Cardiac Rehab

Case: A 58-year-old male has been brought to the Emergency Department from a local gym, where he collapsed after a treadmill exercise for 45 minutes. Colleagues reported finishing his high-intensity exercise without cooling down, walking three minutes towards the door, and collapsing. 

Answer: The objective of the above case scenario is to enhance the importance of three exercise phases, called 'content of exercise.' A similar principle applies during cardiac rehabilitation programs. The three phases are:

• Warm-up
• Conditioning
• Cool down 

Warm-up is recommended for 5 to 10 minutes to gradually increase the heart rate to the target range. Physiologically, a gradual increment in oxygen demand minimizes the abruptly increased risk of ехеrсise-related cardiovascular complications due to a sudden increase in myocardial demand.

Conditioning is also called the training phase, which consists of continuous or discontinuous aerobic activity of about 20 to 45 minutes (or as determined by the person's trainer).

Cooling down for 5 to 10 minutes is considered the most vital part. It involves a gradual recovery. An abrupt discontinuation may cause a sudden decrease in venous return, reducing coronary blood flow. At the same time, myocardial oxygen consumption and demand are still high and may cause ischemic ST-T changes and/or ventricular arrhythmias.

#cardiology

Recommended readings:

1. Parks JC, Marshall EM, Humm SM, Erb EK, Kingsley JD. Effects of a Cool-Down after Supramaximal Interval Exercise on Autonomic Modulation. Int J Environ Res Public Health. 2022 Apr 29;19(9):5407. doi: 10.3390/ijerph19095407. PMID: 35564802; PMCID: PMC9099607.

2. Tessler J, Bordoni B. Cardiac Rehabilitation. 2023 Jun 4. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan–. PMID: 30725881.

3. Dibben GO, Faulkner J, Oldridge N, Rees K, Thompson DR, Zwisler AD, Taylor RS. Exercise-based cardiac rehabilitation for coronary heart disease: a meta-analysis. Eur Heart J. 2023 Feb 7;44(6):452-469. doi: 10.1093/eurheartj/ehac747. PMID: 36746187; PMCID: PMC9902155.

4. Mehra VM, Gaalema DE, Pakosh M, Grace SL. Systematic review of cardiac rehabilitation guidelines: Quality and scope. Eur J Prev Cardiol. 2020 Jun;27(9):912-928. doi: 10.1177/2047487319878958. Epub 2019 Oct 4. PMID: 31581808; PMCID: PMC7262778.