Objectives: To investigate the impact of acute subendocardial ischemia on the dispersion of ventricular refractory periods.Methods: Acute subendocardial ischemia was developed in sheep by partial ligation of the left circumflex coronary artery and rapid pacing of the left atrium. The ventricular effective refractory period (ERP) was measured in 5 left ventricular sites by a programmed premature stimulation technique.Results: The average ERP and ERP dispersion remained unchanged in the control group (n=5, p>0.05). In the study group (n=5), ERP was shortened following subendocardial ischemia. ERP dispersion was decreased significantly from 48 + 9 ms to 36 + 13 ms 30 min after the ischemia (p=0.02). There was neither spontaneous nor stimulation-induced ventricular arrhythmia after ischemia.Conclusion: Acute subendocardial ischemia leads to a homogenous reduction of ventricular ERP. This may partially explain why subendocardial ischemia is associated with a low incidence of ventricular arrhythmia.
|Number of pages||4|
|Journal||Experimental and Clinical Cardiology|
|Publication status||Published - 2007|