Myocardial contractility assessment

Kikura M, Ikeda K. Comparison of effects of sevoflurane/ nitrous oxide and enflurane/nitrous oxide on myocardial contractility in humans. Load-independent and noninvasive assessment with transesophageal echocardiography. Anesthesiology 1993 79(2) 235-43. 

How can the end systolic pressure-volume relations (ESP-ESV) be employed in an assessment of myocardial contractile reserve ... 

This final section explores in a preliminary manner, an approximate method for assessing the contractile state and myocardial contractile reserve in terms of ejection fraction-afterload-preload relationships. The analysis is based on the concept of developed stress defined here to be the difference of end systolic stress and end diastolic stress. 

The development of practical methods for the assessment of myocardial contractility continues and while the ESP-ESV concept provides one approach for quantitating changes in the contractile state, it requires further modification in order that it may be employed for patient to patient comparison. The preliminary studies described here on the basis of the developed stress concept shows some promise, however, further studies are required to examine the relationships between peak systolic pressure and end diastolic volume in order to explore an alternative definition for developed stress. 

Figure 4.4 Effect of a free-radical scavenger M-(2-mercaptoproplonyl)-glycine (MPG) on the recovery of contractile function following 15 min of regional ischaemia in the dog heart, (a) MPG infused 1 min before reperfusion, (b) MPG infused 1 min after reperfusion. Contractile function was assessed as changes in ventricular wall thickening measured using an ultrasonic pulsed-Doppler epicardial probe. Note The free radical scavenger MPG can reduce myocardial stunning only when present during the first minute of reperfusion. Redrawn with permission from Bolli et af. (1989).

For assessing viability of a non-contractile myocardial region, the non-fasting, fed patient is given an oral glucose load and resting perfusion images are... 

Isolated Tissue Myocardial tissue harvested from an animal or even in some cases from man can be used to assess possible effects of a test article on the contractile state of the myocardium. Isolated atria, papillary muscles, trabeculae, or strips taken from papillary muscles or the ventricular wall have been used for this type of study (Toda, 1969 Brown and Erdmann, 1985 Brown et al 1987 Wilson and Broadley, 1989 Saetrum Opgaard et al 2000). 

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