Cardiology - Short Answer Questions (SAQ)

Question 1:

A 66 year old male presents to ED with chest pain. His pulse 100, BP 90/58.

The CT1 doctor has commenced Oxygen and given the patient 3 mg buccal nitrate

1. What does the ECG show? What is the diagnosis?


2. What would you tell the SHO to do?


3. List 5 treatment options.


4. Which vessel is involved?

Answer

Answer

A 66 year old male presents to ED with chest pain. P100, BP 90/58.

The SHO has commenced Oxygen and given the patient 3mg buccal nitrate

1. What does the ECG show? What is the diagnosis?

• Rate 60bpm


• ST elevation II, III, AVF


• ST depression aVL, V1-V6.


• Inf MI with RV involvement.

2. What would you tell the CT1 to do?

• Remove nitrate


• Lie patient flat.

3. List 5 treatment options.

• Aspirin 300mg


• IV fluid bolus 100-200mg to increase filling pressure RV


• IV opiate plus anti emetic eg metoclopramide


• Depending upon local policy –thrombolysis or PCI.

4. Which vessel is involved?

• Right Coronary Artery (RCA)

Question 2:

A 61 year old man presents with central chest pain, he is a NIDDM.

He has a troponin I level of <5.

1. Describe the ECG


2. Give 5 components of the TIMI score.


3. The patient has received aspirin, nitrates and analgesia, give 3 further pharmacological interventions as the patient has ongoing pain.

Answer

Answer

A 61 year old man presents with central chest pain, he is a NIDDM.

He has a troponin I level of <5.

1. Describe the ECG

• Sinus rhythm


• Rate 75bpm


• Marked ST depression V3-V6

2. Give 5 components of the TIMI score.

• Age >60


• Elevated cardiac marker


• Previous stenosis> 50%


• ST depression on presenting ECG


• Three or more risk factors for coronary artery disease eg Cig, FH, hypertension, hypercholesterolaemia, DM


• Aspirin use in preceding 7 days

The patient has received aspirin, nitrates and analgesia, give 3 further pharmacological interventions as the patient has ongoing pain.

• IV opiate eg DM 5mg IV


• IV nitrate infusion titrated to symptoms/BP


• LMWH eg enoxaparin 1mg/kg


• Beta blocker eg Atenolol 5mg


• Clopidogrel 300mg


• Glycoprotein IIb/IIIa inhibitor.

Question 3:

56-year-old man presents with a 2 hour history of severe central chest pain, vomiting and sweating +++.

On arrival in ED he is seen by a junior doctor who gives Oxygen, gets IV access and an ECG and gives a 5mb buccal tablet and diamorphine 2mg with anti-emetic.

His observations on arrival were P=95/min BP= 169/105.

The doctor comes to ask for your help, as the patient is now more sweaty and confused with a BP 85/45.

1. Describe the ECG.


2. What is your diagnosis?


3. Why is the patient hypotensive?


4. Which coronary vessel is likely to be involved?


5. How would you manage this patient?


6. What does the following ECG show?

Answer

Answer

56-year-old man presents with a 2 hour history of severe central chest pain, vomiting and sweating +++.

On arrival in ED he is seen by a junior doctor who gives Oxygen, gets IV access and an ECG and gives a 5mb buccal tablet and diamorphine 2mg with anti-emetic.

His observations on arrival were P=95/min BP= 169/105.

The doctor comes to ask for your help, as the patient is now more sweaty and confused with a BP 85/45.

1. Describe the ECG.

• 1^st degree heart block


• ST elevation II,III,aVF, ST depression I, aVL, T inversion V1-V4

2. What is your diagnosis?

• Inferior MI with involvement of RV

3. Why is the patient hypotensive?

• Right ventricular infarction, and buccal nitrate tablet

4. Which coronary vessel is likely to be involved?

• Right Coronary Artery

5. How would you manage this patient?

• Give gentle fluid bolus 100-200ml saline and reassess BP


• Depending upon local hospital protocol give thrombolysis or refer for PCI

6. What does the following ECG show?

• Complete heart block

Question 4:

A 21 year old male presents with palpitations. He brings with him a copy of his ECG recorded by his General Practitioner 3 weeks ago (A).At present he is on a cardiac monitor with P= 180, BP 100/60, Alert and orientated but feeling dizzy.

