Ischaemic Heart Disease Flashcards
Define IHD
decreased blood supply to heart muscle resulting in chest pain (angina pectoris).
May present as stable angina or acute coronary syndrome.
How can ACS be subdivided?
Unstable angina: rest pain due to ischaemia, without cardiac injury
NSTEMI: ST depression, subendocardial injury
STEMI: ST elevation with transmural infarction
Define Myocardial Infarction
cardiac muscle necrosis resulting from ischaemia
Describe the epidemiology of ischaemic heart disease
COMMON
5/1000 PA
Prevalence: > 2 %
M > F
Describe the aetiology of Angina Pectoris
Myocardial O2 demand exceeds supply
Often due to atherosclerosis
Rarer causes: coronary artery spasm (e.g. cocaine), arteritis + emboli
List 9 risk factors for IHD
Male Age FH DM HTN Hyperlipidaemia Smoking Diet + exercise Alcohol
Describe the pain that characterise ACS
Acute-onset chest pain
Central, heavy, tight, crushing
Radiates to L arm, neck, jaw or epigastrium
Occurs at rest
More severe + frequent pain than previously occurring stable angina
What are 3 associated symptoms of ACS?
Dyspnoea
Sweating
N+V
What may occur in elderly or diabetic patients with ACS?
Silent infarcts
Describe the presenting symptoms of stable angina
Constricting discomfort in the chest, neck, shoulders, jaw + arms on exertion
Relieved by GTN/ rest within 5 mins
What are 8 signs of ACS?
May be NO CLINICAL SIGNS Pale Sweating Restless Low-grade pyrexia Check both radial pulses to r/o aortic dissection Arrhythmias/ New heart murmurs Disturbances of BP Signs of complications (e.g. acute HF, cardiogenic shock)
What are the appropriate bloods to take for suspected ACS?
FBC U+E's (electrolyte imbalance, renal function) Glucose Lipid profile Amylase (pancreatitis could mimic MI) CRP
Which cardiac enzymes rise in ACS and when?
CK-MB (within 6h)
Troponin I + T (3-6h after infarction, peak at 12-24h, remain raised for up to 14 days)
Describe ECG findings for NSTEMI
ST depression or T wave inversion
Describe ECG findings for STEMI
Hyperacute tall T waves
ST elevation (> 1mm in limb leads, > 2 mm in chest leads)
New-onset LBBB
Later: T wave inversion, Pathological Q waves
What may a CXR in ACS show?
Complications of ischaemia eg, pulmonary oedema
Cardiomegaly
Enlarged mediastinum
What is the medical management strategy of stable angina?
Symptomatic (GTN)
Anti-anginals (BBs/CCBs)
RF reduction (statin + aspirin)
List 4 side effects of nitrates
Hypotension (vasodilation)
Tachycardia (reflex)
Headaches (dilation of cerebral vessels)
Flushing
Which CCB’s can be used as monotherapy in angina?
Rate limiting:
Verapamil
Diltiazem
Which b-blockers are used in angina?
Metoprolol
Timolol
Bisoprolol
Carvedilol
What is the further management of angina not controlled with monotherapy?
- Increase to max. tolerated dose
- Add other class (CCB/ BB)
Which calcium channel blockers can be used in conjunction with beta blockers?
Long acting dihydropyridines:
Amlodipine
Modified release Nifedipine
Modified release Felodipine
If addition of a CCB or BB is not tolerated in a symptomatic patient with angina, what drugs can be used third line?
Long acting nitrate
Ivabradine
Nicorandil
Ranolazine
If a patient is taking both a BB and CCB but is still symptomatic, how can they be managed?
Refer to cardiologist for angiography
Only add a 3rd drug whilst awaiting assessment for PCI or CABG
Describe the conservative management of stable angina
Stop smoking
Lose weight
Exercise
How do you treat patients with stable angina when pharmaceutical methods are ineffective?
Percutaneous coronary intervention
Coronary Artery Bypass Graft
Describe the acute management of ACS
MONA
Morphine IV if severe pain
Oxygen if sats <94%
Nitrates if ongoing chest pain/ HTN
Aspirin 300mg
What are the eligibility criteria for PCI?
