cardio Flashcards
what is included in acute coronary syndromes (G)
unstable angina, STEMI, NSTEMI
acute coronary syndromes- occlusion, infarction (G)
OCCLUSION
- ua- partial of minor coronary artery
- NSTEMI- partial of major or total of minor coronary artery
- STEMI- total of major
INFARCTION
- ua- no infarction, just ischaemia
- NSTEMI- subendothelial infarction (area far away from coronary artery occlusion dies)
- STEMI- transmural infarction
acute coronary syndromes- ECG, troponin and creatinine kinase MBn (G)
ECG
- ua- normal, may show some ST depression/ T wave inversion
- NSTEMI- ST depression and T wave inversion, no Q waves
- STEMI- ST elevation in local leads (2+), Q waves (pathological) after some time
TROPONIN AND CREATININE KINASE MB
- ua- normal
- NSTEMI- elevated (increased with infarction)
- STEMI- elevated (increased with infarction)
troponin vs creatinine kinase mb for ACS (G)
troponin has a shorter half life than CK-MB so CK-MB better after a few days
coronary artery anatomy (G)
aorta -> RCA, LCA
RCA supplies the RA, RV, inferior LV, posterior septal area
LCA -> circumflex, LAD
Circumflex -> LA, posterior LV
LAD -> anterior LV, anterior septum
unstable angina definition (G)
Myocardial ischaemia at rest or on minimal exertion with the absence of myocardial injury- cannot be relieved with GTN or rest
unstable angina aetiology (G)
atherosclerotic plaque rupture and subsequent thrombosis and inflammation
unstable angina risk factors (G)
non-modifiable: age, gender, race.
Modifiable: hypertension, obesity, high LDL, smoking
unstable angina pathophysiology (G)
atherosclerotic plaque ruptures and thrombus forms around the ruptured plaque, causing partial occlusion of the minor coronary artery, causing reduced blood flow → myocardial ischaemia → angina
unstable angina key presentation (G)
central crushing chest pain, radiates to arms, neck and jaw. Is not relieved by GTN or rest, persists longer than 20 minutes, crescendo chest pain (frequent, easier to provoke)
unstable angina other symptoms (G)
sweating, dyspnoea, nausea, fainting, palpitations
unstable angina investigations (G)
1st: history
gold: ECG (ST normal or depression, NO ELEVATION), biomarkers (no troponin increase)
other: CT angiography- shows extent of occlusion
unstable angina differential diagnosis (G)
stable angina, pericarditis, myocarditis
unstable angina / NSTEMI management- immediate and long term (G)
immediate- MONAC
-morphine
-oxygen (if sats <94%)
-nitrates (GTN)
-aspirin (300mg)
-clopidogrel (75mg)
GRACE score- (6 month risk of death or repeat MI after NSTEMI)
prevention: 6As
-aspirin (300mg initial -> 75mg life)
-another antiplatelet: clopidogrel (75mg 12 months)
-atorvastatin (80mg life)
-atenolol or other BB eg metoprolol (BB or CCB)
-ACEi
-aldosterone antagonist if clinical heart failure (eg eplerenone once daily)
low risk: modify risk factors and monitor
high risk unstable angina, always for NSTEMI: invasive coronary angiography and PCI
unstable angina complications (G)
MI, stroke, heart failure
why is diabetes a major risk factor for silent MIs
-diabetic neuropathy
-patients don’t feel the anginal pain so may misdiagnose and die from sudden collapse
MI- type 1 vs type 2
T1- IHD- MI due to acute coronary event
T2- increased demand / reduced supply of oxygen or ca vasospasm
T3- sudden cardiac death/ cardiac arrest
T4- Associated with procedures eg PCI, stenting, CABG
NSTEMI definition (G)
non ST elevated MI. Acute ischaemic event causing myocardial cell necrosis and troponin release
NSTEMI aetiology (G)
rupture and thrombosis of atherosclerotic plaque causing partial occlusion of major CA or total occlusion of minor CA
NSTEMI risk factors (G)
non mod: age, male, race. Modifiable: hypertension, diabetes, obesity, high LDL, smoking
NSTEMI pathophysiology (G)
atherosclerotic plaque rupture and thrombosis causes partial occlusion to the coronary artery, this causes necrosis of cardiac tissue and infarction to the subendothelium
NSTEMI key presentation (G)
central crushing pain, radiating down arm, neck and jaw. Not relieved by rest or GTN spray. It persists for over 20 mins, feeling of impending doom
NSTEMI signs (G)
tachycardia
high/low BP
4th heart sound
NSTEMI other symptoms (G)
sweating
N+V
dyspnoea
fatigue
palpitation
NSTEMI investigations (G)
1st/gold
-ECG- ST depression, T wave inversion. Also R wave regression and biphasic T waves
-Biomarkers- elevated troponin
other: CT angiography, bloods
NSTEMI complications (G)
heart failure,
ruptured infarcted ventricle,
ruptured interventricular septum,
mitral regurgitation,
arrhythmias,
heart block,
post-MI pericarditis (Dressler syndrome)
STEMI definition (G)
ST elevated myocardial infarction. Ischaemic event leading to death of heart tissue and troponin release
STEMI aetiology (G)
rupture and thrombosis of plaque causing complete occlusion of major coronary artery lumen
STEMI risk factors (G)
non-mod: age, male, race.
