Different recognizable patterns in a patient with normal systolic function. Panel A shows the normal pattern. Panel B shows the 'R pattern'. This pattern has a prolonged EFT and usually shows E-A reversal. Panel C shows the 'C pattern'. This pattern has a shortened EFT. Panel D shows an indeterminate pattern with E and A merging. The normal pattern in panel A could also be an 'RC pattern' a combination of the R and C patterns. This can only be identified based on the clinical circumstance.