2. IHD
• Patients with IHD can present with chronic stable
angina or with acute coronary syndrome.
• Acute coronary syndrome includes STEMI and NSTEMI/
Unstable angina
3.
4. DEFINITION
• Myocardial ischaemia is a dual state composed of
inadequate myocardial oxygenation and accumulation of
anaerobic metabolites and occurs when myocardial
oxygen demand exceeds the supply.
• Myocardial infarction is defined as the death of
myocardial myocytes due to prolonged ischaemia.
5. ANGINA PECTORIS
• An imbalance between CBF and myocardial oxygen
consumption can precipitate ischaemia manifesting as
angina.
• Develops due to partial occlusion or chronic narrowing of
a segment of coronary artery.
• Atherosclerosis is most common cause of impaired CBF.
6. ANGINA PECTORIS CONT..
• When imbalance between myocardial oxygen supply-demand
becomes extreme, it results in CHF,
Dysrhythmias and myocardial infarction.
• Chronic stable angina refers to chest pain or discomfort
that does not change appreciably in frequency or
severity over 2 months or longer.
7. ACUTE CORONARY SYNDROME
ST Elevation myocardial infarction
Pathophysiology
Plaque rupture : STEMI occurs due to decrease in CBF
due to formation of acute thrombus at a site where an
atherosclerotic plaque ruptures, fissures or ulcerates.
Typically vulnerable plaques more prone to rupture.
8. Diagnosis
1. Chest pain
2. Serial ECG changes indicative of MI
3. Increase and decrease of serum cardiac enzymes
9. UNSTABLE ANGINA/NSTEMI
• UA is defined as angina at rest, angina of new onset, or
increase in severity or frequency of previously stable
angina.
• Due to imbalance between myocardial oxygen supply
and demand.
• Typically rupture of atherosclerotic coronary plaque
leads to thrombosis, inflammation and vasoconstiction.
10. COMPLICATIONS
1. Dysrhythmias – VF,VT, AF and Heart block.
2. Pericarditis – Dressler s Syndrome
3. Mitral regurgitation
4. Ventricular Septal rupture
5. CHF and Septic shock
6. Myocardial rupture
7. Right ventricular infarction
8. Cerebrovascular accident
11. RISK FACTORS
i.Life style and smoking
ii.Recent myocardial infarction
iii.Congestive cardiac failure
iv.Peripheral vascular disease
v.Angina pectoris
vi.Diabetes mellitus
vii.Hypertension
viii. Hypercholesterolemia
ix. Dysrrhythmias
x. Age and Sex
xi. Renal dysfunction
xii.Obesity
12. 1. PREOPERATIVE EVALUATION
A) History
1. History of cardiac symptoms
• Chest pain, Palpitations, Syncope, Breathlessness,
Orthopnea, Paroxysmal Nocturnal Dyspnea
2. Exercise tolerance :- It depicts the cardiac reserve.
• Excellent -history of participation in sports like swimming,
football, tennis, basket-ball, skating etc.
• Adequate-patient able to climb stairs, run a short
distance.
• Poor- able to do leisure activities only e.g. slow daily
activities in the house only.
13. 3. Angina pectoris:-It is the symptomatic manifestation of
myocardial ischaemia characterized by typical substernal
pain which is evoked by physical exertion and relieved by
rest or sublingual nitroglycerine.
4. Myocardial infarction:-
According to Tarhan et al –
• Incidence of perioperative re-infarction is 37% if the time
elapsed is less than 3 months,
• 16% when time elapsed is 4-6 months and
• 5% when time elapsed is more than 6 months.
• This is the basis for recommendation to wait for 6 months
after MI for elective major surgery
14. 5. Co-existing noncardiac diseases
i. Peripheral vascular disease
ii. Cerebro vascular disease
iii. COPD in patients with history of cigarette smoking
iv. Renal dysfunction may be associated with chronic
hypertension
v. Diabetes- May be the cause of silent MI
vi. Anaemia, polycythemia, thrombocytosis when
present will need careful management
15. 6. Current medications-
Awareness about the medications that patient is taking is
important during anaesthesia.
• All cardiac medications like beta blockers, calcium
channel blockers, nitrates should be continued until the
morning of surgery.
• Patient may be on anticoagulants which should be
stopped 5-7 days prior to surgery.
7. Congestive heart failure, Dysrrhythmias
16. EXAMINATION
• Assessment of vital signs like blood pressure, pulse rate
and rhythm, jugular venous, pulse, oedema, pallor,
cyanosis, clubbing , jaundice, lymphadenopathy.
