Cardiology Flashcards
1
Q
What is the diastolic phase of the cardiac cycle?
A
Heart chamber is in a state of relaxation and fills with blood
2
Q
What is the systolic phase of the cardiac cycle?
A
The heart chambers contract and pumps blood to body via the arteries
3
Q
What valves close in S1
A
Mitral and tricuspid
4
Q
What are the three shunts in fetal circulation?
A
Foramen ovale
Ductus arteriosus
Ductus venosus
5
Q
What do the fetal shunts become in the adult structure?
A
Foramen ovale - Fossa Ovalis
Ductus anteriosis- Ligamentum Arteriosum
Ductus Venosus - Ligamentum Venosus
6
Q
What is the mechanism of action of aspirin?
A
(Anti-platelet)
Cox-1 inhibitor
Inhibits the production of tromboxane A2
7
Q
What is the mechanism of action of Clopidogrel?
A
Inhibits ADP-mediated platelet activation
Irreversibly inhibits binding if ADP to the purine receptor on platelets
8
Q
Complications of acute MI
A
Ischemic (angina, re-infarction)
Mechanical (heart failure, cardiogenic shock)
Arrhythmic (atrial or ventricular arrhythmia, SA or AV node dysfunction)
Embolic (CNS or peripheral)
Inflammatory (pericarditis)
Sudden cardiac death
9
Q
Where to auscultate for the Aortic valve?
A
Medial end of the 2nd right intercostal space
10
Q
Where to auscultate for the Pulmonary valve
A
Medial end of the second left intercostal space
11
Q
Where to auscultate for the Tricuspid valve?
A
4th intercostal space at the lower left sternal border
12
Q
Where to auscultate for the Mitral valve?
A
5th left intercostal space at the mid- clavicular line
13
Q
What does JVP determine?
A
whether right atrial pressure is high or normal
14
Q
What cardiac disease impacts electricity of the heart
A
Arrhythmia
15
Q
What happens to vessel walls in hypertension?
A
Can damage arteries, making them less elastic.
Arterial walls thicken as a response to wall stress
16
Q
Where do the coronary arteries originate from?
A
The root of the aorta
17
Q
The left main coronary artery divides into
A
1) the left anterior descending artery
2) the circumflex artery
18
Q
Where does the right coronary artery supply blood to?
A
The right ventricle, the right atrium, the SA node, AV node
19
Q
What is cardiac output?
A
The amount of blood pumped by the heart in a minute
20
Q
What are the determinants of cardiac output?
A
Heart rate, contractility, preload, and afterload
21
Q
How do you measure Ejection Fraction (EJ)?
A
Stroke volume over End diastolic volume
22
Q
Which valves close when the ventricles contract?
A
Mitral and tricuspid
23
Q
Layers of the heart
A
Endocardium
Myocardium
Epicardium
24
Q
What is the pericardium?
A
fibro-serous sac that encloses the heart and the roots of the great vessels
25
What is the definition of myocardial infarction?
Death of cardiac tissue (myocardial necrosis)
26
What is the definition of angina?
Chest pain or discomfort due to inadequate supply of oxygen to the heart
27
Defining factors for stable angina?
1) Constricting discomfort in the front of the chest/ neck/ shoulders/ arms
2) it is precipitated by physical exertion
3) Relieved by rest or GTN spray in 5 minutes
28
ECG definition of a STEMI
STEMI = >1mm ST elevation in at least 2 consecutive limb leads
Or >2mm ST elevation in at least 2 consecutive precordial leads
Or new onset left-bundle branch block
29
What is cardiac preload?
The force that stretches the cardiac myocytes prior to contraction. It is the volume of blood in ventricles at end of diastole
30
What is cardiac afterload?
Pressure or resistance the left ventricle has to overcome to eject blood (squeeze)
31
Valves on left hand side of heart?
Aortic (AV) and mitral (SL)
32
Chronic management of patient after MI
-Aspirin
-Second antiplatelet – Clopidogrel, prasugrel or ticagrelor
-B-blocker – slows HR and decreases risk of arrhythmia
-ACE inhibitor – decrease LV dilation reducing preload
-Statin
33
Acute management of MI
MONA
Morphine –> given for pain relief (+ metoclopramide antiemetic)
Oxygen –> given if SpO2 is below 94%
Nitrates –> GTN given to vasodilate veins and reduce preload on the heart
Aspirin –> loading dose of 300mg given
34
Describe the coronary artery territories on an ECG
Leads I , aVL , V5 , V6 (Lateral Territory )=> Circumflex artery
Leads II, III, aVF (Inferior Territory) => Usually Right Coronary Artery but Left Circumflex artery in ‘left dominant’
Lead V1-V4 (Anterior Territory) => LAD artery
35
Diagnosis of STEMI
ECG: ST elevation (>1-2 mm in at least two contiguous leads)
Or new LBBB
Troponin: Raised
36
Management of STEMI
- Within 120 minutes -> Emergency Coronary Angiography +/- PCI
- If no PCI in 2 hours, fibrinolytic agent => Coronary Angiography +/- PCI in 2-24 hours after fibrinolysis.
