Cardiovascular Flashcards
Ischaemic heart disease definition
Inadequate blood supply caused by an imbalance between the supply and demand of oxygen (and other nutrients) to the heart tissue. Divided into three segments: 1. Angina 2. Acute coronary syndrome 3. Myocardial infarction
Ischaemic heart disease aetiology
Restriction of blood flow to a region of myocardium may be caused by:
- atheroma
- thrombosis
- spasm
- embolus
- coronary ostial stenosis
Decrease in supply of oxygenated blood to the myocardium:
- anaemia
- hypotension (decreased flow to heart)
- hypoxemia
Increased demand of heart tissue:
- hypertension
- tachyarrhythmia
- valvular heart disease
- hyperthyroidism
- hypertrophic cardiomyopathy
Myocardial ischaemia most commonly occurs due to obstructive coronary artery disease (CAD) in the form of coronary atherosclerosis
Ischaemic heart disease risk factors
Modifiable:
- diabetes mellitus
- hyperlipidemia
- hypertension
- kidney disease
- obesity
- physical inactivity
- cigarette smoking
- alcohol
Non-modifiable
- age
- family history (not relevant if occured over 55yrs old)
- male (oestrogen in women is protective)
Environmental exacerbating factors:
- cold weather
- heavy meals
- emotional stress
Ischaemic heart disease pathophysiology
look at myles’ table
Angina definition
A major symptom of stable IHD. Characterised by chest pain. Main types are stable and unstable.
Angina aetiology
Stable angina:
narrowing of the artery from a plaque - symptoms felt at >70% occlusion
Unstable angina:
likely due to the development of a thrombus from plaque rupture. Comes under the umbrella term of acute coronary syndromes
Angina risk factors
same as atherosclerosis
Angina signs and symptoms
Stable angina:
- central chest pain on exertion
- relieved by GTN spray
- radiation of pain to neck, jaw and arm
Untable angina:
- new onset pain without exertion
- gets worse quickly
- GTN spray does not relieve symptoms
Angina 1st line investigations
Stable:
- resting ECG - often normal, may reveal ST-T changes (St depression and T wave inversion) suggestive of ischaemia or Q waves indicative or prior infarction
- Lipid profile - usually raised LDLs
Unstable:
- ECG - may be normal or have transient ST segment depression or T wave inversion
- cardiac biomarkers - troponin not usually elevated as there is no acute myocardial damage
Angina gold standard investigations
Stable: perfusion MRI
- less available but best option
- CT coronary angiography not great at determining severity
Unstable: coronary angiography is the gold standard for assessing the presence and severity of CAD and allows for concurrent treatment with angioplasty and stenting if needed.
Angina differential diagnosis
Other anginas:
- prinzmetal’s angina - coronary artery syndrome
- microvascular angina - syndrome X - predominantly women, abnormal structure causing increased resistance
- crescendo angina - artery becomes so narrow blood struggles to flow even at rest
- unstable vs stable
Chest pain not related to myocardial ischaemic: - preicarditis/myocarditis - pulmonary embolism/pleurisy - chest infection/pleurisy - dissection of the aorta - GORD, spasm or ulceration - musco-skeletal psychological
Angina management
Stable (prevent it becoming unstable):
- education for lifestyle factors - smoking, weight, exercise, diet…
- anti platelet therapy - aspirin and clopidogrel or other P2Y12 inhibitor
- lipid-lowering therapy - primary options are statins - secondary are ezetimibe or alirocumab
- beta blocker
- sublingual GTN
- antihypertensives - beta-blockers and ACE inhibitors or angiotensin-II receptor antagonists
- blood sugar control (if needed)
- percutaneous Coronary Intervention (PCI) (for more severe cases)
Unstable (for ongoing confirmed unstable angina):
- may have PCI
Antiplatelet therapy - aspirin + P2Y12 inhibitor, may consider GPIIb/IIIa antagonists
- statin +/- ezetimibe
- beta blocker
- ACE inhibitor
- lifestyle education
May also consider ca++ channel blockers for underlying HTN
Angina prognosis
Reasonably good
Very low death rate per annum considering age
- cardiovascular events (includes non-fatal MIS, hospital admissions etc) a bit higher
- reassure patients diagnoses with angina
Acute coronary syndrome (NSTEMI) definition
Non-ST elevation myocardial infarction.
Myocardial infarction occurs when cardiac myocytes die due to myocardial ischaemia. NSTEMIs are usually a retrospective diagnosis made after troponin results and sometimes other investigations (echocardiogram, cardio angiogram)
NSTEMI aetiology
NSTEMIs are usually a result of a transient or near-complete occlusion of a coronary artery or acute factor that deprives myocardium of oxygen. Different from a STEMI as there is not usually complete occlusion of the affected coronary artery
NSTEMI risk factors
see unstable angina
NSTEMI pathophysiology
common mechanism of all ACS is rupture or erosion of the fibrous cap of a coronary artery plaque. This leads to platelet aggregation, localised thrombosis, vasoconstriction and distal thrombus embolisation.