• In systemic examination, cardiovascular system should
be examined for heart sounds & any murmur.
• Further evaluation is needed as per the findings.
• Respiratory system also needs to be assessed in details
17. LABORATORY INVESTIGATIONS
Routine investigations
• Hb – Anaemia
• CBC – Leucocytosis, Thrombocytopenia
• Renal function tests
• Coagulation profile
• Chest X ray
• ECG
18. Specific investigations like
A) Noninvasive :
• Echocardiography - to know ejection fraction, any valvular
lesion , wall motion abnormalities, LV function and pressure
gradients,
• Holter monitoring, Treadmill test, thallium scintigraphy
to detect myocardium at risk,
• Radionuclide ventriculography,
• Dobutamine stress test(DST) for evaluating inducible
ischemia in patients who have poor functional capacity,
B) Coronary angiography in patients where DST is positive.
19. ANAESTHETIC MANAGEMENT
Anaesthesia goals
i. Stable haemodynamics
ii. Prevent MI by optimizing myocardial oxygen supply and
reducing oxygen demand
iii.Monitor for ischaemia
iv. Treat ischemia or infarction if it develops
v. Normothermia
vi. Avoidance of significant anaemia
20. • Management depends upon the type of surgery whether
emergency or elective.
• For emergency surgery, proceed for the surgery with
medical management of cardiac ailment.
• For elective surgery perioperative management
depends upon various clinical risk factors and surgery
specific risk factors.
22. SURGERY SPECIFIC RISK FACTORS
1. High risk surgeries- emergent major operations particularly
in the elderly, aortic and other major vascular surgery,
anticipated prolonged surgical procedures associated with large
fluid shifts or anticipated blood loss --- cardiac risk > 5%.
2. Intermediate risk surgeries- carotid endarterectomy,
head and neck surgery, intraperitoneal and intrathoracic
surgery, prostate surgery -- cardiac risk 1- 5%.
3. Low risk procedures:- endoscopic procedures, superficial
procedures, cataract surgeries, breast surgery
Cardiac risk < 1%.
28. PREOPERATIVE MANAGEMENT
• Main reason for risk stratification is to identify patients at
increases risk. So as to manage them with
pharmacologic and other perioperative interventions that
can ameliorate perioperative cardiac events.
29. 1. Optimisation of medical management
2. Revascularization by PCI (BMS, DES)
3. Revascularization by surgery( CABG)
30. TREATMENT
1. Identification and treatment of diseases that can
precipitate or worsen ischaemia.
2. Reduction of risk factors for coronary artery disease.
3. Lifestyle modification
4. Pharmacological management of angina
5. Revascularization by coronary artery bypass grafting
(CABG)or percutaneous coronary intervention (PCI) with
or without placement of intercoronary stents
31. Reduction of risk factors and lifestyle modification
• Cessation of smoking
• Maintainence of ideal body weight- low fat , low
cholestrol diet
• Regular exercise
• Treatment of hypertension .
• Lowering of LDL cholesterol by drugs or diet
32. MEDICAL MANAGEMENT
1. Antiplatelet drugs
2. B Blockers
3. CCB
4. Nitrates
5. Ace inhibitors
33. 1. Antiplatelet drugs – Low dose aspirin (75-300 mg/day)
decreases the risk of cardiac events in patients with stable or
unstable angina. Ticlopidine, clopidogrel, Gp 11b/111a
inhibition(Abciximab, Eptifibatide, Tirofiban) are commonly used
that prevent platelet aggregation.
2. β-Adrenergic Blocking Agents : These drugs decrease
myocardial oxygen demand by reducing heart rate and
contractility. Optimal blockade results in a resting heart rate
between 50 and 60 beats/min. Patients on long-standing β-
blocker therapy should have these agents continued
perioperatively.
34. 3. Calcium Channel Blockers :
• The effectiveness of CCB is due to their ability to decrease
vascular smoothy muscle tone, dilate coronary arteries,
decrease myocardial contractility and oxygen consumption,
and decrease arterial pressure
• CCB reduce myocardial oxygen demand by decreasing cardiac
afterload and augment oxygen supply by increasing blood flow
(coronary vasodilatation).
• Verapamil and diltiazem also reduce demand by slowing the
heart rate.
