Quiz 1 Flashcards
1
Q
Where do the irregular impulses of atrial fibrillation classically originate from?
A
Atrial fibrillation occurs due rapid impulse generation by an ectopic atrial focus, most commonly adjacent to or within the pulmonary vein orifices.
2
Q
What term is used to describe a reduction in neutrophils?
A
Neutropaenia is a reduction in neutrophils.
3
Q
what is neutrophilia
A
Neutrophilia is an increase in neutrophils.
4
Q
Which of the following would result in dead space ventilation?
- pulmonary oedema
- pulmonary fibrosis
- acute respiratory distress syndrome
- emphysema
A
Emphysema causes airway obstruction and the formation of large bullae, resulting in dead space ventilation.
5
Q
What is the pattern of ST elevation in ST elevation myocardial infarction?
A
The correct answer is ST elevation in contiguous leads.
ST elevation MI presents with ST elevation in contigous leads with reciprocal ST depression.
6
Q
what is widespread ST elevation suggestive of
A
pericarditis
7
Q
Which of the following does not directly indicate anaemia?
- reduced haemoglobin
- reduced red cell count
- reduced mean cell volume
- reduced haematocrit
A
Reduced haemoglobin, haematocrit and red cell count are all markers of anaemia.
Mean cell volume provides information about the type of anaemia, though in itself is not a marker of anaemia.
8
Q
Which of the following is a cause of red blood cells in urine?
- haemolysis
- liver failure
- rhabdomyolysis
- glomerulonephritis
A
Glomerulonephritis is an important cause of red blood cells in urine. While haemolysis and rhabdomyolysis may cause a positive urine dipstick for blood, this is due to the presence of haemoglobin or myoglobin respectively, rather than red blood cells.
9
Q
You are working in the emergency department, and a 22 year old normally healthy male presents with nausea and vomiting. You perform a urine dipstick which reveals the following:
acidic pH
glucose +++
Ketones++
what. is likely diagnosis: UTI Rhabdomyolysis alcoholic ketoacidosis diabetic ketoacidosis
A
The reduced pH, ketones and significant glucose suggest diabetic ketoacidosis. This is a common first presentation in type 1 diabetes.
10
Q
What does the term glycosuria refer to? diabetes mellitus glucose in urine glycogen in urine ethylene glycol in urine
A
Glycosuria refers to the presence of glucose in urine.
11
Q
Which of the following is NOT a cause of an obstructive pattern on spirometry?
- asthma
- bronchiectasis
- emphysema
- idiopathic pulmonary fibrosis
A
Asthma, chronic obstructive pulmonary disease (chronic bronchitis and emphysema) and bronchiectasis are common causes of an obstructive pattern.
Idiopathic pulmonary fibrosis is a type of interstitial lung disease which would produce a restrictive pattern
12
Q
What is the significance of a prolonged PR interval?
A
prolonged atrioventricular conduction time.
13
Q
Which of the following is NOT a cause of hypoventilation?
- morphine
- myasthenia gravis
- chest wall deformity
- high altitude
A
High altitude reduces the partial pressure of oxygen in inspired air, but does not have a significant effect on ventilation.
14
Q
What does the P wave on an ECG represent?
- atrial repolarisation
- atrial depolarisation
- atrial contraction
- ventricular depolarisation
A
The P wave represents depolarisation of the atria.
15
Q
what might hyperkaleamia produce on an ECG
A
tented T waves
16
Q
Which of the following is most correct about a narrow QRS complex?
- A narrow QRS complex originates from the sinoatrial node
- A narrow QRS complex originates from the atria
- A narrow QRS complex may originate from anywhere above the ventricle
- A narrow QRS complex originates from the ventricles
A
A narrow complex rhythm may originate anywhere above the ventricle - from the sinoatrial node, the atria or the AV node.
17
Q
Your next patient, a 25 year old male, presents with brown urine. He just started going back to the gym after a long hiatus and states that his muscles ache after a workout yesterday. You perform a urine dipstick which reveals the following: Haematuria
You are concerned about haematuria, and so you perform urine microscopy: comes back normal
what is the most likely diagnosis?
- renal calculus
- haemolysis
- rhabdomyolysis
- glomerulonephritis
A
The dipstick detects myoglobin and free haemoglobin as blood, and the microscopy confirms that there are no red cells in the urine. The recent gym visit and brown urine suggest rhabdomyolysis. Haemolysis is possible, however the normal urine urobilinogen goes against this.
18
Q
What diabetic medication acts by causing excretion of glucose in urine?
