Cardiology Flashcards
Coronary Artery Anatomy
1) Left Coronary Artery
- Left Anterior Descending a.
- Left Circumflex a.
2) Right Coronary Artery –> AV nodular a. and Post. Interventricular a.
Conduction System of Heart
- Sinoatrial node (pacemaker)
- Atrioventricular node
- Bundle of His
- Bundle Branches
- Purkinji fibres
2 Major Cardiac Biomarkers
- Troponin - peak 1-2days, elevated up to 2 weeks (MI, CHF, PE, myocarditis). Check at presentation and 8 hours later.
- CK-MB - peak 1 day, elevated 3 days (MI, myocarditis, pericarditis)
Left HF Symptoms and Signs
Symptoms:
- Venous congestion –> Dyspnoea, orthopnoea, PND, Nocturnal cough
- Low CO –> Poor exercise tolerance, fatigue, weight loss, Nocturia
Signs:
- Venous congestion –> Inspiratory crepitations
- Low CO –> Pulsus alternans, Systemic Hypotension, Cool extremities, slow cap refill, peripheral cyanosis, Mitral regurgitation, S3 gallop
Coronary Angiography Contraindication
Coronary angiography is a radiographic visualisation of the coronary vessels after injection of radiopaque contrast media. Contraindicated in severe renal failure
Right HF Symptoms and Signs
Symptoms:
- Venous Congestion –> peripheral oedema, ascites, fatigue, anorexia
Signs:
- Venous Congestion –> Peripheral oedema, elevated JVP with abdominojugular reflex and Kussmauls sign, hepatomegaly, pulsatile liver
- Low CO –> Tricuspid regurg
Causes of Heart Failure
Left Heart Failure:
- Ischaemic Heart Disease
- Hypertension
- Valvular Heart Disease
- Cardiomyopathy
- Myocarditis
- Alcoholism
- Infections - endocarditis
- congenital heart disease
- pericardial disease
- amyloidosis, haemochromatosis, sarcoidosis
Right Heart Failure:
- Left Heart Failure
- Cor pulmonale
- PE
- … And all the causes for LHF
Investigations in HF
Imaging:
- Transthoracic Echocardiogram
- ECG
- CXR
Bloods:
- BNP
- FBC
- LFTs
- UEC
- TFTs
- Lipid profile
- HbA1c
Findings on CXR in HF
A - Alveolar oedema
B - Kerley B lines
C - Cardiomegaly
D - Dilated prominent upper lobe veins
E - Pulmonary Effusions
Acute Treatment of HF
LMNOPP
L) Loop diuretic (frusemide)
M) Morphine
N) Nitroglycerin
O) Oxygen
P) Positive airway pressure
P) Positioned sitting upright with feet over edge
Chronic HF Treatment
Lifestyle Modification –> Stop Smoking, exercise –> Treat cause of HF —> Treat exacerbating factors Fluid management (Limit intake) and reduce sodium intake
- ACE-I —> Captopril 6.25 mg orally, times daily
- Beta-Blocker –> Bisoprolol 1.25mg daily (or carvediol, nebivolol, metorolol succinate
- Aldosterone antagonist –> Spironolactone 25mg orrally, daily
- Loop Diuretic –> Frusemide 20-40mg daily
- Can also add… Digoxin + Nitrate
Ischaemic Heart Disease Risk Factors
- HTN
- Dyslipidaemia
- Smoking
- Diabetes
- Obesity
- Age
- Family History
- Male
- Depression
- CKD, SLE, RA Metabolic syndrome
Stable vs Unstable Angina
Stable Angina - Induced by effort, relieved by rest
Unstable Angina - Characterised by prolonged (>20 min) angina at rest; new onset of severe angina; angina that is increasing in frequency; longer in duration; or lower in threshold
The 3 typical features of angina
- Constricting/ heavy discomfort to the chest, jaw, neck, shoulders or arms
- Symptoms brought on by exertion
- Symptoms relieved within 5 minutes of rest or GTN
Investigations for angina
Lab tests:
- Hb
