Changes in left and right ventricular performance and volumes in seven-year survivors of acute myocardial infarction

We describe the spontaneous long-term changes in right (RV) and left (IV) ventricular performance during a 7-year period after acute myocardial infarction (AMI). Radionuclide ventriculography was performed in the second week after AMI in 201 patients. RV and LV ejection fractions, and LV end-diostolic and end-systolic volumes were determined. A follow-up after 7 years was performed in 55 survivors. Of these, 16 patients were also examined after 1 year. During the 7-year follow-up period, LV ejection fraction decreased from 0.49 to 0.45 (p <0.01). LV end-diastolic volume increased from 161 to 210 ml (30%) (p <0.01), and LV end-systolic volume from 83 to 123 ml (48%) (p <0.01). In patients without recurrent AMI, coronary artery bypass grafting surgery, or angiotensin-converting enzyme inhibitor therapy (n = 37) during follow-up, no change in average LV ejection fraction was observed. Nevertheless, this subgroup had substantial increases in LV end-diastolic volume, from 157 to 190 ml (21%) (p = 0.002) and in LV end-systolic volume, from 80 to 105 ml (31%) (p <0.001). In a subgroup of patients also reinvestigated after 1 year (n = 16), there was a 15% increase in LV end-diastolic volume the first year after AMI with an additional 10% increase in LV end-diastolic volume between years 1 and 7. Corresponding figures for LV end-systolk volume were 20% and 12%, respectively. Hardly any association was apparent between LV ejection fraction, LV end-diastolic volume, and LV stroke volume at discharge far subsequent LV dilatation. In conclusion, LV dilatation after AMI continued for several years after the acute injury. RV election fraction was unaffected by the late remodeling process. LV volumes and ejection fraction determined within 2 weeks after AMI could not predict subsequent LV dilatation in survivors.