Ischaemic heart disease, myocardial infarction and CABG

1Definition

IHD, also called coronary artery disease (CAD), is a condition in which the heart muscle gets less blood and oxygen than it needs. The cause is usually atherosclerosis of the coronary arteries.

Angina pectoris is chest pain or discomfort caused by temporary ischaemia of the heart muscle. The muscle is not permanently damaged.

Myocardial infarction (MI) is death of heart muscle caused by prolonged ischaemia.

ACS is the umbrella term for sudden ischaemia. It covers unstable angina, NSTEMI and STEMI.

PCI, also called angioplasty or PTCA, opens the blocked artery from inside with a balloon, and usually leaves a stent behind.

CABG is open-heart surgery. The surgeon joins a graft vessel around the blocked part of the coronary artery so blood can bypass the block.

2Classification and grading

The coronary spectrum

MI can also be described by site (anterior, inferior, lateral, posterior) and by depth. A full-thickness (transmural) infarct usually shows ST elevation and later Q waves. A subendocardial infarct affects the inner layer only.

Grading scales examiners ask for

Killip class grades heart failure in the first days after MI: I no failure; II crackles in the lower lungs or a third heart sound; III frank pulmonary oedema; IV cardiogenic shock.

Universal Definition types of MI: type 1 is plaque rupture with clot; type 2 is a supply–demand mismatch (for example severe anaemia or fast arrhythmia); type 3 is sudden cardiac death; types 4 and 5 are related to PCI and CABG.

3Causes and risk factors

Main cause: atherosclerosis. Fatty plaque builds up in the artery wall and narrows the lumen. Less common causes include coronary spasm, an embolus, a tear in the artery (dissection), and extra demand from severe anaemia or a very fast heart rate.

4Pathophysiology to impairments

Examiners never ask for pathophysiology alone. They ask for "clinical reasoning for the impairments". This chain is that reasoning.

The heart muscle's oxygen demand rises with heart rate, blood pressure and the force of contraction. Supply falls when a coronary artery narrows. Ischaemia starts when demand is greater than supply.

Why physio cares about healing time

Dead muscle is slowly replaced by scar. The scar takes about 6–8 weeks to become firm. Early activity is safe and helpful, but heavy straining is avoided until the scar matures.

Extra problems after CABG

• Pain from the sternotomy and graft sites makes breathing shallow and cough weak.
• Anaesthesia, ventilation and lying flat reduce lung volumes. This leads to basal atelectasis.
• Guarding of the chest stiffens the shoulders and thoracic spine and causes a rounded posture.
• Graft sites in the leg or forearm can swell, hurt or get infected.

5Clinical features

Angina

• Central chest tightness, heaviness or pressure. Patients often describe it as a weight rather than a sharp pain.
• Spreads to the left arm, jaw, neck or back.
• Triggered by exertion, cold, heavy meals or emotion.
• Stable angina settles within a few minutes of rest or a nitrate under the tongue.

Myocardial infarction

• Severe chest pain lasting more than 20 minutes, not relieved by rest or nitrate.
• Sweating, nausea and vomiting, breathlessness, weakness, and a sense of impending doom.
• Signs: fast or slow pulse, low blood pressure, extra heart sounds, and crackles at the lung bases if the left ventricle is failing.
• Inferior MI often causes a slow pulse or heart block, because the right coronary artery usually supplies the SA and AV nodes.

After CABG

Expect a patient with sternotomy and graft-site pain, chest drains, shallow breathing, reduced breath sounds at the lung bases, a weak cough, tiredness, a swollen leg or forearm at the graft site, and stiff shoulders. The S19 case ("unable to raise his hands above head") is this last problem.

6Investigations

Write only what changes physio decisions. That is what examiners look for in a case answer.

