Cardiac Rehab: Phases and Exercise Prescriptions

The Four Phases of Cardiac Rehabilitation

Cardiac Rehabilitation (CR) is a comprehensive, multidisciplinary program designed to help patients recover from cardiac events like a myocardial infarction (MI), heart surgery, or angioplasty. It's a structured journey that guides the patient from the hospital bed back to an active and healthy life. This process is typically divided into four distinct phases.

The World Health Organization (WHO) provides a detailed guideline that breaks down this structure. As you read, focus on the primary goal and setting of each phase.

To summarize the progression:

• Phase I (Inpatient): Begins in the hospital once the patient is medically stable. The focus is on early, low-level mobilization to counteract bed rest effects, patient education on their condition, and discharge planning. All activities are closely monitored.
• Phase II (Immediate Post-Discharge): A transitional phase at home, typically lasting 4-6 weeks. It bridges the gap between hospital discharge and formal outpatient rehab. Support is often provided via phone calls or home visits. Patients gradually increase their daily activities (e.g., walking).
• Phase III (Structured Outpatient Program): This is the core, supervised exercise and education program, usually run in a hospital or clinic setting. Patients attend sessions 2-3 times a week, where their exercise prescription is progressively advanced.
• Phase IV (Long-term Maintenance): The final phase, focused on independent, lifelong maintenance of exercise, diet, and other lifestyle changes. This often takes place in community settings like gyms or local support groups.

This short video provides a great visual summary of the phases and the role of therapy within each.

Principles of Exercise Prescription

Prescribing exercise for cardiac patients requires a systematic approach to ensure safety and efficacy. It's not just about choosing exercises, but about personalizing the intensity, duration, and progression based on a thorough assessment.

1. Assessment and Risk Stratification

Before any exercise program begins, every patient must be assessed to determine their risk of an adverse event during exercise. This is a critical safety step that will dictate the level of supervision and monitoring required.

The Physiopedia article on Cardiac Rehabilitation provides an excellent, concise summary of the key elements of assessment, including inclusion/exclusion criteria and the risk stratification process.

A key takeaway is that patients are stratified into low, moderate, or high-risk categories. A high-risk patient (e.g., one with complex arrhythmias or severely depressed left ventricular function) will require much more intensive monitoring and a slower progression than a low-risk patient.

2. The FITT-VP Principle

Once the patient is assessed and risk-stratified, their exercise program is designed using the FITT-VP principle:

• Frequency (how often)
• Intensity (how hard)
• Time (duration)
• Type (mode of exercise)
• Volume (total amount)
• Progression (how to advance)

Intensity is the most critical parameter to control. It is prescribed and monitored using:

1. Heart Rate (HR): A target heart rate (THR) zone is calculated, often using the Karvonen formula (Heart Rate Reserve method) if a maximal exercise test was done. For Phase I, a simpler formula like Resting HR + 20-30 bpm is used.
2. Rate of Perceived Exertion (RPE): The Borg Scale (6-20) is used to gauge the patient's subjective feeling of effort. This is vital because HR can be affected by medications like beta-blockers. The target is typically 11-14 ("fairly light" to "somewhat hard").
3. Metabolic Equivalents (METs): METs quantify the energy cost of an activity. 1 MET is the energy used at rest. Exercise is prescribed by targeting activities within a specific MET range.

The following table, derived from the WHO guidelines, summarizes the FITT principle as applied to different phases.

3. Understanding MET Levels

Being able to connect specific activities to their MET level is a crucial skill for your exam. It allows you to judge whether an activity is appropriate for a patient at a certain stage of recovery.

This video from OT Miri provides an excellent and memorable guide to MET levels, grouping activities in a way that is easy to recall.

Notice the logical progression: from seated, personal care activities at low MET levels, to household chores, then light recreation, and finally more vigorous exercise. Understanding these progressions is more effective than trying to memorize every single activity.

Conclusion

Today's lesson provided a structured overview of cardiac rehabilitation, a critical area of physiotherapy practice. We established the journey a patient takes through four distinct phases and then delved into the principles that guide the creation of a safe and effective exercise program.

Key Takeaways:

• Cardiac rehabilitation is a multiphase process: Phase I (inpatient), Phase II (post-discharge transition), Phase III (supervised outpatient exercise), and Phase IV (long-term maintenance).
• Exercise prescription must begin with a thorough assessment and risk stratification to ensure patient safety. Patients are categorized as low, moderate, or high risk.
• The FITT-VP principle (Frequency, Intensity, Time, Type, Volume, Progression) provides the framework for designing exercise programs.
• Intensity is the most critical variable, monitored using Target Heart Rate (THR), Rate of Perceived Exertion (RPE), and Metabolic Equivalents (METs).
• Activities are progressed logically, from low-MET tasks like self-care to higher-MET recreational and vocational activities, always guided by the patient's response.

In our next lesson, we will build upon the principles of Phase I rehabilitation by focusing specifically on physiotherapy techniques for positioning and early mobilization in the ICU and post-cardiothoracic surgery, looking at the unique challenges and strategies for managing the most critically ill patients.