Cardiac rehab

Annotations:

• The aim of cardiac rehab is to help a patient recover and get back to as full a life as possible after having a cardiac event or cardiac surgery. It aims to promote health and keep the pt well when they go home.

1. Phase 1
   1. Resp care
   2. Early mob

      Annotations:

      • Anti-thrombotic, confidence building. empowering, reconditioning. Start with MoS and then progress. If the patient needs to do stairs in their daily life then practice stairs pre-discharge to make sure they can do it safely. Stairs = MET value of 4
   3. Post-op posture

      Annotations:

      • Correct their posture. Esp if they have had a unilateral incision as you are more likely to adopt an abnormal posture e.g. thoracostomy.
   4. Education

      Annotations:

      • Give them advice on lifestyle modification and give them an idea of what to expect in phase 2.
2. Phases

   Annotations:

   • Phase 1 = in patient hospital stay Phase 2 = post-discharge. The at home in between period Phase 3 = the outpatient cardiac rehab phase Phase 4 = phase 4 instructors for the rest of their life
3. Who for?

   Annotations:

   • Helpful for: - heart attack - coronary angioplasty - heart surgery such as coronary bypass -if have a implantable cardioverter defibrillator (ICD) - stable heart failure Also helpful for those with cardiomyopathy, stable angina or congenital heart disease.
4. Phase 2

   Annotations:

   • The at home period prior to intensive rehab. 2-6 weeks in duration Adopt a positive healthy out-look Follow a structured exercise programme. Avoid - wind because it takes more effort to walk. Avoid - cold because it causes peripheral vasoconstriction causing the heart to work harder.
5. Phase 3

   Annotations:

   • Outpatient rehab phase - 4-6 weeks post event. Duration of programme = 6-12 weeks. Often lose people at stage 2 or 3 that are not motivated enough to carry on.
   1. Risk stratification and EF

      Annotations:

      • Before joinng phase 3 pts need to be risk stratified. Risk stratification involves using the patients cardiac history and current cardiac status including results from cardiac echo (ultrasound of the heart) to assess the likelihood of future adverse events.AACVPR stratification: Classified into low moderate or high risk. You only need one of the factors in the group above to be moved up.  Higher risk patients need a gentle start of their exercise prescription.Higher risk patients may have impaired LV function causing  decreased ejection fraction (EF). EF = SV/EDV70/120ml = 60% EFEF > 50% = normal ventricular function - low riskEF 40-49% = mod ventricular function - mod riskEF <40% = poor ventricular function - high risk Consequences of a poor EF:A low EF means a low SV. This means the heart rate has to increase to try and maintain CO. This requires increased oxygen demand to work at a higher rate. Coronary artery pathology prevents adequate perfusion and therefore increases the risk of ischaemia and arrythmias. With heart failure you get increased HR (decreased  filling time) which causes CO compromise causing inadequate coronary perfusion and increased risk of ischaemia and arrhythmias. Once a patient has been risk stratified a decision can be made regarding: - suitability to take part in phase 3 - degree of monitoring necessary - pt:staff safety ratio
   2. Exercise exclusions

      Annotations:

      • - unstable angina - resting SBP >200mmHg dbp >110mmHg - orthostatic BP drop > 20mmHg with symptoms on exs (BP drops due to positional changes) - critical aortic stenosis - acute systemic illness or fever - uncontrolled atrial or ventricular arrhythmias - uncontrolled sinus tacchycardia - uncompensated CHF - 3rd degree heart block - active pericarditis/myocarditis - recent embolism - thrombophlebitis (vein inflammation caused by thrombus in the vein) - resting ST segment >2mm - uncontrolled diabetes (resting blood glucose >400mg/dl
   3. Testing prior to rehab
      1. Exercise tolerance test (ETT)

         Annotations:

         • 1. Maximal exercise tolerance test consists of exercising on a treadmill following a defined protocol, the Bruce protocol, over approximately 20 minutes. The test begins gently and gradually the level of intensity is increased through a combination of increased treadmill speed and incline.Intensity of exercise is measured in in METs where 1 MET (metabolic equivalent) is the amount of energy expended at rest or 3.5 ml oxygen per kilogram per minute.[3]The test is divided into seven stages of three minutes and there is also a less strenuous version called the modified Bruce.ECG is recorded throughout and blood pressure measured intermittently.ETT might be prematurely stopped for any of the following: development of chest pain, presence of ST elevation, very deep ST depression, arrhythmias, hypotension or if the patient becomes tired and is unable to continue. In addition, elevation of blood pressure to dangerous levels such as >170/120 mm Hg should also lead to termination of the test.Beta-blockersand digoxin can interfere with the results so are usually stopped before the ETT.
      2. Functional exercise test

         Annotations:

         • E.g. 6MWT, shuttle walk, chester step test, astrand cycle ergometer.
         1. Chester step test

            Annotations:

            • The step height varies for different participants (from 0.15 to 0.30 meters) - there are standardized criteria for choosing a step height based on the subjects age and physical activity history. The initial step rate is 15 steps per minute and every 2 minutes the tempo increases by 5 steps per minute. The stepping rate is set by a recorded metronome and guided verbal instructions, which are played on a cassette tape or compact disc. When the subject reaches 80% of age estimated heart rate maximum and/or an RPE of 14 on Borg’s 6–20 scale, they are told to stop the test.
            1. HR max

               Annotations:

               • 220-age = HR max 220-age-30 = HR max if you are on beta blockers because beta blockers are known to reduce HR. To calculate 80% = HRmax x 0.8. On the chester step test when they get to 80% of HRmax you stop the test.
            2. MET score

               Annotations:

               • You can calculate a MET score to aid exercise prescription and empower the pt. Get an estimated VO2 max and convert into METs.
               1. What is a MET?

