ECG diagnoses Flashcards

1
Q

P wave duration, amplitude & Characteristics

A

P duration < 0.12 sec = 3 small squares

P amplitude < 2.5 mm

Notched P waves “P mitrale” = Left atrial enlargement. Normal amplitude but increased duration (> 3 small squares )

If the P is not seen in LII, look for it in V1

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2
Q

FREQUENCY CALCULATION

A

Vertical bar every 15 big squares

30 bigs squares = 6 sec

Number of Rs x 10 in 6 sec = Heart frequency

300, 150, 100, 75, 60, 50, 40

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3
Q

PR interval duration

A

0.12 - 0.20 sec

3 - 5 small squares

1 big square = 0.20 seg = 200 ms

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4
Q

Prolong PR interval cause

A

> 1 big square or > 220 ms

1st degree AV Block

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5
Q

Short PR interval cause

A

< 0.12 sec or < 3 small squares

Presence of an accessory pathway

Asocc with delta wave = WPW

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6
Q

ECG Normal Axis

A

Lead I: QRS (+)

AVF: QRS (+)

(0 to +90)

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7
Q

ECG Left deviated Axis

A

Lead I: QRS (+)

AVF: QRS (-)

(0 to +90)

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8
Q

CAUSES OF LEFT AXIS DEVIATION

A

Left ventricular hypertrophy

Left bundle branch block

Wolff-Parkinson-White Syndrome

Horizontally orientated heart: Short patient, pregnant or ascites

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9
Q

ECG Rigth deviated Axis

A

Lead I: QRS (-)

AVF: QRS (+)

(+90 to +180)

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10
Q

CAUSES OF RIGHT AXIS DEVIATION

A

Right ventricular hypertrophy

Pulmonary embolism

Lateral/posterior wall STEMI

Chronic lung disease: COPD

Sodium-channel blockade: TCA poisoning

Wolff-Parkinson-White syndrome

Dextrocardia

Normal paediatric ECG <2yo

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11
Q

Left Ventricle Hypertrophy (LVH) in the ECG

A

Left deviated Axis
V6: QRS (+) & T (-)
V1: QRS (-) & T (+)

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12
Q

Left Ventricle Hypertrophy (LVH) CAUSES

A
  1. Essential hypertension
  2. Hypertrophic Obstructive Myocardiopathy (HCOM)
  3. Subaortic and Aortic stenosis
  4. Aortic regurgitation
  5. Mitral regurgitation
  6. Coarctation of the aorta
  7. Ventricular septal defect (VSD)
  8. Infiltrative cardiac processes: Amyloidosis, Fabry disease, Danon disease
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13
Q

HYPERTROPHIC OBSTRUCTIVE CARDIOMYOPATHY (HCOM) in the ECG

A

Classic dagger Q waves on the left precordial leads

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14
Q

Right Ventricle Hypertrophy (LVH) in the ECG

A

Right deviated Axis:
V6: QRS (-) & T (+)
V1: QRS (+) & T (-)

Normal QRS duration

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15
Q

Right Ventricle Hypertrophy (LVH) causes

A
  1. Acyanotic Congenital Heart Diseases: ASD & VSD
  2. Pulmonary valve stenosis (Amiodarone)
  3. Tricuspid valve regurgitation
  4. Tetralogy of Fallot
  5. Lung diseases: Pulmonary fibrosis, chronic obstructive pulmonary disease, and sleep apnoea.
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16
Q

Lead II Isoelectric meanings

A
  1. Right Ventricle Hypertrophy (RVH)
  • Mechanical: Right deviated Axis
  • Electrical Conduction impaired: Normal Axis
  1. Left Branch Bundle Block (LBBB)
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17
Q

Left Branch Bundle Block (LBBB) in the ECG

A

Lead II : P wave wide & prolong PR interval

Axis will be normal or Left deviated

V6: QRS (+) usually notched & T (-) with ST depression

V1: QRS (-)

