Evaluation of post-myocardial infarction regional and global left ventricular function by monoplane ventriculography: superiority of right versus left anterior oblique projection at any infarct location.

OBJECTIVES

To study the significance of serial quantitative regional wall motion analysis, volumes, and ejection fraction findings as well as their prognostic implications derived from cineventriculography in 30 degrees right anterior oblique (RAO) projection in comparison with 60 degrees left anterior oblique (LAO) projection in post-myocardial infarction patients. Ventriculographic left ventricular parameters are accepted surrogates of mortality in myocardial infarction. Nowadays, in contrast to a biplanar approach in most institutions and clinical trials, the investigation is reduced to monoplanar ventriculography. However, it is not known whether the relevance of the two established projections might differ in different infarct topographies.

DESIGN AND METHODS

Two hundred and six consecutive patients with acute myocardial infarction (infarct duration < 6 h) were treated with streptokinase (group I, n = 103) and allocated randomly additional percutaneous transluminal coronary angioplasty (group II, n = 103). Biplanar cineventriculography studies were performed at the acute stage, before discharge, and 6 months after discharge from hospital.

RESULTS

Regional wall motion analysis (using an algorithm of fixed radiants) documented larger hypokinetic areas and intensities on RAO than it did on LAO projections, whereby infarct size and its improvement (stunned myocardium) was displayed more comprehensively, and a higher predictive power for survival (P = 0.0002 versus NS) was shown in anterior and inferior infarcts. No advantage of the LAO projection could be detected for evaluation of lateral infarcts due to circumflex coronary artery thrombosis either. The predictive power of the global function (ejection fraction; the algorithm of disc summation method) established by RAO projection (P = 0.007) was superior to that of LAO projection (P = 0.03). Enlargement of volumes (left ventricular remodeling) could be documented significantly only by the RAO projection; the LAO projection failed to do so. Groups I and II did not differ in any respect.

CONCLUSIONS

The RAO projection has excellent diagnostic and predictive power at any infarct location. In contrast, additional LAO projection provides little information that cannot be obtained reliably from the RAO projection.