Key result
Altered ventricular activation sequence induced T-wave changes mimicking cardiac memory, which was abolished by 4-aminopyridine blocking Ito and reducing the transmural voltage gradient.
Why the study?
Does alteration of ventricular activation sequence and potassium channel blockade affect repolarization and cardiac memory in canine ventricular slabs?
Population
Canine ventricular subepicardial and subendocardial slabs measuring 15 x 30 x 1 to 2 mm
Comparison
Alteration of ventricular activation sequence… vs Simulated normal activation and baseline…
Design
Preclinical
Authors
Loading...
Should not change clinical practice; extends mechanistic insights on Ito and transmural gradients in cardiac memory.
Does alteration of ventricular activation sequence and potassium channel blockade affect repolarization and cardiac memory in canine ventricular slabs?
This preclinical study demonstrates that cardiac memory is influenced by specific potassium channels (Ito) and transmural voltage gradients for repolarization.
Geller et al. (1993) studied Cardiac memory (T-wave changes). Altered activation sequence (ventricular pacing) and 4-aminopyridine (4-AP) vs. Simulated normal activation and lidocaine was evaluated on Action potential characteristics and T-wave changes. Altered ventricular activation sequence induced T-wave changes mimicking cardiac memory, which was abolished by 4-aminopyridine blocking Ito and reducing the transmural voltage gradient.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: