RESUMO
Purpose: Left atrial dysfunction has shown to play a prognostic role in patients with ischemic cardiomyopathy (ICM) and is becoming a therapeutic target for pharmacological and non-pharmacological interventions. The effects of exercise training on the atrial function in patients with ICM have been poorly investigated. In the present study, we assessed the effects of a 12-week combined training (CT) program on the left atrial function in patients with ICM. Methods: We enlisted a total of 45 clinically stable patients and randomly assigned them to one of the following three groups: 15 to a supervised CT with low-frequency sessions (twice per week) (CTLF); 15 to a supervised CT with high-frequency sessions (thrice per week) (CTHF); and 15 to a control group following contemporary preventive exercise guidelines at home. At baseline and 12 weeks, all patients underwent a symptom-limited exercise test and echocardiography. The training included aerobic continuous exercise and resistance exercise. The analysis of variance (ANOVA) was used to compare within- and inter-group changes. Results: At 12 weeks, the CTLF and CTHF groups showed a similar increase in the duration of the ergometric test compared with the control (ANOVA p < 0.001). The peak atrial longitudinal strain significantly increased in the CTHF group, while it was unchanged in the CTLF and control groups (ANOVA p = 0.003). The peak atrial contraction strain presented a significant improvement in the CTHF group compared with the CTLF and control groups. The left ventricular global longitudinal strain significantly increased in both the CTHF and the CTLF groups compared with the control group (ANOVA p = 0.017). The systolic blood pressure decreased in the CTHF and CTLF groups, while it was unchanged in the control group. There were no side effects causing the discontinuation of the training. Conclusions: We demonstrated that a CT program effectively improved atrial function in patients with ICM in a dose-effect manner. This result can help with programming exercise training in this population.
RESUMO
BACKGROUND: the aim of this study was to assess acute changes in left atrial (LA) function during incremental aerobic exercise in patients with heart failure with mildly reduced ejection fraction (HFmrEF) in comparison to healthy subjects (HS). METHODS: twenty patients with established HFmrEF were compared with 10 HS, age-matched controls. All subjects performed a stepwise exercise test on a cycle ergometer. Echocardiography was performed at baseline, during submaximal effort, at peak of exercise, and after 5 min of recovery. RESULTS: HS obtained a higher value of METs at peak exercise than HFmrEF (7.4 vs. 5.6; between group p = 0.002). Heart rate and systolic blood pressure presented a greater increase in the HS group than in HFmrEF (between groups p = 0.006 and 0.003, respectively). In the HFmrEF group, peak atrial longitudinal strain (PALS) and conduit strain were both increased at submaximal exercise (p < 0.05 for both versus baseline) and remained constant at peak exercise. Peak atrial contraction strain (PACS) did not show significant changes during the exercise. In the HS group, PALS and PACS increased significantly at submaximal level (p < 0.05 for both versus baseline), but PALS returned near baseline values at peak exercise; conduit strain decreased progressively during the exercise in HS. Stroke volume (SV) increased in both groups at submaximal exercise; at peak exercise, SV remained constant in the HFmrEF, while it decreased in controls (between groups p = 0.002). CONCLUSIONS: patients with HFmrEF show a proper increase in LA reservoir function during incremental aerobic exercise that contributes to maintain SV throughout the physical effort.
RESUMO
Left atrial dysfunction is associated with exercise intolerance and poor prognosis in heart failure (HF). The effects of exercise training on atrial function in patients with HF with mid-range ejection fraction (HFmrEF) are unknown. The purpose of the present study was to assess the effects of a supervised concurrent training (SCT) program, lasting 12 weeks, on left atrial function of patients with HFmrEF. The study included 70 stable patients, who were randomly assigned into two groups: SCT with (three sessions/week) or a control (CON) group directed to follow contemporary exercise preventive guidelines at home. Before starting the training program and at 12 weeks, all patients performed an ergometric test, a 6 min walk test, and echocardiography. Between-group comparisons were made by analysis of variance (ANOVA). At 12 weeks, the duration of the ergometric test and distance walked at 6 min walk test presented a significant greater increase in SCT compared to the control (between-group p 0.0001 and p 0.004 respectively). Peak atrial longitudinal strain and conduit strain presented an increase of 29% and 34%, respectively, in the SCT, and were unchanged in CON (between-group p 0.008 and p 0.001, respectively). Peak atrial contraction strain increased by 21% in SCT, with no changes in CON (between-group p 0.002). Left ventricular global longitudinal strain increased significantly in SCT compared to control (between-groups p 0.03). In conclusions, SCT improved left atrial and left ventricular function in HFmrEF. Further studies are needed in order to verify whether these favourable effects of SCT on LA function are sustained and whether they will translate into clinical benefits for patients with HFmrEF.