Learning Objectives: AH1 Cardiology Flashcards
Differential diagnosis for chest pain:
think: Cardiac, pulmonary, GI, vascular, mediastinal, MSK, MH other
Loss of consciousness: Differential diagnosis? (list 8)
Think- due to true syncope- (impaired cerebral blood flow) Vs Loss of consciousness due to impaired cerebral perfusion!
Differential for local edema, Generalised oedema?
List 4 for both
Generalized oedema ddx:
- increased hydrostatic pressure/fluid overload ■ HF, pregnancy, drugs (e.g. CCBs), iatrogenic (e.g. IV fluids)
- decreased oncotic pressure/hypoalbuminemia ■ liver cirrhosis, nephrotic syndrome, malnutrition
- increased interstitial oncotic pressure— myxedema
- increased capillary permeability ■ severe sepsis
- hormonal ■ hypothyroidism, exogenous steroids, pregnancy, estrogens
Differential diagnosis for Palpitations? - think causes of sinus tachy, then pathological tachycardias,
Differential diagnosis for dyspnoea? (Excercise, CVS, resp, parenchymal lung disease, pulmonary vascular, neurovascular, anxiety, haem/metabolic
ACS: ST elevation myocardial infarction:
How are the patients likely to present?
What should be done immediatley in pt with suspected ACS?
How do you make a clinical diagnosis of ACS? (e.g what bloods and ECG requirements)
What is the best management strategy for ACS if a patient is close to a teritary hospital?
What should all patients who survive and Acute MI
- ST-elevation myocardial infarction (STEMI) presents with central chest pain that is classically heavy in nature, like a sensation of pressure or squeezing. Examination is variable, and findings range from normal to a critically unwell patient in cardiogenic shock.
- Give a loading dose of aspirin as soon as possible to any patient with suspected acute coronary syndrome.
- Make a clinical diagnosis of STEMI and start immediate treatment when a patient presents with symptoms suggestive of myocardial ischaemia and has persistent ST-segment elevation in at least 2 anatomically contiguous ECG leads.
- A rise in cardiac-specific troponins confirms the diagnosis but do not wait for laboratory results before starting treatment.
- Immediate and prompt reperfusion can prevent or minimise myocardial damage and improve the chances of survival and recovery. Primary percutaneous coronary intervention (PCI) is the best management option for most patients, with fibrinolysis reserved for those without access to timely primary PCI.
- Survivors of acute MI should receive cardiac rehabilitation and be closely followed up to ensure adequate modification of risk factors and optimisation of (and adherence to) pharmacotherapy for secondary prevention, and to monitor for the development of post MI complications and/or residual angina symptoms
What is the definition of ACS? (e.g what is the STEMI requirements)
- Acute myocardial infarction is myocardial cell death that occurs because of a prolonged mismatch between perfusion and demand. In the case of ST-elevation myocardial infarction (STEMI) this is caused predominantly by complete atherothrombotic occlusion of a coronary artery.
- In the appropriate clinical context, a STEMI is diagnosed clinically when there is new (or increased) and persistent ST-segment elevation in at least two contiguous leads of ≥1 mm in all leads other than leads V2-V3 where the following cut-off points apply:
- ≥2.5 mm in men <40 years old
- ≥2 mm in men >40 years old
- ≥1.5 mm in women regardless of age
- 1 mm = 1 small square (at a standard ECG calibration of 10 mm/mV).
Contiguous ECG leads lie next to each other anatomically and indicate a specific myocardial territory
What are the major risk factors for ACS?
What is the Aetiology of MI?
What is the pathophysiology?
Aetiology
- MI is usually a consequence of coronary artery disease. Atherosclerosis with plaque fissuring or rupture and thrombus formation is the underlying aetiology for STEMI in most patients. A small proportion of patients present with STEMI caused by coronary spasm reducing myocardial perfusion, coronary embolism, or following chest trauma or spontaneous coronary or aortic dissection.
Pathophysiology
- Atherosclerotic plaques form gradually over years
- They begin with the accumulation of low-density lipoprotein cholesterol and saturated fat in the intima (the inner layer) of blood vessels.
- This is followed by the adhesion of macrophages to endothelium, then diapedesis and entry into the intima, where they accumulate lipids and become foam cells.
- Foam cells are a rich source of proinflammatory mediators.
- The lesion up to this point is referred to as a fatty streak, and may be reversible to a certain extent.
