Cardiology

Acute Coronary Syndrome (ACS)

Definition and Types

  • ACS is a spectrum of acute myocardial ischemia or infarction.

    • STEMI (ST-Elevation Myocardial Infarction): Positive ECG with ST-elevation, positive troponins.

    • NSTEMI (Non-ST-Elevation Myocardial Infarction): Inconclusive ECG but positive troponins.

    • Unstable Angina: Normal ECG and normal troponins.

Symptoms and Signs

  • Symptoms include:

    • Angina at rest lasting more than 20 minutes, not relieved by GTN.

    • Gripping/heavy pain associated with nausea, sweating, dyspnea, and palpitations.

Investigation

  • Key investigations include:

    • ECG, arterial blood gases (ABG), blood tests (troponins, FBC, lipid profile, HbA1c, U&E, LFT, TFT), chest X-ray (CXR), echocardiogram, blood glucose.

Management

  • Immediate management includes:

    • Aspirin (300 mg), oxygen if saturation <94%, paracetamol 1g (or morphine if severe pain), GTN 1 spray (with caution in hypotension), possible ondansetron 4 mg IV.

  • For Unstable Angina and secondary prevention, use the 6 As:

    • Aspirin (75 mg OD), another antiplatelet (e.g., Clopidogrel for 12 months), Atorvastatin (80 mg OD), ACE inhibitors (e.g., Ramipril), Atenolol (or Bisoprolol), Aldosterone antagonists for heart failure (e.g., Eplerenone).

Complications and Prognosis

  • Complications can include:

    • Death, rupture of myocardium, edema, arrhythmias, aneurysms, Dressler's syndrome.

  • ~10% morbidity, with an increased risk of future events.

Criteria for STEMI

  • Criteria include:

    • Symptoms lasting ≥20 minutes with ECG changes in ≥2 contiguous leads:

      • 2.5 mm ST elevation in V2-3 in males ≤40 years, ≥2.0 mm in males >40 years.

      • 1.5 mm ST elevation in V2-3 in females.

      • 1 mm ST elevation in other leads, new left bundle branch block (LBBB) is always pathological.

  • Decision about PCI (Percutaneous Coronary Intervention) depends on:

    • Symptoms <12 hours and PCI possible within 2 hours.

Management Strategies for STEMI

PCI Management

  • For STEMI:

    • Use Prasugrel or Clopidogrel if the patient is on oral anticoagulants or Ticagrelor if the patient is at high risk of bleeding.

    • Radial access is preferred over femoral access.

    • Use unfractionated heparin (UFH) and bail-out Glycoprotein IIb/IIIa inhibitor.

    • Apply drug-eluting stents during PCI.

If PCI not possible within 2 hours, then Fibrinolysis

  • Use alteplase or other thrombolytics.+ antithrombins.

  • Administer Ticagrelor after. If no ECG resolution after 60-90 minutes, consider PCI.

NSTEMI Management

  • Use GRACE score to assess risk (<3% or >3%).

    • Low risk (≤3% 6-month mortality): Fondaparinux, Ticagrelor.

    • Intermediate/high risk (>3%): If unstable, perform immediate PCI; if stable, perform PCI within 72 hours and provide Fondaparinux, Prasugrel or Ticagrelor, and UFH.

Additional Notes for Management

  • For myocardial infarction associated with cocaine use, consider IV benzodiazepine, avoid beta-blockers.

  • Encourage a Mediterranean-style diet. No recommendation for omega-3s or fish.

  • Exercise: 20-30 minutes of daily activity is beneficial.

  • Sexual activity is permissible after 4 weeks, and PDE-5 inhibitors can be used 6 months post-MI, avoiding if on nitrates.

Risk Factors

  • Modifiable risk factors include smoking, diabetes, hypertension, hypercholesterolemia, and obesity. Unmodifiable risk factors include age, male gender, and family history.

Hypertension

Definition and Classification

  • Hypertension defined as persistently raised blood pressure.

  • Stage classifications based on clinic BP measurements:

    • Stage 1: Clinic BP ≥140/90, ABPM ≥135/85.

    • Stage 2: Clinic BP ≥160/100, ABPM ≥150/95.

    • Stage 3: Clinic BP ≥180/120 = Hypertensive crisis.

Diagnosis

  • If clinic BP is ≥140/90, measure again after 5 minutes on both arms and check cuff placement.

  • Use ambulatory blood pressure monitoring (ABPM) to avoid white coat syndrome.

  • Other investigations include fundoscopy, urine dipstick, ECG, and blood tests (FBC, U&Es, HbA1c, lipids).

Hypertensive Retinopathy Stages

  • Grade I: Barely detectable arterial narrowing.

  • Grade II: Obvious narrowing with focal irregularities.

  • Grade III: Flame and dot-and-blot hemorrhages, exudates, cotton wool spots.