Mod: hypertension, diabetes, obesity, high LDL, smoking
STEMI pathophysiology (G)
atherosclerotic plaque rupture and thrombosis causes complete occlusion of coronary artery leading to transmural injury and infarct to the myocardium
STEMI key presentation (G)
central crushing chest pain, radiates to the arm, jaw and neck. Not relieved by rest or GTN spray, it persists >20 mins, feeling of impending doom
STEMI signs (G)
tachycardia, high/low BP, 4th heart sound
STEMI symptoms (G)
sweating
dyspnoea
N+V
fatigue
palpitations
STEMI investigations (G)
1st/gold:
ECG (ST elevation, after some time: T wave inversion, deep broad Q waves, left BBB)
biomarkers: elevated troponin
other:
CT angiography
bloods
STEMI management (G)
Acute treatment: MONA (morphine, oxygen <92%, nitrates, aspirin)
Primary PCI if available within 120minutes of first medical contact or within 12hours of symptoms,
if unavailable, fibrinolysis to break down clot (e.g., alteplase). Consider PCI if this fails
Secondary prevention: aspirin, clopidogrel (antiplatelet), statin (atorvastatin), metoprolol (BB or CCB), ACEi, modify risk factors
STEMI complications- acute (G)
Heart failure due to ventricular fibrillation
rupture of infarcted ventricle,
rupture of interventricular septum,
heart block,
cardiogenic shocl
arrhythmias,
mitral regurgitation/ incompetence,
STEMI complications- long term (>2 weeks) (G)
-Dressler syndrome (autoimmune pericarditis)
-heart failure
-left ventricular aneurysm
how does an ECG change after MI (G)
-hyperacute T waves
-pathologically deep Q waves
-LBBB
what is indicated by pathological Q waves
transmural infarction- typically appear 6 or more hours after the onset of symptoms
stable angina definition (G)
A symptom of IHD
-central crushing pain due to decreased coronary artery blood flow,
-causes oxygen supply/ demand mismatch in exertion
stable angina aetiology (G)
narrowing of coronary artery by atherosclerosis.
Rare: reduced O2 carrying capacity (anaemia), peripheral resistance (LV hypertrophy), coronary artery spasm
stable angina risk factors (G)
non-mod: age, male, FHx, race
mod: obesity, T2DM, HTN, smoking, cocaine use, high LDL
stable angina pathophysiology (G)
-high oxygen demand on exertion. Narrowing of coronary arteries from atherosclerotic plaque
-reduces blood flow → myocardial ischaemia → angina
-atherogenesis: fatty streak → intermediate lesions → fibrous plaque
stages of atherogenesis
fatty streak
-appears in intimal walls (v early, less than 10 years old
-T cells and lipid laden macrophages- foam cell
intermediate lesions
-foam cells (bigger, taken up more lipid), T cells and vascular smooth muscle cells
-platelets also aggregate and adhere to the side, inside the vessel lumen
fibrous plaques
-advanced
-large lesions (foam cells, T cells, smooth muscle, Fibroblasts, lipids uptake with a necrotic core)
-they develop fibrosis cap over the top of lesion
atherogenesis in stable angina (G)
-symptoms start when 70-80% of lumen is occluded
-fibrous cap is strong and less rupture prone.
