General Info
Definition: Abnormal cardiac rhythms
● Problem with the pumping effectiveness of the heart
● Dysrhythmia & Arrhythmia both mean the same thing
● CAUSES:
○ Physical abnormality
■ Congenital
■ Acquired (structural issues)
○ Factors that can lead to a dysrhythmia
■ Hypoxia
● Deprived of adequate O2 supply at the tissue level
● May/may not be bc of lack of blood flow
■ Ischemia
● Lack of blood flow leading to lack of O2
■ Sympathetic stimulation or enhanced sympathetic tone
■ Drugs
■ Electrolyte disturbances
● K+ (main contributor), Mg, Ca+
■ Bradycardia or tachycardia
■ Stretch (inadequate contraction)
● If it can't stretch, problem with hypertrophy of the atrium &/or ventricles
● Hypertrophy → enlargement or thickening of the tissue, which can lead
to the heart not being able to adequately stretch
● Our body has an innate electricity within the heart, which is necessary for our heart to
function properly
● Depolarization
○ Think → “Contracting” (Heart pushing out the blood as it contracts)
● Repolarization
○ Think → “Resting” (Heart filling with blood. This is a vulnerable period because if
the ventricle contracts before filling, the heart will not rest properly/fill with
blood)
*Side note* Just because someone may have a dysrhythmia, does not mean it requires intervention.
Always assess first!
EKGs/ECGs
● Definition = Recording of the electrical activity of the heart
● Waveforms reflect what is happening (electrically) in the heart
Nursing Implications
● If an abnormal heart rhythm (dysrhythmia) is observed on EKG →
○ Confirm that it's a true rhythm
○ Next, promptly ASSESS pt FIRST to confirm the rhythm
○ DO NOT perform interventions before assessing the pt first
● If you do observe an abnormality, need to assess how the abnormality is
impacting the patient
○ Responses can vary from pt to pt
○ Can be symptomatic or asymptomatic, or present with devastating effects
,Conduction System of Heart
● SA node (Sinoatrial node)
○ Primary pacemaker
○ Beginning of electrical activity
○ Electrical impulse spreads over the atrium & myocardium
○ Electrical impulses 60 to 100 beats/min
○ **P wave on ECG
● AV node (Atrioventricular junction)
○ Second pacemaker
○ Brief delay here → **PR segment on ECG
○ Contraction known as “atrial kick”
● Bundle of His
○ Impulse travels from AV node to Bundle of His
○ Positioned at the ventricles
○ Then the impulse breaks off into the
■ Right bundle branches
■ Left bundle branches
■ R & L → **QRS complex on ECG
● Ventricles
○ Third (final) pacemaker
Types of ECGs
**Electrodes measure the electrical
current Single lead
● 1 view, 1 picture (THIS IS USUALLY USED TO MONITOR A PATIENT)
12 leads
● 12 views, 12 pictures (THIS IS USUALLY USED FOR DIAGNOSING)
● Each picture is a snapshot, each will be slightly different
, ● 12 lead ECG → Only put 10 leads on the pt (produces 12 pictures)
○ Left side → 7
○ Right side → 3
● **Not going to ask for the placement/location of the electrodes
Patient Preparation
● Attached to the chest wall via an electrode pad
● Clip excessive hair on chest wall
● Rub skin with dry gauze
○ Skin needs to be dry, Sweat influences adherence
● Benzoin may be applied to the skin if diaphoretic to support adherence
● May need to use alcohol for oily skin
● Apply electrical conductive gel
Telemetry Monitoring
**Different than ECG
● Commonly used is the 5 lead (can have 3 or 9)
Telemetry ECG
● Observation of HR and Given when:
rhythm at a distant site ● Trying to determine Dx
● Two types ● Evaluating the
○ Centralized monitoring effectiveness of
○ Sophisticated interventions/tx being
alarm system given
(alerts Remember →
dysrhythmias, ● Pt gets ECG when… Theres
ischemia, or been a change in the pts
infarction) status OR Evaluating tx
● Commonly done for
hospitalized pts