Hemodynamic characteristics of congenital aortic stenosis: a quantitative stress echocardiography study.

BACKGROUND: Several investigators have studied the effects of exercise on pressure gradients and valve area measurements in patients with senile calcific aortic stenosis. However, there are limited data on young patients with congenital aortic stenosis. The current study was conducted to assess the dynamic effect of exercise on aortic valve area and to determine whether pressure gradients or valve area determinations correlate with duration of exercise in these patients. METHODS AND RESULTS: Twenty-five young patients with congenital aortic stenosis and 10 normal control patients performed symptom-limited bicycle exercise stress tests with quantitative 2-dimensional and Doppler analysis. Compared with normal patients, there were no significant differences in the directional changes in blood pressure, left ventricular volumes, and ejection fraction. There was no correlation between either peak instantaneous or mean transaortic pressure gradient and exercise duration. A small but statistically significant correlation was detected between the continuity equation aortic valve area and duration of exercise (r = 0.49, P =.013). Aortic valve area did not change with exercise in the patient cohort (1.5 +/- 0.6 vs 1.5 +/- 0.6; P = not significant). CONCLUSIONS: Aortic valve area does not change significantly with exercise in asymptomatic patients with congenital aortic stenosis. Consistent with prior studies, there was no correlation between the duration of exercise and the mean resting aortic valve gradient. A modest but statistically significant correlation was detected between exercise duration and aortic valve area. Further studies are required to determine whether aortic valve area measurements would provide useful adjunctive data on which to base recommendations for participation in competitive sports.

Prevalence of pulmonary hypertension in limited and diffuse scleroderma.

STUDY OBJECTIVES: To characterize the prevalence of undiagnosed pulmonary hypertension in patients with limited and diffuse scleroderma. DESIGN: Prospective cross-sectional study. SETTING: University-based outpatient clinic. PATIENTS: Thirty-four consecutive patients with limited (n = 29) or diffuse (n = 5) scleroderma but without the clinical diagnosis of pulmonary hypertension. MEASUREMENTS AND RESULTS: All patients had 12-lead ECGs and two-dimensional and Doppler echocardiograms. The pulmonary artery systolic pressure (PAs) was calculated as the sum of the Doppler transtricuspid pressure gradient and the right atrial pressure as estimated by the caval respiratory index. Thirty-three patients (97%) had adequate spectral signals of tricuspid regurgitation. The velocity of tricuspid regurgitation ranged from 1.6 to 4.5 m/s. The calculated PAs ranged from 15 to 95 (mean +/- SD = 30 +/- 14 mm Hg). Twelve patients (35% of the total cohort) had pulmonary hypertension defined as PAs of 30 mm Hg or greater. CONCLUSIONS: Undiagnosed elevation of PAs is common in patients with scleroderma. Noninvasive assessment of PAs can be performed accurately in most patients independent of clinical signs of pulmonary hypertension. If successful treatment strategies are identified, it may be possible to identify patients early in the development of pulmonary hypertension and intervene before significant end-organ damage occurs.

Effects of exercise on left ventricular performance determined by echocardiography in chronic, severe mitral regurgitation secondary to mitral valve prolapse.

Data on the effects of exercise on left ventricular (LV) volumes and ejection performance in patients with severe mitral regurgitation (MR) are limited. With use of a matched-pairs design, 10 asymptomatic patients with chronic, severe MR and normal LV systolic function who were not receiving vasodilator therapy (group 1) and 10 matched normal control subjects with no structural heart disease (group 2) performed symptom-limited upright bicycle ergometry with quantitative echocardiographic analysis. An additional 8 patients with severe, chronic MR and normal LV systolic function who were receiving vasodilator therapy at the time of testing (group 3) were studied for comparison. The 3 cohorts exercised for similar periods of time. Group 1 and 3 patients had similar end-diastolic volumes at rest, both of which were significantly greater than those of normal controls. Although resting LV end-systolic volume was greater in groups 1 and 3 than in normal controls, the 3 groups had similar relative percent reductions in end-systolic volume during exercise (30 +/- 12%, 32 +/- 13%, and 30 +/- 24%; p = NS). A similar percent increase in LV ejection fraction was also observed in all 3 cohorts (18 +/- 9%, 15 +/- 9%, and 14 +/- 6%; p = NS). Forward stroke volume increased significantly in group 1 (59 +/- 21 and 71 +/- 18 ml; p <0.001) and in group 3 (59 +/- 17 and 68 +/- 13 ml; p < 0.05). Thus, in asymptomatic patients with chronic, severe MR and normal LV ejection fraction at rest, there is an improvement in LV ejection fraction and an increase in forward stroke volume during exercise. These effects are comparable to those observed in normal controls. Directional differences in the cohort receiving no activity therapy were indistinguishable from either patients receiving vasodilator therapy or normal control subjects.

