Interpretation of ECG & Select Dysrythmias | NURS230 (V2)

what are the different types of ECGs?

1. 3 lead

2. 12 lead

3. continuous

4. single application

5. holter monitoring

6. stress testing

what is the 3 lead ECGs and where are the electrode placed?

a simplified version of a standard 13-lead ECG that uses only three electrodes to record the electrical activity of the heart

1. RED (RA) - placed under the right clavicle near the right shoulder within the rib cage frame

2. YELLOW (LA) - placed under the left clavixle near the left shoulder within the rb cage frame

3. GREEN (LL) - placed under the left side below the pectroal muscles lower edge of left ribcage

what is the 12-lead ECG and where are the electrode placed?

1. V1 - fourth intercostal space on the right sternum

2. V2 - fourth intercostal space at the left sternum

3. V3 - Midway between placement of V2 and V4

4. V4 - fifth intercostal space at the midclavicular line

5. V5 - anterior axillary line on the same horizontal level as V4

6. V6 - mid-axllary line on the same horizontal level as V4 and V5

7. RA (right arm) - anywhere between the right shoulder and the right elbow

8. RL (right leg) - lateral calf muscle

9. LA (left arm) - anywhere between the left shoulder and the left elbow

10. LL (left leg) - lateral calf muscle

what is the difference between continuous, single application, holter monitoring, and stress testing ECG?

what does the ‘snow on grass,’ ‘smoke over fire,’ and ‘poop comes forom the tummy’ mean in term of ECG?

it is the placement of the electrodes for a 5-lead monitor 

1. white at the second right intercostal space

2. black at the second left intercostal space

3. green at the eighth right intercostal space

4. red at the eighth left intercostal space

5. brown at the fourth intercostal space on the right sternal border 

what are the fourh properties of cardiac cells and a brief description of each?

1. automaticity - ability to self-regulate

2. excitability - ability to start the electrical impulse

3. conductivity - ability to transfer the electrical impulse

4. contracbility - ability to contract

what happen when the SA node is no longer working properly?

the AV node take over but can only fire at a lower rate of 40-60 BPM (contrasting to the 60-100 BPM of the SA node)

what happen when the SA and AV node is no longer working properly

the Bundle of His and Purkinje Fibers can take over after both the SA, then the AV node is knocked out, but can only maintain the HR at a rate of 20-40 BPM

what does P wave represent? what is the normal duration?

atrial depolarization - electrical activity that triggers atrial contraction (should have a normal shape of upright and rounded!)

• the normal duration is no more than 0.11 second

what is the normal duration for P wave?

no more than 0.11 second

what does the PR interval represent? what is the normal duration?

time from the start of atrial depolarization (P wave) to the start of ventricular depolarization (QRS complex) - reflects the AV node conductions time?

• the normal range is 0.12-0.20 second

what is the normal duration for PR interval?

0.12-0.20 second

what does PR segment represent?

the flat line between the end of the P wave and the start of QRS complex; represent the delay in the AV node before ventricular depolarization

what does the QRS complex representation? what is the normal duration?

ventricular depolarization - elecrrical activity that triggers ventricular contraction

• the normal duration is between a 0.06-0.10 second

what is the normal duration for a QRS complex?

0.06-0.10 second

what does the ST interval (AKA segment) represent?

flat line between he end of the QRS complex and the start of the T wave; represents the ventricles being; normally isoelectric (flat on the isoelectric line with no depression or elefation) —> elevation or depression suggsts ischemia or injury to the heart tissues

true or false: ST interval should be isoelectric as elevation or depression can significant ischemia or injury to the heart tissues

true

what does the T wave represent?

ventricular repolarization - electrical recovery of the ventricles

what does the U wave represent?

small wave after the T wave (not always visible); thought to represent depolarization of the Purkenje fibers or papillary muscles - prominent in hypokalemia

what does the QT interval represent? what is the normal duration?

the total time the ventricle take to depolarize and depolarize

• the normal duration is less than 0.48 second

what is the normal duration for the QT interval

less than 0.48 seconds

what is the T-wave morphology to look out for? (what does being tall/peaked, flat/inverted, or sudden changes represent)

• Normal: Smooth, slightly asymmetrical, upright in most leads.

• Tall / Peaked T waves: May indicate hyperkalemia — monitor potassium levels, prepare for treatment.

• Flat or Inverted T waves: May indicate hypokalemia, ischemia, or MI — report changes.

