Impact of Right Ventricular Dilatation in Patients with Atrial Septal Defect.

OBJECTIVE: The aim of this study was to examine the relationship between right ventricular (RV) volume and exercise capacity in adult patients with atrial septal defect (ASD) and to determine the degree of RV dilatation for transcatheter ASD closure. BACKGROUND: RV dilatation is an indication of transcatheter ASD closure; however, few studies have reported the clinical significance of RV dilatation. METHODS: We enrolled 82 consecutive patients (mean age, 49 ± 18 years; female, 68%) who underwent cardiac magnetic resonance imaging and symptom-limited cardiopulmonary exercise test before ASD closure. The relationship between RV volume and peak oxygen uptake (VO2) was evaluated. RESULTS: The mean RV end-diastolic volume index was 108 ± 27 ml/m2 (range, 46 to 180 ml/m2). The mean peak VO2 was 24 ± 7 ml/min/kg (range, 14 to 48 ml/min/kg), and the mean predicted peak VO2 was 90 ± 23%. There were significant negative relationships of RV end-diastolic volume index with peak VO2 (r = -0.28, p < 0.01) and predicted peak VO2 (r = -0.29, p < 0.01). The cutoff value of RV end-diastolic volume index <80% of predicted peak VO2 was 120 ml/m2, with the sensitivity of 49% and the specificity of 89%. CONCLUSIONS: There was a relationship between RV dilatation and exercise capacity in adult patients with ASD. RV end-diastolic volume index ≥120 ml/m2 was related to the reduction in peak VO2. This criterion of RV dilatation may be valuable for the indication of transcatheter ASD closure.

Long-term effects of transcatheter closure of atrial septal defect on cardiac remodeling and exercise capacity in patients older than 40 years with a reduction in cardiopulmonary function.

BACKGROUND: Although it has been demonstrated that cardiac remodeling and exercise capacity improve after transcatheter closure of atrial septal defect (ASD), little is known about long-term benefits in middle-aged and elderly patients with a reduction in cardiopulmonary function. OBJECTIVES: To evaluate long-term extent and time course of improvements in cardiac remodeling and exercise capacity in those patients. METHODS: Twenty ASD patients ≥ 40 years of age with a reduction in cardiopulmonary function (predicted peak oxygen uptake [VO(2)] < 65%) were enrolled. Transthoracic echocardiography and cardiopulmonary exercise testing were performed at baseline and at 1 month, 3 months, 6 months, and >12 months after the procedure. RESULTS: At 1 month after the procedure, significant decreases in right ventricular (RV) end-diastolic diameter (38.2 ± 4.4 to 31.9 ± 4.4 mm; P < 0.001) and RV/left ventricular end-diastolic diameter ratio (0.95 ± 0.17 to 0.71 ± 0.13; P < 0.001) occurred, and they were maintained during the follow-up period. Normal RV size was achieved in 11 of 18 patients with RV enlargement. Predicted peak VO(2) did not change at 1 month and 3 months, but it improved significantly after 6 months (53.6 ± 6.5 to 62.1 ± 12.6%; P < 0.01). Sixteen of the 20 patients showed improved predicted peak VO(2). CONCLUSIONS: Cardiac remodeling and exercise capacity could be improved over the long-term period after transcatheter closure of ASD in middle-aged and elderly patients with a reduction in cardiopulmonary function. There were differences in the time course of improvement between cardiac remodeling and exercise capacity in those patients.

Evaluation of exercise capacity using wave intensity in chronic heart failure with normal ejection fraction.

Impaired exercise capacity has been found in patients with diastolic dysfunction with preserved systolic function. Although conventional transthoracic echocardiography (TTE) provides useful clinical information about systolic and diastolic cardiac function, its capability to evaluate exercise capacity has been controversial. The inertia force of late systolic aortic flow is known to have a tight relationship with left ventricular (LV) performance during the period from near end-systole to isovolumic relaxation. The inertia force and the time constant of LV pressure decay during isovolumic relaxation can be estimated noninvasively using the second peak (W(2)) of wave intensity (WI), which is measured with an echo-Doppler system. We sought to determine whether W(2) is associated with exercise capacity in patients with chronic heart failure with normal ejection fraction (HFNEF) and to compare its ability to predict exercise capacity with parameters obtained by conventional TTE including tissue Doppler imaging. Sixteen consecutive patients with chronic HFNEF were enrolled in this study. Wave intensity was obtained with a color Doppler system for measurement of blood velocity combined with an echo-tracking system for detecting changes in vessel diameter. Concerning conventional TTE, we measured LV ejection fraction (EF), peak velocities of early (E) and late (A) mitral inflow using pulse-wave Doppler, and early (Ea) and late (Aa) diastolic velocities using tissue Doppler imaging. Left ventricular EF, E/A ratio, Ea, and E/Ea ratio did not correlate with exercise capacity, whereas W(2) significantly correlated with peak VO(2) (r = 0.54, p = 0.03), VE/VCO(2) slope (r = -0.53, p = 0.03), and ΔVO(2)/ΔWR (r = 0.56, p = 0.02). W(2) was associated with exercise capacity in patients with chronic HFNEF. In conclusion, W(2) is considered to be clinically more useful than conventional TTE indices for evaluating exercise capacity in patients with chronic HFNEF.