<12h since Sx onset + PCI possible in <120 mins of time when fibrinolysys could be given
>12h with evidence of ongoing ischaemia
Which access if prefered in PCI?
Radial prefered to femoral
What drugs must be given prior to PCI?
DAPT: Aspirin + another drug
If NOT taking an oral anticoagulant: PRASUGREL
If taking an oral anticoagulant: CLOPIDOGREL
What drugs should be given during PCI depending on access?
Radial: UFH with bailout GPI
Femoral: Bivalirudin with bailout GPI
glycoprotein IIb/IIIa inhibitor = GPI
What type of stents are used in PCI?
Drug eluting stents
Slow release drugs inhibit scar tissue formation + re-stenosis
Describe PCI
- Catheterise radial/ femoral artery
- Feed guidewire to coronary arteries under XR guidance
- Inject contrast to identify occlusion
- Open occlusion with balloon + place stent to maintain patency
Describe management of STEMI with fibrinolysis
Fibrinolytic: Tenecteplase or Alteplase
+
Anticoagulate at same time: Enoxaparin
+
Start DAPT immediately after
+
Repeat ECG at 60-90 mins, if persistent myocardial ischaemia consider PCI
What is the mechanism of action of alteplase?
Activates plasminogen to form plasmin
Plasmin degrades fibrin leading to clot dissolution + restoration of blood flow
(tissue plasminogen activator tPA)
List 7 contraindications to thrombolysis
Active internal bleeding
Recent haemorrhage, trauma or surgery (inc. dental extraction)
Coagulation + bleeding disorders
Intracranial neoplasm
Stroke < 3 months
Aortic dissection
Recent head injury
Severe HTN
Give 3 sides effects of thrombolytics
Haemorrhage
Hypotension- more common with streptokinase
Allergic reactions may occur with streptokinase
What DAPT should be given immediately after fibrinolysis?
Aspirin + Ticagrelor
OR
Aspirin + Clopidogrel (if high bleeding risk)
Detail the immediate management of unstable Angina and NSTEMI
300mg Aspirin
+
Fondaparinux
if low bleeding risk + no immediate PCI planned
OR
UFH if coronary angiogram planned or creatinine >265
+
Risk assess using GRACE (6 month mortality)
What factors are accounted for in GRACE?
Age
HR + BP
Cardiac (Killip class) + renal function (creatinine)
Cardiac arrest on presentation
ECG findings
Troponin levels
What GRACE risk is considered intermediate and what does this indicate?
> 3%
Coronary angiography with follow-on PCI if necessary within 72h
Which patients with NSTEMI/unstable angina should have coronary angiography (with follow-on PCI if necessary)?
Immediate: if clinically unstable e.g. hypotensive
Within 72h: GRACE score >3%
Consider if ischaemia experienced after admission
If PCI is indicated in an NSTEMI patient, what drugs should they be given prior and during PCI?
Aspirin
+
Prasugrel/ Ticagrelor
OR
Clopidogrel (if on oral anticoagulation)
During: UFH
If a patient has a low risk GRACE score, how are they managed?
Aspirin + ticagrelor
OR
Aspirin + Clopidogrel/ Aspirin alone for high bleeding risk
What management should patients be on post STEMI/ NSTEMI?
- DAPT
- BB e.g. Bisoprolol (or CCB if CI e.g. Verapamil)
- ACEi: Enalapril/ Ramipril (or ARB e.g. Valsartan)
- Statin
- Cardiac rehab
What drug may be initiated post STEMI if patient has S/S of HF or reduced EF?
Aldosterone antagonist e.g. Eplerenone/ Spironolactone
What DAPT should a patient be taking post STEMI/ NSTEMI?
Aspirin 75mg OD lifelong
+P2Y12 inhibitor for 12m:
Prasugrel 5-10mg OD
OR
Ticagrelor 90mg BD
OR
Clopidogrel 75mg OD
What is cardiac rehabilitation?
