Cardiac Flashcards

1
Q

Physiology of Coronary artery disease

A

plaques form in coronary arteries due to atherosclerotic deposits

this occludes the coronary artery supplying the heart

less blood flow to heart → myocardium necrosis due to lack of oxygenation anwd blood flow → acute MI

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Difference between subendocardial and transmural infarct

A

subendocardial: NSTEMI - plaque ruptures to cause partial occlusion to artery, infarct to subendocardial myocardium→ myocardial ischaemia + angina

transmural: STEMI - complete occlusion of artery, → myocardial necrosis + MI

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What drug classes are contraindicated in HF?

A

NSAIDs
CCBs
Trimethoprim
Antidepressants
Drugs causing hyperkalemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is angina definition?

A

temporary loss of blood supply to heart, causing chest pain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What causes angina pectoris (stable)?

A

stable plaque
chest pain brought on by exertion (exercise)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What causes unstable angina?

A

haemodynamically unstable plaque

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the 3 stages of atheroma formation in atherosclerosis?

A

3 stages of atheroma formation:

1) fatty streak formation - lipids deposited in tunica intima layer → deposits + vascular injury → inflammation, ↑ permeability and WBC recruitment to site. Macrophages phagocytose the lipid → foam cell production

2) fibrolipid plaque formation - lipid in tunica intima layer stimulated fibrocollagenous tissue formation → thinning of muscular media

3) complicated atheroma - plaque calcifies as lipid deposits acquire Ca2+ → rupture activates thrombosis (clot formation)

partial occlusion → myocardial ischaemia + angina

complete occlusion → myocardial necrosis + MI

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Primary v secondary MI?

A

1°: primary coronary artery event due to atherosclerosis

2°: secondary due to imbalance in myocardial O2 supply and demand w/o atherothrombosis (eg severe anaemia, coronary artery spasm)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are causes of left-sided heart failure?

A

CAD

HTN, aortic valve disease, mitral valve disease - ↑ workload (afterload)

MI = ↓ myocardial mass

cardiomyopathy eg amyloid, sarcoid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are causes of right sided heart failure?

A

Pulmonary HTN
tricuspid valve disease
pulmonary valve disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Conditions which increase afterload in Right sided HF:

A

increased afterload:

pulmonary HTN - pulmonary vessels are constricted idiopathic

PE in the pulmonary circualtion - inc pressure in pulmonary artery (similar to pulmonary HTN)

cor pulmonale 2 ° to COPD - less ventilation due to hypoxic vasoconstriction of pulmonary vessels (eg capillaries in alveoli), pulmonary artery pressure increases, therefore RV afterload increases as RV must pump more blood to overcome the pulmonary pressure, causes right-sided hyeprtrophy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is SV?

A

amount of blood ejected from LV ventricle with each contraction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Pathophysiology of HF with reduced ejection fraction (HF-rEf) - SYSTOLIC

A

occurs in LV myocardium where blood accumulates in the LV (blood cant get pumped out of heart)

increased preload (FS LAW)

reduced contractility (due to thin, weak myocardium)

Ef less than or equal to 40% (proportion of blood being pumped out of the ventricle)

overall reduced CO

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is preload?

A

increase in ventricular filling = increased in myocardium stretch = increased venous return

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What 3 physiological factors affect SV?

A

preload (∝ to SV)

contractility (∝ to SV)

afterload (NOT ∝ to SV)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is pulse pressure?

A

difference between systolic and diastolic BP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is afterload?

A

pressure that ventricles must overcome to push blood into aorta

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

CO equation

A

CO = HR x SV
(amount of blood pumped in 1 min) = (no of times heart beats in 1 min) x (amount of blood ejected from LV ventricle with each contraction)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

afterload is same as what pressure?

A

diastolic BP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Equation for CO

A

CO = HR x SV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Physical exam signs of Right-sided HF

A

oedema in feet, ankles, legs (sacrum if bed bound)

ascites (fluid in abdo cavity)

hepatomegaly (enlarged, palpable, tender)

raised JVP

Exercise intolerance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Signs and symptoms of Left-sided HF

A

Dyspnoea
Orthopnea (dyspnoea when lying down)
PND
Bibasal creps
Cardiomegaly (displaced apex beat)
Pulmonary congestion and oedema (crackles)
Exercise intolerance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Physiology of Diastolic HF or ‘HF with Preserved Ejection Fraction (HF-PEF)’

A

HF when the myocardium is near-normal

Ef greater than or equal to 50%

the issue lies in filling - decreased filling activity (preload)

increased afterload

myocardium is stiff, non-compliant (doesnt want to stretch)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Conditions which cause decreased preload in diastolic HF?

