Is This Ischemia?

HPI:  Approximately 30 year old female with history of frequent PVCs presents via EMS with palpitations and near syncope. She was driving on the highway today when she had to stop due to abrupt palpitations, SOB, and sensation like she was about to “black out”.

EKG:

EKG Interpretation:
Sinus rhythm with monomorphic PVCs in pattern of bigeminy. Horizontal axis. Inverted T-waves in inferolateral leads (II, III, aVF, V5-V6). Machine says to consider INFEROLATERAL ISCHEMIA.

Discussion:
Is this ischemia? No. Patient is young and otherwise healthy with no risk factors for cardiovascular disease. She has a history of frequent ventricular ectopy, and presentation is concerning for transient ventricular tachycardia. Pattern of T-wave inversions is consistent with “Cardiac Memory”. How to differentiate:

·   Clinical scenario not consistent with ACS
·   Negative T-waves in same leads where PVCs are negative
·   Eventual resolution after resumption of normal electrical activation

Extent and duration of effect correlates with duration of preceding abnormal ventricular conduction. The longer and more profound the electrical disturbance, the longer and more profound Cardiac Memory persists. Most commonly seen with: 
1) Ventricular pacing
2) Intermittent LBBB
3) Pre-excitation in WPW
4) Episodes of ventricular ventricular tachycardia (likely cause in our patient).

Management:
·   High index of suspicion for underlying pathology
·   Provider awareness of phenomenon so as not to initiate unnecessary interventions (Cath lab, etc.)
·   Treatment aimed at underlying derangement as appropriate
·   Inpatient vs. outpatient continuous cardiac monitoring if diagnosis in question

By Dr. Blake Johnson