Cheryl L. Reid

Inhibitory effect of electroacupuncture (EA) on the pressor response induced by exercise stress.

Abstract.We examined the effect of EA on the exercise stress-induced pressor response in healthy adult subjects of both sexes. Each subject was subjected to a bicycle exercise test using a ramp protocol once/week for three or four weeks. Subjects were asked to perform the following tests in random order: 1) a baseline exercise test without EA and 2) exercise after acupuncture at P 5–6, LI 4-L 7 and/or G 37–39 acupoints. Brachial systolic (SBP), diastolic (DBP), and mean blood pressures (MBP), heart rate (HR) and the rate-pressure product (RPP, systolic BP x HR/100) were measured every three min, while a 12 lead ECG was monitored continuously. We observed increases in MBP, SBP, HR and RPP in all 17 subjects during exercise. In 12 of the 17 subjects (71 %), EA for 30 min before exercise, either at Jianshi-Neiguan acupoints (P 5–6) or Hegu-Lique acupoints (LI 4-L 7), led to an increase in maximal workload, and reduced peak SBP, MBP and RPP responses to exercise; EA did not alter DBP or HR responses in these subjects. EA at control acupoints (Guangming-Xuanzhong acupoints, G 37–39) in five subjects did not alter the hemodynamic responses. Seven additional subjects were enrolled to study the effect of EA during a bicycle exercise test using a constant workload. The results were similar, in five of the seven subjects SBP, MBP and RPP after exercise were attenuated significantly by EA at P 5–6. We conclude that EA at specific acupoints improves exercise capacity and reduces the hemodynamic responses in approximately 70% of normal subjects.

Demographics and correlates of five-year change in echocardiographic left ventricular mass in young black and white adult men and women: the Coronary Artery Risk Development in Young Adults (CARDIA) Study

OBJECTIVEnThe goal of this study was to determine the presence and correlates of change (Delta) in left ventricular (LV) mass by echocardiography in young adults.nnnBACKGROUNDnLeft ventricular mass is known to be a powerful independent predictor for cardiovascular disease events in adults. However, little is known about Delta in LV mass over time in young adults.nnnMETHODSnCoronary Artery Risk Development in Young Adults (CARDIA) is a multicenter, longitudinal, population-based study of black and white men and women who were ages 23 to 35 at the time of their initial two-dimensionally directed M-mode echocardiography exam (year 5); half the cohort had a repeat echocardiography exam five years later (year 10). Data were analyzed from 1,189 participants who had paired echocardiography studies. To minimize reader variability, blinded measurements on initial and repeat echocardiography were performed nearly contemporaneously by the same reader.nnnRESULTSnIn multilinear regression analyses, significant (p < 0.05) predictors of year 10 two-dimensional guided M-mode LV mass included initial LV mass, initial body mass index (BMI) and change in BMI for all race/gender subgroups. Initial systolic blood pressure (SBP) was a significant predictor of year 10 LV mass in white men and black women; change in SBP was significant in black women with a trend towards significance in white women. Left ventricular mass remained constant in all race/gender subgroups, except black women, where it increased (by 5.9 g [mean]). Black women also had the largest increases in BMI and SBP. In black women, a five-year weight gain of 20 pounds and a 15-mm Hg increase in SBP would be expected to be associated with a 9% to 12% increase in LV mass.nnnCONCLUSIONSnParticularly in black women, weight and blood pressure control may be important community health and treatment goals to prevent LV hypertrophy.

Hypertension, diuretics and breast cancer risk

It is unclear whether hypertension and antihypertensive medication use are associated with breast cancer. In order to examine these associations, we conducted a case–control study among women aged 50–75 years. Breast cancer cases were ascertained via a population-based cancer registry (n=523) and controls were ascertained via random-digit-dialing (n=131). Participants completed a self-administered questionnaire which queried history of hypertension, antihypertensive medication use and risk factors. Unconditional logistic regression was used to estimate the odds ratio (OR) and 95% confidence intervals (CI), adjusted for age, body mass index (BMI), diabetes, smoking, alcohol use, menopausal status, family history of breast or ovarian cancer, age at first full-term pregnancy and education. History of treated hypertension was associated with significant increased risk of breast cancer (OR, 1.77; 95% CI, 1.04–3.03) and this association appeared only in women with BMI ⩾25u2009kg/m2 (OR, 2.30; 95% CI, 1.12–4.71). Diuretic use was also associated with elevated breast cancer risk (OR, 1.79; 95% CI, 1.07–3.01). The risk associated with diuretic use increased with duration of use (P for trend, <0.01). Use of other blood pressure medications was not found to be associated with breast cancer risk. These results support a positive association between treated hypertension, diuretic use and breast cancer risk among women aged 50–75 years.