- fasting glucose
- fasting lipid profile
- troponin
Imaging:
- Coronary angiogram (gold standard)
- ECG (rule out MI)
- CXR (HF, Valve disease, pericardial disease, aortic dissection)
- Echo - Stress testing
Long Term Treatment for Angina
1) Anti-Angina Medication
- Beta-Blocker - reduce myocardial demand (Atenolol 25mg daily)
- Calcium Channel Blocker Antagonist (Verapamil 120mg orally daily)
2) Address exacerbation factors (Anaemia, tachycardia, thyrotoxicosis)
3) Secondary prevention of CVD - Stop smoking, exercise - Antiplatelet - Address BP (ACE-I) - Address Hyperlipidaemia
4) Symptom Relief - Glyceryl trinitrate 400mcg
5) Revascularisation considered if medical therapy inadequate - CABG - Percutaneous coronary intervention
Most common coronary branch affected in MI
LAD = 50-40%
RCA = 30-40%
LCx = 15-20%
2 types of MI
1) STEMI = transmural full thickness necrosis
2) NSTEMI = sub-endocardial (Troponin rise with no ST elevation)
Clinical features of an MI
- Retrosternal pain acute in onset
- Radiating to the left side of the chest, left arm, neck, lower jaw
- Dyspnoea
- Diaphoresis, syncope, palpitations, N + V
- New murmur
- *Note women and diabetes less likely to experience pain
Potential ECG findings for an MI
- ST elevation > 1mm in chest leads and > 2mm in limb leads in at least 2 cont. leads
- ST depression in leads V1-4 should consider posterior STEMI
- Flat or inverted T waves
- Pathogenic Q waves (occurs later)
- New onset LBBB
- Dominant R waves in V1-3
Investigations for potential MI
1) ECG
2) Troponin
3) Coronary Angiogram
Treatment of MI
Morphine, Oxygen, Nitrate
1) Dual Antiplatelet (continue for 12 months)
- Aspirin 300mg orally then 100mg daily
- Clopidogrel 600mg orally, then 75mg daily
2) Restore coronary Perfusion (If STEMI or new LBBB)
- < 90 min (PCI) Percutaneous Intervention i
- > 120 min (TPA) fibrinolysis - Alteplase
3) Beta-Blocker - Atenolol 25mg daily (Not in decompensated HF)
4) High Dose Statin - 40-80mg atorvastatin daily
5) ACE-I - Captopril 6.25 mg daily
Also modify risk factors - stop smoking, exercise, diabetes, HTN Tx
If you give a patient GTN and it improves chest pain does it mean its cardiac?
Not necessarily - GTN will improve indigestion as well. Give gaviscon - if symptoms improve then its indigestion.
Risk factors for essential Hypertension
- OSA
- Diabetes
- Obesity
- Metabolic Syndrome
- FHx
- Age > 65yo
Complications of HTN
- CAD
- LVH
- Cerebrovascular accident
- HF
- PAD
- CKD
- Retinopathy
Investigations for Hypertension
- ECG – may show evidence of LVH or old infarction
- Lipid panel – may show high LDL, low HDL or high triglycerides
- Urinalysis – may show proteinuria (end organ damage)
- FBC – anaemia accompanies chronic renal failure, polycythaemia may be seen with phaeochromocytoma
- TSH
First Line Medications for Hypertension
- ACE-I (Captopril 12.5-50mg TD)
- ARB (Candesartan 8-32mg OD)
- Ca Channel Blocker (Amlodipine 5-10mg OD)
- Thiazide Diuretic (Hydrochlorothiazide 12.5-50mg OD)
The Definition of Shock
Shock is most commonly defined as the life-threatening failure of adequate oxygen delivery to the tissues and may be due to decreased blood perfusion of tissues, inadequate blood oxygen saturation, or increased oxygen demand from the tissues that results in decreased end-organ oxygenation and dysfunction.