A

B. The 12 lead taken in ED shows

1. Describe ECG A.


2. Outline treatment plan for current attendance


3. Amiodarone is a commonly used antiarrhythmic agent. What are its :

• mode of action                    (1)


• 4 common side effects      (1/2 each)


• 1 contraindication              (1)

Answer

Answer

A 21 year old male presents with palpitations. He brings with him a copy of his ECG recorded by his General Practitioner 3 weeks ago (A).At present he is on a cardiac monitor with P= 180, BP 100/60, Alert and orientated but feeling dizzy.

1. Describe ECG A.

• Sinus


• Rate 80bpm


• Short PR interval


• Widening of QRS with delta waves


• LVH

2. Outline treatment plan for current attendance

• Oxygen, cardiac monitoring, IVA


• Vagal manouvers


• Adenosine if it is SVT


• If in AF, DC cardioversion or IV Amiodarone, early liaison with cardiology.

3. Amiodarone is a commonly used antiarrhythmic agent,, what are its :

Mode of action

• Class III antiarythmic acts to prolong duration of action potential, also acts on fast NA channels and B adrenergic receptors.

4 common side effects

• Hypotension


• Bradycardia


• Skin discolouration


• Corneal microdeposits


• Lung fibrosis


• Hepatic toxicity


• Peripheral neuropathy

One contraindication

• Pregnancy/breast feeding


• 2^nd degree/3^rd degree heart block


• Iodine allergy

Question 5:

A 74 year old female presents after waking at 5 am with sudden severe dyspnoea. SpO2 86% OA, afebrile. CXR shown below.

1. List 4 features shown on CXR


2. What is the diagnosis?


3. Explain by drawing or words Starling’s curve and how it might differ in this patient


4. Give 3 drugs with doses and routes you would use in this patient


5. What is the stimulus for releases of ANP and by what mechanism does it act?

Answer

Answer

A 74 year old female presents after waking at 5am with sudden severe dyspnoea.       SpO2 86% OA, afebrile. CXR shown below.

1. List 4 features shown on CXR

• Cardiomegaly


• Fluid in horizontal fissure


• Kerley B lines


• Alveolar hilar shadowing


• Bilateral pleural effusion

2. What is the diagnosis?

• Acute pulmonary oedema.

3. Explain by drawing or words Starling’s curve and how it might differ in this patient

The Frank–Starling law of the heart  states that the stroke volume of the heart increases in response to an increase in the volume of blood filling the heart (the end diastolic volume) when all other factors remain constant. The increased volume of blood stretches the ventricular wall, causing cardiac muscle to contract more forcefully (the so-called Frank–Starling mechanisms)

Contractility can increase or decrease SV independent of LVEDP

4. Give 3 drugs with doses and routes you would use in this patient

• High flow Oxygen, 15L via non –rebreather mask


• Nitrates, IV GTN, 50mg in 50ml saline starting at 0.6mg/hr, and titrated to response and BP.


• Opiates - 2.5-5mg IV diamorphine


• Frusemide 50mg IV

5. What is the stimulus for releases of ANP and by what mechanism does it act?

• ANP is released by excess volume and hence stretch of atria. Acts as antagonist to rennin-angiotensin system, increases renal sodium excretion so increasing naturesis

Question 6:

A 75 year old female presents with recurrent syncope.

1. Describe the ECG


2. List 4 common potential causes


3. The patient drops her BP to 70/30. How would you manage the patient?

Answer

Answer

A 75 year old female presents with recurrent syncope.

1. Describe the ECG

• Broad complex tachycardia


• Capture beats


• Fusion beats

2. List 4 common potential causes

• Metabolic abnormalities eg hyperkalaemia


• Drugs eg. TCA, quinidine, procainamide, digoxin


• Long QT syndrome (congenital, acquired)


• MI/IHD

3. The patient drops her BP to 70/30. How would you manage the patient?

• Oxygen


• IVA


• If conscious sedate with IV midazolam before DC cardioversion, 150J biphasic, 200J monophasic.


