Classifications, Definitions 12 - Flashcards
Classifying an Aortic Dissection
Stanford, DeBakey and European Cardio society
Stanford - A: Ascending aorta and arch
B - descending, distal to left subclavia
DeBakey:
1 - Ascending into the arch
2 - ascending only
3 - descending only - A above diaphragm, B below
Risk factors for dissection
Hypertension
Advanced Age
Male
Smoker
Family Hx
Pregancy
Trauma
Congenital - Marfans, Ehler’s, Co-arctation, Turners.
Complications of a dissection
By organ system
CVS; aortic regurgitation, MI,. Ischaemia Tampanade Hypertension Hypotension - shock/tampanade Limb ischaemia
Neuro - ischaemic stroke
Paraplegia
Pulm - Effusions
Renal - AKI
Haem - transfusion / coag
GI - mesentEric ischaemia
Imaging for dissection
CXR - mediastinum, heart enlarged. Calfication
TTE - see intimate flap, assess for regurgitation and function
TOE - true and false lumens
CT - confirms diagnosis and plan op.
MRI - extent of flap
Aortograph - gold standard but rare
Manage dissection based on A and B
A and complicated B - CTC
A - surgical emergency, sternotomy and CPB. Reduce BP
B - beta blockers/anti hypertensives
Complicated B - left lat thoracotomy
Classify arrhythmia
By heart rate: >100 tachy < 60 Brady
Where it originates - SVT, VT
Regularity - irregularity
Also - tachy divided into broad and narrow complexes
Commonest arrhythmia is ICU
AF
Type of tachy and causes
Sinus - increased sympathetic tone, or compensating for dilation, low CO, hypoxia, anaemia, hyperthermia
Atrial tachy - channlelopathy, structural
AV tachy - nodal and non-nodal reentrants
VT - electrolytes, K and Mg, and after ischaemia. Maybe long QT
Causes of AF
Hypovolaemia Sepsis Low K, low Mg Hypoxia Ischaemia PE Thyrotoxicosis
When to cardiovert AF
Hypotension <90
Oedema
Chest pain
Reduced GCS
Assess need for anticoag in AF
CHADSVASC score
Define atrial flutter
Supra-ventricular tachycardia
Presence of a re entry circuit in the RA
Atrial rate = 300
AV node blocks rapid flutter waves, therefore vent rate lower
Does not respond to vagal
Adenosine - underlying rhythm, not a cure
Tx - rate control, chemical/electrical cardio
AVNRT
Atrioventricular Nodal Re-Entrant Tachy
Type of SVT - causes palpitations in structurally normal heart
140-280/min
Two functional pathways round AV node
Slow posterior and fast anterior.
Gives rise to:
Slow-fast AVNRT 80% - P waves hidden in QRS,
Fast slow 10%
Slow slow 5%
Tx AVNRT
Vagal
Adenosine
Beta blockers or CCB
Flecanide / Amiodarone
AVRT
AV re-entrant tachy
SVT. Re-entry circuit distinct from AV node
Pre-excitation—> tachy because AV doesn’t delay.
Commonest WPW
WPW and ECG finding
Aberrant conduction via the BUNDLE OF KENT
Accessory path)
Delta wave - slurred upstroke
PR interval <120
T wave deflects opposite to QRS (QRS/T discordance)
Tall R wave, T wave inversion in pre-cordial waves, mimics RVH/LVH
Types of WPW
Type A - positive delta in precordial dominant S in V1 (left side path)
Type B - negative delta wave in V1
Treatment of AVRT
Vagal
Adenosine (may cardiovert)
CCB first line
DCCV
Antidromic AVRT may look like VT, if in doubt treat as VT
What if you get AF with WPW
the AV node is bypassed direct to ventricles
Use of adenosine/b blockers INCREASES conduction and may cause VT or VF
Treat - procainamide of DCCV
Causes of Long QT
Congenital - Romano Ward (AD) Jervell Lange Neilson (AR)
Electrolytes - low K, low Mg, low Ca
MI
SAH
Hypothermia
Drugs - Antiarrhythmics - Amio, sotolol
Abx - eryth, clarity, fluconazole
Ondansetron
TCA/SSRI
Classify anti-arrhythmic
Vaughan Williams Class
1 - Na channel blocker
2 - beta block - bisoprolol/metoprolol - SVT
3 - K block Prolong phase 3, increases AP duration, - amio, SVT/VT
4 - Ca block - reduce SA/AV - verapamil/diltiazem , SVT
Classify group 1 Vaughan William
Na blockers, reduce rate of rise of phase 0
1a - Prolong refractory - Procainamine (SVT/VT)
1b - Shortened ARP - lignocaine/phenytoin (VT)
1c - no change - Flexanide (SVT/VT)
Stages of action potentia
0 depolar (fast Na)
1) Repolar (k efflux
2) Plateura K out, Ca in
3) repolar, Ca closes
4 RMP Na/K
Define asthma
Chronic inflammatory condition of airways
Presents as breathless, wheeze and cough, with diurnal variance
FEV1/FVC < 65%
FEV1 < 70%
Increase by 12% with bronchodilator
associated with autopsy
Pathophys of asthma
Chronic airway inflammation
Smooth muscle hypertrophy
Goblet cell hyperplasia
Increased reactivity, oedema and secretions.
Leads to mucous plugging and scarring - epithelial collagen deposition
Moderate asthma
Increasing symptoms
PEFT 50-75% of best
No severe feature
Severe asthma
One of
PEFR 33-50%
RR>25
HR>110
Can’t complete sentences
Life threatening asthma
Ix: PEFR < 33% SpO2 < 92% PaO2 < 8 Normal CO2
Clinical: Low GCS Exhaustion Hypotension Cyanosis Silent chest arrhythmia Low resp effort