Biomedical subjects

J Fast

Publications and source records attributed to J Fast.

12 recordsLinked to original sources

PubMed1993

Computerized, telephone-based stress management program.

A stress management program that used computerized, telephone-based technology was offered to the public via a free, "800" telephone number. The program was intended to reach a very large number of persons, while requiring a minimum of staff time. The program used an interactive telephone system, employing natural sounding, digitized voice, and touch tone recognition of callers' responses. The program was available 24 hours a day. It composed each message to suit the individual needs and expectations of each caller. A controlled evaluation of the program was conducted to determine how the messages could be worded and presented most effectively. The results suggest that subjects were most likely to find the messages in the program helpful, to carry out the stress management instructions, and to continue calling when the messages were personalized and contained homework assignments.

Adult↗

PubMed1991

Limits of reproducibility of cross-sectional echocardiographic measurements of left ventricular muscle mass.

The total intrinsic variability of echocardiographically determined left ventricular muscle mass was evaluated in this study. Cross-sectional left ventricular echocardiograms were made in 13 normal volunteers (8 men, 5 women), ages 31 to 41 years (mean 36) with an interval period of about eleven months. We used the parasternal long axis view, the short axis view at the papillary muscle level and the four-chamber view from the apex. M-mode recordings were made from the parasternal long-axis view. Left ventricular muscle mass from M-mode recordings was calculated using a simple cube formula and from cross-sectional echo cardiography with an area-length formula. The reproducibility of the left ventricular muscle mass for the methods was respectively 10 +/- 6% and 5 +/- 3% (mean +/- SD). From both methods cross-sectional echo is the method of choice for determining left ventricular muscle mass in man in sequential studies.

Adult↗

PubMed1991

Angiographic appearance and re-operation in an adult patient with the Bland-Garland-White syndrome.

Reconstructive surgery was performed in a 57-year old woman in whom initially the left coronary artery had originated from the pulmonary trunk, producing progressive symptoms of congestive heart failure. Recurrence of shunting was documented by Doppler echocardiography and contrast angiography, necessitating a second surgical intervention 17 months after the first procedure.

Contrast Media↗

PubMed1990

Limits of reproducibility of cross-sectional echocardiographic measurement of left ventricular ejection fraction.

The total intrinsic variability of echocardiographically determined ejection fraction was evaluated in this study. Cross-sectional left ventricular echocardiograms were made in 14 normal volunteers (9 men, 5 women), ages 31 to 41 years (mean 36 years) with an interval period of about 11 months. We used the parasternal long-axis view, the short-axis view at the papillary muscle level and the four-chamber view from the apex. M-mode recordings were made from the parasternal long-axis view. Simpson's rule and area-length formulas were used to calculate left ventricular volumes and the ejection fraction. From the methods under investigation, the Teichholz technique and the bullet method showed the best reproducibility of the ejection fraction with a coefficient of variation of 4 +/- 3% and 6 +/- 4%, respectively (mean +/- SD). The methods of Baran, and the approach using slices, showed rather large coefficients of variation, 14 +/- 11% and 9 +/- 6%, respectively.

Adult↗

PubMed1989

The influence of heart rate and age on diastolic blood flow velocity in the left ventricular inflow tract.

To investigate the relationship between age-related blood flow velocity and heart rate in the left ventricular inflow tract, we studied 118 healthy volunteers (age greater than 15 years). The maximal velocity (Vmax) of the transmitral diastolic flow during early ventricular filling (E) and during filling due to atrial contraction (A) was measured at 3 sites in the left ventricle with pulsed Doppler echocardiography. At all these sites a significant positive correlation was found between the VmaxA and the EA ratio and the interaction of heart rate and age. VmaxA increases if age and heart rate increase. The influence of the interaction of age and heart rate on VmaxA is most pronounced near the mitral annulus. VmaxA is only related to age and decreases with advancing age. Our observations contribute to the explanation of the more important role of the atrial contraction in the elderly.

Adolescent↗

PubMed1989

Endometriosis in multiparous women.