• Sudden changes in T waves are clinically important and should be promptly reported.

what does the Q, R, and S, wave in the complex each represent with the addition of the ST segments?

1. Q wave = the initial ventricular depolarization, specifically the signal traveling down the intraventricular septum from left to right

2. R wave = reflect the major ventricular depolarization, the bulk of both ventricle depolarizing through the Purkinje fibers

3. S  wave = the final phase of ventricular depolarization, specificlaly the activation of the upper parts of the ventricles → depolarization is complex and the ventricle contracts at the end of the QRS complex

4. ST segment = ventricles are fullu depolarized and conractions

how do you determine atrial and ventricular rhythm & regularity on an ECG?

• Atrial Rhythm:

  • Look at P–P intervals (distance between P waves).

  • If evenly spaced → regular atrial rhythm.

  • If uneven → irregular atrial rhythm.

• Ventricular Rhythm:

  • Look at R–R intervals (distance between R waves).

  • If evenly spaced → regular ventricular rhythm.

  • If uneven → irregular ventricular rhythm.

• Tip for both: Use a piece of paper or calipers to mark and compare spacing.

what does it mean if there is not a P wave for every QRS complex?

• Atria are not triggering each ventricular beat.

• Electrical signal may start from AV node or ventricles (junctional or ventricular rhythm).

• Could also indicate heart block — atrial impulses aren't reaching the ventricles.

• Always abnormal → should be reported and monitored.

what does it mean if P waves come after the QRS complex?

• The ventricles are depolarizing before the atria.

• Electrical impulse is coming from the AV node or ventricles, not the SA node.

• This is retrograde atrial depolarization → seen in junctional rhythms or AV dissociation.

• Always abnormal and should be reported/monitored.

what does it mean if P waves are absent on an ECG?

The atria are not depolarizing normally.

• Impulse may not be coming from the SA node.

• Seen in (focus on A-Fib and V-Fib):

  • Atrial fibrillation (most common) - no P waves + irregular rythm

  • Ventricular fibrillation + no P waves + no organized rythm (EMERGENCY)

  • The heart is beating so fast (like in Supraventricular tachycardia) that the QRS complex engulf the P wave in the reading

  • Junctional rhythm (AV node is pacemaker)

  • Sinus arrest / SA node failure

  • Ventricular rhythm

• Should be assessed and reported.

true or false: the PR interval cannot be measured if the P wave is missing

true

true or false: sometimes the heart beats so fast that the QRS complex enguft the P waves in the reading

true

what does it mean if one or more QRS complexes are missing on an ECG?

Missing QRS complexes = ventricles did not contract because the impulse didn’t reach them.

This usually means a heart block or conduction issue.

• One missing QRS (occasionally):
  → May indicate a dropped beat from a 2nd-degree AV block (Mobitz Type I or II).

• Two or more QRS complexes missing in a row:
  → Suggests a more serious block, such as:

  • Mobitz Type II (2nd-degree AV block)

  • 3rd-degree (complete) heart block
    → Ventricles are not getting signals from atria → can lead to low cardiac output or asystole.

• Always abnormal — should be reported immediately.

how many second does each small box on an ECG paper represent?

0.04 second

how many second does each large box on an ECG paper represent?

0.20 second

how many second does 5 large boxes on an ECG paper represent?

1 second

every ________ second (________ large boxes) is marked with a verticle line

3 seconds; 15 large boxes

how can you calculate the heart rate using the small box methods?

AKA Rule of 1500

• count the number of small boxes between two R waves

• use the formular: 1500 divided by the number of small boxes

• example: 20 small boxes = 1500/20 = 75 bpm

• only work if the rhythm is regular

how can you calculate the heart rate using the small box methods?

AKA the Rule of 300

• Count the number of large boxes between two R waves.

• Use the formula: 300 ÷ number of large boxes = heart rate (bpm).

  • Example: 4 large boxes → 300 ÷ 4 = 75 bpm.

• Only work with regular rhythm

true or false: the six-second method, small box method, and large box, can all we use whether the rythm is regular or irregular

false; only the six-second methods can be use when the rythm is either regular or irregular

how do you calculate heart rate using the 6-second method?

• Use this when the rhythm is irregular or regular.

• Count the number of R waves (QRS complexes) in a 6-second strip.

  • A 6-second strip is marked by 3 hash marks or 30 large boxes.

• Then multiply by 10.

  • Heart Rate = Number of QRS complexes × 10

what does a wide QRS complex (over 0.10 secons) mean?

