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