Cardiology Flashcards
Commonest cardiomyopathy
Dilated
What is the pathophysiology behind dilated cardiomypathy?
Systolic dysfunction
Why/When do you hear third heart sound S3?
Filling of the ventricle
Dilated cardiomyopathy, mitral regurg, constrictive pericarditis,
Why/when do you hear S4?
Caused by atrial contraction against a stiff ventricle (coincides with p wave)
e.g. in Ao stenosis, HOCM, HTN
What causes S1?
Closure of mitral/tricuspid valve
What causes S2?
Closure of Ao/pulmonary valves
How does ANP work?
released in response to increased blood volume / HTN
Causes vasodilation:
- natriuretic, i.e. promotes excretion of sodium
- lowers BP
- antagonises actions of angiotensin II, aldosterone
What is associated with variability in intensity of S1?
Complete heart block
What is associated with loud S1
Mitral stenosis
Describe mitral regurg heart sounds
Quiet S1
Widely split s2
S3
most common cause Infective endocarditis?
Staph aureus
what is the commonest cause of infective endocarditis in prosthetic valve (in first two months post surgery)? + indwelling lines
Staph epidermidis / coagulase negative staph
give ECG changes in digoxin toxicity?
bradycardia or AV block a short QT interval a prolonged PR interval ST depression inverted T waves
What ECG changes are pericarditis associated with?
ST elevation
PR depression
Chest pain following MI 6 weeks. What is the likely cause
Dressler’s - autoimmune pericarditis
What type of pulse seen in hypertrophic cardiomypathy?
Jerky pulse
Causes of left axis deviation?
left anterior hemiblock
left bundle branch block
inferior myocardial infarction
Wolff-Parkinson-White syndrome* - right-sided accessory pathway (GOES RIGHT TO LEFT)
hyperkalaemia
congenital: ostium primum ASD, tricuspid atresia
minor LAD in obese people
Causes of right axis devation?
right ventricular hypertrophy left posterior hemiblock lateral myocardial infarction chronic lung disease → cor pulmonale pulmonary embolism ostium secundum ASD Wolff-Parkinson-White syndrome* - left-sided accessory pathway normal in infant < 1 years old minor RAD in tall people
N.b. WPW usually LAD - if Q asks
What is cardiac axis? What is normal?
The axis of the ECG is the major direction of the overall electrical activity of the heart
+90 to -30
What is the mechanism of amiodarone?
K+ channel blocker inhibiting repolarisation and prolonging action potential
[also blocks other channels -
(class III antiarhythmic)
Why are loading doses used with amiodarone?
Long half life
What is the mechanism of class 1 antiarrhythmics? Give the types/ examples for each
Sodium channel blockers (prevent influx of sodium into myocytes –> slower depolarisation [decreasing the slope in phase 0])
1a: procainamide
1b: lidocaine
1c: flecainide
What is the mechanism of class II antiarhythmics?
beta-blockers (e.g. metoprolol or propranolol)
What is the mechanism of class III antiarhythmics? How do they affect ECGs?
K+ channel blockers inhibiting repolarisation and prolonging action potential
Wider/longer QRS and long QT (potential for other arrhythmias)
E.g. amiodarone
What is the mechanism of class III antiarhythmics?
Calcium channel blockers - prevents influx of calcium into cell
also used in lowering BP (prevents smooth muscle contraction in vessels)
e.g. verapamil + diltiazem
Where should you ideally give amiodarone?
via a central line - due to extravasation
What causes a widely split S2?
Pulmonary stenosis
RBBB
Deep inspiration
severe mitral regurg
What causes a loud S2
Pulmonary and/or systemic HTN
Cause of soft S2
Aortic stenosis
Causes of a fixed split S2
ASD
What is the ECG finding in brugada syndrome?
Convex ST elevation V1-3 with T wave inversion (TWI)
Partial RBBB
What is the pathophysiology of brugada syndrome?
Inherited A.D. - sodium channel gene mutation
Predisposes to ventricular tachcyardias
What ECG changes seen in pericarditis?
PR depression ST elevation (saddle)
What is peri-arrest tachycardia? what is the NICE guideline for treatment?
Unstable: shock (hypotension, pallor, sweating, confusion etc); syncope; myocardial ischaemia; heart failure [e.g. raised JVP, crackles etc]
NICE simplified into 1 unified algorithm –> give up to 3 Synchronised DC shocks
Treatment following this is if the QRS is broad or narrow + whether irregular or regular
What is the treatment for broad complex tachycardias?
