Case 1 Test

Question 1

Select the most appropriate measure to calculate the risk of cardiac arrest secondary to acute myocardial infarction within 24 hours after admission to a hospital.

Answer 1

Prevalence
Point prevalence
Period prevalence
= Incidence: This is the proportion of the population who developed the health condition/outcome per unit of time.
Mortality

Question 2

Select the part of the embryonic germ layers from which the heart develops.

Answer 2

Paraxial mesoderm 
Somatic mesoderm
Extraembryonic endoderm
Ectoderm
= Splanchnic mesoderm: The heart develops from the splanchnic lateral plate mesoderm.

Question 3

Select the phase of the cardiac cycle during which the aortic valve closes.

Answer 3

Isovolumetric contraction
Rapid ejection
= Diastole: the closure of the aortic valve occurs during early diastole as the ventricles begin to relax and marks the start of isovolumetric relaxation. As the ventricles relax the pressure inside them drops ultimately leading to closure of the aortic valve to present significant back flow of blood from the aorta. 
= Isovolumetric relaxation
Rapid filling

Question 4

Select the statement that provides the best definition of socio-economic inequalities in health.

Answer 4

Socio-economic inequalities in health are differences in health status between males and females

Socio-economic inequalities in health are differences in health status between people living in rural and urban areas

Socio-economic inequalities in health are differences in health status between people living in the UK and people living in France

= Socio-economic inequalities in health are differences in health status between those with differing occupations: Socio-economic inequalities can also relate to income or occupation or social class.

Socio-economic inequalities in health are differences in health status between people who smoke and people who don’t

Question 5

Select the structure of the conducting system of the heart that passes through the septomarginal trabecula.

Answer 5

Sinoatrial node 
Atrioventricular node 
Atrioventricular bundles
= Right subendocardial branches: Correct. The right subendocardial branches stimulates the interventricular septum, anterior papillary muscles through the septomarginal trabecula (moderator band) and the right wall of the right ventricle. 
Left subendocardial branches

Question 6

Select the term that describes conversion of one kind of tissue into a form that is not normal for that type of tissue.

Answer 6

Apoptosis
Atrophy
Hypoplasia
= Metaplasia
Necrosis

Question 7

The image below shows the heart. Select the most appropriate anatomical feature indicated by label 17.

Answer 7

= Chordae tendineae 
Crista terminalis
Papillary muscle
Septomarginal trabecula
Supraventricular crest

Question 8

Select the structure that forms the flexible membranous component of the septum in atrial septation.

Answer 8

Conotruncal septum
Membranous ventricular septum
Septum intermedium
= Septum primum
Septum secundum

Question 9

Select the region of the heart in which the atrioventricular bundle is located.

Answer 9

Atrial septum
Left atrium
= Membranous interventricular septum: The atrioventricular bundle is located in the membranous interventricular septum. Remember that the atria and ventricles are attatched to the heart's fibrous skeleton allowing for electrical insulation.
Muscular interventricular septum
Right atrium

Question 10

Select the rate of the p waves in the limb lead II ECG strip shown in the image below.

Answer 10

(5 big squares is one second)
= 107 p/m: The rate of the P-waves in this ECG strip is 107 per minute if you assuming regular rhythm with no missed P waves. The time between each P-wave is just under 0.6 seconds on average (each larger box represents 0.2 seconds) this equates to a rate over 100 per minute.

Question 11

Select the heart rate if cardiac output is 3.98 litres per minute and stroke volume 0.078 litres.

Answer 11

co = hr x sv

Question 12

Select the condition that would normally result from the stimulation of baroreceptors.

Answer 12

Atrial flutter
Sinus arrhythmia
= Sinus bradycardia: . Stimulation of baroreceptors will cause sinus bradycardia. When baroreceptors are stimulated, they cause decrease in action potential firing in SAN.
Sinus tachycardia 
Supraventricular tachycardia

Question 13

Select the condition that is characterised by rhythmic fluctuation of heart rate in phase with respiration.