• Meaning: Impulse starts in ventricles or conduction is delayed.

• Possible Diagnosis:

  • Ventricular rhythm / Ventricular tachycardia

  • Bundle branch block

• Nursing action: Check pulse, BP, possible emergency if pulseless VT/VF.

what is the rate, rhythm, P waves characteristics, PR interval duration, and QRS duration of a normal sinus rhythm

1. rate: 60-100 beats/min

2. rhythm: regular

3. P waves: present, consistent configurations, one P wave before each QRS complex with the spacing between each other P waves being regular

4. PR interval: 0.12-0.20 second and constant

5. QRS interval: 0.04-0.10 second and constant

what is the rate, rhythm, P waves characteristics, PR interval duration, and QRS duration of a normal sinus rhythm

1. rate: less than 60 bpm

2. rhythm: regular

3. P waves: present, consistent configurations, one P wave before each QRS complex with the spacing between each other P waves being regular

4. PR interval: 0.12-0.20 second and constant

5. QRS interval: 0.04-0.10 second and constant

what is the main etiology of sinus bradycardia?

1. physical fitness

2. excessive vagal stimulation

3. hypoxia

4. hypothermia

5. disease (e.g, hypothyroidism, hypothermia, beta-blockers, CCBs, MI, increased vagal tone, etc)

6. medications

what are the clinical presentations of sinus bradycardia and how is it managed?

Clinical Presentations

• Often asymptomatic if mild

• Symptoms (if HR too low or perfusion affected):

  • Dizziness or lightheadedness

  • Syncope (fainting)

  • Fatigue

  • Weakness

  • Confusion

  • Hypotension

  • Shortness of breath or chest pain (rare)

Management / Nursing Actions

• If asymptomatic: Usually no treatment, just monitor

• If symptomatic:

  1. Assess ABCs (Airway, Breathing, Circulation) and vital signs

  2. Oxygen therapy if needed

  3. Identify & treat underlying cause (medications, MI, hypothyroidism, electrolyte imbalance)

  4. Medications:

     • Atropine (first-line for symptomatic bradycardia)

     • If atropine is ineffective administer an IV infusion of dopamine or epinephrine as per protocol

  5. Advanced interventions:

     • Temporary pacing if severe, unresponsive bradycardia

     • Permanent pacemaker for chronic sick sinus syndrome

Nursing Tip: Always assess perfusion and symptoms, not just heart rate.

what is the rate, rhythm, P waves characteristics, PR interval duration, and QRS duration of sinus tachycardia?

1. rate: 100-180/min

2. rhythm: regular

3. P waves: present, consistent configurations, one P wave before each QRS complex with the spacing between each other P waves being regular

4. PR interval: 0.12-0.20 second and constant

5. QRS interval: 0.04-0.10 second and constant

what are the common causes of sinus tachycardia?

1. respond to exercise

2. caffeine

3. SNS stimulation

4. fever

5. anemia

6. medications (e.g., decongestants, CNS stimulant, caffeine, illici substances, etc)

7. hyper/hypovlemia

usually it is caused as compensatory mechanism

true or false: sinus tachycardia is concerning but we typically look about for a sustained tachycardia as they are much more concerning

true

what is the clinical manifestations of sinus tachycardia and what are the management for it?

Clinical Manifestations

• Often asymptomatic if mild

• Symptoms (if HR high or sustained):

  • Palpitations / rapid pulse

  • Dizziness or lightheadedness

  • Shortness of breath

  • Chest pain or discomfort

  • Fatigue or weakness

  • Anxiety

Management / Nursing Actions

• Identify & treat underlying cause (most important!)

  • Fever, pain, hypovolemia, anemia, hyperthyroidism, anxiety, medications, hypoxia

• Monitor vital signs and cardiac rhythm

• Supportive care:

  • Oxygen if hypoxic

  • IV fluids if hypovolemia

• Medications (if persistent or symptomatic):

  • Beta-blockers (e.g., metoprolol) or calcium channel blockers

• Nursing Tip: Treat the cause, not just the heart rate

what is the rate, rhythm, P waves characteristics, PR interval duration, and QRS duration of atrial flutter?

1. rate: 250-350/min; ventricular rate varies

1. rhythm: irregular rhythm → rapid atrial depolarization

2. P waves: present but have a ‘saw tooth” appearance

3. PR interval: varies

4. QRS interval: varies (usually normal - 0.06 to 0.10 if there is no bundle branch block)

how do you calculate the ventricular and atrial rate using ECG?

