Left ventricular dyskinesia reversed by intravenous nitroglycerin: A manifestation of silent myocardial ischemia

Abstract

Patients with coronary artery disease (CAD) frequently have left ventricular (LV) wall motion abnormalities in the absence of symptoms. Thirty-one patients with such LV wall motion abnormalities in the absence of symptoms participated in a study of the response of these abnormalities to ascending doses of intravenous nitroglycerin (NTG). In a subgroup of 20 patients the relation between the location of LV wall motion abnormalities and the presence or absence of significant CAD (≥50% diameter reduction), in the vessel supplying the LV region, was assessed. Wall motion improved after intravenous NTG; the ejection fraction increased by 3.7% (mean p < 0.05) and by 9.4% in the 19 patients who responded. There was no significant increase in heart rate; both LV systolic and enddiastolic pressures decreased minimally (12.5 and 3.5 mm Hg, respectively, p < 0.05). The ejection fraction response was observed with NTG doses ≤200 μg and no dose-response relation was apparent. In the subgroup subjected to regional wall motion analysis, the presence of dyskinesia was significantly (p = 0.007) associated with the presence of important CAD in a vessel supplying that region. Further, the fact that wall motion improvement after NTG was significantly (p = 0.002) associated supports the concept that silent ischemia results in LV regional wall motion abnormalities, which can be reversed with low dose intravenous NTG.