Arrhythmias Flashcards
what are the ECG changes for sinus tachycardia
increased P wave in II, decreased P wave in QvR
How do you treat sinus tachycardia
treat underlying cause
what causes sinus tachycardia
increased automaticity via increased SNS tone by hypovolemia, hypoxia, cocain, meth, drugs for increasing HR, pain and anxiety and increased metabolic activity by hyperthryoidism and fever
what causes sinus bradycardia
decreased automaticity via increased vagal tone eg sleeping, athletes, inferior wall MI, slow AV conduction, decreased metabolic activity- hypothermia, hypothyroidism, increased potassium, increased intracranial pressure
normal QRS width
approx 0.12s
when does conduction block occur
if right coronary artery is occluded and causes an inferior wall MI, fibrosis of AV node, increased potassium, drugs like BB or CCB, infiltrative disease eg sarcoidosis and amyloidosis, lymes disease
ECG changes for Atrial flutter
saw tooth waves in II, III, V1 QvF. should be a 2:1 ratio of saw tooth and normal
how do you treat atrial flutter
treat by vagal manoeuvre, then adenosine (blocks AV node), give beta blocker or CCB, then cardioversion
Long term- ablation of abnormal tissue
what happens in atrial flutter
electrical conduction goes around the atrium extra fast
torsades de pointes is caused by
triggered activity when the myocardial cells are irritated during the plateau phase (early after depolarisations) due to decreased potassium, decreased calcium and some drugs. follows prolonged QT syndrome. occurs in ventricles
sick sinus syndrome shows a
mix of tachycardia and bradycardia
AVRT and AVNRT ECG changes
no visible P waves, retrograde P wave in II, III and QvF
atrial fibrillation ECG changes
fibrillation waves, V1, irregularly irregular rhythm
how to tell whether irregular or regular
measure R to R interval using piece of marked paper
V tach ECG changes
width of QRS greater than 0.14s, still have p waves, extreme right axis deviation