Influence of mitral valve morphology on mitral balloon commissurotomy : immediate and six-month results from the NHLBI balloon valvuloplasty registry

Echocardiographic data were analyzed in 555 patients undergoing mitral balloon commissurotomy (MBC). Patients were enrolled in the National Heart, Lung, and Blood Institute Balloon Valvuloplasty Registry from 24 centers. There were 456 women and 99 men with a mean age of 54 years. Before MBC the two-dimensional echocardiographic variables of mitral valve thickness, mobility, calcification, and subvalvular disease were evaluated and assigned scores of 1 to 4. The mitral valve morphology score was related to mitral valve area (MVA) measured after MBC by cardiac catheterization. The leaflet mobility score was related to the immediate post-MBC MVA: 2.2 +/- 0.8 cm2 for grade 1, 1.9 +/- 0.7 cm2 for grade 2, 1.7 +/- 0.7 cm2 for grade 3, and 1.9 +/- 0.9 cm2 for grade 4 (p less than 0.001). Results of the MVA after MBC showed a similar relationship for each echocardiographic variable. The total morphology score (sum of the four variables) showed a weak relationship to MVA immediately after MBC (r = 0.24), which was persistent at 6 months after MBC (r = -0.25). Multiple regression analysis showed that the MVA after MBC is predicted by pre-MBC MVA (p less than 0.001), left atrial size (p = 0.01), balloon diameter (p = 0.02), cardiac output (p = 0.004), and leaflet mobility (p = 0.01). The R2 of the model was 0.31 (p less than 0.001). Total morphology score, leaflet thickness, calcification, and subvalvular disease were not important univariate or multivariate predictors of the results of MBC.(ABSTRACT TRUNCATED AT 250 WORDS)

Safety and results of dobutamine stress echocardiography in women versus men and in patients older and younger than 75 years of age.

The purpose of this retrospective study was to examine 732 consecutive patients who underwent dobutamine stress echocardiography (DSE) in order to compare the safety and result profiles of this test between women versus men and in patients > or = 75 and < 75 years of age. Our study included 416 women (57%) and 316 men (43%; mean age 62 +/- 12 years [range 16 to 93]). Patients were divided into 3 age groups: (1) group I (n = 179): < 55 years (mean 47 +/- 6), (2) group II (n = 447): 55 to 74 years (mean 64 +/- 5), and (3) group III (n = 106): > or = 75 years (mean 80 +/- 4). DSE was more likely to have negative results in women than in men (prevalence of positivity = 20% vs 31%, p = 0.001), but DSE had a similar safety profile in both genders. Women required lower doses of dobutamine and atropine to reach an end point. There was a similar incidence of test positivity in older and younger patients (23% in group I, 24% in group II, and 30% in group III, p = NS). DSE was generally a safe test in patients > or = 75 years, but there was a different safety profile in the elderly group compared with younger patients--specifically, more frequent asymptomatic hypotension (7% in group I, 13% in group II, and 25% in group III, p = 0.0002) and ventricular arrhythmias (26% in group I, 30% in group II, and 41% in group III, p = 0.04), but less frequent chest pain (32% in group I, 23% in group II, and 17% in group III, p = 0.009). Multivariate analysis suggested that the baseline usage of beta blockers was also a major determinant of the safety and ischemia profile during DSE. In conclusion, there were significant gender- and/or age-specific differences in the safety and test result profile of DSE. These differences should be considered when performing or interpreting DSE, particularly in women and in patients aged > or = 75 years.

Reproducibility of Brachial Artery Ultrasound Measurements

Recent findings suggest that systemic artery endothelial function is associated with the preclinical phase of vascular disease and related to traditional atherosclerosis risk factors. Brachial artery diameter changes in response to hyperemia have been proposed recently as a noninvasive tool to assess endothelial function. To evaluate the reproducibility of brachial artery diameter measurements using ultrasound, we studied 12 healthy subjects (eight men and four women, mean age 37 ± 9 years). An ATL HDI 3000 machine with a 5‐ to 10‐MHz broadband transducer was used to image the right brachial artery at rest, approximately 4 cm above the elbow. Gray scale ultrasound and color Doppler long‐axis images were recorded. Brachial arterial outer diameter (i.e., from anterior adventitia to posterior adventitia) and inner diameter (i.e., from anterior lumen‐intima interface to posterior lumen‐intima interface) were measured in each subject by two observers. An offline analysis system was used to make measurements at end‐diastole from four cardiac cycles. Interobserver and intraobserver measurement variabilities (technical error rates) for brachial artery inner diameter were excellent, ranging from 2.5% to 3.8%. However, interobserver technical error rates for outer diameter measurements were significantly greater than those for inner diameter measurements, ranging from 16.3% to 22.1% (P < 0.001), presumably related to the difficulty in accurately defining the adventitial lines. There were no significant differences in interobserver and intraobserver variability for measurements made using gray scale and color Doppler‐aided techniques. We conclude that interobserver and intraobserver reproducibility for brachial artery inner diameter measurements made from ultrasound images is excellent.

