Cardiology Flashcards
(120 cards)
What is are the risks of verapamil and beta-blocker concurrent use?
Heart block + fatal arrest.
Can use nicorandil for angina instead if patient on verapamil.
Which organism is is commonly associated with infective endocarditis amongst IVDU?
Staphylococcus aureus is commonly associated with infective endocarditis amongst IVDU.
What are the organisms which would cause BC negative endocarditis?
Culture negative causes include:
prior antibiotic therapy
Coxiella burnetii
Bartonella
Brucella
HACEK: Haemophilus, Actinobacillus, Cardiobacterium, Eikenella, Kingella)
What is a rare organism causing endocarditis in a native valve?
Staphylococcus lugdunensis is incorrect. This organism is a rare cause of native valve endocarditis.
In which demographic of patients is staph epidermis a cause of endocarditis?
This organism is associated with prosthetic valve endocarditis.
How does the Valsalva manoueuvre work?
Stages of the Valsalva manoeuvre
1. Increased intrathoracic pressure
2. Resultant increase in venous and right atrial pressure reduces venous return
3. The reduced preload leads to a fall in the cardiac output (Frank-Starling mechanism)
4. When the pressure is released there is a further slight fall in cardiac output due to increased aortic volume
5. Return of normal cardiac output
What does a third (S3) heart sound indicate?
S3 (third heart sound)
caused by diastolic filling of the ventricle
considered normal if < 30 years old (may persist in women up to 50 years old)
heard in left ventricular failure (e.g. dilated cardiomyopathy), constrictive pericarditis (called a pericardial knock) and mitral regurgitation
What ECG changes do you see for Brugada syndrome?
1) convex ST segment elevation > 2mm in > 1 of V1-V3 followed by a negative T wave
2) partial right bundle branch block
3) the ECG changes may be more apparent following the administration of flecainide or ajmaline - this is the investigation of choice in suspected cases of Brugada syndrome
What is the most common gene mutation seen in Brugada syndrome?
Mutations in the SCN5A gene (which encode the myocardial sodium ion channel protein are the most common gene abnormality seen in Brugada syndrome
How do thiazide diuretics work?
Thiazides/thiazide-like drugs (e.g. indapamide) - inhibits sodium reabsorption by blocking the Na+-Clˆ’ symporter at the beginning of the distal convoluted tubule
What is the classification criteria for aortic dissection?
DeBakey classification
type I - originates in ascending aorta, propagates to at least the aortic arch and possibly beyond it distally
type II - originates in and is confined to the ascending aorta
type III - originates in descending aorta, rarely extends proximally but will extend distally
What drugs may potentiate the action of warfarin?
Factors that may potentiate warfarin
liver disease:
P450 enzyme inhibitors, e.g.: amiodarone, ciprofloxacin
cranberry juice
drugs which displace warfarin from plasma albumin, e.g. NSAIDs
inhibit platelet function: NSAIDs
What is the medical management of HOCM?
Management
Amiodarone
Beta-blockers or verapamil for symptoms
Cardioverter defibrillator
Dual chamber pacemaker
Endocarditis prophylaxis*
What drugs should you avoid in someone with HOCM?
nitrates
ACE-inhibitors
inotropes
What does Bisferiens pulse indicate?
Bisferiens pulse - mixed aortic valve disease
How does hydralazine work?
Mechanism of action
increases cGMP leading to smooth muscle relaxation
How do you manage aortic stenosis?
Management
if asymptomatic then observe the patient is a general rule
if symptomatic then valve replacement
if asymptomatic but valvular gradient > 40 mmHg and with features such as left ventricular systolic dysfunction then consider surgery
options for aortic valve replacement (AVR) include:
surgical AVR is the treatment of choice for young, low/medium operative risk patients. Cardiovascular disease may coexist. For this reason, an angiogram is often done prior to surgery so that the procedures can be combined
transcatheter AVR (TAVR) is used for patients with a high operative risk
balloon valvuloplasty
may be used in children with no aortic valve calcification
in adults limited to patients with critical aortic stenosis who are not fit for valve replacement
What pulse abnormality is most associated with patent ductus arteriosus?
Patent ductus arteriosus - large volume, bounding, collapsing pulse
What is the target INR for mechanical aortic and mitral valves?
Aortic - 3
Mitral - 3.5
Which protein is effected in HOCM?
HOCM is usually due to a mutation in the gene encoding β-myosin heavy chain protein or myosin binding protein C
Which part of the QRS complex is used for synchronisation?
Electrical cardioversion is synchronised to the R wave
What medications are patients with prosthetic heart valves and mechanical heart valves started on?
1) Prosthetic heart valves: bioprosthetic: aspirin
2) Mechanical: warfarin + aspirin
Which ECG changes do you see in hypothermia?
J-waves are associated with hypothermia
What is the difference in the mechanism of action of fondaparinux and other anticoagulants?
Fondaparinus activates antithrombin III which potentiates the inhibittion of coagulation factors Xa and is given SC.
Direct thrombin inhibitors are normally given IV however dabigatran (DOAC) is an example of a direct thrombin inhibitor which is taken orally.
