Cardiovascular 2 Flashcards
What should be considered when using multiple anti-arrhythmic drugs simultaneously?
when using multiple anti-arrhythmic drugs together
their negative effects on the heart’s pumping ability add up (negative inotropic effects)
This is especially concerning if the heart’s function is already compromised (mycordial infarction)
as it can further decrease its ability to pump blood effectively
Therefore, caution is needed when prescribing these drugs together, particularly in patients with existing heart issues.
How can hypokalaemia affect the pro- arrhythmic effect of many drugs?
Enhances it
when potassium levels are low, the heart is more prone to developing arrhythmias, and the effects of anti-arrhythmic drugs can be intensified, potentially leading to more severe or unpredictable outcomes
Potassium plays a crucial role in maintaining the electrical activity of the heart.
Can a myocardial infarction compromise the function of the heart? (4)
During a heart attack, the blood flow to a part of the heart muscle is blocked, resulting in damage to that area of the heart- leading to cell death, formation of scar tissue
the heart cannot regenerate new muscle cells to replace those damaged during a heart attack- can only form scar tissue
Scar tissue does not contract or conduct electrical impulses like healthy heart muscle, so it can impair the heart’s overall ability to pump blood efficiently (can also increase the risk of abnormal heart rhythms (arrhythmias).
What are potential long term complications of a myocardial infarction? (4)
Heart Failure: The loss of heart muscle function can reduce the heart’s ability to pump blood effectively, leading to heart failure
Arrhythmias: Scar tissue and changes in the heart’s electrical system can increase the risk of abnormal heart rhythms (arrhythmias)
Reduced Exercise Capacity: Some individuals may experience a decrease in exercise tolerance or shortness of breath due to the compromised function of the heart muscle.
Increased Risk of Future Events: Individuals who have had a heart attack are at higher risk of experiencing recurrent heart attacks or other cardiovascular events in the future.
How can a patient significantly improve the heart’s overall health and function following a myocardial infarction? (4)
adopting a heart-healthy diet
regular exercise
quitting smoking
adhering to prescribed medications
What is the recommended treatment for life-threatening new-onset atrial fibrillation?
Emergency electrical cardioversion
What drugs can be used to control ventricular rate in atrial fibrillation if it’s not life-threatening?
a standard beta-blocker(excluding sotalol)
or
rate-limiting calcium channel blocker such as diltiazem or verapamil
If monotherapy fails, a combination of two drugs including a beta-blocker, digoxin, or diltiazem can be used.
How can sinus rhythm (normal heart rhythm)be maintained after cardioversion?
so you’ve just done cardioversion for a patient and treated their abnormal heart rhythms. They now have a normal heart rate and we need to maintain it.
Maintain with:
a standard beta-blocker.
Alternatively,sotalol, flecainide, propafenone, or amiodarone may be considered.
Why should verapamil be avoided in patients treated with beta-blockers?
due to the increased risk of severe hypotension and asystole.
When verapamil and beta-blockers are used together, they can have an additive effect on lowering blood pressure and slowing heart rate. This combination can lead to excessive lowering of blood pressure (severe hypotension) and dangerously slow heart rate (asystole), which can be life-threatening.
What is cardioversion?
Cardioversion is a medical procedure used to convert an abnormally fast heart rate (tachycardia) or other cardiac arrhythmias to a normal rhythm
using either electricity or drugs
When is electrical cardioversion preferred for atrial fibrillation?
Electrical cardioversion is preferred if atrial fibrillation has been present for more than 48 hours
procedure doesnt happen straight away
need to fully anticoagulate patient for at least 3 weeks before
and need to continue anticoagulate for 4 weeks after procedure
What is atrial fibrillation characterized by?
irregular and often rapid heartbeats
What are the symptoms of atrial fibrillation? (3)
palpitations
fatigue
shortness of breath
What complications can atrial fibrillation lead to? (2)
Stroke
heart failure
How does atrial fibrillation lead to an irregualr heartbeat in the ventricles?