-If plaque is prone to rupture -> prothrombotic state; platelet adhesion and accumulation
-results in progressive luminal narrowing
stable angina key presentation (G)
central crushing chest pain radiating to neck, arm, jaw. It is relieved by GTN spray or 5 mins rest. Brought on by exertion
stable angina other symptoms (G)
dyspnoea, nausea, sweating, fainting, fatigue. Symptoms worsen with time
stable angina investigations (G)
1st line: ECG (normal)
gold: CT angiography (shows presence of luminal narrowing/ plaque)
other:
echo with exercise tolerance test (resting is normal, exercise is ischaemia
invasive angiography- shows pressure gradient across stenosis showing atherosclerotic arteries
stable angina differential diagnosis (G)
ACS
stable angina management (G)
Immediate symptomatic relief – GTN spray
Long term relief:
1st line – education/ lifestyle.
Beta blockers and/or CCB (amlodipine. Do not combine BB with non-dihydropyridine CCB). + other antianginal (long-acting nitrates, e.g. isosorbide mononitrate) (1st: CCB/BB → CCB + BB → CCB + BB + another antianginal)
Procedural intervention if pharmacological unsuccessful : PCI (less invasive but risk of stenosis), CABG (better prognosis but more invasive)
Secondary prevention: Aspirin, Atorvastatin, ACE inhibitor
stable angina complications (G)
MI, stroke, heart failure
Prinzmetal angina definition (R)
angina due to coronary vasospasm aka vasospastic angina
prinzmetal angina aetiology (R)
does not correlate with exertion. May be precipitated by smoking, cocaine, marijuana, emotional stress, extreme cold weather
prinzmetal pathophysiology (R)
coronary artery spasms and suddenly narrows
prinzmetal angina key presentation (R)
central crushing chest pain at rest which resolved with GTN spray
prinzmetal angina symptoms (R)
dyspnoea, sweating, nausea
prinzmetal angina investigations (R)
1st: ECG (ST elevation during acute episode), biomarker (not elevated)
gold: coronary angiography (ACh used to provoke spasm)
prinzmetal angina management (R)
1st: GTN spray
other: calcium channel blockers and long acting nitrates
stop smoking, reduce risk factors
AAA definition (G)
dilation of the abdominal aorta >50%,
diameter >3cm,
typically infra-renal,
in elderly men
AAA epidemiology (G)
elderly men
20% rupture anteriorly (very bad)
80% rupture retroperitoneal (less bad)
AAA aetiology (G)
mainly idiopathic
atheroma, trauma, infection
connective tissue disorders: Marfan’s and Ehlers-Danlos syndrome
AAA risk factors (G)
smoking,
atherosclerosis,
obesity,
hypertension,
increasing age
AAA pathophysiology (G)
inflammation and degradation of smooth muscle cells in all layers of vascular tunic →
loss of structural integrity of the aortic wall → widening of the vessel →
mechanical stress (HTN) acts on weakened wall tissue →
dilation and rupture may occur with leukocyte infiltration.
Dilation may disrupt laminar flow and turbulence causing thrombi to form in the aneurysm, and thromboembolism
true vs pseudo AAA
all 3 layers of vascular tunica (intima, media, adventitia)
pseudo- not all 3
inflammatory AAA (G)
usually in younger patients who are smokers
-atherosclerosis in arteries
-same symptoms with pyrexia
AAA key presentation (G)
-normally asymptomatic until rupture
-palpable pulsatile mass in abdomen
-often incidental finding
unruptured AAA other signs (G)
tachycardia, hypotension
Cullens and Grey turners sign in some cases
ruptured AAA symptoms (G)
-sudden epigastric pain radiating to flank
-loss of consciousness
-N+V
-hypovolemic shock
AAA investigations (G)
1st line:
abdominal USS
>3cm, if ruptured- immediate management. Used to assess aorta- cheap, easy, sensitive and specific
gold:
CT angiography
AAA differential diagnosis (G)
acute pancreatitis- typically more associated with grey turner/ cullens sign
appendicitis
AAA management if ruptured (G)
stabilise ABCDE,
Resuscitation measures (oxygen, fluids, aiming for lower than normal BP during fluid resus as higher BP may increases blood loss- known as permissive hypotension)
urgent surgery EVAR (stent through femoral arteries) or open surgery (laparoscopic).
AAA graft surgery- replace weakened wall.
100% mortality with no immediate treatment
AAA management if unruptured (G)
symptomatic- urgent surgical repair (EVAR or open surgery).
If asymptomatic- surveillance and risk management (smoking, diet, exercise, HTN)
If asymptomatic but aneurysm > 5.5cm/ rapidly growing/ 4cm for over a year- elective surgery (EVAR or open)