What are the indications for CTCA outside of chest pain?
Evaluation of suspected coronary anomalies/complex congenital heart disease.
Exclusion of CAD in new-onset heart failure/cardiomyopathy.
Assessment of CABG patency and vascular mapping before repeat CABG surgery.
Exclusion of significant CAD before non-coronary cardiac surgery.
Investigation of left bundle branch block for suspected CAD as an aetiology.
What is the most appropriate application of CTCA?
It is used most appropriately in symptomatic patients with low to intermediate pretest probability of CAD.
When should CTCA not be used?
It should not be used in asymptomatic subjects, patients with known significant CAD or patients with a high pretest probability of CAD.
How does the radiation dose of CTCA compare with invasive coronary angio?
The radiation dose of CTCA was previously two to three times that of invasive coronary angiography but with modern protocols, it is similar or lower.
What are the absolute contraindications to thrombolysis?
  Any previous history of hemorrhagic stroke  History of stroke, dementia, or central nervous system damage within 1 year  Head trauma or brain surgery within 6 months  Known intracranial neoplasm  Suspected aortic dissection  Internal bleeding within 6 weeks  Active bleeding or known bleeding disorder  Major surgery, trauma, or bleeding within 3 weeks  Traumatic cardiopulmonary resuscitation within 3 weeks
What are the indications for digoxin?
CHF (regardless of side) particularly due to chronic overload and supply of energy is not impaired (i.e impaired in hypoxia, thiamine deficiency, thyrotoxicosis
AF - depresses conduction in the AV bundle --> slower ventricular beat. Â Converts flutter to fibrillation and may restore SR on withdrawal - but not first line.
Not for prevention of paroxysmal AF
What does the ECG show?
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QRS > 120ms w/ abnormal morphology
Steep R-wave and absent S wave in leads 1 and V6
Deep rapid S wave in V1 (arrow)
Multiple ST segment elevation (mild), and T-wave polarity is opposite to the ventricular complex
LBBB - reversal of interventricular septum activation with delayed impulse to the LV
What are the limitations of coronary artery calcium scoring?
Current expert consensus does not recommend CAC measurement in asymptomatic low-risk (a 10-year risk less than 10%) or high-risk (a 10-year risk more than 20%) patients, in those with a documented history of CVD or to establish the presence of obstructive coronary artery disease.
What are the indications for coronary calcium scoring?
CAC scoring is only recommended for asymptomatic men aged 45-75 (or women aged 55-75) with an intermediate Framingham score (10-year risk of 10%) in whom a high-risk CAC (more than 100) may prompt a more aggressive approach to risk factor modification. CAC assessment may also be reasonable for assessment of symptomatic patients in the setting of an equivocal treadmill or other functional test.
What are the scoring categories of the Framingham Risk Score?
Individuals with low risk have 10% or less CHD risk at 10 years, with intermediate risk 10-20%, and with high risk 20% or more. However it should be remembered that these categorisations are arbitrary.
Give a scenario where a coronary calcium score would be useful
The type of clinical situation where CAC scoring can be useful is the following: an asymptomatic 45-year-old male smoker with a systolic BP of 120mmHg, no history of diabetes or hypertension, without left ventricular hypertrophy criteria on ECG, and normal cholesterol (eg, total cholesterol 6.0mmol/L, HDL-C 1.0mmol/L) has a 10-year Framingham risk score of 10% (ie, intermediate risk) and lifestyle measures only would be prescribed.
A high CAC score above 100 AU would yield a post-test probability of more than 2% per year for a coronary event and would move the patient into the high-risk category (a 10-year risk above 20%). Such a patient would require the adoption of aggressive secondary (as opposed to primary) prevention strategies.
Goals for blood pressure and lipid levels may be tightened to those of someone known to have coronary artery disease (eg, LDL-cholesterol less than 1.8mmol/L) and medications, along with lifestyle measures, prescribed.
f the CAC score was either very low (less than 10) or zero, the patient's post-test risk for CHD would be lower than 10% per 10-year period (ie, low risk) and lifestyle-only measurements would be prescribed.
What is CHD risk equivalent?
Some patients without known CHD have risk of cardiovascular events that is comparable to that of patients with established CHD. Cardiology professionals refer to such patients as having a CHD risk equivalent. These patients should be managed as patients with known CHD.
CHD risk equivalents are patients with a 10-year risk for MI or coronary death >20%. CHD risk equivalents are primarily other clinical forms of atherosclerotic disease.
