Refractory period (sex) autonomic feedback mechanism, rather than through central chemicals like oxytocin, serotonin, and prolactin. Autonomic feedback is already known to regulate other physiologic systems, such as breathing, blood pressure, and gut motility. This theory suggests that after male ejaculation, decreased wall tension in structures such as the seminal vesicles leads to a change in the fine autonomic signals sent from these organs, effectively creating a negative feedback loop. Such a mechanism is similar to decreased gastric and bowel motility once gastric contents have passed through. Once the feedback loop has been created, the refractory period remains until the loop is broken
Heart failure with preserved ejection fraction echocardiographic parameters to diagnose diastolic heart failure. There are four basic Echocardiographic patterns of diastolic heart failure, which are graded I to IV: Grade III and IV diastolic dysfunction are called "restrictive filling dynamics". These are both severe forms of diastolic dysfunction, and patients tend to have advanced heart failure symptoms: The presence of either class III and IV diastolic dysfunction is associated with a significantly worse prognosis. These patients will have left atrial enlargement, and many will have a reduced left ventricular ejection fraction that indicates a combination of systolic and diastolic dysfunction. Imaged volumetric definition of systolic heart