In atrial fibrillation, the upper chambers of the heart (atria) beat irregularly and rapidly
they fibrillate (quiver)
This can result in **inefficient filling of the ventricles **
and irregular transmission of electrical impulses to the ventricles
leading to an irregular heart rate in the ventricles as well
In atrial fibrillation, drugs are given to CONTROL the ventricular rate but not the atrial rate. Why is this?
controlling ventricular rate is often prioritized as it effectively improves symptoms and reduces risks
What is electrical cardioversion? (3)
an electrical shock is delivered to the heart through paddles or patches placed on the ches
The shock interrupts the abnormal heart rhythm
and allows the heart’s natural pacemaker (the sinoatrial node) to reestablish a normal sinus rhythm.
What is pharmacological cardioversion?
involves the use of medications
such as antiarrhythmic drugs
to help restore normal heart rhythm
What assessments should be conducted for all patients with atrial fibrillation? (2)
risk of stroke
risk of bleeding
How is risk of stroke identified? (8)
CHADSVAC
CHADSVAC
Congestive heart failure (1)
Hypertension (1)
Age 65-74 (1)
Diabetes mellitus (1)
Stroke/TIA/thrombo-embolism (2)
Vascular disease (1)
Age ≥ 75 (2)
Category of Sex Female (1)
What CHA2DS2-VASc score indicates a very low risk of stroke for men and women ?
0 for men
1 for women
means they do not require antithrombotic therapy for stroke prevention
How is the risk of bleeding assesed? (8)
HASBLED score
Hypertension (1)
Abnormal liver function (1)
Abnormal renal function (1)
Alcohol (≥ 8u / week) (1)
Stroke (1)
Bleeding (1)
Labile INRs (<60%) (1)
Elderly (Age >65) (1)
Drugs (antiplatelets or NSAIDs) (1)
With what CHA2DS2-VASc score is oral anticoagulation recommended?
(men and women)
yes we look at stroke score for this
≥ 2 (men)
or ≥ 3 (women)
What HAS- BLED score indicates a high risk of bleeding?
≥ 3
What is the primary function of amiodarone?
alters sinus rhythm to restore normal heart beat
Why may loading doses of amiodarone be required?
Amiodarone has a long half-life
it may take several days or even weeks to reach steady-state levels in the bloodstream when starting amiodarone therapy
so loading doses may be necessary to achieve therapeutic levels quickly.
What are the warning signs associated with amiodarone use? (7)
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Thyroid dysfunction
Corneal micro deposits
Hepatotoxicity
Impaired vision
Neurological effects
Pulmonary toxicity
Photo-toxic skin reactions
How long after stopping treatment with amiodarone can side effects occur?
Side effects can occur up to a year after stopping treatment
(due to the drug’s long half-life)
What is the management strategy for corneal microdeposits caused by amiodarone?
Corneal microdeposits are reversible on withdrawal of amiodarone
(rarely interfere with vision)
How often should thyroid function tests be conducted in patients receiving amiodarone therapy?
before treatment initiation and then every 6 months during treatment
When is serum potassium (K+) measured in patients receiving amiodarone?
before initiating treatment with amiodarone.
Why is a chest x-ray performed before initiating treatment with amiodarone? (2)
assess the patient’s pulmonary status
to screen for potential pulmonary toxicity, such as pneumonitis or pulmonary fibrosis
Amiodarone has been associated with adverse pulmonary effects, including pneumonitis and pulmonary fibrosis,
What is recommended for patients receiving intravenous (IV) amiodarone?
An ECG
amiodarone can have profound effects on cardiac conduction and rhythm
What is the recommendation regarding the use of amiodarone during pregnancy?
Amiodarone should only be used during pregnancy if there is no alternative
(as there is a risk of neonatal goitre associated with its use)
Neonatal goiter= enlargement of the thyroid gland in newborn infants.
Why is breastfeeding discouraged in mothers taking amiodarone? (2)
because the drug is present in significant amounts in breast milk
and there is a theoretical risk of neonatal hypothyroidism due to the release of iodine.
