Cardio Flashcards
inheritance of HOCM
autosomal dominant
where is the hypertrophy in HOCM and how does it lead to sudden death
septal hypertrophy causing LV outflow obstruction
poor prognostic factors in HOCM
young age presentation family history of sudden death abnormal BP changes on exercise non-sustained VT on 24 or 48 hr monitoring syncope increased septal wall thickness
ECG changes of Wolf-Parkinson-White
short PR interval
wide QRS with delta waves (slurred upstroke)
causes of left axis deviation
LBBB left anterior hemiblock WPW with right accessory pathway hyperkalaemia congenital: ostium primum ASD, tricuspid atresia LVH minor LAD in obesity
causes of right axis deviation
Chronic lung disease PE right ventricular hypertrophy left posterior hemiblock ostium secundum ASD WPW with left sided accessory pathway normal in infants <1yr minor RAD in tall people
methodone can have what affect on the heart
prolong QT
what is the physiological reason for prolonged QTs
delayed repolarisation of the ventricles
most commonly defects in the alpha subunit of the slow rectifier potassium channel
normal corrected QT range
how do you calculate it?
<450 in women
QT/squ root of RR (60 divided by HR)
congenital causes of prolonged QT
Jervell-Lange-Nielsen syndrome (inc deafness)
Romano-Ward syndrome (no deafness)
drug causes of prolonged QT
amiodarone, sotalol class 1a antiarrhythmic agents (disopyramide, quinidine, procainamide) TCAs and SSRIs (esp citalopram) methodone chloroquine erythromycin and ciprofloxacin antipsychotics terfenadine (an antihistamine) cocaine
electrolyte and pathological causes of prolonged QT
low K, Ca, Mg, temperature
MI
myocarditis
SAH
Mx of prolonged QT
avoid precipitating drugs/factors B blockers (note sotalol can lengthen QT) implantable cardioverter defibrillators in high risk
Mx of Torsades de pointes
IV Magnesium sulphate
action of enoxaparin/fondaparinux
activates antithrombin III, which potentiates inactivation of Xa
factors in GRACE score
age SBP HR creatinine HF stage cardiac arrest at presentation ST deviation elevated cardiac enzymes
what does GRACE score predict
ACS pts’ risk of in hospital and 6 month mortality
features of pericarditis
chest pain (may be pleuritic) relieved sitting forward non productive cough flu-like symptoms SOB pericardial rub tachypnoea tachycardia
Causes of pericarditis
viral (Coxsackie) TB post MI (Dressler's syndrome) hypothyroidism trauma uraemia (fibrous pericarditis) connective tissue disease
ECG changes of pericarditis
widespread ‘saddle shaped’ ST elevation
PR depression
medical management of stable angina
1.aspirin and statin and b-blocker/CCB (verapamil or diltiazem)
2. increase to max dose (100mg atenolol)
3. add BB or CCB (eg MR nifedipine)
NB dont use BB with verapamil! risk of complete HB
4. add long acting nitrate/ivabradine/nicorandil while awaiting CABG/PCI
most common congenital heart defect
atrial septal defect - ostium secondum (70%)
ECG- RBBB with RAD
Mx of stable SVT
vagal manouvers (valsalva, carotid sinus massage)
adenosine IV 6mg –> 12mg –> 12mg
- C/I in asthmatics, use verapamil
electrical cardioversion
prevention - B-blockers, radio-frequency ablation
C/I to B blockers
uncontrolled HF
asthma
sick sinus syndrome
concurrent verapamil therapy (leads to severe bradycardias)
define pulsus paradoxus
causes
a decrease SBP >10mmHg on inspiration, leading to inability to feel/weakening of radial pulse
severe asthma, cardiac tamponade
define pulsus alternans
cause
alternating strong and weak pulses
severe LVF
define bisferians pulse
cause
“double pulse” - 2 systolic peaks
mixed aortic valve disease
what is a cannon a wave on a JVP and what is the cause
very large a wave (seen due to filling of atria)
due to atrial compression against a closed tricuspid valve
complete heart block, VT/ectopics, nodal rhythm
pathology of the 3rd heart sound?
what conditions are it associated with?
heard in diastolic filling of the ventricle
normal in <30
early sign of LVF (eg dilated cardiomyopathy), also heard in and constrictive pericarditis (pericardial knock)
pathology of the 4th heart sound?
causes?
atrial contraction against a stiff ventricle
AS, hypertension, HOCM
what does IV adenosine do to the heart?
and on the lungs?
causes transient AV heart block
and bronchospasm therefore C/I in asthma
which cardiac enzyme is the first to rise
myoglobin (1-2 hrs, peaks 6-8 hrs)
how long does trop T stay elevated for after MI?
when does it peak?