1. Ventricular Rate (using QRS complexes)

Steps:

1. Count the number of QRS complexes in a 6-second strip.

2. Multiply by 10 → ventricular rate (bpm).

   • Works for regular and irregular rhythms.

3. For regular rhythms, you can also use:

   • Large box method: 300 ÷ number of large boxes between 2 R waves

   • Small box method: 1500 ÷ number of small boxes between 2 R waves

2. Atrial Rate (using P waves or F waves)

Steps:

1. Count the number of P waves (or flutter F waves) in a 6-second strip.

2. Multiply by 10 → atrial rate (bpm).

3. For regular atrial rhythms, you can also measure P–P intervals:

   • Large box method: 300 ÷ number of large boxes between 2 P waves

   • Small box method: 1500 ÷ number of small boxes between 2 P waves

true or false: in atrial flutter, one foci of the SA node is messing up the entire SA node firing

true

how do the nurse know if the atrial flutter have a controlled ventricular rate (CVR) or a rapid ventricular rate (RVR)?

1. CVR = less than 100 bpm

2. RVR = more than 100 bpm

what is the common etiology of atrial flutter?

1. rheumatic or ischemic heart disease

2. controlled heart fialure

3. AV valve disease

4. Pulmonary embolism

5. alcoholism

6. pericarditis

what is the clinical manifestation and management of atrial flutter?

Clinical Manifestations

• Often asymptomatic if the ventricular rate is controlled (less than 100 bpm)

• Symptoms (if rapid ventricular response or decreased cardiac output):

  • Palpitations / rapid pulse

  • Dizziness or lightheadedness

  • Fatigue or weakness

  • Shortness of breath

  • Chest pain or discomfort

  • Anxiety

• Nursing note: Look for irregular ventricular response and signs of decreased perfusion.

---

Management / Nursing Actions

1. Assess ABCs and vital signs

2. Monitor cardiac rhythm

3. Treat underlying cause (e.g., hyperthyroidism, heart disease, infection)

4. Medications:

   • Rate control: Beta-blockers (e.g., metoprolol), Calcium channel blockers (e.g., diltiazem)

   • Rhythm control / cardioversion: Amiodarone or synchronized cardioversion if unstable

   • Anticoagulation: To prevent stroke or a traveling blood clot in general (e.g., warfarin, DOACs)

5. Nursing tips:

   • Observe for hypotension, syncope, or signs of heart failure (if prolonged due to the weakning of the heart muscle over time due to its excessively fast rate)

   • Educate patient on medication adherence and stroke prevention

what is the rate, rhythm, P waves characteristics, PR interval duration, and QRS duration of atrial fibrillation?

1. rate: atrial of more than 400 bpm and ventricular rate varies-

→ caused by multiple atrial foci firing simultaneously (atrial chaos) 

1. rhythm: irregular rhythm → the atria is not contracting and is actually quivering

2. P waves: absence of countable P waves

3. PR interval: no measureable

4. QRS interval: usually normal (0.06-0.10) because ventricular conduction through the AV nodes and bundle branches is intact however the ventricular rhythm will be irregular 

what type of heart rhythm lead to a high risk for clot formation?

1. A-Fib

2. A-Flutter

what is premature atrial contraction (PAC) and is there a need for treatment?

1. premature ectopic beat from atrial tissues followed by a non-compensatory pause

2. P waves often looks different

3. it is mostly harmless just an indicated need for monitoring for patient with weak or diseased heart → it is often referred to as palpitations with no change in cardiac output - no treatment are indicated

what does an ST segment elevation indicate?

1. myocardial stress

2. may also indicate ventricular damage, from multiple causes such angina, CAD, or evolving myocardial infarction where the heart muscle is not getting enough oxygen

what is the rate, rhythm, P waves characteristics, PR interval duration, and QRS duration of supraventricular tachycardia (SVT)?

1. rate: 100-250 bpm

1. rhythm: regular; R-R are consistent

2. P waves: may not be able to visualize P waves as they are often hidden in the preceding T wave due to the fast rate

3. PR interval: may not be able to measure, depending on whether you can see the P wave

4. QRS interval: usually narrow but still within 0.06-0.10

what does supraventrcicular tachycardia mean?

generic term for any tachycardia that originates from a site above the ventricles

true or false: the onset of supraventricular tachycardia is usually sudden

true

what is the clinical manifestations and management of supraventricular tachycardia?

