Several noninvasive techniques have been used for the assessment of systolic and diastolic function. In most forms of cardiac disease however systolic and diastolic dysfunction coexist, hence a combined measure of left ventricular performance may be more reflective than their assessment alone. A recently recommended new Doppler index is supposed to be useful for this purpose. This index is the ratio of the sum of both isovolumic times and the ejection time. The objective of this study was to assess the features of the new index and then to prospectively evaluate the effect of chronic amiodarone treatment on left ventricular function using the new index and standard methods in dilated cardiomyopathy.
Results: Normal values of the new index are within a narrow range, it separates the normal and the dilated cardiomyopathy patients without overlap, it is not heart rate dependent in either group and it is not affected by either mitral regurgitation or left bundle brunch block. The index is inversely related to the relative diastolic filling time in both groups. In severe dilated cardiomyopathy after one year amiodarone treatment there was a significant decrease of heart rate, the new Doppler index and a significant increase of ejection fraction, ejection time and relative diastolic filling time. These changes were significant already at 1 month except the new index. These results suggest that the beneficial effect of amiodarone is due to the increase of diastolic filling time rather than to a positive inotropic effect.
Conclusions: 1. The new Doppler index is simple and can be easily utilized in the differentiation of normal and abnormal left ventricular function: 2 chronic amiodarone treatment may be indicated even in the absence of arrhythmia to improve left ventricular function in severe heart failure.