ECG (3 marks in S24: criteria for acute and evolved MI)

• STEMI: new ST elevation in two neighbouring (contiguous) leads. The threshold is at least 1 mm in most leads. In V2–V3 it is 2 mm for men aged 40 or over, 2.5 mm for men under 40, and 1.5 mm for women.
• Sequence in STEMI: tall (hyperacute) T waves → ST elevation → pathological Q waves → T-wave inversion.
• NSTEMI and unstable angina: ST depression or T-wave inversion.
• Evolved (established or old) MI: pathological Q waves in two neighbouring leads, with T-wave inversion and the ST segment back to baseline. A Q wave is pathological when it is at least 0.03 s wide and 1 mm deep, or any Q wave wider than 0.02 s in V2–V3 (Fourth Universal Definition). Many textbooks use the older rule: wider than 0.04 s (one small square) or deeper than a quarter of the following R wave.

Cardiac markers and their importance in cardiac rehab (7 marks in W25)

• Diagnosis: a rise and fall of troponin, with symptoms or ECG changes, confirms MI and separates NSTEMI from unstable angina.
• Size of the infarct and risk: higher peaks mean more muscle lost, usually a lower EF, and a higher risk group for exercise.
• When to start: Phase I mobilisation begins once markers are stable or falling and there is no new chest pain.
• Safety during rehab: new chest pain during progression is checked with ECG and troponin; a fresh rise means a new infarct, so exercise stops and the plan is reset.
• After CABG: some troponin rise is expected from the surgery itself; the surgeon decides whether it is more than expected.
• Heart failure: BNP helps judge severity and response to treatment, and so how hard to train.

7Medical and surgical management

Emergency treatment of STEMI

• Reperfusion is the priority. Primary PCI should be done within 90 min of first medical contact, or within 120 min if the patient must be transferred to another hospital.
• If PCI cannot be done within 120 minutes, give thrombolysis (clot-dissolving drugs), ideally within 30 min. The W22 case was "thrombolysed".
• Aspirin plus a second antiplatelet drug, and an anticoagulant.
• Give oxygen only if SpO₂ is below 90%.
• Nitrates for pain. Use an opioid only for severe pain.

Long-term drugs and what they mean for exercise

PCI (angioplasty with stent)

• A catheter enters through the radial artery at the wrist or the femoral artery in the groin. A balloon opens the block and a stent keeps it open.
• After femoral access, the leg is kept straight for a few hours according to hospital protocol. Check the groin for bleeding or swelling before walking.
• After radial access, walking can start early. The wrist is protected from heavy loading for a few days.
• Driving: the UK DVLA allows car driving 1 week after successful PCI for an acute coronary syndrome, if EF is at least 40% and no further urgent procedure is planned; otherwise 4 weeks. India has no specific rule, so this is a useful reference. The S20 bank manager who must drive one hour fits here.

CABG

Indications (3 marks in W25):

• Significant left main coronary artery disease.
• Triple vessel disease, especially with diabetes or a weak left ventricle (low EF).
• Two-vessel disease involving the proximal LAD.
• Angina not controlled by medicines when PCI is unsuitable (long, diffuse or complex blocks).
• Failed PCI, or a complication during PCI.
• At the time of other heart surgery (for example valve replacement), or for mechanical complications of MI (ventricular septal rupture, papillary muscle rupture, ventricular aneurysm).

• Approach: median sternotomy. The sternum is split vertically and later closed with steel wires. Unlike a thoracotomy, no major muscle belly is cut, so the main post-op problems are sternal pain and protecting the healing bone.
• Grafts (3 marks in W24): left internal mammary artery (LIMA) to the LAD is the standard because it stays open longest. Other grafts: right internal mammary (RIMA), radial artery, and great saphenous vein.
• On-pump or off-pump: on-pump surgery uses a heart–lung machine while the heart is stopped. Off-pump surgery is done on the beating heart.
• Lines and tubes after surgery: endotracheal tube on a ventilator for a few hours, mediastinal and pleural drains, temporary pacing wires, arterial and central lines, urinary catheter.