- Metformin
- Glicazide
- Empagliflozin
- Pioglitazone
A
Empagliflozin is an sodium-glucose transporter 2 (SGLT2) inhibitor that causes urinary excretion of glucose.
19
Q
Which of the following is a cause of an increased neutrophil count?
- bacterial infection
- B12 deficiency
- lymphoma
- alcohol abuse
A
Bacterial infection is a common and important cause of neutrophilia.
20
Q
What is suggested by an elevated haemoglobin with a normal red cell count?
- Polycythaemia vera
- chronic hypoxia
- EPO-producing tumour
- dehydration
A
relative erythrocytosis is the presence of an elevated haemoglobin and haematocrit with a normal red cell count. This is suggestive of plasma volume contraction, commonly due to dehydration.
21
Q
Which arrhythmia is associated with sawtooth waves?
- AF
- atrial flutter
- VF
- Torsade de pointes
A
atrial flutter
22
Q
Which of the following typically produces a macrocytic, hyperchromic anaemia?
- iron deficiency
- B12 deficiency
- EPO deficiency (chronic kidney disease)
- Thalessemia
A
B12 and folate deficiency tend to cause a macrocytic, hypochromic anaemia.
23
Q
What does erythrocytosis refer to?
- increased red blood cells
- reduced red blood cells
- increased white blood cells
- increased platelets
A
Erythrocytosis refers to an increase in red blood cells.
24
Q
Which of the following would cause lactic acidosis? -hyperglycaemia -hypoglycaemia -seizure - Ethylene glycol toxicity
A
Seizures can cause anaerobic muscle hyperactivity, resulting in lactic acidosis.
25
right bundle branch block ecg
The QRS duration is >120ms, with a broad R wave and absent Q wave in lead V6.
26
how to calculate anion gap
Anion Gap = Na+ - ( Cl- + HCO₃- )
27
Which of the following is a clinical sign of hyperthyroidism?
- Bradycardia
- hyperreflexia
- Loss of the outer third of the eyebrow
- Psychomotor retardation
Hyperthyroidism produces clinical signs such as tachycardia, psychomotor agitation, warm skin, tremor and hyperreflexia.
28
Antithyroglobulin (anti-Tg) antibodies are most specific to which disease?
- Hashimoto's thyroiditis
- Atrophic thyroiditis
- Graves disease
- Postviral thyroiditis
Antithyroglobulin antibodies are present in 80-90% of patients with chronic autoimmune (Hashimoto's) thyroiditis
29
What does blunting of the costophrenic angles suggest?
- pnuemothorax
- consolidation
- collapse
- pleural effusion
costophrenic blunting is a sign of pleural effusion.
30
Which of the following is NOT a cause of sinus node dysfunction?
- idiopathic degeneration
- wolf Parkinson white syndrome
- MI
- lyme disease
Wolff-Parkinson-White syndrome involves an accessory pathway.
The other conditions may affect the sinus node.
31
What is the normal QRS duration?
- 80-120ms (2-3mm)
- 120-160ms (3-4mm)
- 120-200ms (3-5mm)
- 160-200ms (4-5mm)
The correct answer is 80-120ms.
32
How are urine white cells estimated using a urine dipstick?
- Peroxidase reaction
- white cell membrane antibodies
- Leukocyte esterase
- leukocyte microscopy
Leukocyte esterase (LE) is an enzyme produced by white blood cells. If leukocyte esterase is present in urine then this is indicative of an increase in leukocytes in urine, also known as pyuria.
33
what is PR depression associated with
PR depression can be a normal variant, or may be associated with pericarditis or atrial infarction.
34
Which of the following is a symptom of hyperthyroidism?
- weight gain
- cold intolerance
- heat intolerance
- constipation
Hyperthyroidism produces classical symptoms such as weight loss, heat intolerance, tremor, diaphoresis and diarrhoea.
35
What is a water bottle-shaped heart classically associated with?
- transposition of the great arteries
- tetralogy of fallot
- tricuspid atresia
- pericardial effusion
A water bottle-shaped heart (diffuse enlargement with a globular appearance) is a sign of pericardial effusion.
36
Which of the following causes of proteinuria occurs due to overflow of protein, rather than glomerular or tubular injury?
- Focal segmental glomerulosclerosis
- multiple myeloma
- Lupus nephropathy
- membranous nephropathy
in multiple myeloma, an excess of paraprotein (immunoglobulin or light chains) are filtered through the glomerulus and overload the kidney's capacity to filter.