7-10 days,
4-6hrs
What is the maximum time a patient can be in AF to be cardioverted?
<48 hours - heparinise and DC cardiovert with 4 weeks of anticoagulation afterwards
or pharmacological cardioversion (flecainide if no structural heart dz, otherwise amiodarone)
how common is a patent foramen ovale?
~20% of population
What is the scoring system for AF risk profiling and Mx?
CHADSVASc
0 - no Rx
1 - oral anticoagulant (dabigatran an alternative) aspirin 2nd choice
>1 - oral anticoagulant (dabigatran an alternative)
Features and scores of CHADSVASc
what is it used for?
Congestive heart failure, Hypertension, Age (>75=2),Diabetes, Stroke or TIA (2), Vascular dz (PVD and IHD), Age (>65=1), Sex (female=1)
To assess need for medical management of AF
Action of dabigatran
Direct thrombin (factor 2a) inhibitor
What is the indication for dabigatran?
Non valvular AF with a CHADSVASc score >1 in patients who have difficulty maintaining INR control with warfarin or impractical to use warfarin
Mode of action of fondaparinux?
When is it used?
Antithrombin 3 activator (similar to LMWH (enoxaparin) but no heparin induced thrombocytopenia)
Used in ACS treatment
Mx of ACS
300Mg aspirin, O2/pain/n&v, fondaparinux 2.5mg SC OD or unfractionated heparin if angio within 24hrs
GRACE score:
Low risk (1.5-3% 6/12 mortality):300mg clopidogrel then 75mg for 12/12
Higher risk (>3%): clopidogrel plus GP2b/3a inhib (tirofiban/eptifibatide)
NSTEMI risk >3% - angio within 96hrs
what is Ebstein’s anomaly?
congenital cardiac abnormality in which the tricuspid valve septal leaflet is displaced towards the apex, giving a tricuspid regurgitation (pan systolic murmur, pulsatile hepatomegaly, giant v waves on JVP)
driving restrictions on : elective angioplasty CABG ACS pacemaker insertion ICD
angio - 1 week
CABD - 4 weeks
ACS - 4 weeks, or 1 if sucessfully Rx with angio
PPM - 1 week
ICD - for sustained VT - 6 months. If prophylactic - 1 month.
Causes of cyanotic heart disease
tetralogy of Fallot
transposition of the great arteries
tricuspid atresia
pulmonary valve stenosis
Fallot is more common than TGA but TGA seen more commonly in neonates, Fallot in 1-2 months
causes of acyanotic heart disease
VSD (most common) ASD PDA coarctation of the aorta aortic valve stenosis
VSD more common than ASD, but in adults ASD is more commonly a new diagnosis.
classify aortic dissection
what is the anatomical border?
type A - ascending
type B - descending
type B begins distal to the origin of the left subclavian artery
what is the management of an aortic dissection?
type A - BP control (labetalol) aim SBP 100-120, and refer for surgery.
type B - BP control (labetalol), bed rest.
ECG changes due to digoxin
down sloping ST depression (reverse tick)
flattened/inverted T waves
short QT interval
bardycardia, AV block
Good and poor prognostic features of infective endocarditis
Good: Strep infection
Poor: low complement levels, negative blood culture, prosthetic valve, staph aureus
Types of drug in each of the Vaughan Williams antiarrhythmic categories 1 a/b/c 2 3 4
1a - (quinidine, procainamide) Na channel blocker, increases AP
1b - (lidocaine, tocainide) Na channel blocker, decreases AP
1c - (flecainide, propafenone) Na channel blocker, no effect on AP
2 - beta blockers
3 - (amiodarone, sotalol) K channel blockers
4 - calcium channel blockers
Classify stages of heart failure
NYHA classification
Stage 1 - no limitation on Activity
Stage 2 - slight limitation, ordinary activity -> fatigue/SOB. comfortable at rest
Stage 3 - marked limitation, less than ordinary activity -> fatigue/SOB. comfortable at rest
Stage 4 - severe. SOB at rest
Define a capture beat
occasional narrow complex QRS when others are broad, occuring sooner than expected.
