Cardiology 2

Question 1

What creates a bouncing pulse?

Answer 1

aortic regurgitation, anaemia, sepsis cause large stroke volume typically causing a bouncing pulse with a high amplitude and wide pulse pressure

Question 2

what may cause a slow rising pulse?

Answer 2

aortic stenosis

Question 3

what is the JVP determined by?

Answer 3

determined by right atrial pressure

Question 4

what does tricuspid regurgitation do to the JVP wave form?

Answer 4

giant V waves

Question 5

Where does the right atrium receive blood from?

Answer 5

the superior and inferior vena cavae

Question 6

where does the left atrium receive blood from?

Answer 6

the four pulmonary veins

Question 7

what are the atrium and ventricles separated by?

Answer 7

the annulus fibrosus - this forms a skeleton for the AV valves and electrically insulates the atria from the ventricles

Question 8

what is the cardiac silhouette formed by on CXR

Answer 8

the left is formed by the aortic arch, pulmonary trunk, the left atrial appendage and the LBV

The right the silhouette is formed by the RA and the superior and inferior venae cave and the lower right border is formed by the RV

Question 9

where to the left and right coronary arteries arise from?

Answer 9

the left and right sinuses of the aortic root distal to the aortic valve

Question 10

What does the left coronary artery divide into ?

Answer 10

left anterior descending (which runs in the inter ventricular groove
left circumflex artery which runs posteriorly in the atrioventricular groove

Question 11

Which part of the heart does the LAD supply?

Answer 11

supply to the anterior part of the septum and the anterior, lateral and apical walls of the LV.

Question 12

What part of the heart does the circumflex supply?

Answer 12

the posterior and inferior segments of the LV

Question 13

where does the RCA run and what does it supply?

Answer 13

runs in the right atrioventricular groove
gives branches that supply the RA, RV and inferoposterior aspects of the LV

Question 14

Where does the posterior descending artery run and what does it supply?

Answer 14

it runs in the posterior interventricular groove and supplies the inferior part of the of the interventricular septum
This vessel is a branch of the RCA in 90% of people
in the remainder of people it is supplied by the circumflex

Question 15

which coronary artery supplies the SA and AV node?

Answer 15

the RCA supplies the SA node in 60% of individuals and the AV node in 90% of individuals.

Proximal occlusion of the RCA can result in sinus bradycardia and AV nodal block

Question 16

Where is the SA node located?

Answer 16

it is situated at the junction of the superior vena cava and the right atrium

Question 17

Function of SA node?

Answer 17

specialised arterial cells that depolarise at a rate influenced by the autonomic nervous system and by circulating catecholamines.
During normal sinus rhythm, this depolarisation waves propagates through the atria via sheets of atrial myocytes.

Question 18

How is depolarisation conduction from atrial to ventricles?

Answer 18

through the AV node
the annulus fibrosus forms a conduction barrier between the atria and the ventricles, preventing transmission of conduction except through the AV node.

Question 19

where is the AV node located and what is its function ?

Answer 19

The AV node is a midline structure extending from the right side of the inter arterial septum , penetrating the annulus fibrosus anteriorly. It conducts relatively slowly, producing necessary time delay between atrial and ventricular contraction.

Question 20

what is the His-purkinje system composed of ?

Answer 20

the bundle of His extending from the AV node in the inter ventricular septum, the right and left bundle branches passing along the ventricular septum and into the respective ventricles
The anterior and posterior fascicles of the left bundle branch
The smaller Purkinje fibrest that ramify through the ventricular myocardium

The tissues of the His-Purkinje system conduct very rapidly and allow near-simultaneous depolarisation of the entire ventricular myocardium

Question 21

Nerve supply of the heart

Answer 21

The heart is innervated by both sympathetic and parasympathetic fibres.
Adrenergic nerves from the cervical sympathetic chain supply muscle fibres in the atria and ventricle and the eletrical conducting system

Parasympathetic pre-ganglionic fibres and sensory fibres reach the heart through the vagus nerve.

Cholinergic nerves supply the AV and SA nodes via muscarnic (M2) receptors

Question 22

What does activation of beta 1 adrenoreceptors in the heart result in ?