  • Grade IV: Papilledema.

Aetiology

  • Essential Hypertension: No specific identifiable cause.

  • Secondary Hypertension: Can result from conditions like hyperaldosteronism, renal disease, endocrine disorders, and certain medications.

Management

  • Use different medications based on the age, ethnicity, and associated conditions, including:

    • Ace inhibitors, beta-blockers, calcium channel blockers, thiazide-like diuretics.

  • Focus on lifestyle modifications like diet, weight loss, and exercise.

Side Effects of Antihypertensives

  • ACE Inhibitors: dry cough, angioedema, hyperkalaemia

  • Beta Blockers: Bronchospasm, fatigue, cold extremities.

  • Calcium Channel Blockers: Flushing, bradycardia, hypotension.

  • Thiazide-like Diuretics: Electrolyte imbalances, hypercalcemia, and potential for gout.

Ischemic Heart Disease

Definition and Risk Factors

  • IHD is characterized by inadequate blood supply to the myocardium due to factors such as age, smoking, CAD, hypertension, and diabetes.

Symptoms

  • Stable angina: Chest pressure or constriction lasting <20 minutes and provoked by exertion, relieved by rest or GTN.

  • Atypical angina may present differently in women and the elderly.

Investigation

  • Key investigations include ECG and blood tests.

    • If stable angina cannot be excluded: CT coronary angiography, non-invasive functional imaging, or invasively via coronary angiography.

Management

  • Sublingual GTN for immediate relief.

  • Long-term management with antiplatelets, statins, beta-blockers, and lifestyle changes.

Atrial Fibrillation

Definition and Risk Factors

  • Supraventricular tachyarrhythmia characterized by uncoordinated atrial contractions.

Symptoms

  • Palpitations, shortness of breath, chest pain, fatigue, dizziness, syncope.

Investigation

  • ECG, blood tests, and potentially echocardiogram.

Management

  • Rhythm control for reversible causes, rate control with beta-blockers or calcium channel blockers, anticoagulation based on CHADS2VASC and ORBIT scores.

Complications

  • Increased risk of stroke/TIA, bradycardia, hypotension, heart failure.

Advanced Life Support

Algorithm

  • If unresponsive and not breathing normally, start CPR (30:2) and attach a defibrillator.

Shockable rhythms

  • Defibrillate for VF/pulseless VT, followed by immediate resuming CPR.

Non-shockable rhythms

  • For PEA or asystole, administer adrenaline and resume CPR.

Identify Reversible Causes

  • Hypoxia, hypovolemia, hyper/hypokalemia, hypothermia, thrombosis (MI or PE), tension pneumothorax, toxins.

Ventricular Fibrillation and Tachycardia

Definition

  • V-fib: Tachyarrhythmia leading to ineffective contractions of the ventricles.

    • Causes include CAD, acute MI, and electrolyte imbalances.

  • V-tach: Characterized by rapid heart rates with broad QRS complexes.

Management

  • V-fib: Immediate defibrillation and consider antiarrhythmics like amiodarone or lidocaine.

  • V-tach: Immediate DC cardioversion for unstable; if stable, treat with antiarrhythmic medication.

Bradycardia Management

  • For significant bradycardia causing hemodynamic compromise, use atropine or consider transcutaneous pacing.

Cardiac Tamponade

Definition

  • Accumulation of fluid in the pericardial space leading to decreased cardiac output.

Symptoms & Signs

  • Beck's triad: hypotension, elevated JVP, muffled heart sounds. Dyspnea, pulsus paradoxus.

Management

  • Immediate pericardiocentesis is required if unstable.

Deep Vein Thrombosis (DVT) and Pulmonary Embolism (PE)

Definition and Risk Factors

  • DVT: Blood clot in deep veins, commonly lower limbs.

  • PE: Occlusion in pulmonary vasculature due to a clot originating from DVT.

  • Risk factors include recent surgery, immobility, cancer, pregnancy.

Symptoms

  • DVT: Localized tenderness, leg swelling, pitting edema.

  • PE: Shortness of breath, chest pain, hemoptysis.

Investigation and Management

  • Use Wells' score to guide management; confirm with Doppler ultrasound.

  • Anticoagulate based on risk-stratified guidelines.

Cardiac Disorders Related to Valvular Problems

Common Valvular Conditions

  • Mitral Stenosis: Often due to rheumatic heart disease.

  • Mitral Regurgitation: Causes include rheumatic heart disease, valve prolapse, and infective endocarditis.

  • Aortic Stenosis: Common causes include rheumatic heart disease and calcified bicuspid valve.

Symptoms and Signs

  • Symptoms vary with condition, but common presentations include SOB, fatigue, syncope, and characteristic murmurs on auscultation.

Management Strategies

  • Surgical intervention for severe disease, medical management includes diuretics, β-blockers, and anticoagulation as needed.