of myocardium is jeopardized than with painful inflations.

Angina Pectoris↗
PubMed1986

Regional myocardial dysfunction during coronary angioplasty: evaluation by two-dimensional echocardiography and 12 lead electrocardiography.

Balloon inflation performed during percutaneous transluminal coronary angioplasty causes transient total occlusion of the coronary artery and thus provides a model for evaluation of the regional myocardial responses to transient ischemia. Twenty patients with normal left ventricular function undergoing angioplasty of isolated stenosis of the proximal left anterior descending coronary artery were studied. In group A (14 patients) analysis of one inflation-deflation sequence per patient was performed. Group B (six patients) had multiple (greater than 5) inflations; the first and last sequences were analyzed. Assessment included continuous two-dimensional echocardiography with computerized quantitative analysis of regional left ventricular wall motion, and continuous 12 lead electrocardiographic recordings. The mean duration of inflation in group A was 62 +/- 6 seconds (mean +/- SD). The onset of regional left ventricular dysfunction was 12 +/- 5 seconds after inflation. Profound dysfunction was noted in all patients. After 60 seconds of balloon occlusion of the coronary artery, 29% of patients had severe hypokinesia of the ischemic region and 71% had akinesia or dyskinesia. With deflation there was prompt recovery of regional function, with full recovery at 43 +/- 17 seconds. Comparison of data from first and last inflations in group B revealed no significant differences in time to onset of dysfunction, magnitude of dysfunction or time to complete recovery of function. The onset of ischemic electrocardiographic changes lagged behind the onset of wall motion abnormalities, with only 64% of patients showing evidence of ischemia on 12 lead electrocardiograms at 20 seconds of inflation. After 60 seconds, 86% had ischemia detectable by electrocardiography. Thus, balloon inflation during coronary angioplasty leads to profound but reversible regional left ventricular dysfunction. Repeated occlusions of the coronary artery during angioplasty do not have a cumulative ischemic effect. It may be hazardous to apply these findings to patients who have underlying major left ventricular dysfunction and in whom the reversibility of dysfunction and lack of cumulative ischemic effect may not be assured.

Adult↗
PubMed1985

Quantitative flow measurements with Doppler ultrasound: techniques, accuracy, and limitations.

Using Doppler ultrasound, blood-filled structures appearing on a real-time ultrasound image may be interrogated for flow information. Quantitation of the Doppler signal may yield estimates of instantaneous and time-averaged velocity, volume flow rate, and pressure difference. In this article, the techniques of signal analysis used are discussed, together with the sources of error that confront their clinical application.

Blood Flow Velocity↗