In 19 patients with an undesirable hemodynamic condition (n=15) or with regional asynergy and coexistent ST-T change (n=4) during isolated coronary artery bypass grafting (CABG) surgery, one (n=17) or two (n=3) additional saphenous vein grafts were placed onto left anterior descending (LAD) (n=16), right (n=4), and left circumflex (LCx) (n=2) coronary arteries. Diagnosis of the cause of the suboptimal condition was insufficient graft flow in 16 patients, and spasm of the ungrafted coronary artery in 3. Additional myocardial ischemic time was 17 9 minutes, and the graft flow was 59 25 ml/min. Additional bypass was effective in 94.5%. Eighteen patients could be weaned from cardiopulmonary bypass, and 17 (89.5%) survived and were discharged from hospital. Median duration of mechanical ventilatory support and intensive care unit stay was 15 hours and 4 days, respectively. During 63 44 months follow-up, the additional graft was occluded and the treadmill test was positive for ischemia in 2 patients, and one child patient is now considered for redo CABG. Placement of additional bypass grafts thus appeared to be an effective and relatively safe strategy, although the decision has to be made cautiously.