Cardiac Rehabilitation Improves the QRS Fragmentation in Patients With ST Elevation Myocardial Infarction.

INTRODUCTION: We aimed to evaluate the effect of exercise-based cardiac rehabilitation (CR) on the fragmented QRS (fQRS) in patients with ST elevation myocardial infarction (STEMI). METHODS: Ninety-seven patients with STEMI participated CR and 81 patients as a control group were included to the study. The trained patients were grouped according to the presence and persistence of QRS fragmentation on the electrocardiogram (ECG) before and after CR. If the fragmentation was present on the ECG at the beginning of the CR but not on the ECG at the end of CR; the transient group, if the fQRS persists after CR; the persistent fQRS group. ECGs obtained from the control group were grouped according to the presence of a fQRS on ECG. RESULTS: Among the trained patients, 45 (46%) did not have a fQRS before CR, whereas 52 (54%) presented a fQRS before CR, which was persistent in 35 patients (the persistent fQRS group) and transient in 17 patients (the transient fQRS group). Among 81 patients included in the control group, fQRS was persistent in 41 patients. Presence of fQRS on the ECG was significantly decreased with CR and it is better in trained group than the control group (P = .034). There were not significant correlations with other characteristics, except hypertension. CONCLUSION: The existence of the fQRS decreases after CR in patients with STEMI especially in hypertensive individuals, which may be related to improved electrical stability in the myocardium as a predictor of increase in survival and decrease in major cardiac events.

Evaluation of the effect of cardiac rehabilitation on left atrial and left ventricular function and its relationship with changes in arterial stiffness in patients with acute myocardial infarction.

BACKGROUND: The main aim of this study was to detect the possible early effect of cardiac rehabilitation (CR) on left atrium (LA) and left ventricle (LV) function and relation to aortic stiffness in patients with acute myocardial infarction (AMI). METHODS: Fifty-four patients with AMI were enrolled in this study. Left atrial strain analysis was performed by two-dimensional speckle tracking echocardiography. The deceleration time (DT) was measured by pulsed-wave Doppler. The ratio of E/e' to LA peak strain was used to estimate the LA stiffness (Stiffnessstrain ) Aortic elasticity parameters were calculated using the formulas including aortic systolic and diastolic diameter with M-Mode echocardiography and blood pressure. Anterior wall aortic expansion velocity was measured by tissue Doppler imaging. RESULTS: Left ventricle ejection fraction (EF) and LA functional parameters were significantly better in trained subjects. Also in training group, the LV diastolic functional parameters were better in CR group than the control group. Aortic elasticity parameters were better with CR. CONCLUSIONS: In patients with CR, an increase in LA strain was correlated with increase in aortic strain and improved aortic distensibility, likely indicating favorable LA and aortic interactions with exercise training.

P-wave dispersion and its relationship to aortic stiffness in patients with acute myocardial infarction after cardiac rehabilitation.

BACKGROUND: The aim of our study was to investigate the P-wave dispersion from standard electrocardiograms (ECGs) in patients with acute myocardial infarction (AMI) after cardiac rehabilitation (CR) and determine its relation to arterial stiffness. METHODS: This is a prospective study included 33 patients with AMI and successfully re-vascularized by percutaneous coronary intervention (PCI) underwent CR. Left ventricular ejection fraction (LVEF) was measured by biplane Simpson's method. Left atrium (LA) volume was calculated. The maximum and minimum durations of P-waves (Pmax and Pmin, respectively) were detected, and the difference between Pmax and Pmin was defined as P-wave dispersion (Pd = Pmax-Pmin). Aortic elasticity parameters were measured. RESULTS: LVEF was better after CR. The systolic and diastolic blood pressures decreased after CR, these differences were statistically significant. With exercise training, LA volume decreased significantly. Pmax and Pd values were significantly shorter after the CR program. The maximum and minimum P-waves and P-wave dispersion after CR were 97 ± 6 ms, 53 ± 5 ms, and 44 ± 5 ms, respectively. Aortic strain and distensibility increased and aortic stiffness index was decreased significantly. Aortic stiffness index was 0.4 ± 0.2 versus 0.3 ± 0.2, P = 0.001. Aortic stiffness and left atrial volume showed a moderate positive correlation with P-wave dispersion (r = 0.52, P = 0.005; r = 0.64, P < 0.001, respectively). CONCLUSION: This study showed decreased arterial stiffness indexes in AMI patient's participated CR, with a significant relationship between the electromechanical properties of the LA that may raise a question of the preventive effect of CR from atrial fibrillation and stroke in patients with acute myocardial infarction.

Does cardiac rehabilitation improve left ventricular diastolic function of patients with acute myocardial infarction?

OBJECTIVES: We aimed to observe the effect of cardiac rehabilitation (CR) on left ventricular diastolic function in patients with acute myocardial infarction (AMI) and revascularization by percutaneous coronary intervention (PCI). STUDY DESIGN: 82 patients were enrolled the study; 42 who were participating in a CR program, and 40 who did not maintain the program as a control group. Measurements of mitral inflow included the peak early filling (E-wave) and late diastolic filling (A-wave) velocities, the E/A ratio, deceleration time (DT) of early filling velocity and mitral A-wave duration. The early diastolic annular velocity has been expressed as e' with PW tissue Doppler imaging. The mitral inflow E velocity to tissue Doppler e' (E/e') was calculated and isovolumic relaxation time (IVRT) was measured. Measurements of pulmonary venous waveforms included peak systolic (S) velocity, peak anterograde diastolic (D) velocity and the time difference between the duration of the atrial reversal (Ar) and mitral A-wave duration (Ar-A). RESULTS: E/A and septal e' were better with the CR group than the control group. (p=0.048 vs p=0.006 respectively). The difference between E/e' measurements were not statistically significant (p=0.138). The left ventricular diastolic function of patients were partially improved with cardiac rehabilitation. There was no association between infarct-related artery (IRA) and diastolic functional measurements of the left ventricle in the individuals. Only hypertension was found significantly associated with E/A (p=0.000). CONCLUSION: CR improves septal e' and E/A significantly in patients with AMI and revascularized successfully by PCI, especially in those with hypertension.