12.11.21 Cardiac

Heart failure basics

    • Definition

      • Inability of the heart to provide oxygen requirements of tissue

      • Or only at the expense of raised LV filling pressure

    • Causes

      • 50% CAD

      • Idiopathic 25%

      • Valve disease 10%

      • HTN 4%

      • Alcohol 4%

    • Survival varies depending on aetiology

      • But pooled 5-year survival is <50%

    • Signs

      • Raised JVP

      • Hepatojugular reflex

      • 3rd heart sound

      • Displaced apical impulse

      • Murmur

    • CXR

      • A - Alveolar oedema

      • B - B lines

      • C - Cardiomegaly

      • D - Diversion to upper lobe

      • E - Effusion

    • BNP

      • False positive if old, female, AF, LVH, renal or resp failure, PE ...

    • Drugs with survival benefit

      • ACE inhibitor

      • Beta blocker

      • Spironolactone

    • Calcium channel blockers in heart failure

      • NOT diltiazem or verapamil as they decrease contractility

      • Dihydropyridines (e.g. nifedipine) are OK as they have peripheral action

    • Pacing

      • Can help heart failure

      • DON'T put pacing leads, or anything else, in the left heart!

        • cf thrombosis

      • If you need LV pacing, thread it round the veins, on the outside

Angina

    • Definition

      • Chest pain described as constriction/discomfort in chest, +/- radiation

      • Brought on by exercise or emotion

      • Relieved by rest or GTN

    • Not all 3?

      • Only 2 out of 3 = Atypical angina pain

      • 0 or 1 out of 3 = Non-anginal pain

    • Most common cause

      • Atherosclerotic narrowing of coronary arteries

      • Symptomatic if >70%

    • Risk factors

      • Fixed

        • Age

        • Male

        • Genetics

      • Modifiable

        • Tobacco

        • HTN

        • DM

        • Hypercholesterolaemia

        • Depression

        • Obesity

    • Treatment options

      • Lifestyle modification

      • Pharmacotherapy

      • PCI

      • Surgical revascularisation

    • ECG features

      • T wave inversion

      • ST depression

      • LVH

      • LBBB

    • Exercise stress test

      • Very poor specificity

      • Therefore only useful when PPV is high

        • i.e. Previous Hx of CVD

    • Investigation based on risk

      • <10% => Consider non-cardiac cause

      • 10-30% => Do CT calcium score

      • 30-60% => Do functional test

        • Myoperfusion scan

        • Dobutamine stress echo

        • Stress MRI

      • 60-90% => Straight to coronary angiogram

    • CT calcium score interpretation

      • 0 => Consider other causes

      • 1-400 => 64-slice CT coronary angiography

      • >400 => Invasive angiography as you won't see shit on a CT angiogram

    • Treatment

      • Symptoms

        • Start with a beta blocker

        • Add a CCB if still symptomatic

          • Use a non-dihydropyridine (diltiazem, verapamil)

            • Block the AV node and slow rate

        • Then add ranolazine if still symptomatic

          • Sodium channel blocker

        • Plus PRN GTN

      • Secondary prevention

        • B - Beta blocker

        • A - Aspirin

        • S - Statin

        • I - ACEi

        • C - Control risk factors

    • Checkups

      • Glucose

      • Lipids

      • Hb

      • TFTs

      • U+Es

    • Indications for surgery over PCI

      • Disabled

      • > 65

      • Complex 3-vessel disease

      • Left main stem disease

ACS

    • Subtypes

      • STEMI

      • NSTEMI

      • Unstable angina

    • The 11 Ps

      • Pain relief

        • Morphine + cyclizine

      • Paralyse the platelets

        • Aspirin, clopidogrel, LMWH

      • Pacify the plaque

        • High-dose statin

      • Perfuse the myocardium

        • PCI

      • Prevent adverse remodelling

        • ACEi, Beta blocker

      • Predict risk of sudden death

        • GRACE, Echo

      • Protect from sudden death

        • Aldosterone receptor antagonist (eplerenone)

          • NB less anti-androgen effects than spironolactone

      • Promote exercise

      • Prevent smoking

      • Praise health

      • Permit sex after 2 weeks

    • Other things causing a trop rise

      • Myocarditis

      • Tachyarrhythmia

      • DC cardioversion

      • Sepsis

      • Trauma

      • CPR

      • Renal failure

      • Cardiomyopathy

      • PE

Arrhythmias

    • Types and causes

      • Brady

        • Sinoatrial node disease

        • Conduction disease

      • Tachy

        • AF/flutter

        • SVT

          • AVNRT

          • AVRT

          • Atrial tachyarrhythmia

        • VT

        • VF

    • Sinus node disease - subtypes

      • Slow rate

      • Occasional failure

      • Exit failure

      • Tachy-Brady syndrome

    • LBBB

      • Supraventricular origin

      • QRS ≥ 120 ms

      • QS or rS complex in V1

      • RsR' wave in V6

    • Wenkiebach

      • Progressively longer PR, then dropped beat

    • Mobitz II

      • Regular dropped beats

    • Escape

      • Infranodal

        • Broad QRS, as not using normal pathway

      • High junctional

        • Uses His-Purkinje system => Narrow QRS

    • Junctional bradycardia

      • Retrograde P waves

      • Weird STs

      • May see in a paced rhythm

    • AF

      • May be coarse or fine

      • Often originates in areas round the pulmonary vein

      • Bigger heart => Predisposition to AF

        • And AF => Bigger heart, so AF BEGETS AF

    • Atrial flutter

      • Dependent on a SLOW ZONE for re-entry round the circuit

        • So can fix by ablation of this zone

      • Conduction through the AV node may be regular or variable

    • Atrial tachycardia

      • Due to enhanced automaticity

      • With AV block, can look like flutter

    • AVNRT

      • Suspect AVNRT if there's an unexplained tachycardia

      • Dependent on the slow and fast pathways through the AV node

        • Can set up a self-propagating loop

        • This then spreads out to the ventricles and sometimes to the atria too

          • => Retrograde P waves

      • P waves may be buried in other stuff, making it all look weird

    • AVRT

      • Orthodromic

      • Normal pathway carries impulse to ventricles

        • Uses bundle of His => Narrow QRS complexes

      • Impulse retrogradely re-enters the atrium via the accessory pathway

        • P waves follow QRS complexes

      • Antidromic

      • Accessory pathway carries impulse down into ventricles

          • Outside of the bundle of His => Wide QRS, maybe with delta wave

      • Impulse re-enters the atrium retrogradely via the AV node

      • Pathway: Posterioseptal or right-sided

    • Pre-excitation

      • WPW

      • Delta waves

    • VT

      • Types

        • Polymorphic

        • Monomorphic

      • Check the axis to see if it could be coming from the AV node

      • Broad-complex tachycardia is VT until proven otherwise

Notes

    • ACS stats

      • 40% of A&E admission are for chest pain

      • 40% of STEMIs die within minutes

    • LBBB causes

      • Underlying CVD

      • Underlying heart muscle disorder

      • Congenital conduction disorder

      • Calcific aortic stenosis

    • Key drugs for management of angina: BETA BLOCKER AND CALCIUM CHANNEL BLOCKER

    • Normal sinus rhythm vs Atrial premature depolarisations vs SVT

    • Epsilon wave

      • Small positive deflection (‘blip’) buried in the end of the QRS complex

      • Characteristic finding in arrhythmogenic right ventricular dysplasia (ARVD)