NSTEMI key presentations
New onset of chest pain or chest pain at rest or a deterioration of preexisting angina.
NSTEMI signs and symptoms
Often retrosternal pain radiating to the left arm but may also radiate to the lower jaw, neck, both arms, back and epigastrium.
GTN trial: ongoing pain
Angiography should be considered if high risk
NSTEMI 1st line investigations
ECG:
- ST depression
- T wave inversion
- Usually pretty normal so diagnosed by troponin
- FBC
- Troponin: high, >99th percentile of normal.
- Elevated troponin is sign of infarction
- U&Es
- Glucose
- Lipids
- CXR - DDx
NSTEMI gold standard investigations
Urgent coronary angiography for diagnoses and treatment in patients at a high risk for progression to MI or death.
NSTEMI differential diagnosis
Can be distinguished from unstable angina by troponin levels Aortic dissection PE Peptic ulcer Acute pericarditis Psychological Stable ischaemic heart disease
NSTEMI management
Acute presentation:
- antiplatelet therapy
- oxygen
- GTN
- beta-blocker
- calcium channel blocker
- assess need for PCI
- heparin
- GPIIa/IIb inhibitor
Intermediate management: M- morphine N- nitrates vasodilator A- aspirin stops the platelets sticking together C- clopidogrel AntiPlatelet drug
STEMI definition
Acute myocardial infarction is myocardial cell death occurring due to a prolonged mismatch between perfusion and demand. In the case of ST-elevation MI this is caused by complete atherothrombotic occlusion of a coronary artery.
STEMI aetiology
Usually occurs due to complete occlusion of a coronary artery:
- rupture of an atherosclerotic plaque and a consequent arterial thrombosis is the major cause
- coronary vasospasm without plaque rupture
- drug abuse (emphetamines, cocaine)
- dissection of the coronary artery related to defects of the vessel connective tissue
- thoracic aortic dissection
STEMI pathophysiology
Causes full thickness heart damage
STEMI key presentations
Typically presents with central chest pain
- classically retrosternal, crushing, heavy, severe and diffuse
- may radiate to left arm, neck or jaw
- might be described as ‘pressing or squeezing’
- may have associated nausea, vomiting, dyspnoea
STEMI signs and symptoms
In elderly and diabetic patients the symptoms may be atypical and include dyspnea, fatigue, syncope or presyncope
STEMI 1st line investigations
ECG - ST elevation, may be LBBB - tall T waved - ' pathological Q waves' Cardiac troponin - elevated, consider with time context - glucose - FBC - U&Es, creatinine - CRP - Lipids
STEMI management
Immediate management on way to hospital (eg paramedics)
- MONA - morphine, oxygen, nitrates, aspirin
Immediate hospital management M- morphine N- nitrates vasodilator A- aspirin stops the platelets sticking together C- clopidogrel anti platelet drug
Investigations (eg coronary angiography) will confirm if surgery eg PCI needed
- ST elevation of over 2mm in 2 counties chest leads of over 1mm in continuous limb leads
- chest pain or other evidence of ischaemia
- new or presumed left bundle branch block
STEMI monitoring
ECG may show ‘pathological Q waves’ (wide, deep or seen in leads V1-3)
Inverted T waves may appear in days after MI
STEMI complications
- death
- rupture of heart septum/papillary muscles
- oedema (heart failure)
- arrhythmias, sinus bradycardia - usually due to occlusion of the right coronary artery and caused by infarction of the AV node and conduction system
- Dressler’s syndrome - post-infarction pericarditis
Heart failure (ischemic, valvular, myopathic, hypertensive, cor pulmonale) definition
Complex syndrome resulting from any structural or functional cardiac disorder that impairs the ability for the heart to function as a pump to support physiological circulation. This is not a disease rather a syndrome caused by any cardiac problem.
HF definitions:
- HF-REF (reduced ejection fraction) (left ventricular systolic impairment with LVEF <40%)
- HF-PEF (preserved ejection fraction) (LVEF > 50%, with dilated LA > 34ml/m2)
- HF-PH (pulmonary hypertension)
- HF-valve (valve disease) (severe stenosis or regurgitation)
Heart failure epidemiology
It is common (up to 20% in over 75yo), it costs approx 2% of the NHS expenditure. It is also disabling diminishing quality of life (worse than RA and COPD patients).
