Taggart 1983.

Methods	Three‐mo cross‐over trial; endpoints—"heart failure score," CT ratio, systolic time intervals (LVET, PEP, PEP/LVET)
Participants	22 participants; mean age 65; 64% male; 82% Class II; 95% on diuretics, 9% on beta‐blockers; prior dig Rx in 100%; dx—77% ischemic, 9% valvular
Interventions	mean plasma dig level 1.2 ng/mL
Outcomes	for dig versus pla, no significant difference in "heart failure score," CT ratio; LVET 388 & 403 msec (P < 0.001), PEP 128 & 138 msec (P < 0.001), PEP/LVET 0.39 & 0.41 (P < 0.02)
Notes	blind allocation—yes blinded to outcomes—? baselines comparable—NA loss to follow‐up—? dig titrated to level—no
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment (selection bias)	Low risk	A—Adequate

Abbreviations:
 ET = treadmill exercise time.
 class = NYHA functional class.
 EF = ejection fraction.
 pts = participants.
 HF = heart failure.
 dig = digoxin.
 Rx = treatment.
 dx = diagnosis.
 pla = placebo.
 ACEI = angiotensin‐converting enzyme inhibitors.
 EX = bicycle exercise.
 VAS = visual analogue scale.
 JVP = jugular venous pulse.
 CT ratio = cardiothoracic ratio.
 QOL = quality of life.
 LVED = left ventricular end‐diastolic dimension.
 FS = fiber‐shortening fraction.
 Vcf = circumferential fiber shortening velocity.
 LVET = left ventricular ejection time.
 PEP = pre‐ejection period.

mo = month.

wk = week.

yr = year.
 Note: For studies of dig versus pla with additional arms, all data shown are for the dig and pla groups only.