indicates normal AV conduction, so SVT unlikely
causes of an early diastolic murmur
aortic regurgitation pulmonary regurgitation (Graham-Steel murmur)
Causes of a prolonged PR interval
idiopathic hypokalaemia IHD digoxin toxicity aortic root disease eg abscess myotonic dystrophy sarcoidosis lyme disease rheumatic fever
best way of assessing LV function
MUGA nuclear scan, can be performed as a stress test
gold standard for structural imaging of the heart
cardiac MRI
Mx of a PDA
closure with indomethacin (NSAID, PG inhibitor)
beta blockers proven to reduce mortality in HF
bisoprolol and carvedilol
Features of Williams syndrome
rare neurodevelopmental disorder
developmental delay, good language skills, overfamiliar with strangers
supravalvular aortic stenosis
transient hypercalcaemia
contraindication to thrombolysis
active bleeding recent surgery, trauma or haemorrhage coagulation or bleeding disorders severe hypertension >200 stroke <3 months ago pregnancy recent head injury aortic dissection intracranial neoplasm
Moxonidine:
mechonism of action
use
centrally active antihypertensive by decreasing sympathetic tone
used for essential hypertension when other antihypertensives have failed
Complications of PCI
stent thrombosis - 1-2% usually within 1st month. due to platelet aggregation. Presents with MI
restenosis - in 5-20%, within 3-6months. Due to excessive tissue proliferation around stent. Recurrence of angina symptoms.
Risk factors for restenosis of PCI stent
diabetes mellitus
renal failure
stent in a venous bypass graft
pros and cons of drug eluding stent
slows proliferation so slows restenosis but increases risk of thrombosis - need clopidogrel cover for longer
features of Brugada syndrome?
auto dom CVD, may present with sudden death
ECG: ST elevation V1-3 with no Sx of ACS
Na channel disorder
changes more prominent after flecainide (blocks Na channels)
Mx: ICD
How do you diagnose HF
previous MI - echo within 2 weeks
no MI -> BNP
BNP high –> echo within 2 weeks
BNP raised –> echo within 6 weeks
factors which increase BNP level
ischaemia
LVH and RV overload
tachycardia
renal failure
what is the definition of a high and raised BNP
high BNP >400 –> echo within 2 weeks
raised 100-400 –> echo within 6 weeks
normal <100
factors increasing risk of asystole in a bradycardic patient
ventricular pauses >3s
complete HB with broad QRS
recent asystole
mobitz type 2 (2:1 etc)
blind treatment of endocarditis
native valve - amoxicillin
pen allergic/severe/MRSA - vanc + gent
prosthetic valve - vanc + rifampicin + gent
Prinzmetal angina
pathology
Mx
coronary artery vasospasm
Dihydropyridine calcium channel blocker (eg felodipine)
causes of eruptive xanthoma
high TG levels
- familial hypertriglyceridaemia
- lipoprotein lipase deficiency
cause of palmar xanthoma
Remnant hyperlipidaemia
features of tetralogy of Fallot
RV outflow obstruction - varying degrees per pt. Main determinant of TOF severity. resulting R->L shunting
overriding aorta - above both the L and R ventricles.
VSD
RV hypertrophy
indications for ICD
long QT syndromes HOCM previous cardiac arrest due to VT/VF Brugada syndrome previous MI with non sustained VT on 24 hour tape, inducible VT and ejection fraction <35%
Indications for temporary pacemaker
symptomatic/haemodynamically unstable bradycardia resistant to atropine
post Anterior MI with CHB or Mobitz type 2
trifasicular block prior to surgery
what is Beck’s triad and what does it indicate?
hypotension, quiet heart sounds, prominent neck vessels
cardiac tamponade
causes of a split S2 on expiration
aortic stenosis, hypertrophic cardiomyopathy, LBBB, ventricular pacemaker split S2 on inspiration is nomal
causes of a fixed split S2
fixed split = split S2 on both inspiration and expiration
ASD or VSD
features of Takasubo cardiomyopathy
non-ischaemic cardiomyopathy
transient apical ballooning of the myocardium
may be triggered by stress (broken heart syndrome)
chest pain, features of HF, ST elevation, normal coronary angiogram
Rx is supportive.
Mx of patient with new onset AF >48 hours
warfarinise for >3 weeks prior to cardioversion
or do TOE to exclude thrombus in left atrial appendage (LAA), heparinise and DC cardiovert
If high risk of failure to cardiovert (previous failure, AF recurrence), pt should have 4 weeks of amiodarone or sotalol prior to DC cardioversion
Drugs to avoid in wolf parkinson white syndrome
ABCD
adenosine, beta-blocker, calcium channel blockers, digoxin
Classifications of aortic stenosis
normal valve size 3-4 square cm
mild - valve size 2-1.5cm(squ) - pressure gradient 40mmHg
critical - valve <0.6cm squared
Indications for aortic valve replacement
symptomatic severe aortic stenosis
severe or moderate AS pt undergoing CABG or aorta surgery
severe AS with ejection fraction <50%
distinguishing features between SVT with aberrant conduction and VT?
SVT + aberrant conduction - L or R BBB
VT - capture beats, fusion beats, QRS >160ms