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18
Q

Rigth Branch Bundle Block (RBBB) in the ECG

A

V1: QRS (+) Wide-notched and T (-) with ST depression

V6: Prominent S

  • RsR’ on V1 –V2

Axis will be normal or Right deviated

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19
Q

QRS Duration

A

0.06 - 0.10 sec

1.5 - 2.5 small squares

> 2.5 small squares = Wide QRS

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20
Q

Wide QRS causes

A
  • Hyperkalemia.
  • Hyper- or hypo-magnesemia.
  • Supraventricular tachycardia (SVT) + bundle branch block (BBB)
  • SVT with aberrant conduction.
  • Atrial fibrillation (Afib) + Wolff-Parkinson-White syndrome (WPWS)
  • Mono-morphic ventricular tachycardia (VT)
  • Sodium Channel Blockers: Phenytoin, Lidocaine, Triamterene, Lamotrigine, Oxcarbazepine, and Amiloride
  • Drug overdose and toxicities: TCA’s, digoxin, cocaine, lithium, diphenhydramine
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21
Q

Q wave present indicates

A
  1. Post STEMI
  2. Pulmonary Embolism: S1Q3T3
  3. HCOM: Dagger Q waves in left leads
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22
Q

S waves meaning

A

Final DEPOLARIZATION of the ventricles (Purkinje fibers)

Mirror effect, shows the opposite side

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23
Q

U waves meaning

A

Represent REPOLARIZATION of the ventricles (Purkinje fibers).

Best seen in the right precordial leads. Usually not seen.

Amplitude is usually < 1/3 T wave amplitude in the same lead.

Increment in U wave amplitude = Premature ventricular complexes (PVC)