Exercise component
Health education: smoking cessation, reduce alcohol, WL, diet changes
Stress Mx
What are the complications of ACS?
DARTH VADER Death Arrhythmias Rupture Tamponade Heart failure Valve disease Aneurysm Dressler's Syndrome Embolism Re-infarction
List 3 early complications of ACS which are not in DARTH VADER
Heart Block
Cardiogenic shock
Pericarditis
What is used to calculate risk of mortality in patients with unstable angina or NSTEMI?
GRACE Score High scores a/w mortality from cardiac events within 6 months
How do leads localise site of MI?
Inferior: II, III, aVF
Anterior: V1-V4
Lateral: I, aVL, V5/6
Posterior: Tall R wave + ST depression in V1-3
What are the 4 reciprocal changes on ECG seen in posterior MI?
Changes in V1-3
Horizontal ST depression
Tall, broad R wave
Upright T waves
Dominant R waves in V2
Which leads have maximal ST elevation in anterior MI?
SAL
Septal (V1-2)
Apical (V3-4)
Lateral (V5-6)
Describe the mortality of ACS
50% deaths occur within 2h onset of Sx
What indicates a worse prognosis in ACS?
Elderly
LV failure
ST changes
What system stratifies risk post MI?
Killip class (30 day mortality)
I: no clinical signs of HF
II: lung crackles, S3
III: frank pulmonary oedema 38%
IV: cardiogenic shock 83%
Which coronary artery supplies the AVN, thus what type of MI is associated with which arrhythmia post MI? How is this treated?
Right coronary artery
Inferior MI a/w bradyarrythmia, second/ third degree heart block (usually transient lasting hours- days)
Atropine
Which structures may rupture acutely (3-5 days) post MI?
Papillary muscles
Ventricular septal rupture
How does papillary muscle rupture present?
New mitral regurgitation (pan systolic)
Pulmonary oedema
Hypotension
In which type of infarct is papillary muscle rupture more common?
Infero-posterior infarction
How are patients with papillary muscle rupture managed?
Vasodilators
Often require emergency surgical repair
How does ventricular septal rupture present?
Chest pain
Biventricular failure (acute HF)
Shock
New pansystolic murmur
What investigations and management are required for ventricular septal rupture?
Echo: diagnostic + r/o MR
Mx: urgent surgical correction
Which structure can rupture 5 days- 2weeks post MI? How does this present?
Left ventricular free wall
Acute HF
Tamponade (raised JVP, muffled HS, hypotension)
How is left ventricular free wall rupture managed?
Urgent pericardiocentesis + thoracotomy
What causes left ventricular wall aneurysm post MI? Why is this dangerous?
Ischaemic damage weakens myocardium resulting in aneurysm formation
Blood stagnates here, promoting platelet adherence + thrombus formation
How does left ventricular wall aneurysm present?
SOB
Persistent ST-elevation
No chest pain
LV failure: SOB, cough, crackles on auscultation
How is left ventricular wall aneurysm managed?
Anticoagulate (high risk of stroke)
What is Dressler’s syndrome
Late onset post-MI pericarditis
2-6w post-MI
AI reaction against antigenic proteins formed as the myocardium recovers
Give 4 features of presentation of Dressler’s syndrome
Fever
Pleuritic pain
Pericardial effusion
Raised ESR
Describe pericarditis post-MI
<48h post-MI
Pain worse on lying flat
Pericardial rub
Pericardial effusion on echo
What is the most common cause of death following an MI?
Cardiac arrest
Commonly due to developing VF
How may cariogenic shock develop post-MI?
If large part of ventricular myocardium is damaged in infarction the EF may decrease to the point of cariogenic shock
OR
mechanical complications e.g. LVFW rupture
What arrhythmias can arise post-MI?
Tachyarrhythmias: VF, VT
Bradyarrythmias
If suspected re-infarct 4-10 days post initial MI what should be measured?
CK-MB (raises for 3-4 days) instead of troponin (raised for 10 days)
How should glycemic control in diabetic patients with ACS be managed?
Dose-adjusted insulin infusion with regular blood glucose monitoring
(stop other anti-hyperglycaemics)