Answer 22

Activation of beta 1 adreoceptors in the heart results in positive inotropic and chronotropic effects

Question 23

what is inotropic?

Answer 23

Increase cardiac contractility, which improves cardiac output and helps maintain blood pressure and perfusion to the body. Inotropes work by acting on the cardiomyocytes, or heart muscle cells. Positive inotropes increase the force of the heartbeat, while negative inotropes decrease it

Question 24

What is chronotrope?

Answer 24

Change the heart rate and rhythm by affecting the heart’s electrical conduction system and the nerves that influence it. Positive chronotropes increase heart rate, while negative chronotropes decrease it. Chronotropes are used to treat conditions such as hypertension, angina, and arrhythmias

Question 25

what does activation of beta 2 adrenoceptors result in?

Answer 25

activation of beta 2 adrenoceptors in vascular smooth muscle causes vasodilation

Question 26

what causes base heart rate and what causes it to increase

Answer 26

Under resting conditions, vagal inhibitory activity ptr-dominates and the heart rate is slow Adrenergic stimulation, associated with exercise, emotional stress, fever and so one, causes the heart rate to increase.

Question 27

what can happen in disease states to the nerve supple to the heart?

Answer 27

In disease states the nurse supply to the heart may be affected. for example in heart failure the sympathetic system may be up-regulated and DM the nerves themselves may become damaged by autonomic neuropathy so that there is little variation in heart rate.

Question 28

Myocardial contraction?

Answer 28

Each myocyte branches and integrates with adjacent cells An intercalated disc permits electrical conduction via gap junctions and mechanical conduction via the fascia adhering, to adjacent cells The cross links between actin and myosin molecules contain ATPase, which breaks down ATP to provide energy for the contraction During the plateau phase of the action potential, calcium ions enter the cell and are mobilised from the sarcoplasmic reticulum. They bing to the troponin and thereby precipitate contraction by shortening the sarcomere through through the intedigitation of the actin an myosin molecules

Question 29

what regulates the cardiac muscle contraction

Answer 29

the force of cardiac muscle contraction, or the inotropic state, is regulated b the influx of calcium ions through slow calcium channels

Question 30

what is ANP?

Answer 30

atrial natueritic peptide secreted by atrial myocytes in response to stretch vasodilator - reduces BP Acts as a diuretic - promoted renal excretion of water and sodium

Question 31

What is BNP

Answer 31

produced by ventricular cardiomyocytes in response to stretch

Question 32

what does Neprilysin do?

Answer 32

breaks down ANP and BNP and other proteins - in doing so acts a vasoconstrictor

Question 33

what is Poiseuille's law?

Answer 33

resistance Is inversely proportional to the fourth power of the radius .

Question 34

what leads to vasoconstriction and vasodilation?

Answer 34

Neurogenic constirction operates by alpha adreoceptors on vascular smooth muscle Dilation via muscaranic and beta 2 adrenoceptors Systemically and locally released vasoactive substances influence tone; vasoconstrictors include noradrenaline, angiotensin II and endothelin 1 Adenosine, bradykinin, prostaglandins and nitric oxide are vasodilators

Question 35

what is the role of the endothelium ?

Answer 35

Plays a vital role vascular homeostasis It synthesis and releases many vasoconstrictive mediators that cause vasodilation, including nitric oxide, prostacyclin, endothelium derived hyper polarising factor and vasoconstriction including endothelin-1 and angiotensin II. It has a major influence on the key regulatory steps in the recruitment of inflammatory cells and on the formation and dissolution of thrombus Once activated the endothelium expresses surface receptors such as E-selectin, intercellular adhesion molecule type 1 and platelet-endothelial cell adhesion molecule type 1 (PECAM-1) which mediate rolling, adhesion and migration of inflammatory leucocytes into the subintima. The endothelium stores vWF which promotes thrombus formation by linking lately adhesion to denuded surfaces

Question 36

what may damage to the endothelium lead to ?

