CHANGES IN LEFT AND RIGHT-VENTRICULAR PERFORMANCE AND VOLUMES IN 7-YEAR SURVIVORS OF ACUTE MYOCARDIAL-INFARCTION

We describe the spontaneous long-term changes in right (RV) and left ( LV) ventricular performance during a 7-year period after acute myocard ial infarction (AMI). Radionuclide ventriculoraphy was performed in th e second week after AMI in 201 patients. RV and LV ejection fractions, and LV end-diastolic and end-systolic volumes were determined. A foll ow-vp after 7 years was performed in 55 survivors. Of these, 16 patien ts were also examined after 1 year. During the 7-year followup period, LV ejection fraction decreased from 0.49 to 0.45 (p <0.01). LV end-di astolic volume increased from 161 to 210 mi (30%) (p <0.01), and LV en d-systolic volume from 83 to 123 mi (48%) (p <0.01). In patients witho ut recurrent AMI, coronary artery bypass grafting surgery, or angioten sin-converting enzyme inhibitor therapy (n = 37) during follow-vp, no change in average LV ejection fraction was observed. Nevertheless, thi s subgroup had substantial increases in LV end-diastolic volume, from 157 to 190 mi (21%) (p = 0.002) and in LV end-systolic volume, from 80 to 105 mi (31%) (p <0.001). In a subgroup of patients also reinvestig ated after 1 year (n = 16), there was a 15% increase in LV end-diastol ic volume the first year after AMI with an additional 10% increase in LV end-diastolic volume between years 1 and 7. Corresponding figures f or LV end-systolic volume were 20% and 12%, respectively. Hardly any a ssociation was apparent between LV ejection fraction, LV end-diastolic volume, and LV stroke volume at discharge for subsequent LV dilatatio n. In conclusion, LV dilatation after AMI continued for several years after the acute injury. RV ejection fraction was unaffected by the lat e remodeling process. LV volumes and ejection fraction determined with in 2 weeks after AMI could not predict subsequent LV dilatation in sur vivors.