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24
Q

QT segment Duration

A
  • Normal = 0.4 to 0.44 sec
    (2 big squares)
  • Short QT < 0.35 sec
  • Prolong QT > 0.44 sec Predecessor of Torsade pointes(PVT) then VF
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25
Prolong QT Causes
1. HYPOS: - Hypokalaemia - Hypomagnesaemia - Hypocalcaemia - Hypothermia 2. Raised intracranial pressure 3. Drugs 4. Congenital: - Romano Ward syndrome (AD) - Jervell and Lange Nielsen syndrome (AR) - bilateral sensorineural hearing loss -
26
Prolong QT Causes: Drugs
- Antipsychotics - TCAs - SSRIs: Citalopram, Escitalopram - SNRIs: Venlafaxine - Apitypical Antidep: Bupropion - MAOIs: Moclobemide - Antihistamines - Antiarrhythmics: Quinidine, procainamide, flecainide, sotalol, and Amiodarone. - Antimalarial: Chloroquine, Hydroxychloroquine, and quinine - Macrolides: Erythromycin, and Clarithromycin Digoxin
27
TCA Intoxication ECG
28
Prolong QT Symptom
Syncope
29
Prolong QT Management
1. Correct underline causes 2. B-Blockers 3. Implantable cardioverter-defibrillator (ICD) UNSTABLE: Torsade de Pointes Treatment
30
Raised Intracranial Pressure ECG changes
Widespread giant T-wave inversions (“cerebral T waves”) QT prolongation Bradycardia
31
Short QT Causes
HYPERS: Hypercalcemia Hyperkalemia Hyperthermia Digoxin: Salvador Dali Sign
32
PULMONARY EMBOLISM IN ECG
S1 Q3 T3 : Cor Pulmonale * Deep S in Lead I * Q in Lead III * T inverted In Lead III ✓ SINUSAL TACHICARDIA ✓ RBBB can be associated
33
Causes of ST-Segment Elevation
* Being an MI until proven otherwise * Pericarditis * Ventricular aneurysm
34
Causes Of ST-segment Depression
* Myocardium Ischaemia – Non-Stemi * Unstable Angina
35
ACUTE PERICARDITIS ECG CHANGES
ST-segment elevation with reciprocal PR-segment depression in all leads except V1 and AVR
36
Aneurism ECG changes
V1 - V3 ST elevation with concave morphology Deep Q waves
37
Brugada syndrome ECG changes
ST-segment elevation V1-V3 followed by a negative T wave. Association with clinical criteria: - Family history of sudden cardiac death at <45 years old . - Young, Male, Southeast Asian patient - Syncope
38
Takotsubo Cardiomyopathy (Broken Heart) ECG changes
Same ECG that STEMI: T wave inversion leads II, III, aVF, V3-6 In the context of: - Pregnancy with CHF - Sepsis with CHF - Alcohol Cardiomyopathy
39
ECG MI: Anterior wall
Leads Affected: V2 to V4 Vessel Involved: Left Anterior Descending artery (LAD) – Diagonal branch
40
ECG MI: Septal wall
Leads Affected: V1 and V2 Vessel Involved: Left Anterior Descending artery (LAD) – Septal branch
41
ECG MI: Lateral wall
Leads Affected: I, aVL, V5, V6 Vessel Involved: Left Coronary Artery (LCA) – Circumflex branch
42
ECG MI: Inferior wall
Leads Affected: II, III, aVF Vessel Involved: Right Coronary Artery (RCA) – Posterior descending branch
43
ECG MI: Posterior wall
Leads Affected: V1 to V4 Mirror image ST depression V7-V9 Vessel Involved: *Left Coronary Artery (LCA) – Circumflex branch *Right Coronary Artery (RCA) – Posterior descending branch
44
Hyperkalemia ECG changes
5.5 - 6.5 *Peaked T waves 6.5 - 7 *P waves widening, flattening or absent *Prolong PR interval 7 - 9 *Bradyarrhythmias *Prolonged QRS > 9 *Asystole *Ventricular fibrillation *PEA
45
Hypokalemia ECG changes
K < 2.7 mmol/L * Increased P wave amplitude (>2,5 mm) * Prolongation of PR interval (> 1 big square) * Widespread ST depression and T wave flattening/inversion * Prominent U waves - PVC (best seen in V2-V3) * Apparent long QT interval due to fusion of T and U waves (= long QU interval)
46
Digitalis toxicity in ECG
1. ST depression and T wave inversion in V5-6 in a reversed tick pattern. 2. Bradycardia 3. Prolonged PR 4. Shortened QT 5. Arrhythmias, especially heart block or bigeminy
47
Amiodarone overdose ECG Changes
Widening of QRS complex Prolongation of the PR and QT intervals Ventricular tachycardia and ventricular fibrillation
48
Amiodarone overdose ECG Changes
Widening of QRS complex Prolongation of the PR and QT intervals Ventricular tachycardia and ventricular fibrillation
49
List: Narrow Complex (Supraventricular) Tachycardia: ATRIAL – REGULAR
- Sinus tachycardia (ST) - Atrial tachycardia (AT) - Atrial flutter
50
