I'm wonderin' what in the devil could it all possibly mean.

As recording and imaging technology has evolved over the last 100 years, the ejection and filling phases of the cardiac cycle steadily have been divided into subphases.<sup>12 Brutsaert D.L., Sys S.U. Relaxation and diastole of the heart Physiol Rev 1989 ;  69 : 1228-1314

Cliccare qui per andare alla sezione Riferimenti</sup> The present challenge confronting physiologists studying cardiac function is to determine the scientific merit of these subdivisions and define the underlying mechanisms controlling each subphase. Additionally, the physiologist must then seek to understand how these subphases couple together to produce either a normally or pathologically functioning heart. The knowledge gained from a basic understanding of the workings of each subphase of the cardiac cycle at the macroscopic and microscopic levels can then be used to guide research in the development of heart medications and surgical procedures, and possibly in the development of specific gene-targeted therapies. These therapies then can be applied by practicing cardiologists exercising experienced clinical judgement.

In this article, the authors review the major subdivisions of the cardiac cycle, summarize the important mechanisms thought to be operating during each cycle, and examine current thinking regarding how these phases and their mechanisms interact and couple to produce normal and abnormal cardiac diastolic function. The authors believe that by closely examining each part of the cardiac cycle and its relationship to diastolic function, a picture of resolved and unresolved problems of diastole will emerge. This picture may then act as a framework to guide future research, and also act as a tutorial for the clinician who wants to completely understand the current ideas and controversies that surround the study of diastolic function of the heart.