8Complications and prevention

9PT assessment

Subjective

• Present complaints: chest pain (site, character, spread, triggers, relief), breathlessness, palpitations, fatigue, wound pain.
• Event and treatment: date of MI, thrombolysis, PCI or CABG with the post-operative day, grafts used, complications in ICU.
• Risk factors and past history: diabetes, hypertension, lipids, previous heart events.
• Medications, especially beta-blockers and nitrates.
• Social history (this fills the ICF): job and its physical demands, travel and driving, earning role in the family, home floor and lift, Indian or Western toilet, family support, smoking, tobacco, alcohol, diet.
• Patient's own goals and fears.

Objective

• Vital signs at rest and with activity: heart rate and rhythm, BP lying and standing, respiratory rate, SpO₂, temperature.
• Observation: monitors, lines, drains, oxygen, breathing pattern, posture, colour, swelling.
• Chest: expansion, auscultation (listen especially at the bases), cough effectiveness.
• Wounds: sternotomy and graft sites.
• Musculoskeletal: shoulder and thoracic range, posture, muscle strength, calf for DVT signs.
• Function: bed mobility, sit-to-stand, walking distance with vital signs, stairs.

Risk stratification for exercise (asked as 7 marks in S21)

Before Phase II, sort the patient into low, moderate or high risk of a cardiac event during exercise. The AACVPR scheme is the standard. One high-risk feature is enough to make the patient high risk.

To assess risk of developing coronary disease in the first place, count the risk factors in section 3 and use a risk chart such as the WHO risk charts for South-East Asia.

10PT diagnosis by ICF

Nearly every long-answer option in 2016–2026 asks for ICF, a functional diagnosis or impairments. Master this section first.

Worked example from a real paper (W17, 5 + 3 + 7 marks)

"50 years old male businessman had angina since 1 month. Angiography showed major blocks in LAD and other 2 arteries. He was operated for CABG 2 days back. Grafts taken from LIMA, RIMA and radial artery. He needs to drive to work everyday. Write impairments, activity and participation limitation and short term and long term management."

ICF code numbers are not needed. No paper has asked for them.

11Problem list and goals

Goals must be functional, measurable and time-bound, and tied to the patient's own life. Use the examiner's words: short-term goals and long-term goals.

12PT management

Two layouts, because papers ask both ways: by phase ("plan his cardiac rehabilitation") and by impairment ("physiotherapy for each impairment", S19).

Before surgery (when CABG is planned)

• Explain the operation, the ICU, the drains and the plan for the first days. This reduces anxiety.
• Teach deep breathing, holding a full breath in for a few seconds, and a supported huff and cough with a pillow hugged over the chest.
• Teach sternal-safe bed mobility and ankle pumps.
• Record baseline walking distance and vital signs.
• In high-risk patients, inspiratory muscle training before surgery reduced lung complications after CABG in a randomised trial (Hulzebos, JAMA 2006).

Phase I: in hospital

Start when stable. After MI this means no new chest pain, no new ECG changes or dangerous arrhythmias, troponin stable or falling, and no uncontrolled heart failure. This is usually within the first day. After CABG, start on day 1.

Monitor before, during and after every session: heart rate and rhythm, BP, SpO₂, RPE and symptoms. Teach the patient the warning signs and how to use GTN before discharge. Refer to Phase II.

Factors that decide progression of exercise (S24)

Move to the next step only when the patient tolerated the last step:

• Heart rate: rise within the limits (rest + 20 after MI, rest + 30 after surgery); a resting HR above about 120 is a reason to wait.
• Blood pressure: systolic rises a little with effort; a fall of more than 10 mmHg, or diastolic 110 or more, stops progression.
• Rhythm and ECG: no new arrhythmia (atrial fibrillation is common after CABG) and no ischaemic changes.
• Symptoms: no angina, dizziness or marked breathlessness; RPE below 13; SpO₂ stays stable.
• Surgery-related: incision pain controlled (S24: VAS 4 at rest, so treat after analgesia), stable sternum, drains and pacing wires, haemoglobin, fluid balance, chest X-ray (effusion or collapse).
• Recovery: HR and BP back near resting within a few minutes; not unduly tired the next morning.
• Patient factors: age, previous fitness, risk group (EF), diabetes and other diseases, confidence and anxiety.