Excessive iodine exposure, such as that which can occur with medications like amiodarone, can disrupt the normal functioning of the thyroid gland.
Why can drug interactions with amiodarone occur even after treatment has stopped?
has a long half-life.
What severe cardiac complications can arise when sofosbuvir is taken with amiodarone?
can increase the risk of severe bradycardia and heart block.
sofosbuvir= a medication used to treat hepatitis C
What medications may experience increased plasma concentrations when taken with amiodarone? (6)
Please put Fred’s dog down the court
Phenytoin
phenindione
Flecainide
Dabigatran
Digoxin
(The)
Coumarins
What are some medications that can increase the risk of ventricular arrhythmias when taken with amiodarone?
- amisulpride
- atomoxetine
- chloroquine
- citalopram
- disopyramide
- escitalopram
- haloperidol
- hydroxychloroquine
- levofloxacin
- lithium
- mizolastine
- mefloquine
- moxifloxacin
- phenothiazines
- pimozide
- quinine
- sulpiride
- telithromycin
- tolterodine
- tricyclic antidepressants
What cardiac complications are more likely to occur when amiodarone is taken with beta-blockers, diltiazem, or verapamil?(3)
can increase the risk of:
bradycardia
atrioventricular (AV) block
myocardial depression
AV heart block happens when the electrical impulses are delayed or blocked as they travel between your atria (the top chambers of your heart) and your ventricles (the bottom chambers of your heart).
Myocardial depression refers to a condition where the ability of the heart muscle (myocardium) to contract and pump blood is reduced
What drug interaction exists between amiodarone and simvastatin?
increased risk of myopathy
What is the primary function of sotalol?
reduce heart rate in arrhythmias
its a beta- blocker
What safety concern is associated with sotalol use? (2)
Sotalol can prolong the QT interval
which can occasionally lead to life-threatening ventricular arrhythmias.
What monitoring is recommended for patients taking sotalol? (2)
undergo ECG and measurement of corrected QT interval
Additionally, monitor serum electrolytes (potassium, magnesium, calcium)
The corrected QT (QTc) interval is a measurement derived from the QT interval on an electrocardiogram (ECG)
The QT interval represents the time it takes for the heart’s ventricles to depolarize and repolarize during each heartbeat.
What must be corrected before starting sotalol and during its use?
electrolyte disturbances (such as hypokalemia, hypomagnesemia, and hypercalcemia)
What is the primary function of digoxin? (2)
Digoxin slows down the heart rate
while increasing the force of heart contraction
What is the therapeutic range for digoxin?
1 to 2 mcg/L
What are the different bioavailabilities of digoxin in various dosage forms? (3)
IV, tablet, elixir
IV (intravenous) - 100%, Tablet - 50-90%
Elixir - 75%.
What are some warning signs that patients taking digoxin should report to their doctor immediately? (6)
New cars get seen visually
neurological symptoms (weakness, lethargy, dizziness, headache, mental confusion, and psychosis)
any cardiac symptoms (arrhythmias and heart block)
gastrointestinal symptoms (anorexia, nausea, vomiting, diarrhea, abdominal pain)
signs of overdose (toxicity difficult to differentiate from clinical deterioration)
visual symptoms (blurred and/or yellow vision)
in which range is digoxin toxicity likely?
1.5 to 3 mcg/L
How should larger doses of digoxin be administered to avoid gastrointestinal symptoms?
should be divided
to avoid gastrointestinal symptoms such as anorexia, nausea, vomiting, diarrhea, and abdominal pain.
What should be done in the event of a digoxin overdose?
the medication should be stopped immediately
(Toxicity is difficult to differentiate from clinical deterioration, and toxicity is likely through a range of 1.5 to 3 mcg)
What electrolytes should be monitored in patients taking digoxin, and why? (2)
Serum electrolytes, including potassium (K+), magnesium (Mg2+), and calcium (Ca2+)
because toxicity can be increased by electrolyte disturbances such as hypokalemia, hypomagnesemia, and hypercalcemia.
