Objectives: Some investigators have reported that left ventricular (LV) mechanical systolic and diastolic dyssynchrony occurs in coronary artery disease (CAD) patients without earlier myocardial infarction and narrow QRS complex duration. However, earlier studies evaluated LV dyssynchrony only at rest. The purpose of this study was to investigate LV dyssynchrony in CAD patients with preserved ejection fraction during adenosine stress using electrocardiogram-gated myocardial perfusion single-photon emission computed tomography (SPECT).
Methods: The study population included 18 CAD patients and 18 control subjects. CAD patients had significant stenosis in their coronary arteries by coronary angiogram without earlier myocardial infarction. SPECT images were acquired at rest and during stress with adenosine. The regional time to end systole (TES), time to peak ejection, the time from 0 to peak filling during the whole diastolic period (TPF1), and the time from end systole to peak filling during the whole diastolic period (TPF2) were obtained by using the Quantitative Gated SPECT software. The maximal difference (MD), which is the difference between the earliest and latest temporal parameter among 17 segments, was considered to represent LV dyssynchrony.
Results: MD-TES and MD-TPF1 during stress were significantly greater than those of rest in CAD patients (MD-TES: stress=242±107 ms, rest=164±79 ms; P=0.005, MD-TPF1: stress=249±121 ms, rest=164±88 ms; P=0.015) but there were no significant differences in control patients.
Conclusion: LV dyssynchrony was shown in CAD with preserved ejection fraction during adenosine stress.