Assessment of left ventricular function after myocardial infarction.

The low frequency sounds and movements of the heart at the apex were recorded in 5I cases of acute myocardial infarction.Good correlation was found between the changes recorded, the clini- cal and radiological assessment of left heart function, and the left heart pressures.The technique is painless, safe, reproducible, and we believe gives useful additional information as to the func- tion of the left ventricle after acute myocardial infarction.In acute myocardial infarction the impairment of left ventricular function depends upon the severity of the acute injury and the amount of disease already present.The severity of the acute injury is usually assessed indirectly from the electrocardiogram and enzyme changes, and the impairment of left ventricular func- * tion from the presence or absence of 'failure'.'Failure ' is an unsatisfactory term because its definition and implications are open to dis- pute, and small changes either of improve- ment or deterioration are not readily apparent.Left heart catheterization is rarely practical, ethical, or desirable.Recording the chest wall pulsations over the apex of the left ventricle with a simultaneous phonocardiogram and electrocardiogram is an investigation which can be made at the bedside.It has been shown to give useful in- formation about heart function in primary myocardial disease (Shah, Gramiak, and Kramer, i968), valvular heart disease (Nixon and Wooler, I963; Fleming, I968; Epstein et V. al., i968), hypertension (Beilin and Mounsey, I962), and ischaemic heart disease (Benchimol and Grey Dimond, I962).The purpose of this paper is to describe the findings from a study of 5I cases of acute , myocardial infarction and to correlate the information with the results of left heart cathe- terization in I3 cases of coronary heart disease.The investigation suggests that the technique is a simple and useful method for assessing day-by-day changes in left ventricular func-