Clinical presentation:

• Palpitations

• Dizziness or lightheadedness

• Shortness of breath

• Chest pain or anxiety

• May cause hypotension if prolonged

Management:

• Vagal maneuvers (e.g., Valsalva) for stable patients

• Adenosine IV if vagal maneuvers fail

• Beta-blockers or calcium channel blockers for recurrent episodes

• Electrical cardioversion if unstable and symptomatics

what is the rate, rhythm, P waves characteristics, PR interval duration, and QRS duration of premature ventricular contraction (PVCs)?

1. rate: varies

1. rhythm: irregular; R-R are not consistent as it is ectopic beats followed by full compensatory pause

2. P waves: none

3. PR interval: none

4. QRS interval: wide, disorted (over 0.12 second)

5. 3 or more in a row = ‘non-sustained ventricular tachycardia’

true or false: PVCs is more deadly than PACs

true

what does 3 PVC in a row mean?

non-sustained ventricular tachycardia

what is the main cause of PVC?

increased irriation of ventricular cells

Cardiac Causes

• Myocardial ischemia or infarction

• Heart failure / cardiomyopathy

• Valvular heart disease

Electrolyte / Metabolic Causes

• Hypokalemia (low potassium)

• Hypomagnesemia (low magnesium)

• Hypoxia

Medications / Stimulants

• Digoxin toxicity

• Caffeine, nicotine, alcohol

• Sympathomimetic drugs (e.g., epinephrine, albuterol)

Other Causes

• Stress or anxiety

• Fever

• Hyperthyroidism

Nursing Tip: Always assess vital signs, electrolytes, oxygenation, and cardiac history in patients with PVCs.

what is the clinical significance if PVCs occur more than 6 times per minute

• Indicates increased ventricular irritability

• May progress to more serious ventricular arrhythmias (VTach or VFib)

• Nursing action: Monitor vital signs, electrolytes, and cardiac rhythm; assess for ischemia or hypoxia

what does it mean if PVCS occur in pairs (couplets)?

• Two consecutive PVCs → indicates higher risk of ventricular tachycardia

• Nursing action: Continuous ECG monitoring; notify provider if sustained

what does multifocal PVCs mean and why is it important?

• PVCs originate from different ventricular sites → QRS shapes vary

• Indicates more severe ventricular irritability

• Higher risk for VTach or VFib

• Nursing action: Monitor, check electrolytes, medications, ischemia

what is the R-on-T phenomenon?

• Definition: A PVC occurs during the T wave of the preceding beat

• Why it’s dangerous: The ventricles are vulnerable during repolarization → can trigger ventricular tachycardia or ventricular fibrillation

• Nursing action: Immediate monitoring, assess for symptoms, prepare for advanced cardiac life support (ACLS) interventions if unstable

what is ventricular bigeminy, clinical significant, and nursing action?

• Definition: Every other beat is a PVC (normal beat → PVC → normal beat → PVC …)

• Clinical significance:

  • Indicates ventricular irritability

  • May progress to ventricular tachycardia or fibrillation if frequent or symptomatic

• Nursing actions:

  • Monitor vital signs and ECG

  • Assess for chest pain, dizziness, or syncope

  • Check electrolytes, oxygenation, and medications

  • Notify provider if PVCs increase in frequency or become multifocal / R-on-T

what is ventricular trigeminy, its clinical signficant, and the nursing action?

• Definition: Every third beat is a PVC (two normal beats → PVC → two normal beats → PVC …)

• Clinical significance:

  • Shows ventricular irritability, usually less frequent than bigeminy but still abnormal

  • Can progress to more serious arrhythmias if underlying cause not addressed

• Nursing actions:

  • Same as bigeminy: monitor ECG, vital signs, and patient symptoms

  • Assess electrolytes, oxygenation, and cardiac history

  • Notify provider if PVCs increase in frequency, become multifocal, or show R-on-T phenomenon

what are the differences between SVT, sinus tachycardia, and ventricular tachycardia?