Phase II: early outpatient, supervised

Starts soon after discharge and usually runs for about 8–12 weeks. It has four parts: exercise, education, risk-factor control and psychological support. Begin with risk stratification (section 9) and an exercise test or 6-minute walk test.

Each session: warm-up 5–10 min, conditioning 20–60 min, cool-down 5–10 min. A longer warm-up and cool-down lower the risk of ischaemia and arrhythmia at the start and end.

Phase II after PCI for a young, active patient (7 marks in W24)

• No sternal precautions: PCI has no chest wound, so arm work and resistance training can start early. Protect the puncture site: after radial access avoid heavy gripping and wrist loading (racquet and bat sports) for about a week; after femoral access avoid heavy lifting and strenuous leg work for about a week.
• Exercise test first: a symptom-limited test shows the safe heart-rate range and any remaining ischaemia; it sets the intensity.
• Aerobic: 3–5 days a week, starting at moderate intensity (40–60% HRR, RPE 12–13) and progressing towards 60–80% HRR; add interval training once continuous exercise is comfortable.
• Resistance: 2–3 days a week, all major muscle groups, progressing the load gradually.
• Sport-specific stage: skill work at low intensity first, then match-like efforts with warm-up and cool-down; avoid sudden all-out bursts in the early months.
• Return to sport: recreational sport once he trains at the needed intensity without symptoms, ischaemia or arrhythmia; competitive sport only after a cardiologist's assessment (ESC 2020 sports cardiology guideline).
• Other points: antiplatelet drugs cause easy bruising and bleeding, so avoid collision injuries; never stop these drugs without the cardiologist; risk factors still need control even in a fit person.

• Breathe out on effort. Never hold the breath while lifting (Valsalva), because it causes sudden swings in BP.
• Talk test: the patient should be able to talk in short sentences while exercising.

Lifting heavy objects is usually avoided for about 3 months after CABG (NHS advice). Light, pain-free upper-limb exercise with the arms kept close to the body can begin earlier.

Phases III and IV: maintenance for life

• Exercise in the community, at home or in a gym with less supervision.
• Aim for at least 150 min a week of moderate activity plus resistance exercise on 2 days.
• Self-monitoring with RPE and pulse. Regular review of risk factors.

By impairment (for "physiotherapy for each impairment")

13Precautions, contraindications and stop criteria

• Angina during exercise: stop, sit the patient down, give GTN as prescribed. If pain is not better 5 minutes after the first dose, call for emergency help.
• Avoid exercise for 1–2 hours after a heavy meal, and in very hot or cold conditions.
• Avoid heavy isometric holds and breath-holding early on.
• With beta-blockers, use RPE rather than heart rate.
• After femoral PCI, check the groin before walking.

The ACSM thresholds above were checked against two independent reproductions (a WHO-hosted rehabilitation guideline and an insurer's clinical policy). The primary ACSM book was not available.

14Education, lifestyle and home programme

Asked in S16 (7 marks), W20 (3 marks), S23 (7 marks, education for lifestyle disorders), and as the last part of S17, S19 and W19.

Grades of obesity (asked in S21)

A newer staged definition of obesity for Indians was proposed in 2025. It adds waist size and health effects to BMI. Use the cut-offs above in the exam.

Return to activities

Home programme at discharge

• Walk on level ground twice a day, starting with the distance managed in hospital. Add a few minutes each week, keeping RPE at 11–13.
• Deep breathing exercises several times a day for the first weeks after surgery.
• Pain-free shoulder and trunk exercises, with posture correction.
• Check your pulse and use the RPE scale. Carry GTN.
• Avoid straining and heavy lifting. Rest between tasks (energy conservation).
• Report chest pain, unusual breathlessness, palpitations, fainting, wound redness or discharge, or sternal clicking.

