Arrhythmias in Acute Ischaemia Heart Rhythm Service
Perfusion of conduction system SAN 55% atrial branch from RCA 45% proximal branch of Cx
Sinus Bradycardia
SA Block
Sinus Arrest
AV Nodal level PR prolongation 2 nd degree AVB Complete AVB Proximal RCA occlusion Rarely permanent after IMI but pace if persists > 2weeks
Infranodal Conduction Abnormalities New RBBB± LAFB = occlusion proximal to 1 st septal perforator Ominous prognosis 30% risk of VT or VF within 2 weeks post infarct
Infra-nodal Conduction Abnormalities
Intra-Hissal Block
LBBB and MI Rarely due to ant MI usually RBBB More likely bradycardia dependent LBBB (phase 4)
Diagnosis of MI with LBBB ECG is not reliable to diagnose MI in the presence of LBBB
Paced ECG and MI identification Cx occlusion
Paced ECG and MI
Pre excitation MI contralateral to AP mask infarct MI ipsilateral to AP allows recognition
Ventricular arrhythmias Reperfusion arrhythmias
AIVR
Ventricular arrhythmias Sustained MMVT - underlying implies underlying scar substrate NSVT PVT and VF
Supraventricular arrhythmias AT AF