- DAPT
- Anti thrombotic agents
37
What is Coronary Angiography
Insertion of a catheter via the femoral artery or radial artery.
The catheter passed to the coronary artery vessels with x-rays for guidance and contrast dye is injected to allow visualisation of the coronary artery.
Balloon catheter can be inserted to open up a blockage and a stent can be inserted into the blocked artery.
38
Ischemia Vs Infarction
Ischemia: blood flow decreased (results in hypoxia -> insufficient oxygen)
Infarction: blood flow cut off (results in necrosis)
39
Risks of coronary angiography
Bleeding
Infection
Stroke
Haematoma
Contrast-induced nephropathy (CIN)
Myocardial infarction
Hypotension
Arrhythmias
40
Underlying mechanism of action of Beta blockers?
Decrease HR and contractility therefore decreasing oxygen demand of heart.
Contributes to electrical stability.
41
Underlying mechanism of morphine in treatment of ACS
Reduces myocardial oxygen demands by decreasing chest pain and anxiety
42
Underlying mechanism of CABG in treatment of ACS
Restores coronary blood flow by using a healthy patant artery to bridge circulation around an occlusive lesion in atherosclerotic coronary vessel
43
Underlying mechanism of Nitrates in treatment of ACS
Decrease anginal symptoms by inducing coronary vasodilation and improving myocardial oxygen supply, and by decreasing myocardial oxygen demand by decreasing preload through venodilation
44
Underlying mechanism of Ca Channel blockers in treatment of ACS
Decrease myocardial oxygen demand by decreasing heart rate and contractility, decreasing wall stress via decreased blood pressure, and decreasing preload via venodilation
45
What is hypoxemia?
Reduced partial pressure of oxygen in the blood
46
What is hypoxia?
Reduce oxygen flow to tissues
47
Causes of Hypoxia
**CHAD**
**C**O poisoning
**H**ypoxemia
**A**naemia
**D**ecreased cardiac output
48
Causes of hypoxemia
Decreased inspired oxygen
Hypoventilation
V/Q mismatch
R -> L shunt
Diffusion Limitation
49
Reasoning for chest pain symptoms in ACS
Decreased blood flow-> Decrease in oxygen to myocardium -> Metabolic products such as lactate, serotonin and adenosine accumulate.
May activate peripheral pain receptors in the C7 to T4 distribution
50
Indications for an ICD (Implantable Cardioverter Defibrillator)
People at risk of sudden death from arrhythmias including those with:
History of cardiac arrest
Tachycardia or Bradycardia
Cardiomyopathy
Reduced pumping function of heart
51
Where is the mitral (bicuspid) valve located?
Between LA and LV
52
Where is the pulmonary valve located?
Between the RV and pulmonary artery
53
Where is the aortic valve located?
Between LV and aorta
54
The great cardiac vein commences where
Near apex of heart in anterior part of interventricular groove
55
What part of heart does the great cardiac vein drain?
LA and LV (territory supplied by left coronary artery)
56
Most people are right dominant (80-85%). What does this mean?
The posterior descending artery (PDA) is supplied by the right coronary artery (RCA)
57
What is co-dominant circulation ?
Contribution from both the right coronary artery and left circumflex artery (20%)
58
What is left dominant circulation?
The PDA is supplied by the left circumflex artery (LCA).
59
What is coronary dominance?
The vessel which gives rise to the posterior descending artery (PDA)
60
Where does the posterior descending artery supply blood to?
The posterior one-third of the interventricular septum.
61
Where does left anterior descending (LAD) artery supply blood to?
The anterior two-thirds of the septum.
62
The SA and AV nodes are supplied by which artery?
Right coronary artery
63
The left coronary artery divides into which two arteries?
The circumflex artery and left anterior descending (LAD) artery
64
What do the coronary veins do
Take the oxygen poor blood that has been used by the muscles of the heart and return it to RA
65
An embolism in the circumflex branch of LCA is most likely to cause ischemia in which area of heart?
Posterior part of left ventricle
66
What area does circumflex artery supply?