The 3 different types of shock
- Loss of intravascular fluid —> hypovolemic shock
- Inability of the heart to circulate blood —> cardiogenic shock
- Redistribution of body fluid —> distributive shock
Causes of hypovolemic shock
Haemorrhagic fluid loss:
- Trauma (External or Internal haemorrhage)
- Upper GI bleed (Variceal bleeding)
- Postpartum haemorrhage
Non-haemorrhagic fluid loss:
- Diarrhoea, Vomit
- Increased insensible fluid (Burn, SJS)
- Third Space fluid loss
- Renal fluid loss
Causes of Cardiogenic shock
- MI - Arrhythmias
- Tension pneuomothorax
- Cardiac tamponade
- Constrictive pericarditis
- PE
- Restrictive cardiomyopathy
Signs of Shock
Causes of Distributive Shock
1) Septic Shock (Abnormal Response to infection –> capillary leakage and vasodilation)
2) Neurogenic Shock (Loss of sympathetic vascular tone –> vasodilation)
- Spinal cord Injury
- Traumatic brain injury
- Cerebral haemorrhage
- Severe pain
3) Anaphylactic shock (Degranulation of mast cells –> histamine release –> vasodilation and capillary leakage)
Definition of Cardiac Arrest
Cardiac arrest is the abrupt loss of heart function, breathing and consciousness. Sudden cardiac arrest differs from a heart attack, when blood to a part of the heart is blocked. However, a heart attack can sometimes trigger an electrical disturbance that leads to sudden cardiac arrest.
Causes of Cardiac Arrest (Reversible causes and cardiac causes)
Reversibe Causes:
- Hypoxia
- Hypovolaemia
- Hyperkalaemia/ Hypokalaemia
- Hypothermia
- Hydrogen Ion (acidosis)
- Thrombosis (MI)
- Thromboembolism (PE)
- Tension Pneumothorax
- Table and toxins
- Cardiac Tamponade
Common Cardiac Causes
- Ischaemic Heart Disease (MI and CAD)
- Cardiomyopathy
- Prolonged QT from medications + Brugada Syndrome
- Congenital Heart Disease
- Valvular heart disease
4 Specific cardiac rhythms of cardiac arrest
Shockable
- Ventricular fibrilation
- Ventricular tachycardia
Non-Shockable
- Asystole
- Pulseless electrical activity (PEA)
Investigations for Cardiac Arrest
- ECG – May show QT interval, ST-segment or T wave changes; conduction abnormalities; ventricular hypertrophy
- FBC – Low haematocrit in haemorrhage (Hypovolaemia)
- Serum electrolytes – could show abnormality
- ABG – May show respiratory acidosis; metabolic acidosis; resp. acidosis with renal comp., metabolic acidosis with resp comp.
- Cardiac biomarkers – may be elevated (troponin)
- Toxicology
- CXR – may show pneumothorax or other disorder of longs leading to hypoxia
- Echocardiogram – May show valvular abnormalities, myocardial scarring, cardiomyopathy, pericardial effusion
- Coronary angiography – may show signs of CAD
What makes the first and second heart sounds?
- First Heart Sound - Mitral and Tricuspid valves closing (Soft in MR, louder in MS)
- Second Heart Sound - Aortic and Pulmonary valves closing (Softer in more severe aortic stenosis, louder in systemic and pulmonary hypertension)
Causes of 3rd and 4th heart sounds
3rd Heart Sound (Precedes S1) –> LVH
4th Heart sound (Procedes S2) –> Severe HTN
Intensity of Murmurs
Dynamic Manouvres for Heart Murmurs
Left lateral position
- Get patient to roll onto left side which brings apex of heart closer to chest wall, auscultate over mitral area and in axilla
Inspiration
- Get patient to fully inspire and listen over the tricuspid and pulmonary areas. Inspiration will increase venous return and blood blow to right side of heart
Valsalva
- Valsalva manoeuvre and listen over left sternal edge (systolic murmur with hypertrophic cardiomyopathy) and apex (late systolic murmur with mitral valve prolapse)
Deep expiration
- Get patient to lean forward in full expiration and listen to the base of the heart to accentuate aortic regurgitation and pericardial rub
Causes of Aortic Stenosis
- Degenerative calcification
- Rheumatic Endocarditis
- Congenital (Unicuspid/ Bicuspid Valve)
Signs of Aortic Stenosis
- Slow Rising Pulse
- Narrow Pulse Pressure
- LV Heave
- Severe AS - soft S2
Ejection Systolic Murmur - hear at hase, left sternal edge and aortic area, radiates to carotid