37
Which of the following is NOT an ECG feature of myocardial ischaemia / infarction?
- t wave inversion
- st elevation
- st depression
- qt prolongation
The answer is QT prolongation.
The other options are features of myocardial ischaemia / infarction.
38
Which of the following is a cause of normal anion gap metabolic acidosis?
- diarrhoea
- lactic acidosis
- Ethylene glycol
- DKA
Diarrhoea causes a normal anion gap metabolic acidosis.
| The other options cause a high anion gap metabolic acidosis.
39
Which of the following presents with a macrocytic anaemia?
- folate deficiency
- Sickle cell disease
- Autoimmune haemolytic anaemia
- lead poisoning
Folate deficiency causes megaloblastic anaemia, which is macrocytic. Lead poisoning causes a microcytic hypochromic anaemia, while sickle cell and autoimmune haemolysis tend to be normocytic.
40
What broad type of anaemia does thalassaemia fit into?
- Microcytic hypochromic anaemia
- macrocytic anaemia
- Normocytic anaemia
- megaloblastic anaemia
Thalassaemia presents with a microcytic hypochromic anaemia.
41
Why must the QT interval be corrected?
- To adjust for the patient's sex
- To adjust for heart rate
- To adjust for the axis
- To adjust for a prolonged QRS interval
The QT interval shortens with rapid heart rates and lengthens at slower heart rates, as a compensatory mechanism. In order to truly estimate risk it is important to correct for the heart rate, i.e. estimatinng what the QT interval would be at 60 beats per minute.
42
What test result can be used to distinguish between asthma and chronic obstructive pulmonary disease (COPD)?
- FEVâ‚
- FVC
- Bronchodilator reversibility
- total lung capacity
Asthma and COPD both produce obstructive patterns on spirometry. The cornerstone of the asthma diagnosis is proving that there is reversibility of airway obstruction with bronchodilators.
43
Apart from ventricular tachycardia, what is an important cause of wide QRS complexes?
- atrial flutter
- AV nodal reentrant tachycardia
- hypokalaemia
- Bundle branch block
One of the diagnostic criteria for bundle branch block is a widened QRS duration.
Atrial flutter and AV nodal reentrant tachycardia would present as narrow complex tachyarrhythmias.
Hyperkalaemia may cause a widened QRS, not hypokalaemia.
44
Which of the following is a cause of metabolic alkalosis?
- Diarrhoea
- vomiting
- Cyanide toxicity
- addisons disease
vomiting causes acid loss, resulting in a metabolic alkalosis.
The other options are causes of metabolic acidosis.
45
The presence of bilirubin in the urine is NOT compatible with which of the following?
- haemolysis
- acute hepatitis
- liver cirrhosis
- cholestasis
haemolysis
Only conjugated bilirubin is filtered into urine, as it is water soluble while unconjugated biluribin is fat soluble. Therefore, bilirubinuria is an indicator of the presence of any cause of conjugated hyperbilirubinaemia.
46
Which of the following is an irregular narrow complex tachyarrhythmia?
- AF
- typical atrial flutter
- AV reentrant tachycardia
- aV nodal reentrant tachycardia
The correct answer is atrial fibrillation.
| The other options present as regular narrow complex tachyarrhythmias.
47
Which of the following is typically a normocytic normochromic anaemia?
- Iron deficiency anaemia
- thalassemia
- B12 deficiency anaemia
- aplastic anaemia
aplastic anaemia typically manifests as a normocytic, normochromic anaemia.
48
What does the QT interval on an ECG represent?
- The time between atrial depolarisation and ventricular depolarisation
- the time between atrial depolarisation and ventricular repolarisation
- The time between ventricular depolarisation and ventricular repolarisation
- The conduction time between the atria and ventricles
The QT interval indicates of the time from ventricular depolarisation (phase 0) to ventricular repolarisation (phases 1-3). It is the duration of activation and recovery of the ventricular myocardium.
49
Which of the following medications would NOT slow the sinus rate?
- metaprolol
- Diltiazem
- amlodipine
- Digoxin
Amlodipine is a hydropyridine, or vascular-selective, beta blocker. It has no cardiodepressive effects.
The other medications have a negative chronotropic effect.
50
someone has low hb and low red cell count Which of the following indices would provide the most information about the type of anaemia?
- haematocrit
- mean cell volume
- packed cell volume
- Red cell distribution width (RDW)
the mean cell volume is used to determine whether an anaemia is microcytic, normocytic or macrocytic - this is the first step in identifying the cause of anaemia.