Why is monitoring renal function important in patients receiving digoxin therapy?
because the drug is primarily excreted by the kidneys
Dose adjustments may be necessary in patients with renal impairment so that digoxin and its metabolites do not accumalate
How often should digoxin levels be measured in patients with renal impairment?
measure at least every 6 hours
(by taking blood samples and looking at the plasma concentration of digoxin)
What is the target heart rate that should be maintained in patients taking digoxin?
a heart rate above 60 beats per minute
What adjustments should be made in digoxin dosage for patients with renal impairment? (2)
- the digoxin dosage should be reduced
- plasma concentrations should be monitored
What are some drug interactions that can increase plasma concentration when combined with digoxin? (13)
- alprazolam
- amiodarone
- ciclosporin
- diltiazem
- itraconazole
- lercanidipine
- macrolides
- mirabegron
- nicardipin
- nifedipine
- quinine
- spironolactone
- verapamil
How can certain medications affect the risk of cardiac toxicity and digoxin toxicity when taken with digoxin?
Drugs that increase the risk of cardiac toxicity and digoxin toxicity (as cause hypokalaemia):
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- acetazolamide
- amphotericin
- loop diuretics
- or thiazides/related diuretics
Additionally, drugs that impair renal function, can affect plasma digoxin concentrations such as:
- nonsteroidal anti-inflammatory drugs (NSAIDs)
- angiotensin-converting enzyme (ACE) inhibitors
What are the treatment aims for conditions such as atrial fibrillation (AF)?
are to prevent complications such as stroke and venous thromboembolism (VTE)
What are the two main approaches for managing atrial fibrillation (AF)?
by controlling ventricular rate (rate control)
or attempting to restore and maintain sinus rhythm (rhythm control).
What is the preferred first-line option for rate control in atrial fibrillation (AF)?
Rate control in atrial fibrillation (AF) is preferably achieved using a beta-blocker (not sotalol)
or a rate-limiting calcium-channel blocker such as diltiazem or verapamil.
How is rhythm control achieved in atrial fibrillation (AF)?
Rhythm control in atrial fibrillation (AF) is achieved using a beta-blocker.
If a beta-blocker is ineffective or not tolerated, an oral anti-arrhythmic drug such as sotalol, flecainide, or amiodarone can be used.
Give an example of an anti-arrhythmic drug that acts on both supraventricular and ventricular arrhythmias.
Amiodarone
What class of drugs acts on only ventricular arrhythmias?
lidocaine
What is the mode of action of beta-blockers? (2)
reduce cardiac output
by blocking beta-receptors in the heart
(They also act on beta-receptors in the lungs, liver, bronchi, and pancreas)
Why are beta-blockers contraindicated in patients with uncontrolled heart failure?
because they can further reduce cardiac output
exacerbating heart failure symptoms.
Which beta-blockers are water-soluble and unable to cross the blood-brain barrier (BBB)?
- celiprolol
- atenolol
- nadolol
- sotalol
resulting in fewer sleep disturbances and nightmares.
(CANS)
Why are cardioselective beta-blockers preferred in patients with asthma or COPD? (2)
because they have a weaker effect on beta-receptors in the bronchi
reducing the risk of bronchospasm.
How do beta-blockers affect carbohydrate metabolism?
Beta-blockers can affect carbohydrate metabolism
potentially causing either hyper- or hypoglycemia
(in patients with or without diabetes)
Besides reducing cardiac workload, in what other conditions are beta-blockers beneficial? (4)
Beta-blockers are beneficial in angina by reducing the workload of the heart and may prevent the recurrence of myocardial infarction (MI).
They also block sympathetic activity in heart failure, reducing mortality.
Additionally, beta-blockers such as propranolol can be used for symptoms of anxiety
and in the prophylaxis of migraine.
By reducing the force of contraction of the heart muscle, beta-blockers decrease the workload of the heart, thereby reducing oxygen demand.
