OBJECTIVE: Holter monitoring is one option in risk-stratification after acute myocardial infarction (MI). Measurements of heart rate variability (HRV), ventricular tachycardia (VT) and ST-segment elevation (ST upward arrow ) have been useful in predicting clinical outcome. We investigated if a combination of different Holter variables could optimize risk-stratification. DESIGN: One hundred and twenty-one men < 70 years old with a first MI were studied. Holter monitoring for 24 h was started 11 +/- 5 days after MI and analysed for HRV, VT and ST. Follow-up was 10-12 years with cardiac death as endpoint. RESULTS: Thirty-six patients were positive for > or = 1 Holter variable (HRV in 15, VT in 16, ST in 10). At follow-up 22 cardiac deaths had occurred. The prognostic sensitivity of individual Holter variables ranged from 23 to 36%, but increased to 64% if combined. The cardiac death rate in Holter positive patients (39%) was significantly higher than in Holter negative patients (9%) (p < 0.0001). CONCLUSION: By combining measurements of HRV, VT and ST the prognostic importance of Holter monitoring can be significantly improved. The patients can be stratified in a low-risk group with an annual mortality < 1% vs a high-risk group with a cardiac death rate around 40% over the following decade.