Regular:
Treat as ventricular tachcyardia (unless previously confirmed SVT with BBB) –> load amiodarone following by 24hour infusion
Irregular:
either AF with BBB
AF with ventricular pre-excitation
Or torsades de pointes
What is the treatment for narrow complex tachycardias?
Regular:
Vagal manouevres –> IV adenosine
If unsuccessful - consider atrial flutter + control rate
Irregular (probable AF)
- If onset <48hrs - electrical or chemical cardioversion
- beta blockade >48hours
Unprovoked PE length of treatment?
6 months
Provoked PE treatment length
3 months
What condition is associated with Inherited long QT syndrome AND sensorineural deafness?
Jarvell-Lange-nielson syndrome
Congenital causes of long QT syndrome
Jervell-Lange-Nielsen syndrome (assoc with sensorineural deafness)
Romano-Ward syndrome (no deafness)
Drug causes of long QT syndrme
amiodarone, sotalol, class 1a antiarrhythmic drugs tricyclic antidepressants, selective serotonin reuptake inhibitors (especially citalopram) methadone chloroquine terfenadine** erythromycin haloperidol ondanestron
electrolyte imbalance causes of long QT
Hypocalcaemia
Hypokalaemia
Hypomagnasaemia
target INR for mechanical valves?
Aortic - 3.0
Mitral - 3.5
Medications to give for prosthetic valves?
bioprosthetic: aspirin
mechanical: warfarin + aspirin
What infective endocarditis bacteria is associated with patients with colon cancer?
Streptococcus bovis
what infective endocarditis bacteria is associated with
Strep viridans (mitis + sanguinis)
Angina Management
All patients: lifetyle changes, adpirin + statin, sublinguial GTN spray
First line: beta blocker OR CCB (use rate limiting - e.g. verapamil)
If poor response: increase to maximum dose
If still symptomatic: add beta blocker or CCB
If cannot tolerate addition - long acting nitrate (e.g. ISMN)
If still symptomatic: PCI or CABG
Contraindications for beta blockers
Peripheral vascular diseases
Diabetes mellitus
Chronic obstructive pulmonary disease (COPD)
Asthma
Mechanism of action of digoxin
K+/Na+ ATPase inhibitor. Na+ rises in myocytes/intracellular –> calcium influx –> increased contractility of heart –> improved CO
Problem with flecainide as an antiarrhythmic
Pro-arrhythmic
Indications for a temporary pacemaker
symptomatic/haemodynamically unstable bradycardia, not responding to atropine
post-ANTERIOR MI: type 2 or complete heart block*
trifascicular block prior to surgery
When are JVP cannon waves seen
In states where the atria + ventricle contraction is not coordinated:
e.g. ventricular tachcyardia, complete heart block, atrial flutter
Hypertension management:
Poorly controlled hypertension, already taking an ACE inhibitor, calcium channel blocker and a standard-dose thiazide diuretic. K+ > 4.5mmol/l. What should be added next?
alpha or beta blocker
Poorly controlled hypertension, already taking an ACE inhibitor, calcium channel blocker and a standard-dose thiazide diuretic. K+ < 4.5mmol/l. What should be added next?
Add spironolactone
What drug to avoid in HOCM?
ACE-i’s, nitrates, inotropes
ACE inhibitors can reduce afterload which may worsen the LVOT gradient (LVOT obstruction in HOCM)
Treatment for HOCM?
ABCDE:
Amiodarone Beta-blockers or verapamil for symptoms Cardioverter defibrillator Dual chamber pacemaker Endocarditis prophylaxis*
How to calculate ventricular ejection fraction?
(Stroke volume / end diastolic LV volume) x 100
How to calculate stroke volume?
end diastolic LV volume - end systolic LV volume
Causes of prolonged PR interval
idiopathic ischaemic heart disease digoxin toxicity hypokalaemia* rheumatic fever aortic root pathology e.g. abscess secondary to endocarditis Lyme disease sarcoidosis myotonic dystrophy
What is ebstein’s anomaly?
What valve defect is seen?
What arrhythmia is it associated with?
congenital heart defect characterised by low insertion of the tricuspid valve resulting in a large atrium and small ventricle
Tricuspid regurg
WPW (/SVT)
How do you decide the appropriate treatment for primary pulmonary hypertension?
Acute vasodilator testing -
shows if patients have a significant fall in pulmonary arterial pressure following the administration of vasodilators such as intravenous epoprostenol or inhaled nitric oxide
What is the treatment for primary pulmonayr HTN if patient shows a positive response to vasodilator testing?
