I define persistent hypothermia in this thread about the mechanisms of persistent hypothermia. The Graph of Katzung et al. in Pharmacology about Heart Failure:
I am thinking which parts here are critical on temperature. Temperature has a direct effect of reaction rates of chemical reactions here, for instance NE, AII and probably chemical reactions in endothelin such as ET.
Therefore, I am thinking that the relationship between temperature and cardiac performance cannot be linear at all. Some have said me that low temperature can decrease metabolism and oxygen consumption. However, I started to think differently when time goes enough far that is when heart cannot anymore supply enough blood with oxygen. Thus, hypoxia can occur and asymptomatic exodus may occur.
Based on physiology, I can propose that the cardiac output curve shifts to the left (CO1 $\to$ CO2), due to less oxygen being supplied to the heart, similarly EDV1 (end-diastolic volume) shifts $\to$ EDV2 and SV1 (stroke volume) $\to$ SV2. However, the venous return (VR) curve can shift much more, since I propose that the effect of temperature on smooth musculature is relatively bigger than on heart because of proportional size of tissue. So the VR1 shifts to VR2, so EDV2 $\to$ EDV3 and SV2 $\to$ SV3. Consequently, SV3 > SV1, while EDV3 < EDV1. See my draft figure about this:
where EDV (End Diastolic Volume) in the x-axis and SV (Stroke Volume) in the y-axis.
In a healthy person, who have no hypertrophy of ventricles and elastic myocardium, the heart can tolerate this. So such a condition of cardiac failure as in the figure 13-3 is possible.
However, if flexibility of the myocardium, for instance, is not possible, such a pathway may not be possible. The autonomic nervous system may enter the picture and increase vagus nerve stimulation (PS more). However, not sure about the exact pathway.
What is the effect of temperature on cardiac performance? How can temperature decrease cardiac performance?