A

can occur 2° to ischaemic Heart disease/MI

  • muscle replaced with fibrous tissue in ischaemic heart disease
  • this stiffens muscle

restrictive cardiomyopathy (amyloidosis)
- muscle infiltrated with light chains called amyloid deposits accumulate in the myocardium
- myocardium loses ability to stretch/contract

cardiac sarcoidosis
- rare conditions where immune cells accumulate into granulomas and deposit
- causes muscle wall to stiffen

constrictive pericarditis
- when granulation tissue forms in the pericardium
- causes loss of pericardial elasticity
- this leads to restriction in the ventricular filling

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Conditions which increase afterload in diastolic HF?
HTN: high pressure in the aorta so the ventricle increases cardiomyocyte size to compensate =more sarcomere = bigger cell = more power = more blood needing to be pumped out aortic stenosis (aortic valve disease): aortic valve stiffens, LV requires more contractile force to pump blood past it, and myocyte increases
26
Diastolic HF can easily progress into systolic HF
27
What happens if you constantly increase preload in right sided HF?
constantly increased preload over time myocardium constantly hypertrophies loses contractility myocardium weakens over time → RIGHT HF
28
Conditions which increase preload in right sided HF:
Pulmonary valve regurgitation: if pulmonary valve damaged, instead of going to the pulmonary vasculature, will accumulate in RV, expand muscle, RV weakens over time Tricuspid valve regurgitation: tricuspid valve damage, more blood backs into RA and leaks into RV, expands muscle, RV weakens over time
29
How can inferior MI result in HF?
MI: rupture of coronary artery plaque/thrombosis this decreases perfusion to that region of the myocardium therefore less contractility of that leads to HF
30
Why are IV drug users at risk of getting infective endocarditis?
IV drug users have weak tricupid valve infective carditis (bacteria eg S.aureus targets valves as they have poor blood supply, over time valves degenerate) → Right HF IE weakens already weak valves leads to Right HF
31
Compensatory mechanisms in response to low CO (sympathetic NS)
low CO from heart = low arterial BP = less blood getting around body = less tissue perfusion = risk of becoming hypoxic and eventually necrotic ELECTRICAL ACTIVITY: carotid sinus detects low BP - sends signals to medulla - activates sympathetic NS - tries to raise HR, contractility SA node stimulated → increases HR →, therefore, CO increases therefore body becomes tachycardic CONTRACTILITY: fibres stimulate b1 receptors → increases myocardiocyte contractility → inc SV → inc CO → inc BP VENOUS/ARTERIAL: a1 receptors on SMC → inc norepinephrine released → inc vasoconstriction → inc venous returns → inc preload → inc SV → inc CO → inc BP
32
Management of person with confirmed HF-rEF?
step 1 ACEi (or ARB in pts non-compliant with ACEi) and B blocker step 2 MRA (eg spironolactone) in addition to step 1 check Na and K before starting MRA , assess renal function step 3 Replace ACEi with sacubitril valsartan if the ejection fraction is less than 35%. SGLT2i - Dapagliflozin Lifestyle management
33
What is Peripheral arterial disease (PAD)?
narrowing of arteries resulting in restricted blood flow
34
What are 2 types of PAD?
Occlusive - build of plaque (atherosclerosis) or embolus - narrowed artery - reduced tissue perfusion Functional - blood vessels not working properly - intermittent arterial constriction - decreased diameter - less tissue perfusion (eg Raynauds disease - causes numbness in digits)
35
Signs of HF on CXR
A B C D E Alveolar oedema - fluffiness and grey Kerley B lines - small lines of pocket of fluid Cardiomegaly Upper lobe diversion - upper lobe pulmonary venous congestion - elevation of left atrium Pleural effusion
36
When would you start ivabradine (Specialist) for HF pts?
NYHA class II to IV stable chronic HF with systolic dysfunction AND who are in sinus rhythm with a heart rate of 75 bpm or more AND who are given ivabradine in combination with standard therapy including beta-blocker therapy, ACEi and MRAs, or when beta‑blocker therapy is contraindicated or not tolerated AND Ef less than 35%
37
What would you give a patient with LV systolic dysfunction if symptoms persist even after taking ACE inhibitors and Beta-blockers?
MRAs
38
When to give sacubitril valsartan in chronic HF pts?
Sacubitril valsartan is recommended as an option for treating symptomatic chronic heart failure with reduced ejection fraction, only in people: with New York Heart Association (NYHA) class II to IV symptoms and with a left ventricular ejection fraction of 35% or less and who are already taking a stable dose of angiotensin‑converting enzyme (ACE) inhibitors or ARBs
39
What does specialist management of HF-REF involve after steps 1 and 2?
Replace ACEI with sacubitril valsartan if Ef <35% An SGLT-2 inhibitor (empagliflozin or dapagliflozin). Ivabradine for people in sinus rhythm with a heart rate over 75 bpm AND Ef less than 35%. Hydralazine and nitrate (especially if of African-Caribbean descent). Digoxin for people in sinus rhythm to improve symptoms.
40
Aortic stenosis pathophysiology
