Vol. 6, Issue 2, Part B (2024)

Background: High intensity interval training (HIIT) was proved to be safe and effective but there is a gap of evidence regarding safety and efficacy of continuous high intensity exercise training (CHIT) in cardiac patients. This study aims to compare the impact of continuous high intensity versus continuous moderate-intensity training (CMIT) on left ventricular (LV) and left atrial (LA) strain parameters during cardiac rehabilitation.

Methods: A randomized controlled trial was conducted with 60 patients who underwent primary percutaneous coronary intervention (PCI) for anterior ST-segment elevation myocardial infarction. Patients were randomized into two groups: one group received CHIT, while the control group followed CMIT. Echocardiographic assessments, including LV global longitudinal strain (GLS) and LA strain (LAS) parameters, were performed before and after a six-week rehabilitation program.

Results: The CHIT group showed a greater improvement in LV GLS, with a mean increase from-11.27% to-13.58% (p<0.001), compared to the moderate-intensity group, which increased from-12.28% to-13.66% (p<0.001). LA reservoir strain improved from 21.6% to 27.27% in the CHIT group (p<0.001) and from 27.3% to 31.1% in the moderate-intensity group (p<0.001). However, no significant differences were observed between the groups in LA contractile or conduit strain.

Conclusion: CHIT was associated with a more significant improvement in LV function compared to CMIT in post-PCI anterior STEMI patients. However, both regimens resulted in comparable improvements in LAS parameters, suggesting that either training intensity may enhance atrial function in cardiac rehabilitation.