Aortic Valvular Regurgitation: Prevalence and Clinical Characteristics in a Predominantly Obese Adult Population Not Taking Anorexigens

Background: We recently reported the prevalence of aortic regurgitation (AR) by Doppler echocardiography (echo) in obese subjects to be higher than in some previous reports. Objective: To describe the prevalence of AR in an obese population not taking anorexigens as a function of demographic characteristics, cardiovascular risk factors, and other potential predictors. Methods: In 539 adult subjects, cardiovascular status was evaluated by medical history, physical examination, and Doppler echocardiograms performed according to a standardized imaging protocol. Echocardiographic readers were blinded as to each subjects medical and medication histories. Associations of AR with demographic and comorbid factors were examined. Results: Subjects had a mean (± SD) body mass index (BMI) of 35 ± 7 kg/m2, and were predominantly white (87.6%), females (74%), with a mean age of 47 ± 12 years. AR by Food and Drug Administration criteria (≥mild) was present in 4.1% of the subjects. Covariates significantly associated with AR were increasing age (P < 0.001), presence of a history of hypertension (P = 0.001), left ventricular (LV) internal dimensions (P < 0.005), and tricuspid and mitral regurgitation grade (P < 0.001). Conclusions: Clinical and Doppler echo evaluation of a large, predominantly obese, adult population revealed that AR was more prevalent than in some previous reports and was highly correlated with increased age, presence of a history of hypertension, LV internal dimensions, tricuspid and mitral regurgitation.

1020-4 Proximal Isovelocity Surface Area Method Applied to Non-Planar Surfaces: Implications of In Vitro Studies for Clinical Regurgitation and Stenosis

The color Doppler proximal isavelocity surface area (PISA) method accurately estimates volume flow rate (Q) across a planar surface in vitro. This method has been applied clinically to estimating valvular regurgitant flow using a hemispherical formula requiring measurement of a single axial radius. However, since cardiac valves may approximate convex shape, the most accurate PISA formula for calculating Q across a valve should be different from that for a planar model. We evaluated variations of PISA formula in a planar model and two convex-shaped models. Methods Three circular orifice diameters (Oxa0=xa05.2, 8, 12xa0mm) on hemispherical bails (diameter, Dxa0=xa038 and 58xa0mm) and one planar model were studied in a constant flow system (Fig. 1). The radii (A and B) of PISA were measured in axial and transverse views. Flow velocity and actual Q across orifices were varied from 0.3–7.7xa0m/s and 0.9–8.6 l/min, respectively. Results 1) B/A ratios were dependent on actual Q and orifice sizes. 2) B/A ratios were significantly larger for convex models than for a planar model at actual Q below 5 l/min (pxa0lxa00.001) (Fig.2 shows data for orifice Oxa0=xa08 mm at aliasing velocity between 15 and 30 cm/s). 3) In a convex model (Dxa0=xa038 mm), B/A ratios for orifices Oxa0=xa05.2,8,12xa0mm at actual Qxa0=xa01.5 l/min were 1.35xa0±xa00.07, 1.62xa0±xa00.07 and 1.85xa0±xa00.08, respectively (pxa0lxa00.001). The Dxa0=xa058xa0mm convex model demonstrated similar results. Conclusion The shape of PISA for a convex surface is less hemispherical than for a planar surface. Decreased axial radius is partially compensated for by increased transverse radius. Since precise orifice geometry is often unknown clinically, measurement of both PISA axial and transverse radii is important to minimize under-estimation of regurgitant or stenotic flow Download : Download high-res image (92KB) Download : Download full-size image Download : Download high-res image (90KB) Download : Download full-size image

774-5 Effect of Cardiac Translation on Measurement of Left Ventricular Wall Velocities: Implications for Doppler Imaging of Myocardium

Doppler imaging of the myocardium is a new application which has the potential to record myocardial velocities. These recorded velocities, however, include cardiac motion independent of ventricular contraction. A measured myocardial velocity, therefore, represents the net vector of contraction, translation, and rotation. To determine the effects of cardiac translation on myocardial velocities, 2-dimensional (2D) and M-mode echocardiographic recordings were obtained in 10 normal subjects. The average anteroseptal (AS) and posterior wall (PW) velocities were measured by 2D echo directed M-mode in the centerline of the parasternal short-axis view. Translation was measured from 2D echo cine-loop display as the displacement of the epicardial junction of the right ventricular free wall and interventricular septum during systole. The average translational velocity is reported as the component of the displacement vector parallel to the M-mode beam (+xa0=xa0toward transducer). The AS and PW velocities (cm/sec) displayed in the table represent net measured velocities, which include the translational vector. Results AS PW Translation Meanxa0±xa0SD 3.2xa0±xa00.5 4.5xa0±xa01.1 +1.3xa0±xa00.6 Range 2.4 to 4.0 3.4 to 6.9 -l.4 toxa0+xa02.4 In 8/10 subjects the velocity vector was positive. The mean percent error in the M-mode derived velocities due to translation was 41% for the AS wall and 31% for the PW. Conclusions 1) As measured by 2D echocardiography, the magnitude of the translational vector is significant when compared to the M-mode derived myocardial velocities. 2) The relative error demonstrated in the measured velocities may be further modified when applied in two dimensions, due to the angle of incidence of the Doppler beam. 3) New techniques for measuring myocardial velocities, such as Doppler imaging of the myocardium, should incorporate algorithms which correct for the translational vector.