• Cardiology review and CCU admission.

Question 7:

45 year old male presents with 2 hour history of central crushing chest pain, sweaty and vomited twice. No PMH. On Oxygen, ongoing pain.

• What does the ECG show?


• What is the diagnosis?       What blood vessel is involved?


• Give 4 management steps


• Using the same ECG, the patient is a 76 year old man. PMH MI 3/12, 30min pain, now resolved, normal observations. Give 4 management steps

Answer

Answer

45 year old male presents with 2 hour history of central crushing chest pain, sweaty and vomited twice. No PMH. On Oxygen, ongoing pain.

1. What does the ECG show?

• Sinus rhythm


• LBBB

2. What is the diagnosis?       What blood vessel is involved?

Acute MI, cause by proximal occlusion of LAD.

3. Give 4 management steps

• Aspirin300mg


• Nitrate, 5mg sublingual or IV


• Diamorphine 5mg IV ( Morphine if Diamorphine is not available)


• PCI or thrombolysis depending upon local protocol.

4. Using the same ECG, the patient is a 76 year old man. PMH MI 3/12, 30min pain, now resolved, normal observations. Give 4 management steps

• Aspirin 300mg PO


• Clopidogrel 300mg PO


• Enoxaparin 1mg/kg (or Dalteparin) SC


• Request old ECG


• Refer for admission

Question 8:

75 year old male presents having collapse, paramedics had difficult detecting pulse.

1. Describe the ECG, what is the diagnosis?

The patient has another ‘funny do’ in the ED, repeat ECG is below.

2. Describe the ECG

3. How would you manage this patient?

4. What asystolic rhythm might he develop?

Answer

Answer

75 year old male presents having collapse, paramedics had difficult detecting pulse.

1. Describe the ECG, what is the diagnosis?

• Sinus rhythm


• Rate 75bpm


• Left axis deviation (LAD) p


• Prolonged P-R interval


• RBBB


• Incomplete Trifascicular block (1^st degree AV block, RBBB, LAD)

The patient has another ‘funny do’ in the ED, repeat ECG is below.

2. Describe the ECG.

• Complete trifascicular block (LAD, RBBB and Third degree heart block)


• Bradycardia, vent rate of approx 30bpm


• No relationship P and QRS

3. How would you manage this patient?

• Oxygen


• IVA


• Atropine 0.5 mg IV whilst setting up transcutaneous pacing, adrenaline 2-10ug/kg/min


• Cardiology review for pacemaker.

4. What asystolic rhythm might he develop?

• P wave asystole, ie. ventricular standstill

Question 9:

A 30 year old female presents with SOB and dizziness. Her blood pressure 80/40 mm Hg.

1. What is the diagnosis?

2. How would you manage this patient?

Answer

Answer

A 30 year old female presents with SOB and dizziness. Her blood pressure 80/40 mm Hg.

1. What is the diagnosis?

• Narrow complex tachycardia with rate 150bpm (Supra Ventricular Tachycardia)

2. How would you manage this patient?

• Oxygen


• IV access and fluid bolus


• Sedate with IV midazolam (or Propofol) if conscious prior to DC cardioversion 150J biphasic, 200J monophasic


• Amiodarone (if cardioversion unsuccessful) 300mg over 10-20 mins followed by repeat cardioversion. Remaining 900mg over 24 hours.


• Cardiology review

Question 10:

A 39 year old female presents with palpitations and collapse. Her BP on arrival is 95/55.

1. Describe the ECG, what is the diagnosis?

2. Give 3 possible causes

3. How would you manage this patient?

Answer

Answer

A 39 year old female presents with palpitations and collapse. Her BP on arrival is 95/55.

1. Describe the ECG, what is the diagnosis?

• Episode of broad complex tachycardia with alternating axis.


