Dysrhythmias and Heart Conduction System

Study Notes

Dysrhythmias, also called arrhythmias, are conditions involving abnormal electrical activity in the heart, causing irregular heartbeats.
These irregularities range from minor to life-threatening, affecting the heart's ability to pump blood efficiently and impacting overall body function.
Understanding the types, causes, and the heart's conduction system is essential for effective management and treatment.
A well-structured nursing care plan is crucial for monitoring and supporting patients with these conditions to improve outcomes and ensure safety,

Arrhythmia is a condition where the heart beats irregularly—too fast (tachycardia), too slow (bradycardia), or with an abnormal rhythm.
The heart's electrical system usually controls a steady heartbeat.
Malfunctions in this system lead to irregular heartbeats.

The conduction system is a specialized network of cells regulating the heart's rhythm by initiating and propagating electrical impulses.
Sinoatrial (SA) Node: Located in the right atrium, acts as the primary pacemaker generating electrical impulses for each heartbeat.
Atrioventricular (AV) Node: Found at the atria-ventricle junction. Receives impulses from the SA node, delaying them slightly, allowing atrial contraction and emptying blood into ventricles before ventricular contraction.
Bundle of His (AV Bundle): Transmits impulses from the AV node to the ventricles.
Bundle Branches: The bundle of His splits into left and right branches, carrying impulses to the ventricles.
Purkinje Fibers: These fibers spread throughout the ventricles, enabling coordinated ventricular contraction.
This synchronized system facilitates effective blood pumping throughout the body.

Atrial Fibrillation (AFib): Irregular, often rapid, atrial contractions leading to blood clots, stroke, and other complications.
Atrial Flutter: Similar to AFib but typically with a more regular pattern; can progress to fibrillation.
Ventricular Tachycardia (VT): Rapid heart rate originating from the ventricles; can be dangerous and lead to ventricular fibrillation if untreated.
Ventricular Fibrillation (VF): A severe condition where ventricles quiver instead of pumping effectively, often leading to sudden cardiac arrest.
Bradycardia: An abnormally slow heart rate.
Supraventricular Tachycardia (SVT): A fast heart rate originating above the ventricles, often in the atria; generally less dangerous than ventricular arrhythmias.
Premature Ventricular Contractions (PVCs): Extra beats originating in the ventricles; usually benign but frequent PVCs can increase the risk of other arrhythmias.
Premature Atrial Contractions (PACs): Extra beats originating in the atria; usually benign but can be a sign of other arrhythmias.
Long QT Syndrome: A condition where the heart's electrical system takes longer than normal to recharge between beats, increasing the risk of dangerous arrhythmias.
Wolff-Parkinson-White (WPW) Syndrome: An extra electrical pathway in the heart that can lead to episodes of tachycardia.

Diagnosis and Initial Assessment: Includes assessing symptoms (palpitations, dizziness, syncope, chest pain) and obtaining an electrocardiogram (ECG) to determine the type of arrhythmia.
General Treatment Principles: Lifestyle modifications (eliminating stimulants, managing stress), addressing underlying causes (electrolyte imbalances, ischemic heart disease, thyroid issues).
Pharmacologic Management: Antiarrhythmic medications (classified into classes I-IV based on their effects), anticoagulation (in atrial fibrillation to prevent stroke risk).
Non-Pharmacologic Interventions: Cardioversion (electrical or pharmacologic to restore normal rhythm), Ablation Therapy (using radiofrequency or cryotherapy to destroy abnormal pathways).
Implantable Devices (Pacemakers): For bradycardia to ensure a stable heart rate.
Surgery (Maze Procedure): Occasionally used for atrial fibrillation if other methods fail.
Emergent Management for Life-Threatening Arrhythmias: Immediate defibrillation (ACLS protocols), CPR, epinephrine, possibly amiodarone.

Assessment: Evaluate heart rate, rhythm, and blood pressure; identifying presence and type of dysrhythmia.
Nursing Diagnosis: Decreased Cardiac Output, Risk for Ineffective Tissue Perfusion, Anxiety, Knowledge Deficit.
Goals: Maintain/achieve adequate cardiac output with blood pressure and pulse within normal range.
Nursing Interventions: Monitor vital signs, ECG, administer medications, monitor for side effects.
Patient Education: Recognize symptoms of arrhythmia, understand treatment plan, manage risk factors.
Evaluation: Assess patient's response to interventions, ensure adequate cardiac output, satisfactory understanding of management.