Accuracy of quantitation of aortic stenosis using femoral arterial recordings corrected for both temporal delay and systolic amplification.

Our study demonstrates the feasibility of substituting FA recordings, corrected for both temporal delay and systolic amplification, for central aortic recordings in assessing aortic valve stenosis. This method is accurate in estimating the transaortic valve gradient, the calculated valve area, and the calculated valve resistance, and obviates the risks and costs of 2 FA punctures.

Observations suggesting a high incidence of exercise-induced severe mitral regurgitation in patients with mild rheumatic mitral valve disease at rest.

OBJECTIVES: The aim of this study was to determine the hemodynamic effects of upright bicycle ergometry in symptomatic patients with mild, mixed mitral stenosis and regurgitation. BACKGROUND: Patients with seemingly mild rheumatic mitral valve disease often complain of exertional dyspnea or fatigue. These symptoms are usually ascribed to flow-dependent increases in the gradient across the stenotic mitral valve. Although catheterization studies in these patients may demonstrate an increase in mitral valve gradient proportional to an increase in cardiac output, this approach does not specifically address the underlying mechanism of any observed increases in mitral gradient or left atrial (i.e., pulmonary capillary wedge) pressure. Exercise echocardiography is uniquely suited to the dynamic assessment of exercise-induced hemodynamic changes. METHODS: Fourteen symptomatic patients with exertional dyspnea and mild mitral stenosis and regurgitation at rest performed symptom-limited upright bicycle ergometry with quantitative two-dimensional, Doppler and color Doppler echocardiographic analysis. RESULTS: Average pulmonary artery systolic pressure in the 13 patients with adequate spectral signals of tricuspid regurgitation increased from 36 +/- 5 mm Hg (mean +/- SD) at rest to 63 +/- 14 mm Hg at peak exercise (p < 0.001). The mean transmitral pressure gradient in all patients increased from 4.5 +/- 1.4 mm Hg at rest to 12.7 +/- 2.7 mm Hg at peak exercise (p < 0.001). Five patients developed severe mitral regurgitation during exercise. CONCLUSIONS: Patients with exertional dyspnea and mild mitral stenosis and regurgitation at rest demonstrate a marked increase in pulmonary artery systolic pressure and mean transmitral pressure gradient during dynamic exercise. In a subset of these patients, marked worsening of mitral regurgitation appears to be the underlying mechanism of this hemodynamic deterioration. Because of the small sample size, this novel observation must be considered preliminary with respect to the true prevalence of exercise-related development of severe mitral regurgitation. If additional studies confirm the importance of this phenomenon, it has important implications for the management of patients with rheumatic mitral valve disease.

Extraskeletal Ewing's sarcoma of primary cardiac origin.

A 13-year-old boy presented with cardiac tamponade. Echocardiography revealed a large mass extending from the right and left ventricles into a large pericardial effusion. Pathology confirmed the first reported case of a primary cardiac extraskeletal Ewing's sarcoma.

Validation of global and segmental left ventricular contractile function using gated planar technetium-99m sestamibi myocardial perfusion imaging.

OBJECTIVES: The purpose of this study was to test the hypothesis that segmental wall motion analysis determined from gated planar technetium-99m sestamibi myocardial imaging is reproducible and agrees well with echocardiographic data. BACKGROUND: Technetium-99m sestamibi is a new radiopharmaceutical recently approved for myocardial perfusion imaging. Its advantages include a dosimetry that allows use of a dose 10 to 15 times higher than that of thallium-201. As a result, myocardial counts are markedly improved and images can be collected in a gated mode to potentially allow assessment of global and segmental ventricular function. However, the reproducibility and accuracy of technetium-99m sestamibi imaging for measurement of global and segmental left ventricular function have not been evaluated or compared with those of a standard ventricular function technique, such as echocardiography. METHODS: We studied 136 patients referred for clinical technetium-99m sestamibi imaging. One-day rest-stress planar technetium-99m sestamibi protocols were used, gating the stress images. After technetium-99m sestamibi imaging, all patients had standard rest two-dimensional echocardiography. Global and segmental technetium-99m sestamibi and echocardiographic left ventricular contraction was graded qualitatively as normal or abnormal using a four-point grading system. RESULTS: Interobserver and intraobserver agreement was extremely high for global and segmental technetium-99m sestamibi wall motion analysis, with absolute agreements ranging from 0.92 to 1.00 and corresponding kappa values of 0.74 to 1.00 (p < 0.00001). Agreement with global and segmental echocardiographic wall motion was similarly very high, with absolute agreements ranging from 0.93 to 1.00 and corresponding kappa values of 0.75 to 1.00 (p < 0.00001). CONCLUSIONS: Gated technetium-99m sestamibi cardiac imaging provides information with regard to rest global and segmental left ventricular systolic function that is highly reproducible and agrees very well with results of two-dimensional echocardiography.