The left atrium and the posterior-lateral aspect of the left ventricle
67
What are the ECG features of third degree heart block?
No relation between P waves and QRS.
68
What mechanism causes the third heart sound?
Rapid filling of the ventricles.
NOTES
Coincides with ventrticular filling, heard in early diastole in patients with heart failure.
Best heard with the bell of the stethoscope over the apex.
Sounds like 'Ken-tu-ckey' i.e. S1-S2-S3.
69
Which bedside tests may be useful in a patient with hypertension?
1. Opthalmoscopy may show hypertensive retinopathy.
2. Urine dip may show blood or protein.
3. ECG may show left ventricular hypertrophy.
70
What are the adverse effects of beta-blockers?
1. CVS e.g. exacerbation of pulmonary oedema, hypotension, cold peripheries.
2. Resp e.g. bronchoconstriction.
3. CNS e.g. tiredness, sexual dysfunction.
71
What is a Janeway lesion?
A skin lesion seen in infective endocarditis.
72
What are the ECG features of LVH?
(S wave in V1 plus R wave in V5/V6) ≥ 3.5mV (Sokolow-Lyon criteria).
73
Which 3 diseases does 'acute coronary syndrome' include?
1. Unstable Angina.
2. NSTEMI (non ST elevation MI).
3. STEMI (ST elevation MI).
74
What are the ECG features of second degree heart block?
Intermittent dropped QRS, with each QRS still preceded by a P wave.
75
Which leads on the ECG represent the inferior wall of the heart?
II, III, and aVF
76
Mechanism of action of Ticagrelor
anti-platelet medication that prevents activation of the glycoprotein GPIIb/IIIa complex (an essential mechanism for platelet aggregation).
This results in ADP not being able to bind to the GPIIb/IIIa complex and platelet aggregation being limited
77
Mechanism of action of Rivaroxaban (DOAC)
Direct inhibition of clotting factor Xa
78
Warfarin inhibits Vitamin K dependant clotting factors. Which factors are these
Factor II, Factor VII, Factor IX and Factor X.
79
Where does the LAD artery travel?
It travels along the interventricular septum on the anterior surface of the heart to reach the apex of the heart.
80
Which valves are attached to chordae tendinae?
Tricuspid and Mitral
81
Occlusion of the LAD causes anteroseptal myocardial infarction. Where would changes show on ECG?
Leads V1-V4.
82
Occlusion of the right coronary artery causes inferior MI. Where would these changes be seen on an ECG?
Leads II, III and aVF.
83
Thoracic spinal levels at which the three major structures pass through the diaphragmatic apertures is
T8: vena cava has 8 letters
T10: oesophagus has 10 letters
T12: "aortic hiatus" 12 letters
84
What/ where is the Crista Terminalis?
A well-defined fibromuscular ridge formed by the junction of the sinus venosus and primitive right atrium that extends along the posterolateral aspect of the right atrial wall.
85
Where does the RA receive deoxygenated blood from?
The superior vena cava (SVC), the inferior vena cava (IVC), the coronary sinus (covered by the Thebesian valve), and the Thebesian veins.
86
Which blood vessels may be removed and used in coronary artery bypass grafting (CABG)?
Radial artery or saphenous vein
87
The right atrium leads into the right ventricle through which valve?
Tricuspid
88
3 layers of the pericardium
1) Fibrous
2) Parietal
3) Visceral
89
two divisions of serous pericardium
Parietal layer
Serous layer
90
What segment of ECG represents ventricular repolarization?
T wave
91
What does P wave represent?
The wave of depolarisation that spreads from the SA node throughout the atria
92
What does the isoelectric period after the P wave represent on ECG?
The time in which the impulse is travelling to the AV node
93
What does QT interval represent on ECG?
Both ventricular depolarization and repolarization to occur, and therefore roughly estimates the duration of an average ventricular action potential
94
What does the QRS interval represent?
Ventricular depolarization
95
What does the anterior tibial artery continue as in the foot?
The dorsalis pedis artery
96
ECG changes in II, III, aVF would be most likely caused by a lesion of the
Right coronary artery
97
What are most important investigations when assessing a patient with chest pain
ECG
cardiac markers e.g. troponin
98
ECG changes in V1-V4 correlate to which coronary artery?
LAD
99
ECG changes in lead I, V5 and V6 correlate to what coronary artery?
Left Circumflex artery
100
What is hyponatraemia?
Low concentration of sodium in the blood
101
Bifurcation of the abdominal aorta:
L4
102
Mitral stenosis is likely to cause what difference in heart sound
A loud S1
103
Quiet S1 may be
Mitral regurgitation
