Key Points
- To determine whether oral isosorbide dinitrate prevents exercise-induced regional myocardial dysfunction in a conscious canine model of chronic single-vessel coronary obstruction.
- Sonomicrometry telemetrically measured regional segment length and dynamic wall thickness in the left circumflex coronary artery territory of 10 conscious dogs after ameroid constrictor implantation.
- Treadmill exercise runs were performed under control conditions and following oral isosorbide dinitrate administration once coronary obstruction was nearly complete and collaterals had formed (24–42 days).
- Control exercise elicited significant increases in hemodynamic parameters and normal segment percent shortening (P < 0.01).
- Isosorbide dinitrate attenuated exercise-induced elevations in left ventricular systolic and end-diastolic pressures while significantly decreasing end-diastolic dimensions.
- Percent wall thickening and percent segment shortening in the ischemic myocardial zone did not deteriorate significantly during exercise following isosorbide dinitrate treatment.
Structured PICO
Does oral isosorbide dinitrate prevent exercise-induced regional myocardial dysfunction in a canine model of chronic single-vessel coronary heart disease?
PPopulation10 conscious dogs with left circumflex coronary artery obstruction via ameroid constrictor and developed collaterals (24-42 days post-implantation)
IInterventionOral isosorbide dinitrate prior to exercise runs
CComparatorControl exercise runs (without isosorbide dinitrate)
OOutcomeRegional segment length and dynamic wall thickness (regional myocardial function) measured by sonomicrometry during exercisesurrogate
In a canine model of chronic single-vessel coronary disease, isosorbide dinitrate prevents exercise-induced deterioration of regional myocardial function.