(Minority of patients)
Oral CCB’s
What is the treatment for primary pulmonayr HTN if patient shows a negative response to vasodilator testing?
(Most patients)
- Prostacyclin analogues (e.g. iloprost)
- endothelin receptor antagonists (e.g. bosentan)
- Phosphodiesterase inhibitors (e.g. sildenafil)
Long QT drugs
THE MASCOTS: • Terfenadine • Haloperidol • Erythromycin • Methadone • Amiodarone • Sotalol • Chloroquine • Ondansetron • TCAs • SSRIs
MoA fondaparinux
Activates antithrombin III, which in turn potentiates the inhibition of coagulation factors Xa
What organism is associated with IE in colorectal cancer?
Strep bovis
Commonest cause IE?
Staph aureus
Cause of IE in patients prosthetic valve <2 months?
Staph epidermidis
What are the anticoagulation strategies for CHA2DS2-VASc scores?
0 No treatment
1 Males: Consider anticoagulation
Females: No treatment (this is because their score of 1 is only reached due to their gender)
2 or more Offer anticoagulation
What is seen on histology in rheumatic heart disease?
Aschoff bodies (granulomatous nodules)
What CV drugs cause glucose intolerance?
Thiazides + loop diuretics
Beta blockers
Example of thiazide like diuretic?
Indapamide
Common side effect of ticagrelor?
Dyspnoea
What type of drug is dipyridamole? MoA?
Antiplatelet
inhibition of platelet cAMP-phosphodiesterase
Following ACS what is the antiplatelet management plan?
Aspirin lifelong (clopi if CI'ed) AND 12 months ticagrelor
Ticagrelor MoA
Antiplatelet
Same as clopi: P2Y12 inhibitor
TIA/Stroke antiplatelet plan?
Clopidogrel lifelong
OR if CI’ed Aspirin + dipirydamole lifelong
What drug causes closure of PDA? What keeps it open?
NSAID/ibuprofen or indomethacin (closes)
Opens: PG’s
Prior to starting antihypertensives what should you do?
confirm a diagnosis of HTN with ABPM/HBPM
What is double duct sign?
dilatation of the pancreatic duct and common bile ducts seen on CT suggestive of cholangiocarcinoma or pancreatic cancer
EXAM Q: what is the treatment for paroxysmal AF (if patient has no structural heart disease)?
Flecainide
However, if haemodynamic instability –> DC cardioversion
In pulseless VT in ALS algorithm what should you give if no response to 300mg amiodarone?
150mg amiodarone
EXAM Q: if patient has fast AF but also has asthma and heart failure with reduced what should you use to control rate?
Digoxin
CANT USE b blocker as asthma and can’t use rate limiting CCBs (diltiazem or verapamil) as heart failure (remember rate limiting CCBs cause worsening of heart failure as negatively inotropic)
Drugs contraindicated in heart failure
CCBs rate limiting - not verapamil
What CCB is safe to use in HF with reduced ejection fraction
Amlodipine
Example of endothelin-1 receptor antagonist
-sentan
E.g, bosentan, ambrisentan
In pulmonary hypertension what drugs should be used if positive response to vasodilating testing and if negative?
Positive: oral CCB
Negative:
- endothelin 1 antagonist eg bosentan, ambrisentan
- Iloprost (PG analogue)
- phosphodiesterase inhibitors: sildenafil
In infective endocarditis, what ECG sign makes you worried of aortic root abscess?
Prolonged PR
Requires surgery
What complete heart block should you not insert pacemaker?
If followed by INFERIOR MI (as usually resolves)
Most specific finding in acute pericarditis
PR depression
What drug makes clopidogrel less effective?
Omeprazole
Complete heart block following MI, what artery?
RCA
Commonest causes of Aortic stenosis <65 and >65?
<65 bicuspid ao valve
> 65 calcification
Bisferiens pulse?
Mixed aortic valve disease
What drug should not be prescribed in VT and why?
Verapamil/CCB
Precipitates VF
class IV antiarrhythmic which only acts on nodal tissue and significantly increase the risk of ventricular fibrillation.
Definitive treatment for Mitral stenosis
Percutaneous mitral commissurotomy
If patient with CHF is on ace-i and beta blocker but is deteriorating what should you add next to improve prognosis?
Spironolactone
Is psoriasis a risk factor for CVD?
Yes
Trio of treatments recommended whilst awaiting PCI?
Aspirin
Clopidogrel
Prasugrel
MOA of presugrel
Irreversibly blocks P2Y12 at ADP receptors
same as clopidogrel
