Cardiology Flashcards
Atherosclerosis definition
Combination of fatty deposits in artery walls (atheromas) and hardening/ stiffening of vessel walls (sclerosis)
Consequences of atherosclerosis
- stiffening of artery walls -> extra resistance against blood flow -> high blood pressure -> inc strain on the heart
- stenosis -> reduced blood flow (eg angina)
- plaque rupture -> thrombus -> vessel blocked -> ACS
CVD non-modifiable risk factors
- Older age
- Family history
- Male
CVD modifiable risk factors
- Raised cholesterol
- Smoking
- Alcohol consumption
- Poor diet
- Lack of exercise
- Obesity
- Poor sleep
- Stress
End results of atherosclerosis
- Angina
- Myocardial infarction
- Transient ischaemic attacks
- Strokes
- Peripheral arterial disease
- Chronic mesenteric ischaemia
What does QRISK3 calculate
percentage risk that a patient will have a stroke or myocardial infarction in the next 10 years
QRISK3: what threshold for what intervention?
10% or above - should be offered statin
How soon should lipids be checked after starting a statin?
- check 3 months after starting
- increase dose to aim for a greater than 40% reduction in non-HDL cholesterol
When should LFT’s be checked after starting a statin
- check within 3 months of starting and again at 12 months
- Statins can cause a transient and mild rise in ALT and AST in the first few weeks of use - only need to be stopped if rise is <3 times the upper limit of normal
Statin side effects
- Myopathy (causing muscle weakness and pain)
- Rhabdomyolysis (muscle damage – check the creatine kinase in patients with muscle pain)
- Type 2 diabetes
- Haemorrhagic strokes (very rarely)
Statins should be stopped when taking which medication?
macrolide abx (clarithromycin/ erythromycin)
4 methods of secondary prevention of CVD
4 A’s (depends on condition):
* Antiplatelet medications (e.g., aspirin, clopidogrel and ticagrelor)
* Atorvastatin 80mg
* Atenolol (or an alternative beta blocker – commonly bisoprolol) titrated to the maximum tolerated dose
* ACE inhibitor (commonly ramipril) titrated to the maximum tolerated dose
Clinical diagnosis of familial hypercholesterolaemia
* Family history of premature cardiovascular disease (e.g., myocardial infarction under 60 in a first-degree relative)
* **Very high cholesterol **(e.g., above 7.5 mmol/L in an adult)
* **Tendon xanthomata **(hard nodules in the tendons containing cholesterol, often on the back of the hand and Achilles)
At what threshold of sclerosis do exertional symptoms show?
70-80% sclerosed
Cause of angina
- atherosclerosis of coronary arteries -> reduced blood flow to the heart
- high oxygen demand (eg exercise) -> insufficient blood supply -> chest pain
Stable vs unstable angina
- “stable” = symptoms only come on with exertion, always relieved by rest or GTN spray
- “unstable” = symptoms appear randomly at rest -> ACS, requires immediate management
Angina investigations
- Physical examination (e.g., heart sounds, signs of heart failure, blood pressure and BMI)
- ECG (a normal ECG does not exclude stable angina)
- FBC (anaemia)
- U&Es (required before starting an ACE inhibitor and other medications)
- LFTs (required before starting statins)
- Lipid profile
- Thyroid function tests (hypothyroidism or hyperthyroidism)
- HbA1C and fasting glucose (diabetes)
What does cardiac stress testing involve?
- assesses heart function during exertion
- stress the heart with exercise (eg treadmill) or medication (eg dobutamine)
- cardiac function assessed via ECG, echocardiogram, MRI or a myocardial perfusion scan (nuclear medicine scan)
2 types of coronary angiography
- CT coronary angiography - inject contrast and take CT images
- Invasive coronary angiography - insert catheter into radial/ femoral artery, direct through to coronary arteris, inject contrast and take X-ray images (gold standard)
Stable angina management
- R – Refer to cardiology
- A – Advise them about the diagnosis, management and when to call an ambulance
- M – Medical treatment
- P – Procedural or surgical interventions
- S – Secondary prevention
3 aims of medical management of stable angina
- Immediate symptomatic relief during episodes of angina - GTN spray
- Long-term symptomatic relief - beta blocker +/- CCB, specialist drugs (isosorbide mononitrate, Ivabradine, Nicorandil, Ranolazine)
- Secondary prevention of cardiovascular disease (4A’s)
How does GTN work
- GTN causes vasodilation by relaxing vascular smooth muscle
How to use GTN spray
- Take the GTN when the symptoms start
- Take a second dose after 5 minutes if the symptoms remain
- Take a third dose after a further 5 minutes if the symptoms remain
- Call an ambulance after a further 5 minutes if the symptoms remain
What does percutaneous coronary intervention involve?
- inserting catheter into radial/ femoral artery
- guided to coronary arteries -> contrast injected to identify areas of stenosis -> dilate balloon to widen the lumen (angioplasty) and insert stent to keep it open
What does a coronary artery bypass graft involve?
- offered in cases of severe stenosis
- open chest with midline sternotomy incision
- graft vessel attached to the affected coronary artery, bypassing the stenotic area
- usually taken from saphenous vein/ internal mammary artery/ radial artery
PCI vs CABG
- PCI has** faster recovery** and lower rate of strokes as a complication but** higher rate of requiring repeat revascularisation** (further procedures)
ACS Risk factors
Non modifiable
* Family history
* Age
* Ethnicity (S. Asian)
Modifiable
* Smoking
* Poor nutrition
* Sedentary lifestyle
* Alcohol
* Stress
* HTN
* Obesity
* DM
ACS presentation
- central, constricting chest pain
- radiates to jaw or arms
- Sweating and clamminess
- A feeling of impending doom
- Shortness of breath
- Palpitations
- symtoms continue at rest for more than 15 minutes.
What does the RCA supply?
Right atrium
Right ventricle
Inferior aspect of the left ventricle
Posterior septal area
What does the circumflex artery supply?
Left atrium
Posterior aspect of the left ventricle
What does the LAD supply?
Anterior aspect of the left ventricle
Anterior aspect of the septum
Risk factor for silent MI
Diabetes
ECG changes in STEMI
ST-segment elevation
New left bundle branch block
ECG changes in NSTEMI
ST segment depression
T wave inversion