COMMON DYSRHYTHMIAS

  • Instructor: Lynne Modlin, MSN, RN

ATRIAL DYSRHYTHMIAS

Atrial (Narrow) Dysrhythmias

  • Also referred to as supraventricular tachycardia (SVT)
  • Impulse originates outside of the sinus node, specifically from atrial tissue or the AV node
  • Characterized by narrow complex QRS complexes, specifically less than 0.12 seconds

Key Terms

  • Valsalva Maneuver: A breathing technique that can help in diagnosing certain dysrhythmias.
  • Adenosine: A medication used in treating specific types of tachycardia.
  • Supraventricular Tachycardia: Elevated heart rate originating above the ventricles.
  • Carotid Sinus Massage: A technique used in some clinical scenarios for SVT.
  • Narrow-Complex Tachycardia: A fast heart rate characterized by narrow QRS complexes.
  • Accessory Pathway: Extra electrical connection in the heart that can cause arrhythmias.
  • SVT (Supraventricular Tachycardia): A general term encompassing various tachycardias originating from above the ventricles.

COMPARISONS

Sinus Tachycardia vs. Supraventricular Tachycardia (SVT)

  • Sinus Tachycardia at speed: 25 mm/sec, 10 mm/mV
  • Supraventricular Tachycardia (SVT) shown similarly in Lead II: 25 mm/sec, 10 mm/mV

PREMATURE ATRIAL CONTRACTIONS (PAC)

  • Description: A premature contraction originating from the atria.
  • Characteristics: The premature “P” wave appears differently than the P wave originating from the SA node.
  • Two components:
    • Abnormal P waves: they take on a shape that differs from the typical P wave of sinus origin.
    • Early timing: these waves occur prematurely.

PAC Causes & Treatment

Causes:

  • Common causes include:
    • Stress, Fatigue, Anxiety, Excitement: Psychological states can provoke PACs.
    • Stimulants: Includes caffeine and tobacco.
    • Medications: Stimulants such as sympathomimetic drugs, amphetamines.
    • Electrolyte Imbalances: Particularly hypokalemia and hypomagnesemia.
  • PAC usually has no underlying need for treatment, although addressing root causes is important.
    • For treatment: Reduce stress and avoid stimulants. Administer potassium and magnesium in cases of deficiency.

ATRIAL FLUTTER

  • Definition: A condition characterized by a rapid, recurring focal impulse in the atria, often creating a reentrant circuit in the right atrium.
  • Visual Appearance: Sawtooth pattern, often described as a “picket fence” appearance with the flutter waves.

Assessment of Atrial Flutter

  • Loss of Atrial Kick: A reduction in cardiac output of approximately 15-25%
  • Manifestations depend on the ventricular response rate:
    • Controlled Ventricular Response: Less than 100 beats per minute (bpm).
    • Rapid (Uncontrolled) Ventricular Response: Greater than 100 bpm.
  • Symptoms may include:
    • Palpitations, weakness, fatigue, shortness of breath (SOB), nervousness, anxiety, syncope, chest pain, potential for heart failure or shock.

ATRIAL FIBRILLATION

  • Most common form of dysrhythmia worldwide.
  • Characterization:
    • Absence of P waves; instead, presents with a wavy baseline that is irregularly irregular.
    • The rhythm is continuous and chaotic due to rapid, disorganized discharges from multiple atrial foci.
    • Leads to a quivering of the atria, resulting in a loss of atrial kick (decreased cardiac output).
    • Associated with an increased risk of stroke and embolism.

Causes of Atrial Fibrillation

  • Conditions affecting development:
    • Hypertension (HTN)
    • Coronary Artery Disease (CAD)
    • Valvular Disease
    • Chronic Obstructive Pulmonary Disease (COPD)
    • Congestive Heart Failure (CHF)
    • Previous Heart Surgery
    • Congenital Heart Disease
    • Hyperthyroidism

Treatment of Atrial Fibrillation

  • Rate Control is the initial focus before attempting to convert rhythm:
    • Common medications include Digoxin, Amiodarone, Beta-blockers, and Ibutilide.
  • Anticoagulant Therapy: Necessary for prevention of thromboembolic events
    • Examples include Heparin, Enoxaparin, and Warfarin (maintaining INR between 2-3).
  • Additional treatments include synchronized cardioversion and radiofrequency ablation.

CHECKPOINTS FOR ASSESSMENT

Identify the following dysrhythmias:

  • Atrial Fibrillation Symptoms: Choosing hallmark signs
    • A: Sawtooth pattern
    • B: Irregularly irregular rhythm
    • C: Pauses
    • D: Absence of P waves
    • E: Widened QRS

Distinguishing Factor of Atrial Flutter:

  • A: Sawtooth pattern on the baseline
  • B: Wide QRS complexes
  • C: Patient being pulseless
  • D: Possible hypotension
  • E: Ventricular ectopic foci

Rate of Controlled Atrial Fibrillation and Atrial Flutter:

  • A: 40-60 bpm
  • B: Between 60-100 bpm
  • C: Greater than 100 bpm
  • D: They do not share the same controlled rate

PREMATURE VENTRICULAR CONTRACTIONS (PVC)

  • Definition: PVCs arise from an irritable focus in the ventricles and importantly do not show a P wave.
  • Characteristics: QRS is wide (> 0.12 seconds) and appears bizarre.
  • Types of PVCs:
    • Unifocal: Originate from a single focus.
    • Multifocal: Originate from multiple foci.
    • Couplets: Two PVCs occurring together.
    • Bigeminy: PVCs occurring every other beat.
    • Trigeminy: PVCs occurring every third beat.

Significant PVCs

  • Defined as:
    • PVCs occurring within the first four hours of a myocardial infarction (MI).
    • Frequent PVCs, defined as six or more per minute.
    • Multifocal PVCs
    • R-on-T phenomenon: PVCs that occur on the T wave.
    • Bigeminy or couplets of PVCs.

Treatment of PVCs

  • If PVCs are not significant, treatment may only involve removing the underlying causes (e.g., caffeine, stress).
  • Specific treatments:
    • For hypomagnesemia: magnesium sulfate.
    • For hypokalemia: potassium supplementation.
    • Medications: Amiodarone (preferred), Lidocaine.

VENTRICULAR TACHYCARDIA (VTach)

  • Types include Monomorphic VT and Polymorphic VT.

Treatment for VTach

  • Check Pulse:
    • If Positive: Utilize 12 lead EKG, heart monitor, defibrillator, potentially amiodarone or atenolol.
    • If Negative: Initiate rapid response, code blue for shockable rhythm.
  • Identification of Causes based on H's and T's:
    • Causes include Hypoxia, Hypovolemia, Hydrogen ions, Hypothermia, Hyperkalemia, Toxins, Cardiac Tamponade, Tension Pneumothorax, and Thrombosis.

VENTRICULAR FIBRILLATION (VFib)

  • Check Pulse:
    • If negative, undertake rapid response for shockable rhythm, perform CPR.
    • Medications: Epinephrine, Amiodarone, Lidocaine.

ASYSTOLE

  • Check Pulse:
    • If negative, initiate rapid response, code for epinephrine administration.
    • Identify underlying causes using H's and T's.

NURSING CONSIDERATIONS

  • Possible nursing diagnoses include identifying the critical nature of dysrhythmias, potential risk for decreased cardiac output, and patient anxiety.
  • Desired outcomes may include achieving normal sinus rhythm, increased stabilization of heart rate, and reduction in symptoms.
  • High-priority interventions might cover administering medications as prescribed, monitoring vitals closely, and preparing for potential advanced interventions or cardioversion.