The incidence of endometriosis in the general population has been reported to range from 4% to 32%. A more realistic figure is probably 7.5%. An incidence of 7.4% was found in 42 of 566 multiparous women undergoing tubal sterilization at Baylor College of Medicine, Houston. Twelve of the 42 (29%) were less than five months postpartum. Hispanics had an incidence of endometriosis similar to that of whites and blacks. Indigent status had no bearing on the presence of endometriosis. A higher incidence of spontaneous abortion was found in patients with endometriosis, but the difference was not statistically significant.

Abortion, Spontaneous↗

PubMed1988

Limits of reproducibility of mitral pulsed Doppler spectra.

The total intrinsic variability of pulsed Doppler spectra of mitral blood flow was evaluated in this study. Doppler examinations were performed in 10 normal volunteers (7 men, 3 women), ages 29 to 57 years (mean 41) with an interval period of 3 months. The recordings were made in the apical 4-chamber view, using a 2.25-MHz transducer. The sample was placed approximately 1 cm proximal (left atrium) and 1 cm distal (left ventricle) from the middle of the anulus of the mitral valve at the onset of diastole. Processing of the raw Doppler spectra was done in a way that avoided subjective manipulation by the investigators. Mitral peak velocities, accelerations and spectral widths were measured in early diastole and late diastole. From the parameters under investigation, maximal velocities showed the best reproducibility with a range of coefficients of variation of 9 to 13%. Peak acceleration in early diastole and spectral widths showed rather large coefficients of variation, ranging from 19 to 30 and 14 to 24%, respectively. Mitral pulsed Doppler spectra in the left atrium were more reproducible than in the left ventricle.

Adult↗

PubMed1988

Normal diastolic filling patterns of the left ventricle.

Pulsed Doppler measurements on both sides of the mitral valve and M-mode left ventricular echocardiograms were performed in 215 healthy subjects, 120 males and 95 females, between one and 65 years old, in order to evaluate normal diastolic filling patterns of the left ventricle. The relation between the maximum blood velocity during early passive filling (E wave) and during atrial contraction (A wave) was computed from the Doppler spectra obtained proximal and distal to the mitral valve, resulting in the EA ratio. The influence on the EA ratio of age, gender, body surface area, blood pressure, heart rate, PR interval, respiration, wall thickness and basal wall mass of the left ventricle was investigated. The study showed that the EA ratio measured proximal to the mitral valve (in the left atrium) was significantly smaller than the EA ratio measured distal (in the left ventricle) and that the only prominent relations with the EA ratio were those with age and heart rate. The EA ratio declines with age: proximal to the mitral valve from approximately (medians) 2.5 to 1 and distal to it from 3.5 to 1.5. All other physiological variables are weakly related or unrelated to the EA ratio in this group of healthy subjects.

Adolescent↗

PubMed1988

Reference values for pulsed Doppler signals from the blood flow velocity on both sides of the pulmonary valve.

Pulsed Doppler signals were recorded from the pulmonary artery and the right ventricular outflow tract in 215 healthy subjects (120 males, 95 females; 1-65 years). Amplitude spectra from these Doppler signals were stored in digital form together with adjustment data for the instrument and the simultaneously recorded ECG. From these Doppler spectra the median of the maximal velocity (Vmax), the maximal acceleration (Amax) and the dispersion of the velocity distribution around Vmax (width) were calculated. These three median values were used to characterize the Doppler spectra and to define normal values for bloodflow velocities. Thus, calculations were made without observer interacting using a well-defined computer program. The effect of age, gender, body surface area and heart rate were studied. Reference ranges were calculated. There is a slight decrease of the median value of Vmax and Amax in the pulmonary artery during lifetime from 80 to 70 cm s-1 and from 1,200 to 800 cm s-2, respectively. On the other hand, there is no correlation between age and Vmax and Amax in the right ventricular outflow tract. The width of the spectra increases with age at both sites. No significant changes with age were seen with the other variables.

