the abnormal ECG Flashcards
what normally causes an abnormal ECG
abnormal electrics or abnormal muscle
why does RA depol occur prior to LA
the SAN is located in the RA (initiates depol)
what does a tall p wave indicate
> 2.5sq, RA abnormaility e.g. pulmonary disease, congenital heart disease
what does a broad p wave indicate
> 3sq, LA abnormality e.g. valve disease, hypertension, CAD, cardiomyopathy
what does a completely absent p wave indicate?
AF
what does a hidden p wave indicate?
AV reentrant tachycardia
what does an intermittently absent p wave indicate?
sinus arrest/ sinoatrial exit block
what can cause a short PR interval
low atrial pacemaker (SAN), acessory pathway
what can cause a long PR interval
AV block
what is wolff-parkinson-white syndrome and wat does it show on ECG
d-wave, wise QRS, short PR - due to the bundle of kent accessory pathway; can be right or left sides
what 3 abnormalities could a QRS complex have
too wide, too tall, pathological q waves
what can cause a supraventricular origination of a wide QRD (4)
bundle branch block; Brugada patern; toxic conduction delay; wolff-parkinson-white syndrome
what can cause a bundle branch block (4)
CAD, hypertension, valve disease, heart failure
steps of normal ventricular depolarisation (4) and what is seen on lead V1/V6
- septum depolarises L->R
- depolarisation moves through the bundle of his and up the ventricles simultaneously
- L side is completely depolarised first as L is predominant
- complete depolarisation of both
ECG - v1: RS, 6: QR
what can be seen in a bundle branch block ECG (general -4)
broad QRS; uniquely shaped QRS; ST depression; T wave inversion