calcification of aortic valve left blood passes fromLV to aorta LV hypertrophy over time LA also enlarges if left untreated can cause HF
41
Changes to ECG Leads II, III and aVF are associated with with artery?t
Right coronary artery
42
What is pathiphysiology of STEMI?
Complete occlusion of one or more coronary arteries due to a thrombus (made up of aggregated platelets and thrombin) reduces oxygen perfusion to myocardium = transmural infarction
43
Management of STEMI?
MONA is a mnemonic for the initial management of a STEMI. Morphine Oxygen (saturations under 94%) Nitrates Aspirin (300mg loading dose)
44
What produces ST elevation in the precordial leads (V1-3)
Left anterior descending (LAD) occlusion
45
What produces ST changes in the inferior leads (II-III-AVF)?
Right coronary artery (RCA) occlusions
46
What produces ST elevation in the lateral leads (I, AVL and V5-6)
Left circumflex artery (LCA) occlusion
47
Which heart sound is associated with aortic stenosis and how to accentuate, where does it radiate?
Mid-systolic ejection murmur Ask pt to sit forward better heard on held inspiration Radiates to carotid
48
Which heart sound associated with mitral regurgitation and how to accentuate, where does it radiate?
Holosystolic murmur Best heard in left lateral decubitus position Radiates to left axilla
49
How would you detect and diagnose pts with AF?
Perform manual pulse palpation to assess for an irregular pulse if there is a suspicion AF. This includes people presenting with any of the following: breathlessness palpitations syncope or dizziness chest discomfort stroke/TIA 12-lead ECG to cofnirm AF diagnosis
50
ECG Features of AF
Irregularly irregular rhythm No P waves Narrow QRS complex (120 ms)
51
What is orbit bleeding score for?
bleeding risk in AF pts on anticoags
52
What is HAS-BLED score for?
Estimates risk of major bleeding for patients on anticoagulation to assess risk-benefit in AF care
53
WHat causes holosystolic murmur?
whooshing sounds occurs due to mitral/tricuspid regurg, VSD
54
Common causes of mitral regurgitation?
Rheumatic fever ischemic heart disease mitral valve prolapse
55
Common causes of tricuspid regurgitation?
Rheumatic fever Infective endocarditis
56
What is ventricular septal defect (VSD)?
congenital abnormality causing blood to flow between RV and LV due to hole in AV septum
57
How is aortic stenosis murmur best describe and where is it best heard?
crescendo-decrescendo 2nd ICS, right sternal edge border radiates to carotid
58
How is mitral valve prolapse best described and where is it best heard?
mid-systolic click, followed by a mid or late-systolic murmur Heard loudest at the apex
59
How is tricuspid regurgitation murmur best described and where is it best heard?
pan systolic murmur, heard loudest at 4th ICS Lower left sternal border
60
Warfarin moa
inhibits epoxide reductase this prevents the reduction of vitamin K to its active hydroquinone form this in turn acts as a cofactor in the carboxylation of clotting factors II, VII, IX and X and protein C.
61
T or F - Leftsided HF leads to right-sided HF?
true
62
Which vessel connects the aorta and pulmonary artery in foetal life?
Ductus arteriosus
63
What is Staling law?
The Frank-Starling law states that the force or tension developed in a muscle fibre depends on the extent to which the fibre is stretched. In a clinical situation, when increased quantities of blood flow into the heart (increasing preload), the walls of the heart stretch.
64
What does Frank-Staling Law indicate in HF?
SV in a normal heart responds to changes in preload. the greater the EDV in LV, the higher SV should be due to stretch in the cardiac myocytes. This effect only occurs up to a point, as can be seen in HF, which prevents this response from occurring due to excessive stretch of the cardiac myocytes.
65
What is ejection fraction defined as?
SV/EDV = the amount of blood (as a percentag) that is pumped out of a filled ventricle with each heartbeat.
66
What is preload defined as?
the stretch of myocardium or end-diastolic volume of the ventricles
67
A 42-year-old woman presents to the clinic complaining of episodes of dizziness and light-headedness, especially when standing up quickly. On examination, her blood pressure is 120/75 mmHg while sitting and drops to 95/60 mmHg on standing. Her heart rate increases from 70 bpm to 88 bpm upon standing. She has no other significant findings on examination. What nerve is responsible for this reflex?
Vagus nerve - Vagus nerve is correct. The vagus nerve (cranial nerve X) plays a crucial role in the baroreceptor reflex, particularly in mediating the parasympathetic response. When there is a decrease in blood pressure, the vagus nerve activity is reduced, which leads to an increase in heart rate. This response is part of the body's mechanism to elevate blood pressure.
68
Which condition presents with pulsatile hepatomegaly due to the backflow of blood into the liver during the cardiac cycle?
Tricuspid regurgitation
69
What is Becks triad? (acute and chronic)
hypotension, jugular vein distension, and diminished heart sounds
70
What is cardiac tamponade?
acute tamponade triad (hypotension, venous distension, and diminished heart sounds) chronic compression triad (high venous pressure, ascites, and diminished heart sounds)