List: Narrow Complex (Supraventricular) Tachycardia: ATRIAL – IRREGULAR
- Atrial fibrillation (AF) - Atrial flutter with variable block - Multifocal atrial tachycardia (MAT)
51
ATRIAL TACHYCARDIA (AT) & PAROXYSMAL AT: Clinical features
A rapid atrial rate overrides the SA Node and becomes the dominant pacemaker Rhythm arround 150 bpm In a px that has Hx of Heart disease (long standing AHT, valvar deseas, etc) or cocaine use Paroxysmal: SVT and then stop
52
FA important facts
Prevalence: < 55 yo = 0.1% > 80 yo = 10% Risk Factors: - HTA (Most important 20%) - Ischaemic heart disease - Tirotoxicosis - Reumatic fever (aboriginal and in developing countries) Complications: 1) Stroke - Risk: < 65 yo 2.5 - 3% > 65 yo 10% 2) Femoral artery embolism
53
Paroxysmal AF Clinical Features
Spontaneous ends in less than 7 days (usually in 24 h) After heavy alcohol, drugs
54
Paroxysmal AF Management
Rapid = Convert No rapid = No convert NEEDS BETTER EXPLANATION
55
Persistent AF Management
Fails to revert within 7 days Usually converts with syncronized cardioversion Elderly with previous heart conditions, just rate control and anticoagulants. Definitive treatment: AV node ablation + permanent pacemaker
56
Atrial fibrillation (AF): STABLE < 48H Management
1. Rate control (Aim < 110 bpm): A) B-Blockers or CCB (Verapamil. Contraindicated EF<40) B) EF<40 = Amiodarone C) If the previous didn't work or contraindications: Add Digoxin If pharmacological failure WITHOUT left Ventricle systolic dysfunction: Pharmacological cardioversion with Flecainide (EF<40)/Amiodarone or Synchronized CV - CHA2DS2VaSc - Definitive treatment: AV ablation + permanent pacing (pacemaker)
57
Atrial fibrillation (AF): STABLE > 48H Management
1. Rate control (Aim < 110 bpm): A) B-Blockers or CCB (Verapamil. Contraindicated EF<40) B) EF<40 = Amiodarone C) If the previous didn't work or contraindications: Add Digoxin 2. Anticoagulation: LMWH x 5 days. Add Warfarine (INR 2-3) FOR 1 MONTH 3. Synchronized Cardioversion
58
Atrial fibrillation (AF): UNSTABLE
Synchronized Cardioversion
59
CHA2DS2VaSc
CHF (EF<40%) Hypertension Age > 65 yo /// Age > 75 yo = 2 Diabetes mellitus Stroke (no hemorrhagic) or TIA = 2 Vascular disease (PVD) Female
60
CHA2DS2VaSc score
0: No anticoagulation or aspirin 1: Antiplatelets 2 or more: Anticoagulation is recommended if not at high risk of bleeding.
61
Atrial flutter: Clinical Features
AV Node conducts impulses to the Ventricle at a 2:1, 3:1, 4:1 or more. * Degree may be consistent or variable * The foci do not have enough electricity to conduct and produce a Ventricular contraction. * Ps of the foci and the P of SA node that is conducted. * Can be quick rate or normal rate
62
Atrial flutter: ECG Characteristics
Rhythm= Regular P= 4:1 – only P conducted from SA node (Saw-tooth) PR = short QRS= width normal
63
Atrial flutter: Management
Same as AF STABLE < 48H Permanent: - Radiofrequency ablation - Medical: Sotalol, amiodarone
64
Multifocal atrial tachycardia (MAT): ECG Characteristics
Rhythm= Irregular P= DIFFERENTS but all conducted PR= normal QRS= width normal 3 or more P waves, each different in the same ECG
65
Narrow Complex Supraventricular Tachycardia (SVT) : ATRIOVENTRICULAR – REGULAR
- Atrioventricular re-entry tachycardia (AVRT WPW) - AV nodal re-entry tachycardia (AVNRT)
66
Wolf Parkinson White (WPW): ECG Characteristics
* Rhythm: Regular * P: PR is short * W: wide QRS * S: slurring of upstroke (delta wave) (+ FA Irregular rhythm)
67
How to differentiate AVRT of AVNRT
Valsava maneuver are effective in the termination of AVRT NOT to AVNRT REVIEW!!!!!!
68
WPW Management
Refer to cardiologist. Definitive Therapy: Ablation of the accessory pathway. AVOID: - Adenosine - CCB
69
SVT: ECG Characteristics
AVNRT More common (> 60%) than AVRT Heart rate: Regular 150-160 bpm. P waves hidden in T waves QRS: Narrow complex
70
SVT STABLE Management
Step 1: Carotid massage/Valsalva manoeuvre Step 2: Adenosine x 2 (2min) Step 3: Verapamile x 2 (30 min) Step 3: Direct current (DC) cardioversion or pharmacological cardioversion (amiodarone or overdrive pacing may be required. Recurrent: Ablation or amiodarone
71
AF + WPW ECG
Irregular and wide complex tachi with delta wavw
