Flashcards in Cardiology Deck (62):
Cardiology: What is the definition of syncope?
A transient loss of consciousness due to transient global cerebral hypoperfusion characterized by rapid onset, short duration and complete recovery.
Cardiology: What features would suggest vasovagal syncope?
• Long-history of syncope
• Prolonged standing
• Noxious stimulus
• Nausea and vomiting associated.
• Absence of cardiac disease
• After exertion
• After head tilting / carotid pressure
Cardiology: What features would suggest cardiac syncope?
• Known history of cardiac disease
• Evidence of structural abnormality
• Preceded by chest pain / palpitations
• During exercise
Cardiology: What is the treatment for syncope? (In broad terms)
Treat the underlying condition.
E.g. Ischaemia, drug-induced.
Cardiology: What is the normal PR interval? (In squares and time)
3-5 small squares
Cardiology: What is the normal size of a QRS?
3 small squares
Cardiology: What is the first-line treatment for symptom relief in chronic stable angina?
Nitrates, e.g. GTN
Cardiology: What is the mechanism of action of nitrates?
Release of NO to activate and increase cyclic-GMP which causes smooth muscle relaxation and subsequent cardiac vasodilation.
Cardiology: What are the side-effects of nitrates?
Cardiology: What are the contraindications of nitrates?
• Aortic/ Mitral stenosis
• Hypertrophic cardiomyopathy
Cardiology: What is the first-line treatment of chronic stable angina?
Cardiology: What is the mechanism of action for beta-blockers in the treatment of chronic stable angina?
• Reduces sympathetic stimulation to the heart, causing a reduction in heart rate and myocardial contraction.
• Reduces cardiac workload to increase exercise tolerance and reduce symptoms.
Cardiology: If a patient is contra-indicated for beta-clockers what is the first-line treatment for the management of chronic stable angina?
• Non-dihydropyridine calcium channel blocker.
• E.g. Verapamil, Diltiazem
Cardiology: What are the side-effects of beta-blockers?
Bronchospasm, bradycardia, cold peripheries, sleep disturbance, sexual dysfunction, fatigue.
Cardiology: What are the contra-indications of beta-blockers?
Uncontrolled heart failure
2/3rd degree heart block
Severe peripheral arterial disease
Cardiology: Which medications may be added for treatment of chronic stable angina if beta-blockers are not provided sufficient relief?
• 2nd Line - Calcium-channel blockers (Amlodipine, Felodipine, Nifedipine)
• Longer-acting nitrates
• Potassium channel activators (Nicorandil)
Cardiology: What is the mechanism of action of calcium channel blockers in the treatment of chronic stable angina?
• Smooth muscle relaxation due to inhibition of influx of calcium ions.
• Relaxation of coronary and peripheral smooth muscle.
Cardiology: Non-dihydropyridine calcium channel blockers (Verapamil, Diltiazem) have an additional mechanism to other calcium channel blockers, what is it?
Slows conduction of AV node so has a rate limiting effect.
Cardiology: What are the side-effects of dihydropyridine calcium channel blockers? (amlodipine, felodipine, nifedipine)
Cardiology: What are the contraindications for the use of dihydropyridine calcium channel blockers? (Amlodipine, felodipine, nifedipine)
• Uncontrolled heart failure
• Within one month post-MI
• Severe aortic stenosis
Cardiology: What are the side-effects of non-dihydropyridine calcium channel blockers? (Verapamil, diltiazem)
• AV/SA heart-block
• Constipation (Verapamil)
Cardiology: What are the contraindications of non-dihydropyridine calcium channel blockers? (Verapamil, diltiazem)
• 2/3 degree heart block
• Verapamil not to be used with beta-blocker
• Heart failure
• Acute porphyria
Cardiology: What is the mechanism of action of nicorandil in the treatment of chronic stable angina?
• NO donor to acticate cyclic-GMP to act as a vasodilator to both venous and arteries.
• Opens K channels resulting in efflux of K and reduction in Ca causing smooth muscle relaxation.
Cardiology: What are the side-effects of nicorandil?
• GI irritation
Cardiology: What is the acronym for the initial management of a suspected ACS?
• Morphine (5-10mg Given by slow I.V, an anti-emetic will also be needed)
• Aspirin (300mg stat)
Cardiology: What is the MI-5? (Secondary prevention for an ACS)
Cardiology: What is the mechanism of action of aspirin?
• Irreversibly inhibits COX-1 and COX-2.
• This inhibits the production of Thromboxane A2.
• Which in turn inhibits platelet aggregation.
Cardiology: What are the side-effects of aspirin?
• GI irritation
Cardiology: What are the contra-indications and interactions of aspirin?
• Active peptic ulceration, hypersensitivity, bleeding disorder.
• Any other drugs that increase the risk of bleeding.
Cardiology: What is the mechanism of action of clopidogrel?
• A prodrug converted to active metabolite by CYP enzymes.
• Irreversibly blocks py12 receptor on platelet surface.
Cardiology: What are the side-effects of clopidogrel?
• GI irritation
Cardiology: What are the contra-indications and interactions of clopidogrel?
• Active bleeding.
• Any other drug which increases bleeding risk, Fluoxetine (reduces antiplatelet effect), Enzyme inducers (carbamazepine, fluconazole, PPIs)
Cardiology: What is the mechanism of action of ACE-I?