Answer 13

Atrial flutter
= Sinus arrhythmia: Sinus arrhythmia is a normal physiological change in heart rate that occurs in phase with the respiratory cycle. E.G. when HR increases on respiration.
Sinus bradycardia  
Sinus tachycardia 
Supraventricular tachycardia

Question 14

An 82-year-old male presents to his GP with chest pain, shortness of breath and syncopal episodes. He had rheumatic fever as a child. On examination, he has a slow-rising, flat pulse and a narrow pulse pressure. A murmur is heard. After an ECG the GP decides to refer him for imaging of his heart to allow visualisation of the cardiac structures and to check the flow of blood through it. The GP reassures him that this investigation is non-invasive, requires no radiation, and is safe to perform on a patient with metalwork in.

Select the cardiac imaging that the GP has most likely requested.

Answer 14

Cardiac CT
Cardiac MRI 
Coronary Angiography 
Erect Chest Radiography 
= Transthoracic Echocardiography: Uses ultrasound to identify heart structures and blood flow. No radiation/magnets.

Question 15

In complete heart block the rate of atrial contraction at rest may be higher than the normal resting rate of sino-atrial node firing. Select the best explanation for this phenomenon.

Answer 15

Atrial contraction rate is changed by an increase in vagal supply

= Reduced cardiac output elicits a reflex tachycardia

Sino-atrial node activity is replaced by an ectopic focus

The sino-atrial node is re-activated by circus movements

The sino-atrial node is released from overdrive suppression

Question 16

Poor living and working conditions contribute to the poorer health status of people in the lower social classes. Select the type of explanation for the relationship between social class and health that corresponds best to this statement.

Answer 16

Artefact

Cultural and behavioural

= Materialist

Social mobility: Incorrect. This refers to the observation that the healthy are more likely to move up social hierarchy.

Social selection

Question 17

Select the artery that is most commonly occluded in myocardial ischaemia.

Answer 17

Circumflex artery

= Left anterior descending artery: Because this artery is narrower, so more likely to have turbulent flow, which can cause atheroma. Higher blood pressures mean that with each beat, arteries throughout the body swell and stretch more than they would normally. This stretching can injure the endothelial, the delicate lining of all arteries, causing arteries to become stiffer over time. The atheroma develops in the intima (the layer directly under the endothelium). Injured endothelium allows LDL and white blood cells to enter the lining of the artery. The cholesterol and cells build up in the artery wall, eventually forming the plaque of atherosclerosis.

Marginal artery

Posterior descending artery

Right coronary artery

Question 18

Select the best description for why inspiration “splits” the second heart sound.

Answer 18

Filling of the ventricles has fast and slow components

= The aortic valve closes before the pulmonary valve

The mitral valve closes before the tricuspid valve

The pulmonary valve closes before the aortic valve

The tricuspid valve closes before the mitral valve

Question 19

Select the classification of heart block in the limb lead II ECG strip shown in the image below.

Answer 19

First degree heart block

Second degree heart block (Mobitz type I)

Second degree heart block (Mobitz type II)

= Third degree heart block above AV node: The QRS complex is independent of the P waves. The QRS complex is normal in shape and duration and occurs at a rate indicative of the AV node being the pacemaker of the ventricles. The correct answer is therefore third degree heart block above the AV node. If it was below the AV node the QRS wave would be wider as the route the electrical activity would have to take a longer, less direct route across the ventricles.

Third degree heart block below AV node

Question 20

A 3-year-old male presents with an atrial septal defect. Select the structure involved in this condition.

Answer 20

Ductus arteriosus

= Foramen ovale

Ligamentum arteriosum

Sinus venosus

Truncus arteriosis

Question 21

A 60-year-old male suffered a myocardial infarction and had a heart rate of 40beats/min. His right coronary artery was occluded. Select the structure that is most likely to be affected.

Answer 21

Atrioventricular node: The artery occluded and subsequent effect on heart rate indicate that the AV node is most likely to have been affected and the bundle branches have taken over as the pacemaker of the ventricles. The SA node may also have been affected, but this on its own would explain the such a low heart rate which could still be up to 60 beats per minute with an unaffected AV node.

Bundle of His

Purkinje fibres

Right bundle branch

Sinoatrial node

Question 22

A mother gives birth to a baby who dies within a week of delivery. Autopsy reveals severe cardiac malformations. Select the most likely underlying abnormality.

