UNIQUE_STUDY STUVIA
Cardiac exam med surg 1
Medical Surgical Nursing (Bridgewater College)
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Cardiac
Exam
Chapter 26, 27 and 28
Ventricular Tachycardia
- Three or more PVCs in a row, occurring at a rate exceeding 100 bpm > Causes are
similar to that of PVC
- Higher risk of lethal VT with larger MIs and lower ejection fraction
♥ Ventricular and atrial rate: ventricular rate = 100 - 200 bpm, atrial depends on
underlying rhythm
♥ Ventricular and atrial rhythm: regular, atrial rhythm may be irregular
♥ QRS shape and duration: duration is 0.12 seconds or more; bizarre, abnormal shape
♥ P Wave: very difficult to detect, so the atrial rate and rhythm may be indeterminable
♥ PR interval: very irregular, if P waves are seen
♥ P:QRS ratio: difficult to determine, but if P waves are apparent, there are usually more
QRS complexes than P waves
Treatment
Determine whether VT is monomorphic (consistent QRS shape and rate), or polymorphic
(varying QRS shape and rate)
Procainamide may be used for monomorphic stable VT (n no MI or HF)
IV amiodarone for pt with imparied cardiac function or acute MI
Lidocaine immediate short term for pt with imparied cardiac function
Cardioversion is the treatment for symptomatic patients.
Defibrillation is the treatment of choice for pulseless VT. Long term
management
Pt with ejection fraction of less than 35% implantable cardioverter
defibrillator (ICD)
� Ejection fraction greater than 35% may be managed with amiodarone.
Ventricular rate is above 200 bpm, then the presence of an accessory
pathway should be suspected
Torsades de pointes is a polymorphic VT preceded by a prolonged QT
interval, which could be congenital or acquired.
central nervous system disease; certain medications
- low levels of potassium, calcium, or magnesium.
Ventricular Fibrillation
- Rapid, disorganized ventricular rhythm that causes ineffective quivering of the ventricles
- Causes: CAD, MI, untreated or unsuccessfully treated VT, cardiomyopathy, valvular
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heart disease, several proarrhythmic medications, acid-base and electrolyte
abnormalities, electrical shock, Brugada syndrome
♥ Ventricular rate: greater than 300 bpm
♥ Ventricular rhythm: extremely irregular, without a specific pattern
♥ QRS shape and duration: irregular, undulating waves without recognizable QRS
complex
- Characterized by absence of audible heartbeat, palpable pulse, and respirations
- Early defibrillation is critical
Treatment
- CPR until defibulizer
� administration of amiodarone and
- Seizures after resuscitation indicate severe anoxic brain damage
Atrial Fibrillation
- Uncoordinated atrial electrical activation that causes a rapid, disorganized, and
uncoordinated twitching of atrial musculature
- Ventricular rate depends on ability of AV nodes to conduct the atrial impulses, level of
sympathetic and parasympathetic tone, presence of accessory pathways, and effects of
medications
- Atrial fibrillation causes electrophysiologic changes in the atrial myocardium
Cause is unknown
- May occur in the postop period of any major surgery, structural heart disease,
inflammatory or infiltrative disease. dilated/ hypertrophic/ restrictive cardiomyopathy.
CAD, HIN, congenital disorders, HF, hyperthyroidism, obstructive sleep apnea, large
alcohol consumption
- Younger than 60 with no underlying pathophysiology is called lone atrial fibrillation
- Linked to increased risk of stroke, dementia, premature death
♥ Ventricular and atrial rate: atrial rate = 300 - 600 bpm,ventricular rate = 120 –200
bpm
♥ Ventricular and atrial rhythm: highly irregular
♥ QRS shape and duration: usually nonnal, but may be abnormal P wave: no
discernible
♥ P waves; irregular undulating waves that vary in amplitude and shape are seen
(F wave)
♥ PR interval: cannot be measured
♥ P:QRS ratio: many:1
- Tests to diagnose: history and physical examination (irregular pulse, jugular venous
pulsations, S, heart sounds), 12 lead ECG, echocardiogram, blood tests (thyroid, renal,