Resting Asynchronous Left Ventricular Contraction Abnormality Analyzed by a Phase Method in Spastic Angina Pectoris

Quantitative phase analysis of equilibrium ventriculography was performed to study the character of left ventricular (LV) wall motion abnormalities in patients with spastic angina pectoris, who may have clinically and electrocardiographically silent ischemia combined with myocardial stunning, during rest and hyperventilation stress testing. Phase analysis of the left ventricle at rest was performed by equilibrium radionuclide ventriculography in 13 control subjects and 36 patients with spastic angina pectoris. First-pass methodology along with hyperventilation stress testing was performed to assess spasm occurrences. Phase analysis of equilibrium multigated blood-pool scintigrams was performed to evaluate LV asynchrony at rest. The mean s.d. of LV phase distribution in the patients with variant and vasospastic angina was greater than that in the healthy control subjects (11.28 +/- 1.79 and 10.02 +/- 1.57 degrees versus 6.16 +/- 1.07 degrees). In addition, the mean s.d. of LV phase distribution in the variant angina group was greater than that in the vasospastic angina group. Furthermore, a linear correlation was found between the s.d. of LV phase distribution at rest and the percent decrease in ejection fraction during hyperventilation stress. Asynchronous LV contraction without significant hypokinesis was detected at rest in spastic angina pectoris. The severity of this asynchronous contraction corresponded well with decreases in ejection fraction during hyperventilation stress testing. Thus, analysis of the s.d. of LV phase distribution at rest is expected to provide useful information regarding LV asynchrony in spastic angina pectoris.