• Torsade de pointes

2. Give three possible causes

• Hypomagnesaemia


• Hypokalaemia


• Long QT syndrome congenital eg romano-ward, acquired eg TCA, quinidine, procainaide


• Brugada syndrome.

3. How would you manage this patient?

• Oxygen


• IVA – magnesium 2g IV 10 mins


• Treat underlying causes, if no improvement DC cardioversion


• Cardiology / Refer CCU.

Further read: Lifeinthefastlane

Causes of Prolonged QT syndrome:

• Genetic: Romano Ward, Lange Neilson


• Electrolytes: Hypokalaemia, hypomagnesaemia, hypocalcaemia


• Environmental: Hypothermia


• Drugs: Quinine, sotalol, amiodarone, organophosphates, antihistamines


• Cardiac: Myocarditis, IHD


• SAH
  

Chest Pain of Recent Onset Nice 2010:

• ECG asap


• O2- if sats <94% - aim for 94-98% unless at risk of hypercapnic respiratory failure


• Stable Angina unlikely if: continuous/prolonged; unrelated to activity; bought on by breathing in; association with dizziness, palpitations, tingling, swallow problem.


• Hx: chest pain radiating to both arms, with sweating and nausea lasting >15minutes


• Initial Trop T: if norm repeat 10-12 hrs


• Stable Angina: constricting; ppt by exertion; relieve <5mins by rest/GTN
  

CHADS2  - The CHADS2 score is a clinical prediction rule for estimating the risk of stroke in patients with atrial fibrillation.

• C Congestive heart failure 1


• H Hypertension: blood pressure consistently above 140/90 mmHg (or treated hypertension on medication) 1


• A Age ≥75 years 1


• D Diabetes mellitus 1


• S2 Prior Stroke or TIA or Thromboembolism 2

Score 0 aspirin; 1 aspirin or warfarin; 2 or more warfarin risk/benefit

The San Francisco Syncope Rule (SFSR) is a simple rule for evaluating the risk of adverse outcomes in patient who present with fainting or syncope. The mnemonic for features of the rule is CHESS (or CHEST):

• C - History of congestive heart failure


• H - Hematocrit < 30%


• E - Abnormal ECG


• S - Shortness of breath


• S - Triage systolic blood pressure < 90 A patient with any of the above measures is considered at high risk for a serious outcome SFSR has a sensitivity of 74-98% and specificity of 56%
  

Anti-ischaemic agents:

Beta-blockers:

• Effects on beta-1 receptors that decrease in myocardial oxygen consumption.


• The target heart rate for a good treatment effect should be between 50 and 60 eat per minute.


• Significantly impaired AV conduction and history of asthma or of acute LV dysfunction should NOT receive beta-blockers.

Nitrates:

• Venodilator leads to decrease pre-load and LV end-diastolic volume, resulting in a decrease in myocardial oxygen consumption. Titrated upwards until symptoms are relieved unless side effects occur.

Recommendations for anticoagulation:

• Fondaparinux is recommended on the basis of the most favourable efficacy/safety profile


• Enoxaparin has less favourable efficacy/safety profile than fondaparinux should be used if the bleeding risk is low.


• Aspirin irreversibly inhibits COX-1 in platelets, thereby limiting the formation of thromboxane A2, thus inhibiting platelet aggregation.
  

Non Cardiac conditions with troponin elevations:

• CCF


• Aortic dissection, aortic valve disease, or hypertrophic cardiomyopathy


• Cardiac contusions, ablation, pacing, cardioversion


• Inflammatory diseases, e.g. myocarditis


• Pulmonary embolism, severe pulmonary hypertension


• Chronic or acute renal dysfunction


• Acute neurological disease, including stroke or SAH


• Drug toxicity


• Burns, if affecting >30% of body surface area


• Rhabdomyolysis


• Critically ill patients, especially with respiratory failure, or sepsis
  

Relevant Videos

Relevant Videos

 

Cardiology - Short Answer Questions (SAQ)

Critical Appraisal Practice Paper 4 (Diagnostic)

Total marks: 23
Time allowed: 90 mins

You might wish to download the paper. Do it in 90 minutes and then compare with the answers provided here.