Haematocrit and packed cell volume are synonymous. These would be reduced in anaemia, though would not provide significant further information.
The red cell distribution width refers to the variation in size of red blood cells. Though this result is useful, it does not provide nearly as much information as the MCV.
51
What would NOT be a cause of slow atrial fibrillation in a patient with previously known AF?
- Complete heart block
- metoprolol
- digoxin
- Thyrotoxicosis
Thyrotoxicosis would increase the heart rate, increasing the likelihood of atrial fibrillation with rapid ventricular rate.
The other options would slow the heart rate and potentially cause slow AF.
52
In what disease are plasma cells likely to be seen in the peripheral blood in large numbers?
- Plasma cell myeloma
- plasma cell leukaemia
- Waldenstrom's macroglobulinaemia
- diffuse large B cell lymphoma
Plasma cell leukaemia presents with large numbers of circulating plasma cells, and carries a very poor prognosis.
Plasma cell myeloma, or multiple myeloma, manifests with plasma cells in the bone marrow but plasma cells are rarely seen in peripheral blood.
Waldenstrom's macroglobulinaemia tends to manifest with plasmacytoid lymphocytes, though plasma cells are occasionally seen on the bone marrow.
53
Which of the following causes an increase in circulating platelets?
- aplastic anaemia
- B12 deficiency
- acute bacterial infection
- alcohol abuse
Acute infection and inflammation are important causes of thrombocytosis.
54
```
you see a 40 year-old female in clinic, who presents with fatigue and a facial rash. As part of your workup, you perform a urine dipstick:
leukocyte esterase +
blood +++
protein +++
Which of the following is MOST compatible with the findings?
-UTI
-Systemic lupus erythematosus
-dehydration
-pregnancy
```
the blood and protein in her urine, as well as the facial rash, raise concern for SLE with lupus nephritis.
55
Which of the following would result in respiratory acidosis?
- hyperventilation
- hypoventilation
- hypoxia
- hypocapnia
Hypoventilation causes hypercapnia, resulting in respiratory acidosis.
Hyperventilation results in respiratory alkalosis and hypercapnia.
Hypoxia may be a result of hypoventilation.
56
Which of the following would result in a left-to-right shunt?
- Asthma
- COPD
- Pneumonia
- PE
In patients with pneumonia, the affected alveoli fill with pus and are perfused but not ventilated. This results in a left-to-right shunt as blood supplied to those vessels supplying these pus-filled alveoli bypasses the lungs.
The other options would result in dead space ventilation.
57
Which of the following are lateral ECG leads?
- II, II, aVF
- V1,V2
- V3,V4
- I, aVL, V5, V6
I, aVL, V5, V6
58
Which of the following are inferior ECG leads?
- II, III, avF
- V1,V2
- V3,V4
- I, aVL, V5, V6
II,III,avF
59
Which of the following causes left shift of the oxygen dissociation curve?
- increased pH
- Decreased pH
- Hyperthermia
- Increased 2,3-DPG
increased pH
60
Which of the following shifts the oxygen dissociation curve to the right?
- Hyperthermia
- hypothermia
- alkalaemia
- Reduced 2,3-DPG
hyperthermia
61
In a patient with wide complex tachycardia, what does AV dissociation suggest?
- SVT with bundle branch block
- SVT with accessory pathway
- ventricular tachycardia
- pacemaker rhythm
AV dissociation is almost 100% specific for ventricular tachycardia.
62
Which of the following is a glomerular cause of proteinuria?
- acute tubular necrosis
- Fanconi syndrome
- multiple myeloma
- membranous nephropathy
membranous nephropathy
Glomerular causes of proteinuria include minimal change disease, membranous nephropathy, focal segmental glomerulosclerosis, and secondary glomerulonephropathies.
63
Which of the following is NOT a clinical sign of hypothyroidism?
- alopecia
- tremor
- tongue enlargement
- Loss of the outer 1/3 of the eyebrow
A tremor tends to be seen in patients with hyperthyroidism.
64
What does pyuria refer to?
- red cells in urine
- white cells in urine
- squamous epithelial cells in urine
- lipids in urine
white cells in urine
65
Which of the following is a cause of primary hyperthyroidism?
- iodine deficiency
- Grave's
- Atrophic thyroiditis
- radioiodine therapy
Grave's disease is a common cause of primary hyperthyroidism.
66
What does increased urine specific gravity indicate?
- excessively concentrated urine
- excessively dilute urine
excessively concentrated urine
67
What disease causes an abundance of small mature lymphocytes and smudge cells?