Beta-blockers decrease the heart rate, which reduces myocardial oxygen demand. This can be particularly beneficial during exertion when the heart requires more oxygen.
What are the therapeutic uses of digoxin?
Digoxin is used to increase the force of myocardial (heart muscle) contraction
and reduce conductivity of the AV node.
It can be used for atrial fibrillation and heart failure.
What is the dosing frequency of digoxin?
Digoxin has a long half-life, allowing for once-daily dosing.
However, if a patient is not responding to the medication, the dose can be increased to one tablet twice daily.
When should blood monitoring be conducted for patients taking digoxin?
If blood monitoring is required, a sample should be taken at least 6 hours after a dose of digoxin.
How can the risk of hypokalemia be managed in patients taking digoxin? (3)
Patients can take
- potassium-sparing diuretics
- potassium supplements
- foods high in potassium, such as bananas.
What are the signs and symptoms of digoxin toxicity? (7)
“Nothing Beats Walking Among Peaceful, Harmonious Atmospheres.”
- nausea/vomiting
- blurred/yellow vision
- weight loss
- anorexia
- palpitations
- hallucinations
- abdominal pain
What should be considered regarding the bioavailability of liquid and tablet formulations of digoxin?
Liquid and tablet formulations of digoxin
have different bioavailabilities,
meaning the patient’s dose may need to be adjusted accordingly.
What is the primary mechanism of action of tranexamic acid, and for what medical conditions can it be used?
Tranexamic acid inhibits fibrinolysis
can be used to prevent bleeding associated with excessive fibrinolysis (e.g., surgery, dental extraction) and in the management of menorrhagia.
What conditions are included under venous thromboembolism (VTE)?
- deep-vein thrombosis (DVT)
- pulmonary embolism (PE)
Who should undergo risk assessment for VTE upon admission to the hospital?
All patients admitted to the hospital should undergo a risk assessment for VTE upon admission.
Which patients are considered to be at high risk for VTE? (6)
Patients considered to be at high risk for VTE include those
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- anticipated to have a substantial reduction in mobility
- obesity
- malignant disease
- history of venous thromboembolism
- thrombophilic disorder
- patients over 60 years old
What pharmacological prophylaxis options are available for high-risk patients to prevent VTE? (3)
Let’s Unite Freely.”
- low molecular weight heparin
- unfractionated heparin (if the patient is in renal failure)
- fondaparinux
What is the initial treatment for deep-vein thrombosis (DVT) and pulmonary embolism (PE)?
low molecular weight heparin or unfractionated heparin via intravenous (IV) infusion.
ALSO:
Warfarin is usually started concurrently
the heparin needs to be continued for at least 5 days and until INR is ≥2 for at least 24 hours.
Why is laboratory monitoring for unfractionated heparin essential during treatment?
Laboratory monitoring for unfractionated heparin is essential
preferably on a daily basis
to ensure therapeutic levels and to prevent complications (such as bleeding or inadequate anticoagulation)
Why are heparins preferred in pregnancy?
they do not cross the placenta
reducing the risk of harm to the fetus
Why are low molecular weight heparins (LMWHs) preferred over unfractionated heparin in pregnancy?
have a lower risk of osteoporosis and heparin-induced thrombocytopenia.
When should treatment with heparins be stopped during pregnancy?
Treatment with heparins should be stopped at the onset of labour
and advice should be sought from a specialist regarding management.
What should be done if hemorrhage occurs in a patient receiving heparin therapy?
If hemorrhage occurs, heparin should be withdrawn.
If rapid reversal of the effects is required, protamine sulfate can be administered as a specific antidote.
However, it only partially reverses the effects of low molecular weight heparins.
How does unfractionated heparin compare to low molecular weight heparins (LMWHs) in terms of onset of action and duration of action?
Unfractionated heparin initiates anticoagulation rapidly but has a short duration of action
while LMWHs have a longer duration of action.