Heart failure aetiology
Main causes:
- ischaemic heart disease
- cardiomyopathy
- hypertension
- valvular heart disease
- cor pulmonale (linked to underlying respiratory issues)
Heart failure risk factors
age, male
Heart failure key presentations
Paroxysmal nocturnal dyspnea - very specific symptom - episodes of shortness of breath that occur during the night
Othopnea - patient can’t breathe when they lie flat
Cardinal signs - SOB, fatigue, ankle oedema
Heart failure signs and symptoms
- SOB
- Fatigue
- ankle swelling and oedema
- cold peripheries (inadequate perfusion)
- displaced apex beat
- raised JVP
- added heart sounds and mumurs
- ascites (fluid in abdominal cavity)
Heart failure 1st line investigations
NT-proBNP - will be significantly raised in heart failure
Transthoracic ECHO - needed if NT-proBNP raised ECG - unlikely to be normal. Use to identify aetiology such as MI or arrhythmia
Heart failure management
- diuretics eg furosemide
- mineralocorticoid receptor antagonist eg spironalactone
- sacubitril-valsartan
- cardiac resynchronization therapy
- implantable defibrillator
- left ventricular assist device
- heart transplant
Hypertension definition
High blood pressure
Stage 1 - 140/90 and 135/85
Stage 2 - 160/100 and 150/95
Hypertension aetiology
Normally primary (unknown and due to lifestyle and age). Can be secondary eg Conn’s
Hypertension key presentations
usually asymptomatic
Hypertension signs and symptoms
ACE inhibitors: side effects: hypotension, dry cough, contraindicated in early pregnancy
ARB blocker: ‘sartans’ eg candesartan side effects: hypotension, hyperkalemia, contraindicated in pregnancy
CCBs: side effects: peripheral vasodilation; flushing, headache, oedema; negatively chronotropic (slowing of heart); bradycardia, AV block; constipation (gut calcium channels)
BBs: can be B1 selective (cardio selective) or non-selective. Side effects: contraindicated in asthma, fatigue, headache, bradycardia, cold peripheries
Diueritcs: side effects: hypovolaemic (mainly loop diuretics), hypotension, hypokalemia, hyponatremia, impaired glucose tolerance (mainly thiazides)
Alpha blockers
Renin inhibitors
Centrally acting drugs
Atrial fibrillation definition
A type of supraventricular tachyarrhythmia
Atrial fibrillation aetiology
Associated with all types of cardiac disease. Most commonly associated with HTN, CAD and MI. Mitral valve disease can also be a cause, as can hyperthyroidism.
Atrial fibrillation signs and symptoms
Common presentation:
- presence of risk factors
- palpitations
- tachycardia
- irregular pulse
- chest pain
- dizziness
- SOB
Atrial fibrillation diagnosis
ECG: Irregularly irregular QRS complexes Absence of P waves QRS usually < 120ms unless patient has other conducting problems ECHO if suspected valvular disease
Atrial fibrillation management
Hemodynamically unstable: immediate heparin and attempted cardio version with synchronised DC shock
Hemodynamically stable:
- rate control - patient not in severe tachycardia but will still have Afib rhythm, BBs are first line; CCBs or Digoxin are second line
- rhythm control - returns to sinus rhythm, given to patients with reversible causes, or new onset of Afib, achieved by cardioversion
Cardioversion - process of returning patient to normal sinus rhythm
- electrical cardio version - controlled shock delivered
- pharmacological cardio version - amiodarone
- long term BBs for rate and rhythm control
Atrial fibrillation complications
Risk of thrombosis in atria causing stroke Use of CHA2DS2-VASc score C - congestive heart failure H - HTN A - age D - diabetes S - stroke/TIA/thomboembolism V - vascular disease A - age S - sex category
If risk >1 offer anticoagulation therapy
Atrial flutter definition
Type of supraventricular tachycardia. Atrial rates are usually above 250bpm.
Atrial flutter aetiology
Due to finctional or structural abnormalities of the atria. Structural abnormalities include atrial dilation due to for example; scars from atrial surgery, prior atrial ablation sites and idiopathic fibrosis within the atrium. Can be precipitated by toxic and metabolic conditions.
Atrial flutter signs and symptoms
Usually occurs as part of an acute disease process Identifying underlying (cardiac, respiratory, diabetes, hyperthyroidism).
Palpitations, dizziness, syncope
Atrial flutter diagnosis
ECG is diagnostic
- organised ‘sawtooth pattern’
- important factor is a regular beat
Murmers or rubs on auscultation suggest valvular disease, pericarditis, or congenital heart disease
Atrial flutter management
- Beta-blockers
- Definitive treatment is catheter ablation
Atrioventricular block definition
Cardiac electrical disorder defined as impaired (delayed or absent) conduction from the atria to the ventricles.
Can be separated into degrees of severity:
- first degree - delay in conduction at AV node
- second degrees (types I & II) - not every atrial depolarisation is conducted to the ventricles
- third degree (complete) - not atrial impulses at all make it through to the ventricles. Ventricles respond by generating an escape rhythm. Atria and ventricles contract but at their own intrinsic rate
Atrioventricular block aetiology
Causes include fibrosis and calcification of the conduction system, CAD and medication such as AV-nodal blocking agents (ie BBs, CCBs, digitalis, adenosine), anti arrhythmic medications such as sodium-channel blockers. May be due to congenital defects or damage from surgery or other cardiac interventions.
Atrioventricular block presentation
Patients tend to be older males with underlying cardiovascular disease. May have acid-base disturbance or neuromuscular disease.
Usually bradycardia.
Blood pressure is often high with a wide pulse pressure.
Syncope may be present