CARDIAC -REHABILITATION – MYOCARDIAL INFARCTION

Cardiac rehabilitation (CR) is multidisciplinary and may include the physician, nurse, physical and occupational therapists, exercise physiologist, nutritionist, and social service caseworker. CR begins in the hospital and extends indefinitely into the maintenance phase. 

• Phase 1 – inpatient component
• Phase 2 – outpatient component (exercise-training period) 
• Phase 3 – maintenance period 

Decades ago, patients with myocardial infarction (MI) were traditionally given 8 weeks of bedrest. In the pivotal study done by Levine and Lown in 1952, chair rest and low-level activity was found to be more beneficial compared with bedrest. Today, the patient with a noncomplicated MI may be hospitalized for as few as 3 to 5 days. 

PHASE 1

Inpatient cardiac rehab uses a team approach based on activity progression, patient education, and hemodynamic and ECG monitoring, together with medical and pharmacological management. A physical therapist:

• Monitors activity tolerance
• Prepares for discharge
• Educates the patient to recognize adverse symptoms with activity
• support risk factor modification techniques
• provides emotional support and
• collaborates with other team members 

Subjective ratings of perceived exertion and objective observation of patient effort during exercise training become increasingly important as it is common for the patient to be on beta-blocker. Vital sign monitoring occurs before and after and, if possible, during activity. The intensity of the activity is considered to be low level, and perceived exertion for the patient should be comparable to the “fairly light range” of the Borg RPE Scale. There are a variety of inpatient cardiac rehab programs, frequently progressive based on levels of increasing energy costs (e.g., MET levels). An example: 

Symptom recognition and appropriate action are the two key elements the patient needs to understand well before discharge. Gradual increments in exercises considering environmental factors may be a reasonable alternative to outdoor exercise for safety reasons. 

PHASE 2

Patients commonly undergo a symptom-limited maximal stress test (ETT) at 4 to 6 weeks after MI. For a negative ETT, a safer exercise prescription would be 65% to 80% of the peak HRmax achieved on the test. 

For a positive ETT, it is important to keep MVO2 below the patient’s ischemic MVO2 during aerobic training. clinical measure of MVO2 is the product of HR and SBP, known as the rate pressure product (RPP = HR × SBP). A good safety tip is to not exceed 90% of the ischemic RPP.

Resistance exercise has been shown to be a safe and effective method for improving strength and cardiovascular endurance, modifying risk factors and enhancing self efficacy in low-risk cardiac patients. Resistance training may begin with the use of elastic bands and light hand weights (1 to 3 lb) and progress to a load that allows 12 to 15 repetitions comfortably. Resistance training should not begin until the patient has been in a CR for at least 3 weeks and is at least 5 weeks post-MI or 8 weeks post-CABG. 

Guideline for resistance training include:

• exercising large muscle groups before small
• stressing exhalation with exertion
• avoiding a sustained tight grip
• focusing on rate of perceived exertion (RPE) 11 to 13 (Borg`s scale) 
• using slow, controlled movements; and
• stopping exercise with any warning of concerning or uncomfortable signs or symptoms

PHASE 3

The American Heart Association (AHA), American College of Sports Medicine (ACSM), and American Association of cardiovascular and Pulmonary rehabilitation (AACVPR) all advocate the importance of muscular fitness for the patient with cardiac impairment and support the inclusion of resistance training into the patient’s exercise program. 

Maintenance phase include 2 primary therapeutic goals:

• improvement of physical condition
• prevention of ischemic episodes

To be able to achieve the therapeutic goals, patients need following take home education notes: 

• planned exercise sessions with details of leisure time and rest
• self-monitoring can be done by palpating pulse or RPE using Borg`s scale. It is also important to be aware of other symptoms or signs that may suggest exercise intolerance, such as light-headedness, mental confusion, dyspnoea, and inability to carry on a brief conversation while performing an activity.
• Having a heart-healthy diet – keeping a diet chart and keeping a check on calorie intake is a key to long term good health maintenance
• Patients receive written information regarding the desired action of their medications, potential side effects, dosage, and timing of medications. Patients should also know which nonprescription drugs such as cold, sinus, allergy, or anti-inflammatory medications they should avoid because of possible interactions with prescription drugs. Patients should also be encouraged to disclose all herbal remedies and supplements that they may be taking.
• Cessation of smoking and alcohol abuse, keeping up with active lifestyle, proactively keeping a check on stress and learning to cope and reduce the impact of harmful lifestyle on heart health can add to the success of CR. 

The American College of Sports Medicine and the American Heart Association recommend that anyone over age 40 with two or more risk factors should have an ETT before beginning an aerobic or strengthening exercise program. The purpose of the ETT is to identify the presence of any latent ischemia.

(Source: Physical Rehabilitation by Susan B. O`Sullivan, Schmitz, Fulk, Sixth edition)