SVT (Supraventricular Tachycardia)

• Origin: Above ventricles (atria or AV node)

• Rate: 150–250 bpm

• Rhythm: Regular

• P waves: Often hidden in T wave

• QRS duration: Narrow (0.06–0.10 sec)

• Clinical significance: Rapid rate → dizziness, hypotension

• Nursing action: Vagal maneuvers, adenosine, beta-blockers, cardioversion if unstable

Sinus Tachycardia

• Origin: SA node

• Rate: 100–150 bpm

• Rhythm: Regular

• P waves: Normal, before each QRS

• QRS duration: Narrow (0.06–0.10 sec)

• Clinical significance: Usually physiological; rarely dangerous

• Nursing action: Treat underlying cause; monitor

Ventricular Tachycardia (VT)

• Origin: Ventricles

• Rate: 100–250 bpm

• Rhythm: Usually regular

• P waves: Usually absent or dissociated

• QRS duration: Wide (>0.12 sec)

• Clinical significance: Life-threatening; may progress to VF → cardiac arrest

• Nursing action: Immediate ACLS if unstable, antiarrhythmic drugs, possible defibrillation

what is the rate, rhythm, P waves characteristics, PR interval duration, and QRS duration of ventricular tachycardia (VT)?

1. rate: more than 100 bpm

1. rhythm: regular

2. P waves: usually absent or dissociated

3. PR interval: can’t be measure

4. QRS interval: wide (more than 0.10 second)

what are the clinical significance and management of ventricular tachycardia (VT)?

Clinical Significance

• Life-threatening arrhythmia

• Ventricles beat rapidly and ineffectively → reduced cardiac output

• Can lead to:

  • Hypotension

  • Syncope or dizziness

  • Chest pain

  • Pulseless VT → ventricular fibrillation → cardiac arrest

• Often associated with heart disease, MI, electrolyte imbalance, or drug toxicity

---

Management / Nursing Actions

1. Assess patient immediately

• Check pulse, blood pressure, LOC, and ECG

2. If pulseless VT (emergency)

• Start CPR immediately

• Defibrillation per ACLS protocol

• Administer IV antiarrhythmic drugs (e.g., amiodarone, lidocaine)

3. If VT with pulse (hemodynamically stable)

• Continuous cardiac monitoring

• IV antiarrhythmics

• Prepare for synchronized cardioversion if unstable

4. Identify and treat underlying cause

• Electrolyte imbalances (K⁺, Mg²⁺)

• Ischemia / MI

• Drug toxicity

Nursing Tip: VT is always a serious arrhythmia — rapid recognition and intervention are critical.

why is VT more symptomatic than SVT?

SVT (Supraventricular Tachycardia)

• Origin: Above ventricles

• Ventricular contraction: Normal → cardiac output okay

• Symptoms: Usually mild (palpitations, dizziness)

VT (Ventricular Tachycardia)

• Origin: Ventricles

• Ventricular contraction: Ineffective → cardiac output drops

• Symptoms: Severe (hypotension, syncope, chest pain, pulseless)

Key point: VT reduces cardiac output → more dangerous as it can lead to cardiac arrest; SVT usually tolerated better.

what are the general causes of VTach?

1. MI

2. hypokalemia

3. hypomagnesemia

4. valvular disease

5. drug toxicity

during which heart rhythms might a patient be pulseless?

• Pulseless VT → ventricular tachycardia without effective cardiac output

• Ventricular fibrillation (VF) → chaotic ventricles, no cardiac output

• Asystole → no electrical activity, no cardiac output

• Nursing tip: These are emergencies → start CPR and follow ACLS protocol immediately

what is the rate, rhythm, P waves characteristics, PR interval duration, and QRS duration of ventricular fibrillation (V-Fib)?

1. rate: cannot reliably identify the heart rate

1. rhythm: irregular

2. P waves: cannot be identified

3. PR interval: cannot be measured

4. QRS interval: cannot be identifed

what are the common causes of ventricular fibrillations (V-Fib)?

1. patient with V-Tach initially that progresses into V-Fib

2. MI

3. hypokalemia

4. hypo magnesia

5. shock

6. trauma

what are the heart rhythm that are commonly caused by hypokalemia (low potassium, K+)?

• Premature ventricular contractions (PVCs)

• Ventricular tachycardia (VT)

• Ventricular fibrillation (VF)

• U waves on ECG

• Flattened T waves

what are the heart rhythm that are commonly caused by hypomagnesemia (low magniesum Mg2+)?

• Torsades de Pointes (a type of polymorphic VT)

• PVCs

• VT / VF

what heart rhythm common progresses into V-Fib?

V-Tach

what is asystole and how do you confirm?

1. complete cessation of all electrical activity → usually preceded by VF or ventricular escape rhythm

2. check ECG electrodes and connections

3. confirm in 2 leads

4. zero cardiac output