Do's and don'ts after discharge (S25)

15Prognosis and discharge criteria

Prognosis depends on the size of the infarct (EF), arrhythmias, risk-factor control and taking part in rehab. Exercise-based cardiac rehab reduces heart attacks by about 28% and hospital admissions by about 35%, probably reduces deaths, and improves quality of life; home-based and digitally supported programmes work about as well as centre-based ones (Cochrane review update, 2026: 107 trials, 26,886 people).

Discharge from Phase I: stable vital signs at rest and with activity; independent in self-care and walking at about 3 METs; managed one flight of stairs without symptoms; knows the home programme, warning signs and wound care; referred to Phase II.

Discharge from Phase II: goals met; exercises safely and independently with self-monitoring; risk factors addressed; ready for Phase III–IV.

16Exam corner

Past questions (MUHS, 2016–2026)

Wording cleaned up from scanned papers.

• S16 Q3(a), 5 + 10 marks55-year-old male farmer, chronic alcoholic, myocardial ischaemia 2 days back. (i) Functional diagnosis. (ii) Physiotherapy management in detail.
• S17 Q4(a), 5 + 7 + 3 marks60-year-old male bank manager, CABG for triple vessel disease 3 days back; chronic smoker, hypertensive, BMI 30. Discuss ICF, Phase 1 and Phase 2 cardiac rehabilitation, and lifestyle modifications.
• W17 Q4(a), 5 + 3 + 7 marksThe worked example in section 10.
• S18 Q4(a), 15 marks60-year-old male shopkeeper with anginal pain, breathlessness and anxiety, in ICU for 3 days; chronic alcoholic, obese, hypertensive. Discuss ICF and cardiac rehabilitation.
• W18 Q4(a), 5 + 10 marks60-year-old shopkeeper, CABG 1 week back, with hypertension and diabetes. Functional diagnosis and cardiac rehabilitation in detail.
• S19 Q4(a), 5 + 7 + 3 marks55-year-old male bank manager, CABG for triple vessel disease 3 weeks back; discharged on day 3 but did not follow physio advice; chronic smoker not ready to quit; trying to change his diet; BMI 30, low HDL; wound healed but cannot raise his hands above his head. (i) Impairments with clinical reasoning. (ii) Physiotherapy for each impairment. (iii) Lifestyle modification with reasons.
• S20 Q4(a), 3 + 5 + 7 marks65-year-old retired female nurse with stable angina and ventricular dysfunction, EF 25%, diabetic, refused surgery, on conservative treatment. Impairments, activity and participation limitation, short- and long-term management.
• S20 Q4(b), 3 + 5 + 7 marks50-year-old male bank manager, angioplasty 2 days back after an inferior wall MI a week back; wants to return to work early; drives 1 hour to work. Same question as above.
• W20 Q4(a), 5 + 10 marks50-year-old male executive, chronic smoker, hypertensive; sudden chest pain spreading to the left arm and upper back; ST elevation with pathological Q waves; raised CK-MB and troponin; now stable. Discuss ICF and plan cardiac rehabilitation in detail.
• S21 Q4(b), 5 + 7 + 3 marks43-year-old businessman, CABG 20 days back, type 2 diabetes for 5 years, BMI 32. Plan Phase II cardiac rehabilitation with ICF; give grades of obesity.
• W22 Q4(b), 5 + 5 + 5 marks50-year-old in ICU with breathlessness and severe chest pain; ST elevation and T inversion in II, III, aVF; thrombolysed. Discuss ICF and plan short- and long-term physiotherapy.
• W19 Q3(a), 5 + 5 + 5 marks55-year-old senior executive, CABG for triple vessel disease 2 days ago; stopped smoking 6 months ago; hypertensive; married with 2 children, wants to resume his job. Functional diagnosis; Phase I cardiac rehabilitation; importance of lifestyle modification for him.
• S23 Q3(b), 15 marks50-year-old schoolteacher admitted with chest pain and hypertension, treated conservatively. Functional diagnosis and physiotherapy management.
• S24 Q3(a), 15 marks55-year-old executive, on-pump CABG 3 days ago; incision pain VAS 4/10 at rest; resting HR 96/min, BP 140/90 mmHg; cannot sit up or sleep; dyslipidaemia and hypertension for 15 years. Functional diagnosis; Phase I cardiac rehabilitation; factors you would consider for progressing exercise.
• S25 Q3(a), 5 + 5 + 5 marks60-year-old man with severe chest discomfort spreading to the left shoulder, jaw and upper back; deep Q waves in II, III and aVF; echo shows inferior wall hypokinesia, EF 40%. ICF; Phase I physiotherapy; do's and don'ts after discharge.
• S26 Q4(a), 15 marks (four parts)55-year-old office manager with an inferior wall MI, haemodynamically stable; chronic smoker, hypertensive, diabetic for 2 years, poor compliance. (i) Phases of cardiac rehabilitation with their aims; (ii) physiotherapy in hospital until discharge; (iii) convalescence from discharge to 6 weeks; (iv) rehabilitation after 3 months.
• 7-mark questionsPhase I cardiac rehabilitation following MI (W16, W17). Importance of lifestyle modification in preventing IHD (S16). Risk assessment and stratification for coronary artery disease (S21). Phase 2 cardiac rehabilitation after PTCA to the LAD in a 45-year-old executive who wants to play sport (W24). Patient education for lifestyle disorders (S23). Cardiac markers and their importance in cardiac rehabilitation (W25).
• 3-mark questionsRisk factors for coronary artery disease (S17). Three modifiable and three non-modifiable risk factors (W17). Phase I of cardiac rehabilitation (S20). Lifestyle modifications after CABG (W20). ECG criteria for acute and evolved MI (S24). Grafts used in CABG (W24). Karvonen's formula in cardiac rehabilitation (W25). Indications of CABG (W25).