- Subsequent evolution involves migration of smooth muscle cells from the media, and their proliferation and deposition of extracellular matrix, including proteoglycans, interstitial collagen, and elastin fibres.
- Some of the smooth muscle cells in advanced plaques exhibit apoptosis.
- Plaques often develop areas of calcification as they evolve.
- The plaque initially evolves with the artery remodelling outwards, followed by encroachment on the arterial lumen. Eventually the stenosis can limit flow under conditions of increased demand, causing angina.
STEMI typically occurs after abrupt and catastrophic disruption of a cholesterol-laden plaque. This results in exposure of substances that promote platelet activation and aggregation, thrombin generation, and thrombus formation, causing interruption of blood flow. If the occlusion is severe and persistent, myocardial cell necrosis follows.
- On interruption of blood flow in the coronary artery, the zone of myocardium supplied by that vessel immediately loses its ability to shorten and perform contractile work.
- Early hyperkinesis of the non-infarcted zones occurs, probably as a result of acute compensatory mechanisms including increased sympathetic activity and Frank-Starling mechanism. As necrotic myocytes slip past each other, the infarction zone thins and elongates, especially in anterior infarction, leading to infarction expansion.
- If a sufficient quantity of myocardium undergoes ischaemic injury, left ventricular (LV) systolic function becomes depressed; cardiac output, stroke volume, blood pressure, and compliance are reduced; and end systolic volume increases.
- Clinical heart failure occurs if 25% of myocardium has abnormal contraction, and cardiogenic shock occurs on loss of >40% of LV myocardium.
- Decreased compliance and increased LV end diastolic pressure give rise to diastolic dysfunction.
How are MIs Classified?
What is the “Fourth Universal Definition of myocardial infarction”? (acute MI Types 1,2,3) What implications do each of these classifications have on management (they are different..)
Acute coronary syndrome (ACS)
- Historically ACS has been divided into three clinical categories according to the presence or absence of ST-segment elevation on a presenting ECG and on elevations of cardiac troponin T or I.
- ST-elevation myocardial infarction (STEMI): ECG shows persistent ST-segment elevation in at least two anatomically contiguous leads.
- Non-STEMI (NSTEMI): ECG does not show ST-segment elevation, but cardiac biomarkers are elevated. The ECG may show ischaemic changes such as ST-segment depression, T-wave inversion, or biphasic T waves.
- Unstable angina pectoris: non-specific ischaemic ECG changes, but cardiac biomarkers are within the normal range.
Case examples of ACS:
Outline some key recommendations for Urgent assessment and diagnosis of STEMI:
What is the classification of Cardiogenic shock?
What are important differentials to consider with pt presenting with chest pain?
Always consider alternative diagnoses that might explain the presenting symptoms and/or ST elevation on ECG, including:
- Aortic dissection (ST elevation can be present on the ECG)
- Pulmonary embolism (ST elevation or ST depression can be present on the ECG)
- Pericarditis (ST elevation can be present on the ECG)
- Myocarditis (ST elevation can be present on the ECG)
- Pneumothorax
- Pneumonia
- Intracranial pathology (e.g., subarachnoid haemorrhage)
- Gastro-oesophageal reflux disease
- Oesophageal spasm
- Costochondritis
- Anxiety or panic.
Outline ECG leads associated with each vessels:
Lateral circumflex-
Inferior RCA
Septal (LAD) -
Anterior (LAD)
Lateral circumflex or diagonal
How can a previous”silent MI’ be diagnosed?
Anterior STEMI ECG
-Example key fetaures?
Aneterolateral STEMI example:
Key features?
Inferoposterior STEMI
Key features ECG?
What are key features on hx and examination for ACS?
What are key investigations to undertake in patient with suspected ACS?
DDx for ACS?
Criteria for ACS - ST elevation ECG?
Criteria for acute, evlovling or recent MI?
Criteria for established MI?
ACS Qld Health clinical pathway page 1:
ACS Qld Health clinical pathway page: Day 1 Pathway (Acute STEMI/NSTEMI)
Investigations?
Medications?
Observations/Treatments? (how often and what and why)
Nutrition and mobility?
Education and discharge planning?
Qld Health treatment pathway unstable angina/Late presentation MI:
Investigations?
Medications and pain management?
Observations and treatments?
Nutrition/mobility?
Education/discharge planning?
Management pathway QLD health 24 hours post inital management: (inpatient guidelines)
Treatments?