Why are LMWHs generally preferred over unfractionated heparin? (3)
LMWHs are generally preferred because they are
- effective
- have a lower risk of heparin-induced thrombocytopenia
- require less frequent dosing due to their long duration of action.
Why can unfractionated heparin be used in patients at high risk of bleeding?
because its effect can be terminated rapidly by stopping the infusion.
What are the signs of heparin-induced thrombocytopenia, and when does it typically develop?
Signs of heparin-induced thrombocytopenia include:
- a 30% reduction in platelet count
- thrombosis
- skin allergy
It typically develops after 5–10 days of heparin therapy
What should be done if heparin-induced thrombocytopenia occurs?
heparin should be stopped
and an alternative anticoagulant such as argatroban or danaparoid should be given.
Platelet counts should return to the normal range in those who require warfarin.
How can heparins contribute to hyperkalemia, and which patients are more susceptible?
Heparins inhibit aldosterone secretion, which can result in hyperkalemia.
Patients that are more susceptible include:
- diabetes mellitus,
- chronic renal failure
- acidosis
- raised plasma potassium
- those taking potassium-sparing drugs
Plasma potassium concentration should be monitored before and during treatment, particularly if treatment is to be continued for longer than 7 days.
What is the recommended immediate treatment for transient ischemic attack (TIA), and what alternative is suggested if aspirin is contraindicated?
The recommended immediate treatment for TIA is aspirin 300 mg.
If aspirin is contraindicated, clopidogrel 75 mg should be taken immediately.
A transient ischaemic attack, also called a “mini stroke”, is a serious condition where the blood supply to your brain is temporarily disrupted
What is the recommended initial management for ischemic stroke?
Alteplase is recommended if it can be administered within 4.5 hours of symptom onset.
24 hours after thrombolysis:
Treatment with aspirin 300 mg once daily for 14 days should be initiated
(If aspirin is contraindicated, clopidogrel 75 mg once daily is recommended)
Thrombolysis refers to a medical treatment aimed at dissolving or breaking down a blood clot (thrombus) that is blocking an artery in the brain, thereby restoring blood flow to the affected area.
What should be considered for long-term management after a transient ischemic attack (TIA)?
modified-release dipyridamole in combination with aspirin is recommended.
If aspirin is contraindicated, just use the modified-release dipyridamole alone
IF BOTH are contraindicated, clopidogrel alone is recommended.
What is the recommended long-term treatment for ischemic stroke?
Clopidogrel is recommended as long-term treatment for ischemic stroke.
If clopidogrel is contraindicated, modified-release dipyridamole in combination with aspirin is recommended.
How should stroke associated with atrial fibrillation be managed in the long term?
warfarin
When should a statin be initiated after the onset of stroke symptoms, and what lifestyle modifications should be advised to all stroke patients?
A statin should be initiated 48 hours after stroke symptom onset.
All patients should be advised to make lifestyle modifications, including beneficial changes to diet, exercise, weight, alcohol intake, and smoking.
What is a transient ischemic attack?
temporary episode of neurological dysfunction caused by a brief interruption in the blood supply to part of the brain.
It typically lasts for a few minutes to a few hours and resolves completely within 24 hours.
TIAs are often referred to as “mini-strokes” and serve as warning signs for a potential impending stroke.
Although TIAs do not usually cause permanent brain damage, they should be taken seriously as they indicate an increased risk of stroke in the near future.
How long does it typically take for the anticoagulant effect of warfarin to develop fully?
at least 48 to 72 hours.
What is the target INR (International Normalized Ratio) for most indications of warfarin therapy?
2.5
What is the recommended duration of warfarin therapy for isolated calf-vein deep vein thrombosis (DVT)?
6 weeks
When should warfarin therapy be continued for at least 3 months?
for unprovoked proximal DVT or PE
may be required long term
What are the warning signs of haemorrhage associated with warfarin therapy, and how can it be reversed?
nosebleeds, bleeding from wounds, bruising, etc.
It can be reversed with phytomenadione.