Flashcards in Arrhythmias Deck (103)
Premature Atrial Complexes, the beat arises from...
within the atria
What do premature atrial complexes look like on ECG?
Early P waves with different morphology than the normal sinus P wave; QRS is normal
Premature Atrial Complexes are usually asymptomatic but when symptomatic may cause....
palpitations or give rise to PSVTs
If premature atrial complexes are symptomatic, how can they be treated?
Causes of premature atrial complexes:
Premature Ventricular complexes
Early beat from a focus in the ventricle that then spreads to the other ventricle. PVCs can occur in patients with or without structural heart disease
Causes of premature ventricular complexes:
structural heart disease
Premature Ventricular complexes on ECG
Wide, bizarre QRS followed by a compensatory pause
***Wide QRS because conduction is slower because it is not going through the normal conduction pathways, but through ventricular muscle
Most patients with premature ventricular complexes are asymptomatic, but if symptomatic experience:
If PVCs are symptomatic, may treat with
Patients with frequent PVCs and underlying heart disease are at increased risk of
Sudden death due to cardiac arrhythmia, especially VFib and may benefit from an ICD
2 successive PVCs
Sinus beat followed by a PVC
2 sinus eats followed by a PVC
multiple foci in atria fire continuously in chaotic pattern leading to Irregular, rapid ventricular rate
In aFib the atrial rate is
>400 bpm (most beats are inhibited at the AV node so the ventricular rate is about 75-175 bpm)
aFib plus underlying heart disease equals marked increased risk of ...
thromboembolism and hemodynamic compromise
Signs and Symptoms of aFib
Fatigue and exertional dyspnea
Palpitations, dizziness, angina, syncope
Irregularly irregular pulse
How does aFib contribute to thromboembolic events?
Due to ineffective contraction, blood stasis occurs which leads to formation of intramural thrombi that can then embolize to brain
ECG findings in aFib:
Irregular RR intervals with tiny erratic spikes with wavy baseline. No identifiable p waves.
Irregularly irregular rhythm
Treatment for aFib in a hemodynamically unstable patient
Immediate electrical cardioversion to sinus rhythm
Treatment of aFib in hemodynamically stable patient
Rate control (60-100 bpm) with Beta blocker or calcium channel blocker
Cardioversion (electrical preferred over pharm)
Anticoagulation to prevent embolic cerebrovascular accident
What are choice pharmacologic agents for cardioversion?
why must a patient in aFib receive anticoagulation prior to cardioversion?
risk of embolization during cardioversion is significant, especially if aFib has been present for >48 hours
How long should aFib patients be anticoagulated for?
3 weeks before cardioversion and 4 weeks after cardioversion
What is the goal INR range for aFib patients?
INR of 2-3 is goal
Treatment of chronic aFib includes
Beta Blocker or CCB for rate control
Anticoagulation with warfarin (unless under age 60 with lone-aFib)
delivers shock in synchrony wiht QRS so that it does not hit T wave which could result in VFib
Purpose of Cardioversion
terminate certain dysrhytmias like PSVT or VT