• CCB are uniquely effective in deceasing severity and
frequency of angina pectoris due to coronary artery spasm
(Printzmetals or Variant angina)
35. 4. Nitrates
• Nitrates relax all vascular smooth muscle, Venodilatation
greater than dillatation of arteries
• They reduce myocardial oxygen demand by decreasing
venous and arteriolar tone and reducing the effective
circulating blood volume (cardiac preload), thus reducing wall
tension afterload.
• Nitrate-induced coronary vasodilatation preferentially
increases subendocardial blood flow in ischemic areas.
• Nitrates can be used for both the treatment of acute ischemia
and prophylaxis against frequent anginal episodes.
36. REVASCULARISATION
• Revascularisation by CABG or Percutaneous Coronary
Intervention(PCI) with or without placement of intra
coronary stents is indicated when optimal medical
therapy fails to control angina pectoris.
• It is indicated for specific anatomic lesions like left main
stenosis > 70%, Combination of two or three-vessel
disease with LAD stenosis > 70% , Impaired left
venticular contractility (Ejection fraction <50%)
37. RECOMMENDED TIME INTERVALS TO WAIT FOR
ELECTIVE NON CARDIAC SURGERY
Procedure Time to wait
Balloon Angioplasty 2-4 wks
Bare metal stent 4-6 wks
CABG 6 wks
Drug eluting stent 12 months
40. PREANAESTHETIC CONSIDERATIONS
• Preoperative visit to the patient is very important.
• A good rapport should be made with the patient and
written consent obtained.
• Patient should be explained about the risk of surgery
and anaesthesia.
• It is important to continue the medications till the day of
surgery like beta blockers,calcium channel blocker
,digitalis.
• Potassium level should be normal as hypokalemia can
cause digitalis toxicity.
• Anticoagulants should be stopped.
41. PREMEDICATION
• Significance of premedication in allaying anxiety in
cardiac patients is of paramount importance.
• This is to prevent increase in B.P. and HR which can
disturb the myocardial oxygen supply and demand and
can induce ischaemia.
• Tab Diazepam 5mg or Alprazolam 0.5mg night before
surgery.
• Tab Ranitidine 150 mg night before surgery and Inj
Ranitidine 50 mg IV 1 hr before surgery
42. INTRAOPERATIVE MANAGEMENT
MONITORING
• Incidence of ischaemia in the intraoperative period is low
as compared with pre and postoperative period.
i. ECG is the most commonly used monitoring tool .
Monitoring three ECG leads ( II,V4,V5 or V3,V4,V5 )
improves recognition of ischaemia. The ST segment
trending system also helps in the detection of ischaemia
ii. Blood pressure
iii. Pulse oximetry
43.
44. iv. Capnography
v. Temperature monitoring
vi. Urine output monitoring
vii. Central venous pressure
viii. Pulmonary artery pressure and cardiac output – can
be measured with as required. In a haemodynamically
unstable patient, the requirement of volume or inotropes
can be judiciously calculated and response monitored
closely
ix. TEE is the most sensitive monitor for ischaemia.
45. CHOICE OF ANAESTHETICS
1. Intravenous anaesthetics
Thiopentone—It reduces myocardial contractility, preload and
blood pressure.
• There is slight increase in heart rate and should be
administered slowly and with caution.
Propofol-— It reduces arterial blood pressure and heart rate
significantly. There is dose dependent reduction in myocardial
contractility.
• It can be used in with good ventricular function but is not good
induction agent for patients with CAD.
Ketamine-—It is not good in IHD and valvular heart disease
patients.
• It is however a useful agent in situations like cardiac
tamponade and cyanotic heart disease.
46. • Midazolam—It produces decrease in mean arterial
pressure and increase in heart rate. It provides excellent
amnesia and is widely used for patient with CAD
• Etomidate—It causes minimum haemodynamic changes.
It is excellent for induction in patients with poor cardiac
reserve.
47. 2. Narcotics —
• Morphine is the preferred drug for its relative cardiac
stability and very good analgesic effect.
• It produces arterial and venous dilatation, resulting in
reduction of afterload and preload.
• Newer narcotic analgesic agents like fentanyl, alfentanyl
and sufentanil also provide adequate cardiac stability
and pain relief.
48. 3. Inhalational agents- Isoflurane is recommended in
patients with good myocardial contractility.
• Halothane has the disadvantage of myocardial
depression and potential of dysrrhythmias.
4.Nitrous oxide—It provides stable haemodynamics in
cardiac patients.