Answer 22

Atrial septal defect

Coarctation of the aorta

Fallot’s tetralogy

= Transposition of great arteries: The most likely underlying abnormality in this case, would be transposition of the great arteries which can be fatal in the early weeks of life if not treated, unlike Fallot’s Tetrology which only presents later, not likely to cause mortality within a week.

Ventricular septal defects

Question 23

A 50-year-old woman has presented to her local emergency department as she is having persistent palpitations. An ECG shows a fast irregular rhythm with no visible P waves.

Select the cardiac arrhythmia this woman is most likely to have.

Answer 23

Asystole
Atrial flutter
= Atrial fibrillation
Ventricular fibrillation
Ventricular tachycardia

Question 24

A 57-year-old male develops severe crushing chest pain. He is diagnosed with a myocardial infarction based on his electrocardiogram and troponin levels. One week later, he again complains of precordial pain and develops a fever of 38.9°C. Auscultation reveals a loud friction rub. Select the most likely diagnosis in this case.

Answer 24

Caseous pericarditis
Fibrinous pericarditis: increase in friction.
Hemorrhagic pericarditis 
Purulent pericarditis 
Serous pericarditis

Question 25

A 66-year-old man has dizziness on standing from his chair or bed. He visits his GP who, after careful history and examination, identifies an ejection systolic murmur, suggestive of aortic stenosis.

Select the surface position at which this murmur would be best auscultated.

Answer 25

Left sternal edge, fourth intercostal space

Left sternal edge, second intercostal space

Right midclavicular line, fifth intercostal space

Right sternal edge, fourth intercostal space

= Right sternal edge, second intercostal space: The infundibulum is closest to the thoracic cage and is the best position for auscultation of the pulmonary area.

Question 26

A 7-year-old boy was admitted to the paediatric ward with suspected meningitis. You are doing the ward round when the emergency buzzer sounds. You reach his room where the team have already started CPR. He goes on to have successful defibrillation.

Select the description that best explains defibrillation.

Answer 26

= Involves delivering an adequate electrical current through the heart causing simultaneous depolarisation of all myocardial cells that are at that moment fully refractory: this is defib, the others involve changing the rhythm.

Involves delivering an electrical current that is synchronised to convert an abnormal rhythm to a normal sinus rhythm.

Involves delivering regular electrical current to improve cardiac haemodynamic function until the underlying problem resolves or a permanent pacing strategy is applied

Involves sensing intrinsic cardiac electric potentials, and, if these are too infrequent or absent, transmit electrical current to the heart to stimulate myocardial contraction

Involves the use of a device that is capable of storing ECG data automatically in response to a significant arrhythmia or in response to patient activation

Question 27

An 82-year-old male presents to his GP with chest pain, shortness of breath and syncopal episodes. He had rheumatic fever as a child. On examination, he has a slow-rising, flat pulse and a narrow pulse pressure. A murmur is heard.

Select the murmur that was most likely heard.

Answer 27

Continuous Machinery Murmur (Across the back)

Early Diastolic Murmur (In full expiration with patient sat forward)

= Ejection Systolic Murmur (2nd Intercostal space, right sternal edge) : aortic stenosis

Friction Rub Murmur. (5th Intercostal space, left sternal edge)

Pansystolic Murmur (5th Intercostal space, mid-axillary line)

Question 28

Select the major cause of chronic heart failure in United Kingdom.

Answer 28

Anaemia
Haemorrhagic shock
= Ischaemic heart disease
Myocarditis
Valvular heart disease

Question 29

From the labels A-E in the diagram of a normal ECG in below, select the measurement that increases to be greater than 0.2 seconds in 1st degree heart block.

Answer 29

Answer is PR interval, not PR segment!

Question 30

Mr Smith is a 70-year-old man who has visited his GP as he has been feeling increasingly breathless and has had the occasional pain in his chest. He takes medication for high blood pressure and high cholesterol.

On examination, the GP hears a loud ejection systolic murmur primarily at the right upper sternal edge, which radiates to his carotid arteries.

A problem in what structure of the heart is leading to Mr Smith’s signs and symptoms?

Answer 30

= Aortic valve: Aortic valve stenosis is described above.

Patent foramen ovale

Mitral valve

Pulmonary valve

Tricuspid valve