72
SVT + WPW ECG
Regular and narrow but abnormal QRS
73
Wide Complex Tachycardia: REGULAR
- Ventricular tachycardia (VT) - Regular SVT with bundle branch block or aberrant.
74
Wide Complex Tachycardia: IRREGULAR
- Ventricular fibrillation (VF) - Polymorphic VT (PVT) - Torsade de Pointes - AF with Wolff-Parkinson-White syndrome - Irregular SVT with bundle branch block.
75
Ventricular arrhythmias (WIDE complex) list
* Premature ventricular contractions (PVCs) * Accelerated idioventricular rhythm * Monomorphic ventricular tachycardia * Polymorphic ventricular tachycardia * Ventricular fibrillation * Torsades de pointes * Arrhythmogenic right ventricular dysplasia * Re-entry ventricular arrhythmia
76
Premature ventricular contractions (PVCs): Clinical Features
* PVC or Ventricular extrasystoles (95% benign) * Patient feels like he skipped a beat. * The PVC does not generate a beat, because the ventricles are half-filed.
77
Premature ventricular contractions (PVCs): ECG Characteristics
P= normal P conducted PR = normal QRS= normal and a PVC following a T, Then a compensatory pause (always)
78
PVCs in bigeminy
Premature ventricular beats occurring after every normal beat are termed (1:1) 1 Normal QRS 1 PVC (repeat)
79
PVCs in trigeminy
PVCs that occur at intervals of 2 normal beats to 1 PVC (1:2)
80
PVCs in couplet
Normal QRS + PCV + PVC (repeat)
81
PVCs in triplet
Normal QRS + PVC + PVC + PVC (Repeat)
82
Non-sustained ventricular tachycardia (NSVT) Definition
Groups of three PVCs (Couplets or Paired PVCs) and last less than 30 seconds (> 30 sec = VT)
83
Non-sustained ventricular tachycardia (NSVT) STABLE: Management
◦ First line: metoprolol (BB) ◦ Second line: Verapamil (CCB) or flecainide if BB are Contraindicated. NO OPTION FOR EF <40 ◦ If symptoms persist: amiodarone. ◦ Last option: catheter ablation.
84
MONOMORPHIC VT: Characteristics
QRS = Same shape and amplitude T = WIDE COMPLEX * Pulseless or perfusing * Can deteriorate into VF or unstable VT if sustained and not treated. Mechanism: Re-entry loop from one ectopic area so all the QRS look the same.
85
Usually cause of MONOMORPHIC VT
MI (ischaemia) in 1 area
86
SUSTAINED VT STABLE: Management
Sustained VT w/ no structural heart disease: * First Line: beta-blockers (never a BB is acute left heart failure) (eg: atenolol, metoprolol tartrate/IV) * Second Line or if CI to BB: flecainide or verapamil. ◦ Sustained VT w/ structural heart disease * First line: Amiodarone or sotalol.
87
POLYMORPHISM VT: Characteristics
QRS = Different shape and amplitude * Can be non-perfusing or perfusing * Consider electrolyte abnormalities or drugs toxicity as the possible etiology * Re-entry loop from multiple ectopic areas, different areas with different morphology on ECG.
88
TORSADE DE POINTES: Characteristics
* QRS reverses polarity and the strips shows a spindle effect. * It is a variant of polymorphic VT with normal or long QT intervals * Can deteriorate to VT or VF * Drugs that causes prolonged QT and electrolyte abnormalities like hypomagnesemia can cause Torsade de points.
89
STABLE TORSADE DE POINTES: Management
Magnessium Sulphate 10 mmol in slow IV bolus NEVER Sodium Bicarbonate!!!
90
UNSTABLE TORSADE DE POINTES: Management
UNSYNCRONIZED (DC) CARDIOVERSION
91
TORSADE DE POINTES: Most common cause
Drugs toxicity (QT prolonging medications)
92
VENTRICULAR FIBRILLATION (VF): Characteristics
* Chaotic electrical activity with no ventricular depolarization or contraction. * There is no pulse or cardiac output. * Small amplitude – no pulse is possible or rhythm
93
Unstable Tachys and VF - SHOCKABLE -Management
UNSYNCRONIZED CARDIOVERSION Adrenaline 1 mg after 2nd shock Amiodarone 300 mg after 3rd shock Note: CPR X 2 min between shocks
94
PULSELESS ELECTRICAL ACTIVITY (PEA)
* Electrical rhythm, with no pulse detected. * PEA can be called electromechanical dissociation * CONSIDER AND CORRECT: “4H and 4T"
95
Non-Shockable Rhythms
PEA Asystole SINUS BRADY + NO PULSE
96
Non-Shockable Rhythms Management
Adenaline 1 mg inmediatly Then every 2 CPR (X 2 min) Adrenaline again.
97
UnstableList of Bradyarrhythmias with P WAVES PRESENT
1. Sinus bradycardia 2. Sinus node dysfunction a) Sinus Pause. b) Sinus Arrest. c) SA Nodal Exit Block. 4. AV Blocks (I, II, III)
