The beneficial impact of interval training on cardiorespiratory fitness in patients after myocardial infarction and Covid-19 undergoing early cardiac rehabilitation.

Objective: Aim: Patients referred for cardiac rehabilitation after myocardial infarction (MI) often had a Covid-19 infection. To date, there is no evidence-based guidelines of cardiac rehabilitation in this group. The aim of the study was to assess cardiorespiratory fitness using the cardiopulmonary exercise test (CPET) in patients after MI and Covid-19 infection undergoing interval trainings(IT)..

Methods: Materials and Methods: 30 patients mean age: 55.4±12.2 years, after MI and Covid-19 infection up to 6 months before MI were included in the study (SG, study group). The control group (CG) consisted of 30 men without a history of Covid-19. All subjects completed a series of 24 IT on a cycloergometer and 30 minutes of breathing exercises after the IT.CPET was performed before and after rehabilitation.

Results: Results: After rehabilitation, a significant increase in the following parameters based on CPET was achieved in the SG -peak oxygen consumption( pVO2) 20.3±4.8 vs. 23.4±4.6 ml/kg/min, p<0.001; oxygen pulse: 13.3±3.4 vs. 14.4±3.4 ml/beat, p<0.001; respiratory exchange ratio(RER) 1.12±0.1 vs. 1.26±0.1, p<0.01;minute ventilaton(VE) 56.4±19 vs. 71.2±21.9 l/min, p<0.001;max voluntary ventilation(MVV) 106.3±37.0 vs. 118.0±28.2 l, p=0.02. The percentage of patients with severe and moderate symptoms of cardiorespiratory insufficiency was significantly reduced, respectively: 16.7% vs. 6.7% and 46.7% vs. 26.7%, p<0.01.The percentage of patients with mildly reduced performance increased: 16.7% vs. 46.7%, p<0.05. Patients from the CG had good physical performance at the beginning, which did not significantly improve after rehabilitation.

Conclusions: Conclusions: Interval trainings and breathing exercises were safe and significantly improved the cardiorespiratory fitness of patients with a history of myocardial infarction and Covid-19 infection.