Chapter 26??

Categories
- Originate in the sinus node:
- Sinus bradycardia
- Sinus tachycardia
- Originate outside of the sinus node:
- Premature atrial contractions (PACs)
- Supraventricular tachycardia (SVT)
- Atrial flutter
- Atrial fibrillation

Definition:
- A dysrhythmia that proceeds normally through the conduction pathway (regular) but at a slower than usual rate (<60 beats/min).
Causes:
- Normal physiological occurrences
- Physical fitness
- Pathologic causes such as:
- Heart disorders
- Increased intracranial pressure
- Hypothyroidism
- Digitalis toxicity
Signs & Symptoms:
- Syncope
- Dizziness
- Weakness
- Fatigue
- Shortness of breath
- Chest pains
Treatment:
- None unless symptomatic
- Medications such as atropine sulfate IV
- Pacing options, including noninvasive transcutaneous cardiac pacing

Definition:
- A dysrhythmia that proceeds normally through the conduction pathway (regular) but at a faster than usual rate (100-150 beats/min).
Physiological Responses Include:
- Strenuous exercise
- Anxiety and fear
- Pain
- Fever
- Hyperthyroidism
- Hemorrhage
- Shock
- Hypoxemia
- Dehydration
Signs & Symptoms:
- Dizziness
- Shortness of breath
- Hypotension
- Light-headedness
- Rapid heartbeat
- Chest pain
- Palpitations (sensations of a racing heartbeat)
- Cool and pale skin
- Syncope
Treatment:
- None unless symptomatic
- Treatment of underlying cause

Definition:
- A condition where neural tissue in the atrial conduction system initiates an early electrical impulse. The P wave may resemble other conducted impulses or may have slight variations due to initiation elsewhere in the atria rather than the SA node (irregular).
Causes Include:
- Caffeine consumption
- Nicotine use
- Other sympathetic nervous system stimulants
- Heart disease
- Metabolic disorders such as hyperthyroidism
Signs & Symptoms:
- Heart palpitations
Treatment:
- None unless frequent or symptomatic
- Steps to eliminate cause

Definition:
- A dysrhythmia where the heart rate is consistent but beats at a dangerously high rate (≥150 beats/min). Diastole is shortened, preventing adequate heart filling.
Consequences:
- Cardiac output drops
- Risk of heart failure
Signs & Symptoms (related to low cardiac output):
- Chest pain
- Hypotension
- Syncope
- Reduced renal output
- Shortness of breath
- Light-headedness
- Rapid heartbeat
- Palpitations (sensations of racing heartbeat)
- Cool and pale skin
Treatment Options:
- Valsalva maneuver
- Immersion of the face in water
- IV adenosine
- IV digitalis
- Adrenergic blockers
- Calcium channel blockers
- Cardioversion

Definition:
- A disorder where a single atrial impulse outside the SA node causes the atria to contract at an extremely rapid rate (200-400 contractions/min).
Characteristics:
- Regular rhythm
- AV node conducts only some impulses to the ventricle, resulting in a slower ventricular rate than atrial rate
- Atrial waves exhibit a characteristic sawtooth pattern
Signs & Symptoms (related to low cardiac output):
- Chest pain
- Hypotension
- Syncope
- Reduced renal output
- Shortness of breath
- Light-headedness
- Rapid heartbeat
- Palpitations
- Cool and pale skin
Treatment Options:
- Synchronized cardioversion
- Chemical cardioversion including IV digitalis and IV propranolol

Definition:
- A disorder where several areas in the right atrium initiate impulses leading to disorganized, rapid atrial activity (the atria quiver instead of contracting). The ventricles respond randomly to atrial stimuli resulting in an irregular ventricular heart rate.
Signs & Symptoms (related to low cardiac output):
- Chest pain
- Hypotension
- Syncope
- Reduced renal output
- Shortness of breath
- Light-headedness
- Rapid heartbeat
- Palpitations
- Cool and pale skin
Complications Include:
- Inadequate cardiac output
- Blood clot formation leading to increased stroke risk
- 1.5% risk in people aged 50 to 59
- 30% risk in people aged 80 to 89
Treatment Options:
- Heparin IV, especially if sustained for >48 hours
- Oral anticoagulants like aspirin and Coumadin IV or PO for persistent cases
- Chemical cardioversion including IV amiodarone and IV digitalis
- Synchronized cardioversion
- Maze procedure to create a new conduction pathway

Categories Include:
- Premature Ventricular Contractions (PVC)
- Ventricular Tachycardia
- Ventricular Fibrillation

Definition:
- A condition where ventricular contraction occurs before the SA node fires.
- Characterized by the absence of a P wave and a wide, bizarre QRS complex.
- Patients may experience a "fluttering" sensation in the chest.
Signs & Symptoms Include:
- Pallor
- Nervousness
- Sweating
- Fainting
Causes Include:
- Stress
- Anxiety
- Fatigue
- Alcohol withdrawal
- Nicotine use

Definition:
- A disorder originating from a single point in the ventricles causing them to fire at an increased rate (150 to 250 beats/min).
- Results in decreased cardiac output and can lead to ventricular fibrillation (VF).
Management Strategies:
- If pulsed, cardioversion or drug administration is necessary
- If pulseless, immediate defibrillation is required

Definition:
- A critical state where the rhythm of the heart is that of a dying heart; the ventricles quiver without effective pumping.
Consequences:
- No cardiac output is generated, requiring immediate defibrillation.

Include:
- 12 Lead ECG
- Electrophysiology (EP) study to diagnose the structural cause of dysrhythmias

Treatment methods may involve:
- Antiarrhythmic medications
- Defibrillation
- Device implantation such as Implantable Cardiac Defibrillator (ICD) or Zoll Life Vest