Answer 36

Damage to the endothelium may disturpt the balance of regulation of vascular tone and BP and lead to vascular dysfunction, tissue ischaemia and hypertension

Question 37

What happens when an intravascular thrombus forms?

Answer 37

once intravascular thrombus forms, tissue plasminogen activator is rapidly released from a dynamic storage pool within the endothelium to induce fibrinolysis and thrombus dissolution

Question 38

what happens to JVP during inspiration and expiration?

Answer 38

JVP falls on inspiration Rised on expiration

Question 39

what happens to BP and HR during inspiration and expiration?

Answer 39

Inspiration BP falls and HR increases Expiration BP rises and HR slows

Question 40

what is pulses paradoxus?

Answer 40

exaggerated fall in BP during inspiration seen in severe airway obstruction (asthma/COPD) Also characteristic of cardiac tamponade

Question 41

what does the P wave represent on ECG?

Answer 41

atrial depolarisation

Question 42

What is the normal PR interval ?

Answer 42

0.12-0.2 seconds it reflects the duration of AV nodal conduction

Question 43

What is the QRS complex?

Answer 43

ventricular myocardial depolarisation

Question 44

what is the t wave?

Answer 44

ventricular repolarisation

Question 45

what is considered a wide QRS?

Answer 45

>0.12 seconds

Question 46

what is a normal QT interval

Answer 46

male < 0.44 seconds Female < 0.46 seconds

Question 47

what causes prolonged QTC ?

Answer 47

congenital long QT syndrome low potassium low magnesium low calcium some drugs

Question 48

Indications of exercise ECG

Answer 48

to confirm diagnosis of Angina To evaluate stable angina to assess prognosis following MI To assess outcome after coronary revascularisation To diagnose and evaluate the treatment of exercise induced arrhythmias

Question 49

What are the high risk finding on exercise ECG?

Answer 49

low threshold for ischaemia fall in BP on exercise Widespread, marked or prolonged ischaemia on ECG Exercise induced arrhythmia

Question 50

when is stress testing contraindicated?

Answer 50

ACS decompensated heart failure severe HTN

Question 51

what calculation is used to estimate the pressure gradient across a valve?

Answer 51

Bernoulli equation =4x(peak velocity (m/sec))2

Question 52

What is TOE useful for?

Answer 52

useful for imaging structures like the left atrial appendage, pulmonary veins, thoracic aorta and intertribal septum which may be poorly visualised on TTE

Question 53

what is a stress echo?

Answer 53

used in patients with suspected CAD who are unsuitable for exercise stress testing - such as mobility problems or pre-existing bundle branch block Give a high dose of an inotrope such as dobutamine myocardial segments with poor perfusion will become ischaemic and contact poorly under stress manifesting a wall motion abnormality on the scan Low dose dobutamine can induce contraction in hibernating myocardium such patients may benefit from bypass surgery or PCI

Question 54

when is CTCA useful?

Answer 54

in the initial assessment of patients with chest pain and a low or intermediate likelihood of disease, it has a high negative predictive value in excluding coronary artery disease

Question 55

What is CMR useful for?

Answer 55

useful for imaging the aorta, suspected dissection and can define anatomy of the heart and great vessels in patients with congenital heart disease Useful for detecting infiltrative conditions affecting the heart and good to evaluate the RV which is difficult by echo physiological data can be obtained Erin the signal returned from moving blood to allow quantification of blood flow across regurgitant or stenotic valves It is also possible to asses regional wall motion in patients with suspected coronary disease or cardiomyopathy Myocardial perfusion and viability can be assessed Delayed enhancement can be used to identify myocardial scarring and fibrosis

Question 56

What is left heart catheterisation used for?

Answer 56

it involves assessing there arterial circulation, usually through the radial artery to allow catheterisation of the aorta, LV and coronary arteries. Used for coronary angio to give info about extent and severity of coronary stenosis, thrombus and calcification Left ventriculography can be performed during the procedure to determine the size and function of the LV and to demonstrate MR.

Question 57

what is right heart catheterisation used for?

Answer 57

to assess the right heart and pulmonary artery pressures to detect intracardiac shunts by measuring oxygen saturation in different chambers