                  Annotations:

                  • = Metabolic equivalent It is an indication of functional aerobic capacity. 1 MET = oxygen uptake/use at rest. i.e. 1 MET = 3.5mlO2/kg body weight/min
   4. Assessments

      Annotations:

      • - ETT and clinical assessment - Functional capacity assessment - Co-morbidity e.g. COPD - Habitual activity level - Attitude to exercise - Readiness to change Assessments are necessary for: - safe exercise prescription - objective measures of improvement during the programme and for review - Appropriate long term exercise goals
      1. Re-assessment at each visit

         Annotations:

         • Meet the triage service: - Check for changes in meds, symptoms or the presence of any systemic illness. Gives the opportunity to discuss home exercise e.g. respond to it/any issues.
   5. FITT principle

      Annotations:

      • F - 2 classes a week and 1/2 times a week home exs. And brisk walk on other days. I - 60-75% HR max if low risk (B blockers). 12-13 on Borg RPE. T - 20-30 mins conditioning (progressing) T - CV endurance, large mm groups. E.g. circuit interval training includes some strengthening. 
   6. The circuit

      Annotations:

      • Design a circuit that:- keeps the feet moving at all times to maintain VR and CO and to keep the HR steadily elevated.- consider mm balance- consider posture- co-morbidities may necessitate exs adaptations e.g. vision, hearing, balance- early stages should include strength training- avoid positional changes because elderly baroreceptors don't cope.- Avoid high resistance exs- Needs to be adaptable for home exs Conditioning phase lasts for 20-30 mins. Contains active rest stations and CV stations. HR target =60-75% of HR max 12-14 on Borg RPE scale.
      1. Monitoring intensity

         Annotations:

         • Important to make sure the pt is being challenged, not working at too low or too high a level. 1. Self monitoring - symptoms during and after exercise e.g. SOB, sweating, fatigue, angina pain - RPE - HR monitor (pulse) 2. Staff monitoring - observation (pallor etc) - assess symptoms, HR, BP - accurate recording
   7. Warm- up

      Annotations:

      • Prepares body and mind for exercise by: - increasing HR in a safe manner - increases blood flow to sk mm and myocardium via SNS and metabolites causing VD of coronary arteries and the metabolites cause VD of arterioles to active sk mm A cardiac rehab warm up will NEVER BE LESS THAN 15 MINS THIS EXTENDED WARM UP DECREASES THE RISK OF ISCHAEMIA LEADING TO DECREASED RISK OF ARRHYTHMIAS - VIA GRADUAL CORONARY ARTERY VD.
      1. Components

         Annotations:

         • 1. Mobility exs 2. Pulse raising exs 3. Stretches (HR will decrease) 4. Pulse raising exs
   8. Cool down

      Annotations:

      • 10-15 mins Ending with slow walk and stretches Faciliates a gradual slowing of HR and a gradual lowering of BP. (As SNS is switched off and catecholamines are dispersed causing a decrease in cardiac workload.) Also - lactic acid is dispersed          - heat is dissipated
6. Phase 4

   Annotations:

   • Within the community. Longterm management of fitness and health. Some people go on to this stage and others maintain their own level of fitness after stage 3.
7. Deconditioned state

   Annotations:

   • The heart is not an effective/nergy efficient organ Skeletal and cardiac muscles are not capable of efectively and efficiently extracting and utilising O2 to manufacture ATP. Importantly an inefficient sk mm system will place high demands on the unfit heart. i.e. if the type 1 sk mm fibres can only extract a small percentage of O2 presented to them by a limited capillary system, then they will require the heart to work harder to increase the blood supply. But a heart with CAD may become relatively ischaemias it works harder.
8. Central adaptations

   Annotations:

   • These are mainly adaptations that occur at the level of the heart - in response to regular aerobic exercise/training - to enhance the volume of blood ejected per cardiac contraction, (stroke volume), and hence the volume of blood/O2 delivered to the muscles. SV can be increased by: 1. CARDIAC DILATION - cardiac chambers esp the ventricles enlarge over time. Larger ventricles can accommodate larger volumes of blood whilst relaxed and filling. A heart that is better filled  can eject larger volumes of blood on each contraction 2. INCREASED CONTRACTILITY - Get increased senstivity to SNS as a result of conditioning. Therefore SV increases allowing HR to lower a little. Higher HRs are more likely to tip the heart into ischaemia. 3. MYOCARDIAL HYPERTROPHY - heart can contract more forcefully because it has a larger muscle mass (more XB opportunities) Conclusion: AT all submaximal intensities of exercise HR will be lower compared to a de-conditioned person. A lowered HR is generally desirable, as a low HR facilitates adequate filling of the ventricles in diastole and good perfusion of the myocardium (since coronary artery blood flow only happens during diastole).
9. Peripheral adaptations

   Annotations:

   • Muscles have a greater ability to extract and utilise the O2 delivered. Mechanisms by which O2 extraction can be enhanced... 1. INCREASED MYOGLOBIN - its presence reduces the O2 diffusion distance 2. INCREASED CAPILLARY DENSITY - aerobically trained muscles have a better supply of capillaries.Higher capillary to muscle fibre ratio, reduced diffusion distance. 3. INCREASED NUMBER (SIZE) OF MITOCHONDRIA  4. INCREASED PROVISION OF AEROBIC ENZYMES 
10. Laws of training

    Annotations:

    • Specificity: Tailor it to the patient e.g. for cardiac patients, involve large mm groups as this will benefit them the most. Overload: muscles must be challenged/stressed in order to stimulate physiological adaptations resulting in a training effect. Reversibility: Training effects are short-lived so need to stress the importance of long term exercise.