Document Detail

Exercise training improves left ventricular diastolic filling in patients with dilated cardiomyopathy. Clinical and prognostic implications.
MedLine Citation:
PMID:  7758184     Owner:  NLM     Status:  MEDLINE    
BACKGROUND: Patients with dilated cardiomyopathy (DCM) often have left ventricular (LV) diastolic dysfunction that can precede the development of systolic dysfunction. Recent reports showed that exercise training (ET) improves the exercise capacity of these patients. Although this improvement is primarily due to peripheral adaptations, the contribution of LV diastolic filling has not been well defined. The purpose of this study was to determine whether ET can induce changes in LV diastolic filling that can account for an increase in exercise capacity and whether these changes can influence prognosis. METHODS AND RESULTS: We prospectively studied 55 consecutive patients (mean age, 55 +/- 7 years) with DCM. Patients were randomized into a training group (36 patients) or a control untrained group (19 patients) and matched for clinical and functional characteristics. All patients underwent a pulsed Doppler echocardiographic study, a radionuclide angiographic study, and a cardiopulmonary exercise test before and after a 2-month ET program. On the basis of the Doppler LV diastolic filling pattern at the beginning of the study, patients were prospectively divided into three subgroups: A (restrictive pattern), B ("normal" pattern), and C (abnormal relaxation pattern). In the trained group, peak VO2 (+12%; P < .0001), peak workload (+8.5%; P < .005), and lactic acidosis threshold (+12%; P < .0001) were significantly increased after training without changes in LV ejection fraction. However, only subgroup C demonstrated significant improvement in peak VO2 (+15%; P < .005). No changes were observed in the untrained group. In the trained subgroups a significant increase in rapid filling fraction (RFF), peak filling rate (PFR), peak early filling velocity (E), and E/A ratio was noted. A significant decrease in atrial filling fraction (AFF), peak atrial filling velocity (A), deceleration time of early filling velocity (EDT), and isovolumic relaxation time (IVRT) was observed only in subgroup C. No changes were found in untrained subgroups. A good correlation was found between Doppler and radionuclide LV diastolic filling parameters before and after training (P < .0001). Multiple stepwise regression analysis demonstrated that pretraining E/A ratio (P < .0001) and peak heart rate (P < .0002) were positive predictors of pretraining peak VO2. Posttraining increase in exercise tolerance (P < .0001) and increase in E/A ratio (P < .0001) were the strongest predictors of an increase in peak VO2. The independent predictors of cardiac events were a greater RFF and a shorter IVRT and EDT. Stepwise logistic regression showed that Doppler LV diastolic filling patterns are independent predictors of overall cardiac events (P = .02), and restrictive pattern has a worse prognosis compared with B (P = .04) and C (P = .007). However, ET did not reach statistical significance (P = .54) as a predictor of cardiac events. CONCLUSIONS: These data demonstrate that ET induces significant improvement in exercise capacity only in patients with DCM and a pattern of abnormal LV relaxation. The improvement in peak VO2 is significantly correlated with an increase in peak early filling rate and peak filling rate as well as a decrease in atrial filling rate. Doppler echocardiography may be a valuable tool in the prognostic assessment of patients with DCM who will benefit from exercise training.
R Belardinelli; D Georgiou; G Cianci; N Berman; L Ginzton; A Purcaro
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Publication Detail:
Type:  Clinical Trial; Comparative Study; Journal Article; Randomized Controlled Trial    
Journal Detail:
Title:  Circulation     Volume:  91     ISSN:  0009-7322     ISO Abbreviation:  Circulation     Publication Date:  1995 Jun 
Date Detail:
Created Date:  1995-06-23     Completed Date:  1995-06-23     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0147763     Medline TA:  Circulation     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  2775-84     Citation Subset:  AIM; IM    
Divisione di Cardiologia I, Ospedale Cardiologico G.M. Lancisi, Ancona, Italy.
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MeSH Terms
Blood Flow Velocity / physiology
Cardiomyopathy, Dilated / diagnosis,  physiopathology,  rehabilitation*
Coronary Circulation / physiology
Diastole / physiology
Disease-Free Survival
Echocardiography, Doppler, Pulsed
Exercise Test
Exercise Therapy*
Exercise Tolerance / physiology
Gated Blood-Pool Imaging
Middle Aged
Mitral Valve / ultrasonography
Multivariate Analysis
Proportional Hazards Models
Prospective Studies
Ventricular Dysfunction, Left / diagnosis,  physiopathology
Ventricular Function, Left / physiology*

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