Cardiac exam med surg 1 Medical Surgical Nursing (Bridgewater College) Cardiac Exam
Chapter 26, 27 and 28
Ventricular Tachycardia
- Three or more
... [Show 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)
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Ventricular Fibrillation
- Rapid, disorganized ventricular rhythm that causes ineffective quivering of the ventricles
- Causes: CAD, MI, untreated or unsuccessfully treated VT, cardiomyopathy, valvular
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
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- 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
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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, [Show Less]