Paper: Mallampati test as a predictor of laryngoscopic view

Biomed Pap Med Fac Univ Palacky Olomouc Czech Repub. 2010 Dec;154(4):339-43.

Download (PDF, 65KB)

1. Provide a summary / abstract for the paper. (Up to 5 marks)

Answer

Answer

This should include all or some of the following points:

Aim. To determine the accuracy of the modified Mallampati test for predicting the difficulty of subsequent tracheal intubation.

Design. A cross-sectional, clinical, observational, non-blinded study. A quality analysis of anaesthetic care.

Setting. Operating theatres and department of anaesthesia in a university hospital in the Czech Republic.

Material and methods. Following local ethics committee approval and patients’ informed consent to anaesthesia, all adult patients (> 18 yrs) presenting for any type of non-emergency surgical procedures under general anaesthesia requiring endotracheal intubation were enrolled.

Prior to anaesthesia, Samsoon and Young"s modification of the Mallampati test (modified Mallampati test) was performed.

Following induction, the anaesthetist described the laryngoscopic view using the Cormack-Lehane scale. Classes 3 or 4 of the modified Mallampati test were considered a predictor of difficult intubation. Grades 3 or 4 of the Cormack-Lehane classification of the laryngoscopic view were defined as impaired glottic exposure.

The sensitivity, specificity, positive and negative predictive value, relative risk, likelihood ratio and accuracy of the modified Mallampati test were calculated on 2x2 contingency tables.

Results. Of the total 1,518 patients enrolled, 48 had difficult intubation (3.2%).

We failed to detect as many as 35.4% patients in whom glottis exposure during direct laryngoscopy was inadequate (sensitivity 64.4%).

Compared to the original article by Mallampati, we found lower specificity (82.4% vs. 99.5%), lower positive predictive value (0.107 vs. 0.933), higher negative predictive value (0.986 vs. 0.928), lower likelihood ratio (3.68 vs. 91.0) and accuracy (0.819 vs. 0.929).

Conclusion. When used as a single examination, the modified Mallampati test is of limited value in predicting difficult intubation in elective surgery patients.

2. Give three weaknesses of the study design and suggest improvements for these (up to 3 marks)

Answer

Answer

Strengths - there aren’t that many!

• They did get ethical approval


• The sample size was large


• Sample recruited from a good cross section of patients undergoing elective surgery

Weaknesses – there are lots of these!

• Patients studied are elective not emergency patients, so use in emergency situations cannot be inferred.


• It’s unclear who assessed the Mallampati Score but it’s likely to be the same anaesthetist who also assessed the outcome (laryngoscopic grade).


• It’s unclear what grade of anaesthetist assessed Mallampati or laryngoscopic grade.


• ? only one person assessed Mallampati Score.


• The person assigning the Cormack / Lehane grade was not unaware of the previously assigned Mallampati Score. In diagnostic studies it is important that the outcome is assigned without knowledge of the intervention test result.

The study could have been improved (for an EM readership) by:

• Studying a group of patients needing emergency airway control.


• The authors could have described in more detail who exactly was assigning the Mallampati Score e.g. grade, level of training etcc.. and how this was done.


• More than one assessor could have done this. The authors could have got two people to do this to ensure consistency and assessed agreement using a Kappa statistic or similar. This would help the reader to assess if the Mallampati Score was reproducible enough to make it worth doing amongst a wider range of clinicians.


• Someone else (who didn’t do the Mallampati Score) should have assigned the Cormack & Lehane Grade. The C&L grade given could have been influenced by knowledge of the Mallampati Score.

3. Name one checklist which is useful in evaluating the quality of diagnostic papers such as this. Give two further questions / points within this checklist not covered by the weaknesses you have mentioned in question 2. above. (up to 3 marks)

Answer

Answer

Common checklists include QUADAS and STARD (see below)

The STARD statement can be found here (it is similar to QUADAS):

http://www.stard-statement.org/

In this study the “index test” is the Mallampati Score and the “reference standard” is the Cormack & Lehane Grade. You should go through this checklist with the study and see how many weaknesses you can now identify!

