Table 1

Frequency of Missing Data for Dyssynchrony Study Measures

Echocardiographic MethodEchocardiographic Dyssynchrony MeasuresMissing Rates Excluding 31 Patients Without Any Echocardiographic Data (n = 324)Missing Rates Including 31 Patients Without Any Echocardiographic Data (n = 355)
M-modeSeptal-posterior wall motion delay (≥130 ms)80 (24.7%)111 (31.3%)
Pulsed DopplerInterventricular mechanical delay (≥40 ms)9 (2.8%)40 (11.3%)
LV filling time relative to RR (≤40%)34 (10.5%)65 (18.3%)
LV pre-ejection interval (>140 ms)2 (0.6%)33 (9.3%)
M-mode + pulsed DopplerLeft lateral wall contraction overlap with LV filling (≥0)122 (37.7%)153 (43.1%)
(n = 310)(n = 341)
Tissue Doppler imagingTime difference between lateral and septal peak systolic wall velocity (≥60 ms)126 (40.6%)157 (46.0%)
SD of time to peak velocity (≥32 ms)176 (56.8%)207 (60.7%)
Maximum difference of time to peak velocity (≥median)75 (24.2%)106 (34.2%)
Maximum difference of time to onset systolic velocity (≥median)75 (24.2%)106 (34.2%)
Delayed longitudinal contraction (≥2)77 (24.8%)108 (31.7%)
Maximum difference of time to peak velocity outside IVCT (≥110 ms)77 (24.8%)77 (31.7%)
Maximum difference of time to peak displacement (≥median)222 (71.6%)253 (74.2%)

Echocardiographic assessments for each of the 12 prospectively evaluated dyssynchrony measures were categorized as missing data if the images were determined by the core laboratories to be of poor quality.

IVCT = isovolumic contraction time; LV = left ventricular.

  • Twenty patients in atrial fibrillation or enrolled at sites not performing tissue Doppler imaging.