Observations?
Education?
Thrombolysis pathway QLD health:
What are indications for thrombolysis?
What are absolute contraindications to thrombolysis?
What are relative contraindications to thrombolysis?
Outtline management for thrombolysis according to QLD health pathway:
- Observations/ e.g IV access x2
- Treatments (medications including thrombolytic agent)
- Ongoing management
Management principles for STEMI/PCI avaliable:
Medications/Supportive management and assessments?
What primary CVD prevention techniques should be implemented in all patients?
Secondary prevention?
Complications of ACS?
CHF:
What are non pharmaological Preventitive strategies for HF?
Prevention of heart failure- pharmological?
What agents are shown to have preventive benefits for HF?
What investigations are recommended for diagnosis of HF?
- 12 lead ECG - Assess cardiac rhythm, QRS duration, and presence of underlying ischaemia or LV hypertrophy
- CXR: recommended in new HF- to detect signs of pulmonary congestion and identify alternative cardiac or non cardiac for pts symptoms
- Plasma BNP or proBNP- recommended for diagnosis in pts with HF
- Transthroracic echocardiogram- to improve diagnostic accuracy and in new patients to assess cardiac structure and function- including the measurement of LV ejection fraction (to classify diagnosis- which will dictate management
- Coronary angiography or Cardiac magnectic resonance imaging (CMR) should be considered in patients with low to intermediate pretest probability of CAD, to distinguish ischaemic and non ischaemic causes of ventricular dysfunction
- Non invasive function testing- Stress echocardiography, single photon emission CT (SPECT) /PET
- CMR with LGE should be considered in patients with heart failure associated with increased LV wall thickness that remains unexplained following clinical evaluation, including a 12-lead ECG and echocardiogram to identify inflammatory and infiltrative cardiomyopathies
- Either PET or bone scintigraphy may be considered in patients with heart failure associated with increased LV wall thickness that remains unexplained following clinical evaluation, including a 12-lead ECG and echocardiogram to identify infiltrative cardiomyopathies.
- Transthoracic echocardiography should be considered in patients with heart failure with reduced ejection fraction (HFrEF) 3–6 months after the start of optimal medical therapy, or if there has been a change in clinical status, to assess the appropriateness for other treatments, including device therapy (implantable cardioverter defibrillator [ICD] or cardiac resynchronisation therapy [CRT], or both).
- BNP and NT proBNP levels may be considered in patients with an established diagnosis of heart failure for prognostic stratification.
Acute heart failure: Recommendations for investigations and management:
- Investigation and management of precipitating factors is recommended in all patients presenting with acute heart failure. Acute coronary syndrome (ACS), hypertensive crisis, arrhythmia, mechanical catastrophe (e.g., ruptured interventricular septum, mitral papillary muscle or LV free wall, or acute valvular regurgitation), and pulmonary embolism should be confirmed or excluded, and managed immediately
- Monitoring of peripheral arterial oxygen saturation
- oxygen therpay recommended in patiend with 02 less than 94%
- non-invasive ventilation should be considered in all patients with acute pulmonary oedema/congestion who remain Hypoxaemic and tachypnoeic despite oxygen therapy to improve symptoms and requirement for intubation
- IV loop diuretics asre recommended- assist with congestion and improve symptoms of fluid overload
- IV vasodilators may be considered in patients with systolic BP more than 90mgHg to relieve symptoms
- Intravenous iontropic therapy: Consider in all pts with signs of peripheral hypoperfusion (usually with systolic BP <90mmHg) and congestion refractory to other treatments- to overall improve end organ dysfunction
Pharmological management of chronic heart failure:
What medications and benefits associated with each?
ACE inhibitors
- An ACE inhibitor is recommended in all patients with HFrEF associated with a moderate or severe reduction in LVEF (LVEF less than or equal to 40%) unless contraindicated or not tolerated to decrease mortality and decrease hospitalisation
- An ACE inhibitor may be considered in patients with HFrEF associated with a mild reduction in LVEF (LVEF 41–49%) unless contraindicated or not tolerated to decrease mortality and decrease hospitalisation.
Beta blockers
- A beta blockera is recommended in all patients with HFrEF associated with a moderate or severe reduction in LVEF (LVEF less than or equal to 40%) unless contraindicated or not tolerated, and once stabilised with no or minimal clinical congestion on physical examination to decrease mortality and decrease hospitalisation.
