Cardiology emergencies: Tachyarrhythmias Flashcards by Amina Qureshi

How do you explain to a patient what tachycardia and tachyarrhythmia is?

Heart beats faster than normal, so heartrate is usually over 100 bpm

When the heartrate is fast and also has an irregular rhythm, this is called a tachyarrhythmia

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How do you explain to a patient the common causes of tachyarrhythmias? TACHIES

Thyrotoxicosis: Overactive thyroid gland causes increased heart rate

Alcohol withdrawal, anaemia

Cardiac issues eg. heart failure, valve disease, channelopathies, ischaemic heart disease (most common)

Haemorrhage secondary to trauma, cardiac surgery

Intervals (WPW), infection (fever)

Embolus (pumonary)

Sepsis

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How do you explain to a patient tachyarrhythmias are diagnosed?

Main test: ECG

Further tests to confirm diagnosis:
Holter monitor: It records 24-48 hour tape of heartbeat

Electrophysiology study: Catheters inserted into heart through a cut in the groin, to map electrical pathways and find source

Exercise stress test: Monitoring the heart’s electrical activity and blood pressure while the patient does exercise, like walking on a treadmill, to confirm if bradyarrhythmia is causing mild/moderate/severe symptoms

Blood tests: Thyroid hormone level and electrolyte levels

Tilt table test: Shows how the body reacts to changes in position. It can help find the cause of fainting or dizziness

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What are the 3 groups of tachyarrhythmias?

Sinus tachycardia

Supraventricular tachycardia

Ventricular tachycardia

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How do you explain to a patient what sinus tachycardia is?

Heart beats unusually fast (over 100 bpm) but with a regular rhythm, and originates in the SA node (pacemaker)

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How do you explain what physiological sinus tachycardia is?

Normal, expected increase in heart rate due to a trigger

Eg. anaemia, fever, overactive thyroid, compensation for heart failure, alcohol, caffeine

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How do you explain to a patient what psychogenic sinus tachycardia is?

Increased heart rate as a normal physiological response to psychological stress or emotional feelings

eg. fear, anxiety, panic attacks, somatic symptom disorder

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How do you explain to a patient what inappropriate sinus tachycardia is?

Heart rate is persistently higher than normal (over 100 beats per minute at rest) without a clear, identifiable cause

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How do you explain to a patient what supraventricular tachycardia is?

Heart beats very fast, usually between 100 and 300 beats per minute, due to abnormal electrical signals originating in the heart’s upper chambers (atria) (above the ventricles) but not in the SA node

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What are the main types of SVT? FAT

F: (atrial) Fib/flutter

A: AVNRT, AVRT (WPW)

T: (atrial) tachycardia: Single or multifocal

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What is atrioventricular nodal reentrant tachycardia (AVNRT)?

Short circuit near the AV node causes the electrical impulses to travel in a loop

Most common SVT

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What is atrioventricular reentrant tachycardia (AVRT)?

Extra electrical pathway (accessory pathway) exists between the atria and ventricles, allowing a loop to form so that electrical signals re-enter the atria

eg. Wolfe-Parkinson-White: Bundle of Kent pathway

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What is focal atrial tachycardia?

Single ectopic focus in the atria causes abnormal electrical impulses to be regularly generated

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What is multifocal atrial tachycardia (MAT):

Multiple ectopic foci within the atria generate electrical impulses

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What is atrial flutter?

Re-entrant circuit in right atrium, which causes regular but rapid atrial contractions

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What is atrial fibrillation?

Ectopic sites (eg. pulmonary veins) firing random electrical signals and reentrant circuits in left atrium, which causes irregular and rapid atrial contractions

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How do you explain to a patient what ventricular tachycardia is?

Heart beats very fast, usually between 100 and 300 beats per minute, due to abnormal electrical signals originating in the heart’s main pumping chambers, the ventricles

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What are the 4 types of ventricular tachycardias?

Pulse VT

Pulseless VT

Ventricular fibrillation

Polymorphic VT: Torsades de pointes

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What is pulseless ventricular tachycardia?

A specific type of VT where the heart is beating regularly but so rapidly that it cannot effectively pump blood, resulting in a lack of pulse

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What is ventricular fibrillation?

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Lower heart chambers contract in a very rapid and uncoordinated manner. As a result, the heart doesn’t pump blood to the rest of the body

What is polymorphic VT?

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Bottom chambers of your heart (ventricles) beat too quickly and in a varying pattern

What is torsades de pointes?

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A type of polymorphic VT characterised by a prolonged QT interval and a distinctive “twisting of the points” morphology where the QRS complexes change amplitude and axis, “twisting” around the isoelectric line

How is the type of tachyarrhythmia initially diagnosed?

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12-lead ECG and assess QRS complexes

Narrow or broad complex tachycardia
If narrow: Regular or irregular
If broad: Regular or irregular

What is the difference between a narrow-complex tachycardia and a broad-complex tachycardia?

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Narrow-complex: QRS is less than 3 small boxes wide

Indicates that impulses are conducted through normal His-purkinje system and originates above ventricles

(AVNRT, AVRT, SVTs)

Broad-complex: QRS is more than 3 small boxes wide

Indicates that there is abnormal conduction in ventricles or SVT with abnormal conduction

(VT, SVT with aberrancy)

What are the narrow-complex, regular tachycardias?