- acute lymphoblastic leukaemia
- chronic lymphocytic leukaemia
- diffuse large B cell lymphoma
- follicular lymphoma
Chronic lymphocytic leukaemia presents with abundant small mature lymphocytes and smudge cells.
Acute lymphoblastic leukaemia presents with lymphoblasts, which are large immature cells.
Lymphoma tends to present with lymphadenopathy, and peripheral blood lymphocytosis is an uncommon feature.
68
What is the direction of lead I, II, III, aVF, aVL, aVR on an ECG?
```
I: -90
II: 150
III: 30
aVF: 90
aVL: -30
aVR: -150
```
69
What is the direction of lead aVF on an ECG?
- heparin
- burns
- Acute bacterial infection
- splenectomy
heparin-induced thrombocytopaenia is an important cause of reduced circulating platelets.
70
Turbid (cloudy) urine suggests which of the following?
- UTI
- blood in urine
- glucose in urine
- dehydration
Cloudy or turbid urine suggests pyuria, due to infection or inflammation.
71
Which of the following cardiovascular risk factors is least associated with risk of atrial fibrillation?
- smoking
- hypertension
- diabetes
- obstructive sleep apnoea
hypertension, diabetes and obstructive sleep apnoea are all associated with atrial fibrillation.
72
which of the following is NOT strongly associated with QT prolongation?
- amiodarone
- fluconazole
- Anidulafungin
- Azithromycin
The correct answer is anidulafungin.
The other options are associated with QT prolongation.
73
Which gland secretes thyroid stimulating hormone (TSH)?
- thalamus
- hypothalamus
- anterior pituitary
- posterior pituitary
anterior pituitary
74
What is the T wave on an ECG representative of?
- ventricular repolarisation
- ventricular depolarisation
- ventricular relaxation
- ventricular contraction
the T wave represents ventricular repolarisation.
75
Which of the following is a cause of eosinophilia?
- allergy
- bacterial infection
- steroid administration
- viral infection
allergy
76
Which of the following causes lymphocytosis?
- acute bacterial infection
- acute viral infection
- corticosteroids
- malnutrition
acute viral infection
77
What score may be used to assess the stroke risk of a patient with atrial fibrillation?
- HAS-BLED
- CHADSVASc
- Well's score
- CURB-65
The CHADS2 or CHADSVASc scores can be used to assess cardioembolic stroke risk in patients with atrial fibrillation.
The HAS-BLED score is used to assess risk of bleeding in these patients, to guide in weighing up the risk of anticoagulation.
The Well's score is a pulmonary embolus risk score, and CURB-65 is a pneumonia severity score.
78
What is an elevated A-a gradient suggestive of?
- high altitude
- hypoventilation
- sepsis
- V/Q mismatch
An elevated A-a gradient indicates that the partial pressure of Oâ‚‚ is higher in the alveoli than in arterial blood, indicating a V/Q mismatch.
79
Which of the following is a cause of eosinophilia?
- bacterial infection
- viral infection
- fungal infection
- parasitic infection
The primary physiologic role of eosinophils is to defend against parasites.
Other important causes of eosinophilia include allergy and drug reactions.
80
If TSH, T3 and T4 (in a thyroid function test are all reduced then:
- primary hypothyroidism
- primary hyperthyroidism
- subclinical hypothyroidism
- central hypothyroidism
The TSH, T3 and T4 are all reduced, which suggests a central cause of hypothyroidism.
81
Which antibodies are pathognomonic of Grave's disease?
- anti TPO
- Anti-thyroglobulin
- anti TSH receptor
- Anti-TRH receptor
Anti-TSH receptor antibodies are pathognomonic of Grave's disease.
82
What is the optimal position of an endotracheal tube?
- just below the vocal chords
- at the level of the carina
- At the level of the aortic knuckle
- Within the right main bronchus
An endotracheal tube should be below the larynx and above the carina, optimally at the level of the aortic knuckle.
83
The presence of urobilinogen in urine is NOT compatible with which of the following?
- haemolysis
- acute hepatitis
- cholestasis
- liver cirrhosis
Bilirubin is converted to urobilinogen by bacteria within the intestines, reabsorbed and excreted by the kidneys.
An increase in urine urobilinogen cannot occur in the context of cholestasis, as conjugated bilirubin is unable to pass into the gut and be reabsorbed.