- Specifically, bisoprolol, carvedilol, metoprolol (controlled release or extended release) or nebivolol
- Beta blocker may be considered in patients with HFrEF associated with mild reduction in LVEF- 41-49%
MRAs: (mineralocorticoid antagonists)
- An MRA is recommended in all patients with HFrEF associated with a moderate or severe reduction in LVEF (LVEF less than or equal to 40%) unless contraindicated or not tolerated, to decrease mortality and decrease hospitalisation for heart failure
- MRA may be considered in patients with HFrEF associated with a mild reduction in LVEF (LVEF 41–49%) unless contraindicated or not tolerated, to decrease mortality and decrease hospitalisation for heart failure
Diuretics (Loop diuretics)
- A diuretic should be considered in patients with heart failure and clinical symptoms, or signs of congestion, to improve symptoms and manage congestion.
Angiotensin receptor blockers (ARBs)
- An ARB is recommended in patients with HFrEF associated with a moderate or severe reduction in LVEF (LVEF less than or equal to 40%) if an ACE inhibitor is contraindicated or not tolerated, to decrease the combined endpoint of cardiovascular mortality and hospitalisation for heart failure.
- An ARB may be conisdered in patients with HFrEF associated with a mild reduction in LVEF (LVEF 41–49%) if an ACE inhibitor is contraindicated or not tolerated, to decrease the combined endpoint of cardiovascular mortality and hospitalisation for heart failure.
ARNI: Angiotensin receptor neprolysin inhibitor:
Angiotensin receptor neprilysin inhibitor (ARNI)
- An ARNI is recommended as a replacement for an ACE inhibitor (with at least a 36-hour washout window) or an ARB in patients with HFrEF associated with an LVEF of less than or equal to 40% despite receiving maximally tolerated or target doses of an ACE inhibitor (or ARB) and a beta blocker (unless contraindicated), with or without an MRA, to decrease mortality and decrease hospitalisation.Strong
- Concomitant use of ACE inhibitors and ARNIs are contraindicated and these medications should not be administered within 36hours of each other, because of an increased risk of angioedema.
Ivabradine
- Ivabradine should be considered in patients with HFrEF associated with an LVEF of less than or equal to 35% and a sinus rate of 70 beats per minute (bpm) and above, despite receiving maximally tolerated or target doses of an ACE inhibitor (or ARB) and a beta blocker (unless contraindicated), with or without an MRA, to decrease the combined endpoint of cardiovascular mortality and hospitalisation for heart failure
Hydralazine plus nitrates:
- Hydralazine plus nitrates may be considered in patients with HFrEF if an ACE inhibitor and ARB are contraindicated or not tolerated to decrease mortality.Weak
- Hydralazine plus nitrates may be considered in black patients of African descent with HFrEF despite receiving maximally tolerated or target doses of an ACE inhibitor (or ARB) and a beta blocker (unless contraindicated), with or without an MRA, to decrease mortality and hospitalisation for heart failure.
Digoxin:
- Digoxin may be considered in patients with HFrEF associated with sinus rhythm and moderate to severe symptoms (New York Heart Association [NYHA] Class 3–4) despite receiving maximally tolerated or target doses of an ACE inhibitor (or ARB) to decrease hospitalisation for heart failure
What are non drug interventions for heart failure? (think education)SNAP
What is the Indication, MOA, Adverse effects, and precautions to be taken with the following medications
ACE inhibitors
Angiotensin receptor antagonists (Sartans)
What is the indication, MOA, adverse effects and precautions for the following medications?
Beta blockers
Indication, Mechanism of action, side effects, precautions:
Aldosterone antagonists?
Sacubitril with valsartan?
Indication, Mechanism of action, side effects, precautions:
Diuretics
Ivabradine
Indications, Mechanism, side effects, precautions for the following:
Digoxin (HF)
What role do implantable devices play in HF? (e.g defib,)
What drugs should be avoided in heart failure?
Take home messages when managing HF - just read
What is the NYHA classification for HF? (Outline the 4 stages and associated features) (pt symptoms)
What is the definition of heart failure?
How can is it defined in terms of LVEF?
What are most common causes of heart failue (aetiology)
What is the pathophysiology of HF?
What is the framingham criteria for the diagnosis of CHF?
Case examples: and other presentations- just read.
What needs to be covered in patient history - HF?
Physical examination findings for HF
Important investigations?
Key diagnostic features in heart failure? (clinical features)