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)