4. The table 3 below is taken from the results section.

 Summarise the results in the table in one sentence. What is the Mann-Whiney U test? (Up to 2 marks)

Answer

Answer

Men are taller and heavier than women!

The Mann Whitney U Test is a test used to compare continuous (or ordinal) data in two independent groups, when the data is non parametric (i.e does not follow a normal distribution). It is analogous to a t-test which does the same thing but for normally distributed data.

 5. Construct a 2 x 2 table illustrating the main data from the current study (not Mallampati’s original). (Up to 2 marks)

Answer

Answer

		Actual Difficulty of Intubation(by Cormack Lehane Grade)
		Difficult (3/4)	Easy (1/2)
Predicted Difficulty of Intubation (Mallampati Class)	Difficult (3/4)	31	258	289
	Easy (1/2)	17	1212	1229
		48	1470	1518

6. Use your table in 5. above to demonstrate how the positive likelihood ratio and the accuracy were calculated. Explain how you would interpret the positive likelihood ratio in this study. (4 marks)

Answer

Answer

Positive LR = Sensitivity / 1 – Specificity

Sensitivity = a / a+c = 31 / 48 = 0.646

Specificity = d / b+d = 1212 / 1470 = 0.824

Positive LR = 0.646 / 0.176 = 3.67

Accuracy = total number (%) of “correct” predictions = a + d / a + b + c + d

Accuracy = 1243 / 1518 = 81.9%

LR+ above 10 means that a positive test (i.e. a higher Mallampati Score) will significantly increase the post test probability (of a difficult intubation) enough to make the test worth doing. Figures below 10 (like 3.67) mean that a positive test doesn’t really alter your chances of predicting the outcome enough to make it worth doing.

 

7. The authors used Fishers Exact Test to statistically compare their results with the results of Mallampati. Describe the indications for using this test as opposed to a Chi Squared Test? (Up to 2 marks)

Answer

Answer

Fishers Exact Test is used for 2 x 2 data when the expected count in any of the 4 boxes is “low”. The rule of thumb is if the expected number is less than 10 in any box then Fishers Exact Test should be used.. The expected number in any box can be calculated by multiplying the total of the column by the total row value and dividing by the overall number of patients / data points.

The authors appear to have used 2 x 2 tables for each of the possible outcomes. An example for “true negative” is illustrated below.

		Study
		Adamus et al	Mallampati et al
Observed Result	True Negative	1212	181	1393
	Not True Negative	306	29	335
		1518	210	1728

Thus for box d (value 29), the expected value is 210 (the total column value) x 335 (the total row value) / 1728 (the overall total). This is 40.1. In this case all the expected values are greater than 10 and so Chi Squared could have been used. However, for some of the others (e.g. false positives), the expected values will be low so I suppose the authors went for Fishers Test for consistency!

8. What are your conclusions overall? Is this paper going to influence your practice? Briefly suggest any ideas for future research in this area? (Up to 2 Marks)

Answer

Answer

Overall this paper is not great and is unlikely to influence your practice. There are multiple weaknesses and potential areas of bias. In addition the results are very different from the original Mallampati Study.

The authors hint at the other factors which allow a good assessment of the airway (e.g. weight or patients etc..). A better study might look at the whole LEMON acronym which you are probably familiar with from ATLS. It could be done in an ED setting with independent assessment of LEMON and the final C&L grade / ease of intubation.

Finally given that the study results are so different from the original Mallampati Study you could propose some secondary research (a systematic review, Best BET or even CTR!) to answer the question posed.

Mallampati test as a predictor of laryngoscopic view. Biomed Pap Med Fac Univ Palacky Olomouc Czech Repub. 2010 Dec;154(4):339-43.

A clinical sign to predict difficult tracheal intubation: a prospective study. Can Anaesth Soc J. 1985 Jul;32(4):429-34.

 

Critical Appraisal Practice Paper 4 (Diagnostic)