• Reduces formation of Angiotensin II from angiotensin I.
• Results in reduced vasoconstriction and reduced formation of Aldosterone (Which promotes sodium and water retention)
Cardiology: What are the side-effects of ACE-I?
• Renal impairment
• Hepatic impairment
Cardiology: What are the contra-indications and interactions of ACE-I?
• Use with caution in renal impairment. Bilateral renal artery stenosis, severe aortic stenosis.
• Diuretics, nephrotoxic drugs.
Cardiology: What is the mechanism of action of ARBs (sartans)?
• Direct antagonist of Angiotensin II - blocks the vasoconstriction and aldosterone release.
Cardiology: What are the side-effects of ARBs?
• Renal impairment
Cardiology: What are the contra-indications and interactions of ARBs?
• Cautions - renal artery stenosis, renal impairment.
• Diuretics, use with ACE-I only under specialist supervision.
Cardiology: What is the definition of hypoxia?
• A lack of oxygen resulting in a decrease in aerobic oxidative respiration resulting in cell injury.
Cardiology: What is the definition of ischaemia?
A lack of blood supply to a tissue or drainage away from a tissue due to stenosis or obstruction of a vessel. This results in a loss of oxygen and a build up of toxic metabolites. Tissue injury is quicker from ischaemia than hypoxia.
Cardiology: What is the definition of infarction?
Irreversible damage to a tissue due to ischaemia and hypoxia.
Cardiology: What are the mechanisms of cell injury?
• Decreased ATP production
• Membrane damage
• Increased intracellular calcium
• Increased oxygen derived free radicals
Cardiology: Give some differentials for chronic stable angina.
• Reflux oesophagittis
• Aortic Dissection
• Costochondral pain
• Varicella zoster
Cardiology: What are the three indications for coronary bypass surgery (According to AHA)
• 3 vessel disease
• 2 vessel disease with LV impairment
Cardiology: What are the four life-threatening causes of chest pain that you should never miss?
• Tension pneumothorax
• Dissecting thoracic aneurysm
Cardiology: What are the three main causes of aortic stenosis?
• Calcific degeneration
• Bicuspid valve
Cardiology: What are the complications of aortic stenosis? (Cardiac)
Pressure build up in the left ventricle leading to left ventricular hypertrophy, LV dilation and LV failure.
Cardiology: What pulse do you get with aortic stenosis?
Cardiology: What is the classification of severe aortic stenosis, in terms of mean gradient mmHg, Jet velocity and valve area.
• Mean gradient >40mmHg
• Jet velocity m/s >4.0
• Valve area cm2
Cardiology: In which four situations is AVR recommended for aortic stenosis?
• Symptomatic severe AS.
• Severe AS undergoing CABG
• Severe AS undergoing surgery on aorta or other heart valves.
• Severe AS and LV systolic dysfunction.
Cardiology: What are the two structures that allow blood to bypass the lungs in the fetal circulation?
• Ductus arteriosus
• Foramen Ovale
Cardiology: What changes occur in the fetal lungs following birth?
• Birth causes the infant to take first breaths.
• Lungs fill with air and alveolar fluid is cleared.
• Pulmonary capillaries absorb oxygen from the air, pulmonary arterioles dilate causing pulmonary vascular resistance to fall dramatically.
• Blood flows into the pulmonary vascular system.
Cardiology: What causes the ductus arteriosus to close following birth?
• Due to decreased pulmonary vascular resistance, the pressure in the pulmonary artery falls.
• This causes blood to flow from the aorta through the Ductus arteriosus into the pulmonary artery.
• The ductus closes in response to oxygen by the contraction of smooth muscle.
Cardiology: How does the foramen ovale close following birth?
• Due to increased blood flow returning from the lungs, the pressure in the left atrium increases.
• As blood flow returning from placaenta is decreased, the pressure in the right atrium decreases.
• Both these changes close the foramen ovale by pressing the septum primum against the septum secundum.
Cardiology: What structures do the ductus arteriosus, ductus venosus, umbilical arteries and umbilical vein become?
• Ductus arteriosus - ligamentum arteriosum
• Ductus venosus - ligamentum venosum
• Umbilical arteries - Medial umbilical ligaments
• Umbilical vein - ligamentum teres
Cardiology: What are the symptoms of persistent pulmonary hypertension of the newborn?
• Right to left shunting across PDA and PFO
• Lower limb sats
Cardiology: What is the treatment for pulmonary hypertension of the newborn?
• Oxygen, ventilation, nitric oxide.
• Extracorporeal membrane oxygenation.
Cardiology: What is Starling's law of the heart?
The ability of the heart to change its force of contraction and therefore stroke volume in response to changes in venous return.
Cardiology: The presence of a bicuspid aortic valve is associated with which conditions?
• Aortic root dilation
• Heyde's syndrome
• Williams syndrome
• Turner's syndrome
Cardiology: What are the symptoms of aortic stenosis?
- Syncope - Exertional
(May be asymptomatic in earlier stages)
Cardiology: What are the initial investigations for suspected aortic stenosis?
• FBC - ensure not anaemic
• Renal function
• ECG (Heart block, LBBB)
• CXR (coarctation, heart failure, aneurysm.)