The NCEP's ATP III guidelines also list diabetes as a CHD risk equivalent since it also has a 10-year risk for CHD around 20%. NCEP ATP III CHD risk equivalents are:
  clinical coronary heart disease (CHD)
  symptomatic carotid artery disease (CAD)
  peripheral arterial disease (PAD)
  abdominal aortic aneurysm (AAA)
  diabetes mellitus
  Chronic Kidney Disease
What are the ECG changes in LVH?
Increased R wave amplitude in the left-sided ECG leads (I, aVL and V4-6)Â
Increased S wave depth in the right-sided leads (III, aVR, V1-3).
How do you recognise left axis deviation on ECG?
 QRS is positive (dominant R wave) in leads I and aVL QRS is negative (dominant S wave) in leads II and aVF
What are the causes of left axis deviation?
LVHInferior MILBBBWPW
What ECG finding is suggestive of left main coronary artery occlusion?
A pattern of widespread ST depression plus ST elevation in aVR > 1 mm is suggestive of left main coronary artery occlusion.
What do you make of ST depression localised to a specific territory on ECG?
ST depression localised to a particular territory (esp. inferior or high lateral leads only) is more likely to represent reciprocal change due to STEMI. The corresponding ST elevation may be subtle and difficult to see, but should be sought.
When is T-wave inversion considered to be evidence of myocardial ischemia?
    At least 1 mm deep    Present in ≥ 2 continuous leads that have dominant R waves (R/S ratio > 1)    Dynamic — not present on old ECG or changing over time
NB. T wave inversion is only significant if seen in leads with upright QRS complexes (dominant R waves). T wave inversion is a normal variant in leads III, aVR and V1.
What is Mobitz II heart block?
Significance?
A-V blockPR of constant interval
Constant PR interval until P waved dropped with P-P interval twice normal
Likely to progress to CHB
What does the ECG show?
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Constant PR interval until P waved dropped with P-P interval twice normal
This the Mobitz II (the bad one)
What is Wenkebach block?
Significance?
Lengthening PR interval until P waved dropped with P-P interval variable. Grouped beats.
Need follow up but less likely to progress to CHB
What does this ECG show?
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ST elevation primarily localised to leads I and aVL is referred to as a high lateral STEMI.It is usually associated with reciprocal ST depression and T wave inversion in the inferior leads.
Occlusion of the first diagonal branch (D1) of the left anterior descending artery (LAD) may produce isolated ST elevation in I and aVL
Occlusion of the circumflex artery may cause ST elevation in I, aVL along with leads V5-6.
What ECG findings are best used to differentiate PE from ACS?
Negative T waves in both leads III and V1 (Part of an RV strain pattern - can be in other right sided things too)
How do you recognise right axis deviation?
    QRS is positive (dominant R wave) in leads III and aVF    QRS is negative (dominant S wave) in leads I and aVL
What does the ECG show?
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QRS is positive (dominant R wave) in leads III and aVFQRS is negative (dominant S wave) in leads I and aVL
Right axis deviation
How is the cardiac axis defined?
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RA is negativeLA is positive
A depolarization wave is always positive on ECG when it is heading toward the left.
V1 and V2 are always negative for this reason and reflect the septum
Leads II and II are the feet leads and are always positive
Name the different infarct patterns on ECG
The different infarct patterns are named according to the leads with maximal ST elevation:
    Septal = V1-2
    Anterior = V2-5
    Anteroseptal = V1-4
    Anterolateral = V3-6, I + aVL
    Extensive anterior  / anterolateral = V1-6, I + aVL
ECG findings in PE
Sinus tachycardia - the most common abnormality; seen in 44% of patients.
Complete or incomplete RBBB - associated with increased mortality; seen in 18% of patients.
Right ventricular strain pattern –  T wave inversions in the right precordial leads (V1-4) ± the inferior leads (II, III, aVF). This pattern is seen in up to 34% of patients and is associated with high pulmonary artery pressures.
Right axis deviation – seen in 16% of patients.Â
Dominant R wave in V1 - a manifestation of acute right ventricular dilatation.
SI QIII TIII  pattern – deep S wave in lead I, Q wave in III, inverted T wave in III. This "classic" finding is neither sensitive nor specific for pulmonary embolism; found in only 20% of patients with PE.
What are the causes of acute cor pulmonale (i.e. any disease that causes right ventricular strain / hypertrophy due to hypoxic pulmonary vasoconstriction)?
  Severe pneumonia  Exacerbation of COPD / asthma  Pneumothorax  Recent pneumonectomy  Upper airway obstruction
How do you define a low-voltage ECG?
Peak-to-peak QRS <5mm in the limb leads or <10mm in the precordial leads