Adolescent↗

PubMed1987

Reference values for pulsed Doppler signals from the blood flow on both sides of the aortic valve.

Pulsed Doppler signals were recorded in 215 healthy subjects, 120 males and 95 females, between 1 and 65 years of age. The measurements were performed in the left ventricular outflow tract (LVOT) and in the ascending aorta (AAO). Amplitude spectra from the Doppler signals were stored in digital form together with adjustment data for the instrument, the simultaneously registered ECG and respiration signal. The maximum velocity (Vmax), the maximum acceleration (Amax) and the width of the velocity distribution around Vmax (width) were derived from these spectra and used for the characterization of the signals. These parameters were computed without observer interaction using a computer program. Effects of age, sex, body surface area, heart rate and respiration were studied. Reference ranges were calculated. The following conclusions can be drawn: Vmax and Amax in the AAO decrease clearly with increasing age from approximately 100 to 60 cm s-1 and from 2000 to 1000 cm s-2 (medians), respectively. The variation of the width in the AAO is greater for people over 45 years. Vmax, Amax and width in the LVOT increase slightly with advancing age from approximately 60 to 80 cm s-1, 800 to 1000 cm s-2 and 12 to 15 cm s-1 (medians), respectively. These parameters of flow were either unrelated or only weakly related to other physiological variables in this study group.

Adolescent↗

PubMed1986

Abnormal wall movements of the right ventricle and both atria in patients with pericardial effusion as indicators of cardiac tamponade.

A retrospective study on 126 patients with pericardial effusion showed cardiac tamponade to be present in 39 patients and absent in 87. We evaluated the distribution of the pericardial effusion as well as the effect of hydrodynamic compression on the different heart chambers. Small to large volumes of pericardial fluid were found in both groups of patients. Abnormal wall movements were only present if pericardial effusion was adjacent. Hydrodynamic compression signs consisted of abnormal wall movements of both atria at end-diastole continuing into systole, and of the right ventricle in early- and mid-diastole. Most of the patients with cardiac tamponade showed an abnormal motion pattern of both right atrium and ventricle (13 patients) or of the right atrial wall alone (12 patients). Abnormal motion of the right ventricle alone was seen in 6 patients, of both atria and right ventricle in 4 and of the left atrium alone in 1 patient. False-negative diagnoses of cardiac tamponade occurred in 3 of the 39 patients and false-positives in 2 of the 87 (sensitivity 92%, specificity 98%). Measurements of the duration of the inversion of both atria increased the specificity of these abnormal wall movements to 100%. Echocardiography can help to identify those patients who are clinically at risk and need pericardial drainage.

Adult↗

PubMedDate not supplied

Effects of aging on cardiac blood flow velocities.

The effects of aging on cardiac blood flow velocities are important as a description of the natural history of the aging process and as a reference for evaluation of the aging cardiovascular system. We therefore studied these effects in 215 healthy volunteers, 120 males and 95 females, between 1 and 65 years old. Pulsed Doppler signals were recorded proximal and distal to the mitral (M) and tricuspid (T) valves, in the left ventricular outflow tract (LVOT), in the ascending aorta (AAO), in the right ventricular outflow tract (RVOT), and in the pulmonary artery (PA). Systolic (S) flow velocity patterns consist mainly of one peak. Diastolic blood flow velocity is characterized by two peaks: one due to early filling (E) of the ventricle and a second as a result of atrial contraction (A). All peaks are characterized by the maximum of the median velocity curve (Vmax). With age increasing from 1 to 65 years, VmaxS decreases in the AAO (40%) and PA (10%), VmaxE decreases on both sides of the M valve (proximal-50%; distal-30%), and the T valve (proximal-20%; distal-30%). However, with increasing age VmaxS increases in the LVOT (25%), and VmaxA increases on both sides of the M valve (proximal-20%; distal-50%) and proximal to the T valve (30%). VmaxS in the RVOT and VmaxA distal to the T valve did not show a relation with age. These observations demonstrate that in a normal population Vmax in the heart and great vessels is age dependent at most sites.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