49. 5. Muscle relaxants-
• Muscle relaxants with minimal or no effect on heart rate
and systemic blood pressure (Vecuronium ,Rocuronium,
Cisatracurium) are attractive choices for patients with
IHD.
• Histamine release and resultant decrease in blood
pressure caused by atracurium are less desirable.
• Vecuronium produces minimum haemodynamic
alterations and is suitable for use in cardiac patients.
50. 6. Glycopyrrolate— Reversal with anticholinesterase
anticholinergic drug can be safely accomplished in
patients with IHD.
• It is preferred over atropine since it produces less
tachycardia
51. REGIONAL ANAESTHESIA
Advantages :
• Excellent pain control, Decreased DVT, Avoids stress
response to intubation.
Demerits :
• Hypotension from uncontrolled sympathetic blockade and
need for volume loading can result in ischemia.
• Larger doses of local anaesthetic can cause myocardial
toxicity and myocardial depression.
• Use of epinephrine with local anaesthetic is not
recommended.
52. MANAGING INTRAOPERATIVE COMPLICATIONS
1. Intraoperative ischaemia
A) If patient is haemodynamically stable —
• Beta blockers ( I/V metoprolol upto 15mg)
• I/VNitroglycerine
• Heparin after consultation with surgeon
B) If patient is haemodynamically unstable –
• Supportwith inotropes
• Use of intraoperative ballon pump may be necessary
• Urgent consultation with cardiologist to plan for earliest possible
cardiac catheterization
2. Other complications like dysrrhythmias, pacemaker dysfunction
should be managed accordingly
53. POST OPERATIVE MANAGEMENT
Goals are same as intraoperative
i. Prevent ischaemia ii. Monitor for MI iii. Treatment for MI
• Most cardiac events occur within first 48 hours and
delayed cardiac events occur within first 30 days as a
result of secondary stress.
• Post operative stress of extubation, pain, sepsis,
haemorrhage, anaemia, respiratory problems can
increase the demand on the heart and should be
minimized and treated.
54. PERIOPERATIVE MI
• Ischemic cardiac morbidity is the most common cause of
perioperative death around 10-40%
• (PMI) is most important predictor of short- and long-term
morbidity and mortality associated with non-cardiac
surgery.
• Prevention of a PMI is a prerequisite for the
improvement in overall postoperative outcome.
55. • Perioperative myocardial ischemias (PMIs) are likely to
occur in patients undergoing urgent or emergent surgery.
• MIs in the modern era are more likely to occur in the first
72 hours following surgery.
56. WHY MI OCCURS IN THE FIRST FEW
POST OP DAYS?
• Loss of intravascular blood volume
• Tachycardia from inadequate pain control
• Poor breathing efforts by the patient due to surgical site
pain
• Surgery stimulates inflammatory response leading to
hypercoagulability which increases the thrombosis risk
60. DIAGNOSIS
According to the definition of WHO , at least 2 of the 3
criteria must be fulfilled to diagnose MI:
typical ischemic chest pain
Increased serum concentration of creatine kinase (CK-MB)
Typical ECG finding including development of
pathological Q waves.
61. AHA GUIDELINES
• Increase in cardiac enzyme markers (trop I and Trop T).
• Symptoms of MI
• New Q waves
• ST segment elevation or depression
62. MONITORING
• ECG monitoring standard.
• ST segment depression is a more common indicator of
myocardial ischemia in surgery patients than is ST
segment elevation. ST segment depression occurs in 20
to 50% of patients undergoing surgery.
• A multilead system to detect ischemia (V3, V4, V5 for
maximal detection).
• , leads V3 to V4 have a higher incidence and a greater
degree of maximal myocardial ischemia than does lead
V5.
• automated ST segment monitors promise to increase
the detection .
63. • Most (>80%) PMIs occur early after surgery, are
asymptomatic, of the non-Q-wave type (60–100%),
• most commonly preceded by ST-segment depression
rather than ST-segment elevation.
• Long- duration (single duration >20–30 min or
cumulative duration >1–2 h) rather than merely the
presence of postoperative ST-segment depression,
seems to be the important factor associated with
adverse cardiac outcome.
64. • Patients manifest MI in the immediate postoperative
period, with its associated pain, adrenergic stress,
hypothermia, hypercoagulability, anemia, shivering, and
sleep deprivation.
• clinical practice is to obtain a 12-lead ECG in the first 24
hours following surgery in high-risk patients, and then
perhaps daily for the next 2 to 3 days
65. • capillary wedge pressure (PCWP) monitoring in patients
undergoing surgery has low sensitivity and specificity in
detecting ischemia.