Sinus tachycardia Focal atrial tachycardia AVRT AVNRT Atrial flutter

What are the narrow-complex, irregular tachycardias?

Atrial fibrillation MAT Atrial flutter with variable block

What are the broad-complex, regular tachycardias?

Monomorphic VT

What are the broad-complex, irregular tachycardias?

Polymorphic VT Ventricular fibrillation

What are the common symptoms of tachyarrhythmias?

Palpitations Dizziness or lightheadedness Chest pressure or discomfort Shortness of breath Anxiety or panic Syncope or near-syncope

How can you tell if the patient has sinus tachycardia/SVT/VT based on their symptoms?

Sinus tachycardia: Gradual onset with mild symptoms, relieves with rest or treatment of underlying trigger SVT: Sudden onset with moderate symptoms and sudden stop (common in healthy, young individuals) VT: Sudden onset of severe symptoms that aren't relieved and can result in sudden cardiac death (common in structural heart disease eg. post MI, cardiomyopathy)

What are the causes of atrial fibrillation? PIRATES

P: ulmonary embolism, pulmonary disease, post-operative I: schemic heart disease, idiopathic (“lone atrial fibrillation”) R: heumatic valvular disease (mitral stenosis or regurgitation) A: nemia, alcohol (“holiday heart”), age, autonomic tone (vagal atrial fibrillation) T: hyroid disease (hyperthyroidism) E: levated blood pressure (hypertension), electrocution S: leep apnea, sepsis, surgery

How does sinus tachycardia appear on ECG?

Regular rhythm with present P waves, QRS, T waves: Main finding is high heart rate Severe sinus tachycardia: 'camel hump' appearance due to p wave hidden in preceding t wave

If a patient is tachycardic, what is the initial management?

Assess with ABCDE approach and give appropriate interventions eg. maintain airway, give oxygen Constant cardiac monitoring with 12-lead ECG, pulse oximetry, blood pressure Establish IV access Treat identifiable and reversible causes

What is the difference between stable and unstable tachycardia?

Unstable tachycardia: Life-threatening symptoms eg. shock, syncope, heart failure, heart attack, hypotensive, confusion due to haemodynamic instability Stable tachycardia: No life-threatening symptoms, patient is haemodynamically stable

How is unstable tachycardia treated?

1. Synchronised DC cardioversion (up to 3 times) 2. Ineffective synchronised DC cardioversion: Give 300mg IV amiodarone then another synchronised shock 3. Ineffective: Give 900mg IV amiodarone over 24 hours

If a patient has stable tachycardia, what should you do next?

12-lead ECG to confirm type of tachyarrhythmia

If a patient has a narrow-complex regular tachycardia, what is the treatment?

1. Vagal maneuvers 2. 6mg IV adenosine bolus, if ineffective then give 12 mg then another 12 mg Continuous ECG monitoring to see if sinus rhythm is restored

If a patient has a narrow-complex regular tachycardia that is not controlled by vagal maneuvers and adenosine, how do you treat it?

Ineffective due to patient having atrial flutter or patient can't have adenosine (don't give in asthma) 1. Rate or rhythm control with beta-blocker, CCB or digoxin

If a patient has a narrow-complex irregular tachycardia, how do you treat it?

Assume atrial fibrillation 1. Rate or rhythm control

If a patient has a broad-complex regular tachycardia, how do you treat it?

Assume pulse/monomorphic VT 1. Give 300mg IV amiodarone, then 900mg IV amiodarone over 24 hours

If a patient has a broad-complex irregular tachycardia, how do you treat it?

IV amiodarone (300mg IV over 10-20 minutes, followed by a 900mg infusion over 24 hours). Procainamide (10-15 mg/kg over 20 minutes) can also be used for stable patients if amiodarone is unsuitable

How do you treat polymorphic VT, in a stable patient?

Magnesium Sulfate: 1–2 g IV over 15 min (can repeat) Isoprenaline

What is the definitive treatment of sinus tachycardia?

Treat underlying cause

What is the definitive treatment of SVTs eg. AVNRT, AVRT, focal/multifocal atrial tachycardia?

Catheter ablation: Thin tubes inserted into heart blood vessels and uses heat or cold to create small scars that block the faulty electrical signals

What is the definitive treatment of atrial flutter, and what is the alternative treatment?

Definitive: Catheter ablation Alternative: ABC drugs approach

What are the 4 treatment options for AF?

Catheter ablation and pulmonary vein isolation: Better for paroxysmal AF ABC approach with rate control: Persistent AF ABC approach with rhythm control: Persistent AF AV node catheter ablation and pacemaker insertion: Permanent AF

What is the ABC approach with rate control, for treatment of AF?

Avoid stroke: Calculate CHADVASC score, if more than 1 in men or more than 2 in women then give anticoagulation (DOAC or warfarin) Better symptom control: Control rate with either beta-blockers (atenolol, bisoprolol), non-dihydropyridine CCB (verapamil, diltiazem), digoxin Comorbidity management

What is the ABC approach with rhythm control, for treatment of AF?

Avoid stroke: Calculate CHADVASC score, if more than 1 in men or more than 2 in women then give anticoagulation (DOAC or warfarin) Better symptom control: Control rhythm with either sodium channel blockers (propafenone, flecainide), potassium channel blockers (amiodarone, sotalol) Comorbidity management

Cardiology emergencies: Tachyarrhythmias Flashcards

(49 cards)