84
what electrolyte imbalance can cause u waves on ecgs
hypercalcaemia or hypokalaemia
85
diagnosis for The TSH is reduced with a normal T3 and T4,
- subclinical hyperthryoidism
- subclinical hypothyroidism
- primary hyperthyroidism
- primary hypothyroidism
subclinical hyperthyroidism
86
Which of the following tends to present as diffuse consolidation, rather than localised consolidation?
- lobar pneumonia
- Cryptogenic organising pneumonia
- non small cell lung cancer
- pulmonary oedema
Pulmonary oedema tends to be diffuse, while the other conditions tend to cause lobar consolidation.
87
What is the significance of a prolonged PR interval?
- delayed atrial depolarisation
- Prolonged atrioventricular conduction time
- prolonged ventricular contraction
- Delayed ventricular recovery
prolonged atrioventricular conduction time
88
```
Your next patient, a 32 year old female, presents with increased frequency of urination. You perform a urine dipstick, which reveals the following:
alkaline urine
leukocyte esterase ++
nitrites ++
blood +
```
most likely diagnosis
- UTI
- Polycystic kidney disease
- interstitial cystitis
- pregnancy
UTI
89
The bilirubin that is excreted in urine and measured on a dipstick is:
- unconjugated bilirubin
- conjugated bilirubin
- Stercobilin
- urobilirubin
only conjugated bilirubin is filtered into urine, as it is water soluble while unconjugated biluribin is fat soluble. Therefore, bilirubinuria is an indicator of the presence of any cause of conjugated hyperbilirubinaemia.
90
which of the following would NOT result in a respiratory alkalosis?
- pain
- anxiety
- opioids
- hypoxia
opioids can cause hypoventilation, resulting in respiratory acidosis.
Pain and anxiety may cause hyperventilation, resulting in respiratory alkalosis.
Hypoxia can stimulate the respiratory drive, resulting in tachypnoea, hyperventilation and respiratory alkalosis.
91
Which of the following does not cause complications resulting in ketones in the blood and urine?
- diabetes mellitus
- glomerulanephritis
- alcoholism
- starvation
Diabetic ketoacidosis, alcoholic ketoacidosis and starvation ketosis are important causes of ketone generation.
92
what are Kerley B lines due to?
- thickening of the inter lobar septae
- Fluid within the alveoli
- pulmonary scarring
- Fluid in the deep septae
Kerley B lines, a sign of pulmonary oedema (amongst other conditions), occurs due to interlobular septal thickening.
93
Which of the following is a cause of absolute erythrocytosis (increased haemoglobin and red cell count)?
- Polycythaemia vera
- dehydration
- iron deficiency
- haemolysis
Polycythemia vera is an important cause of erythrocytosis.
Dehydration may cause an increased haemoglobin and haematocrit, however the red cell count tends to be normal (relative erythrocytosis).
Iron deficiency and haemolysis both cause anaemia, not erythrocytosis.
94
What is the normal QRS duration?
- 80-120ms (2-3mm)
- 120-160ms (3-4mm)
- 120-200ms (3-5mm)
- 160-200ms (4-5mm)
80-120ms (2-3mm)
95
Pencil cells are commonly seen in which type of anaemia?
- anaemia of chronic disease
- aplastic anaemia
- Megaloblastic anaemia
- iron deficiency anaemia
Pencil cells are commonly seen in iron deficiency anaemia.
96
What does the QT interval on an ECG represent?
- The time between atrial depolarisation and ventricular depolarisation
- The time between ventricular depolarisation and ventricular repolarisation
- the conduction time between the atria and ventricles
- The time between atrial depolarisation and ventricular repolarisation
The QT interval indicates of the time from ventricular depolarisation (phase 0) to ventricular repolarisation (phases 1-3). It is the duration of activation and recovery of the ventricular myocardium.
97
Which of the following are anterior ECG leads?
- II,III,aVF
- V1,V2
- V3,V4
- I, aVL, V5, V6
V3 and V4
98
What is the rationale behind giving anticoagulation to patients with atrial fibrillation?
- Prevent atherosclerotic stroke
- prevent cardioembolic stroke
- Prevent pulmonary embolus
- prevent MI
Due to irregular contraction of the atria, atrial fibrillation is associated with atrial thrombus formation. These thrombi are at risk of embolising to the brain and causing cardioembolic stroke.
99
Which of the following medications would NOT slow the sinus rate?
- metoprolol
- digoxin
- Amlodipine
- Diltiazem
amlodipine is a hydropyridine, or vascular-selective, beta blocker. It has no cardiodepressive effects.
The other medications have a negative chronotropic effect.