• PCWP as a monitor for myocardial ischemia is not
routinely used, but the pulmonary artery catheter
provides useful information about a patient's
intravascular volume status, myocardial performance,
and organ perfusion
66. • TEE has also been proposed as a monitor for
intraoperative myocardial ischemia. .
• regional wall motion abnormalities were more sensitive
than ST segment change on the ECG in detecting
intraoperative ischemia .
• However, it has been concluded that ischemia
monitoring with TEE during noncardiac surgery
appeared to have little incremental clinical value over
preoperative clinical data and Holter monitoring in
predicting perioperative ischemic outcomes
67. MANAGEMENT
Two principal strategies have been used
1. Preoperative coronary revascularization
2. Pharmacological treatment
68. TREATMENT OF PERIOPERATIVE
MYOCARDIAL ISCHAEMIA
1. Prevention of MI :
• Prevent tachycardia.
• Maintenance of adequate depth of anaesthesia and judicious use
of ultra short acting B blockers.
• Adequate measures to attenuate pressor responses to laryngoscopy
and endotracheal intubation.
• If haemodynamic aberrations are associated with myocardial
ischaemia, they may precede and be the cause of ischaemia .
69.
70. 2. Treatment of MI without accompanying
haemodynamic alterations:
In patients with haemodynamic alterations,
nitroglycerine can be useful as it decreases preload and
wall tension, dilates epicardial coronary arteries, and
increases subendocardial blood flow.
71. 3. Treatment of MI accompanied
by tachycardia and hypertension:
• disturbs the myocardial oxygen demand and supply
balance.
• After ensuring adequate ventilation, oxygenation and
anaesthetic depth, B blockers may be administered in a
titrated manner provided there is no evidence of CHF or
bronchospasm.
72. 4. Treatment of MI accompanied by tachycardia and
hypotension:
• MI occurs due to drastically reduced myocardial oxygen
supply.
• Prompt volume replacement to restore coronary
perfusion pressure and slow the rate.
73. 5. Severe resistant MI :
• One which is resistant to all antianginal drugs.
• Here intraaortic balloon pump (IABP) can be useful
as it acutely decreases myocardial oxygen requirements
and may increases the oxygen supply.
74. TREATMENT OF PERIOPERATIVE
MYOCARDIAL INFARCTION
• Ensure adequate depth of anaesthesia, oxygenation (100%) and
ventilation
• Once the diagnosis of acute MI is made, it is important to monitor
the patient carefully.
• 100% oxygen should be administered and volatile
agent discontinued.
• Aspirin 325 mg is administered orally (through ryle’s tube if unable to
take orally) and is continued thereafter.
• Prompt and aggressive treatment of changes in HR and/or BP is
indicated.
75. • Tachycardia is treated with IV B blockers like Esmolol 50-100 μg IV or
propranolol 0.5-1 mg/kg IV, until heart rate is < 90/min.
• Nitroglycerine is the drug of choice in the presence of normal to modestly
elevated systemic BP started at1-2 μg/kg/min to maintain SBP 90 to 110
• Morphine is a venodilator that reduces ventricular
preload and oxygen requirements and also acts as an analgesic .
• Hypotension should be rapidly treated in order to
restore coronary perfusion pressure (CPP). Moderate hypotension often
responds to volume expansion with 300- 500ml of crystalloid.
• If severe hypotension (60-80mmHg systolic) persists despite volume
expansion, vasoactive or inotropic drugs may be given to elevate CPP
above critical value.
76.
77. POST OPERATIVE CARE
• Continuous ECG monitoring for post op MI
• Provision of supplemental oxygen
• Adequate post operative pain relief
• Continuation or institution of beta blockade
• Temperature control – Post operative shivering.
• Maintenance of hemodynamics with IV fluids
• DVT prophylaxis
78. REFERENCES
• Anaesthetic Considerations in Cardiac Patients Undergoing Non
Cardiac Surgery. Tej K. Kaul, Geeta Tayal. IJA 2007; 51 (4) : 280-
286
• Perioperative Myocardial Infarction. Circulation. 2009;119:2936-
2944. American Heart Association
• Perioperative Myocardial Ischaemia and Infarction-a Review.
Satinder Gombar,Ashish Kumar Khanna, Kanti Kumar Gombar. IJA
2007; 51 (4) : 287-302
• Textbooks Stoeltings, Millers, Barash