98
SINUS Bradyarrhythmia causes
Normal in athletes and during sleep. In acute MI it may be protective and beneficial. B-blockers can cause sinus bradycardia
99
Bradyarrhythmia: SINUS NODE DYSFUNCTION ECG Characteristics
Rhythm= Irregular P= all same PR= constant - Normal QRS= width normal Mechanism: SA node discharges irregularly * The pacing rate of SA node varies with respiration, specially in children and elderly
100
SINUS BRADY + NO PULSE Causes
Tension Pneumothorax Cardiac Tamponade NO SHOCKABLE!!!!
101
Bradyarrhythmia: SINUS ARREST – DROPPED BEAT ECG Characteristics
Rhythm= irregular P= all same - dropped beat PR= Normal QRS= width normal. After the dropped beat, cycles continue on time. * Cardiac output may decrease causing syncope or dizziness.
102
Sinus arrest Investigation
Holter
103
Bradyarrhythmias Emergency Management
People with asymptomatic bradycardia usually need no treatment A) Correction of the cause (cardiac infections, Ischaemia, hypos, drugs: digoxin, beta-blockers, CCB, amiodarone) B) Pharmacological: 1. Atropine 0.5 mg bolus IV (Repeat every 3-5 min - MAX 3 mg) 2. Isoprenaline 3. Adrenaline / Epinephrine (Hypotension) 4. Dobutamine (CHF) C) Transcutaneous Pacemaker (If ineffective pharmacological or MOBITZ 2 / 3rd degree AV Block)
104
Combinations of drugs that block the atrioventricular (AV) node
Verapamil + Beta-blocker
105
Bradycardia due to drug toxicity MANAGEMENT: B-Blockers
First-line antidote: Glucagon Second-line: Inotropes (adrenaline, dobutamine, ­isoprenaline)
106
Bradycardia due to drug toxicity MANAGEMENT: Calcium channel blockers
First-line antidote: Calcium gluconate Second-line: Glucagon
107
Bradycardia due to drug toxicity MANAGEMENT: Digoxin
Digoxin-specific antibodies (Fab fragments) Allergenic and expensive. Only to be used in life-threatening ­arrhythmias attributed to digoxin.
108
Bradyarrhythmias: AV Blocks List
The most common cause of bradycardia. Mechanism: AV node dysfunction * First-degree heart block, which manifests as PR prolongation * Second-degree heart block * Type 1 Second-degree heart block, also known as Mobitz I or Wenckebach * Type 2 Second-degree heart block, also known as Mobitz II or Hay * Third-degree heart block, also known as complete heart block
109
Bradyarrhythmias: 1ST DEGREE AV BLOCK ECG Characteristics
Rhythm= Regular P= Normal - all conducted PR= PROLONGED QRS= width normal - Benign - If associated with MI, it can lead to AV defects. - Usually caused by drugs.
110
Drugs that cause 1st degree AV Block
Antiarrhythmics: Quinidine, procainamide, disopyramide, flecainide, encainide, propafenone, beta-blockers, amiodarone, sotalol, calcium channel blockers Digoxin Magnesium
111
ECG Characteristics: 2ND DEGREE TYPE 1 / MOBITZ I / WENCKEBACH
Rhythm= Irregular P= normal – a P is blocked PR = Progressively longer until one P wave is totally blocked and produces no QRS. QRS= width normal
112
Causes: 2ND DEGREE TYPE 1 / MOBITZ I / WENCKEBACH
1. B-blockers 2. Digoxin 3. Calcium channel blockers 4. Ischaemia involving the right coronary artery.
113
ECG Characteristics: 2ND DEGREE TYPE 2 / MOBITZ II / HAY.
Rhythm= Regular P = Look normal at the same pace, all regular. Some P’s are blocked (Eg 3:1) PR = Normal in the conducted P QRS= Width normal Mechanism: Conduction error in the bubble of His.
114
Clinical features: 2ND DEGREE TYPE 2 / MOBITZ II / HAY
ALWAYS SYMPTOMATIC: Dizziness, palpitations, weakness, and syncope. ALWAYS URGENT REFER AND PACEMAKER
115
ECG Characteristics: 3RD DEGREE AV BLOC
Rhythm= Regular 25 - 50 rpm P= look normal at a regular pace – none conducted PR = Absent QRS= abnormal
116
Clinical Features: 3RD DEGREE AV BLOCK
Mechanism: Lack of conduction of atrial impulse to ventricle leading to independent contractions. Signs & Symptoms: - Hypotension - Large volume pulse - Increased JPV (CANNON WAVE) - Systolic murmur Can lead to asystole and cardiac arrest. ALWAYS PACEMAKER
117
Pacemaker in the ECG
Spike + QRS + T No p wave
118
The Reversible Causes of Cardiac Arrest: 4 Hs, 4 Ts
Hypoxia Hypokalaemia/hyperkalaemia Hypothermia/hyperthermia Hypovolaemia Tension pneumothorax Tamponade Thrombosis Toxins