Technique cards for this topic: exercise testing, exercise physiology, scales, bed rest, cardiac rehabilitation, ECG and investigations, cardiac drugs.

Keywords to underline in your answer

ICF impairment activity limitation participation restriction facilitator barrier Phase I–IV early mobilisation METs RPE HR rest + 20 FITT-VP Karvonen risk stratification sternal precautions supported cough stop criteria secondary prevention

Answer skeleton: any CABG or MI long answer

1. Restate the case in two lines: age, job, diagnosis or surgery with day, other conditions, key social detail.
2. [ICF, 5] Draw the ICF model, fill every box from the case, add a one-line functional diagnosis and 2–3 reasons.
3. Problem list, then short- and long-term goals linked to his work and home.
4. [Management, 7–10] Phase I with the "13 / 20 / 30 / 120" limits and progression; Phase II FITT-VP with a worked target heart rate; Phase III–IV in two lines.
5. Stop criteria and precautions in a short list (sternal precautions if CABG).
6. [Add-on, 3] Whatever was asked: lifestyle with reasons, grades of obesity, outcome measures.

Draw these

• The ICF model (section 10): in every long answer
• The phases timeline (section 12): in any cardiac rehab answer
• The plaque-to-impairment chain (section 4): for "impairments with clinical reasoning"

Viva questions

1. Why do you use RPE rather than target heart rate in a patient on a beta-blocker?
2. What is the rate–pressure product and why does it matter?
3. Why is the LIMA preferred for grafting the LAD?
4. Which leads show an inferior MI, and what complication do you watch for during mobilisation?
5. When will you stop a Phase I session?
6. What are sternal precautions? What does "keep your move in the tube" mean?

Linked practical spots

• ECG with ST elevation in II, III and aVF: inferior STEMI, right coronary artery.
• ECG with pathological Q waves: an old or evolving infarct.
• Incentive spirometer: name it, its use, and its limits after CABG.