Neither of these situations constitutes a diastolic heart failure.Stiffening of the left ventricle contributes heart failure with preserved ejection fraction, a condition that can be prevented with exercise.In diastolic heart failure, the volume of blood contained in the ventricles during diastole is lower than it should be, and the pressure of the blood within the chambers is elevated. Diastole
During diastole, the ventricular pressure falls from the peak reached at the end of systole. When this pressure falls below the atrial pressure, atrio-ventricular valves open (mitral valve at left side and tricuspid valve at right side) and the blood passes from the atria into the ventricles. First, ventricles are filled by a pressure gradient but near the end, atria contract (atrial kick) and force more blood to pass into ventricles. Atrial contraction is responsible for around 20% of the total filling blood volume. (In atrial fibrillation, this additional 20% filling volume is lost and the patient may experience systolic heart failure symptoms). Complete left ventricular filling is essential to maintain maximum cardiac output. Left ventricular filling is dependent upon ventricular relaxation and compliance, mitral valve area, atrio-ventricular gradient, atrial contraction and end-systolic volume. Diastole has four phases: isovolumetric relaxation, rapid filling, diastasis and atrial contraction. All of these phases can be evaluated by Doppler echocardiography. Non-diastolic dysfunction
Though HFpEF is characterized by a normal ejection fraction, this parameter is a rather poor index of the hearts contractile function.
Bickerstaff brainstem encephalitis is a rare inflammatory disorder of the central nervous system, first described by Edwin Bickerstaff in 1951. It may also affect the peripheral nervous system, and has features in common with both Miller Fisher syndrome and Guillain–Barré syndrome. Signs and symptoms
In order to diagnose Bickerstaff brainstem encephalitis, ataxia and ophthalmoplegia must be present. These are also diagnostic features of Miller Fisher syndrome, and so Bickerstaffs is only diagnosed if other features are present which exclude Miller Fisher syndrome. These may include drowsiness, coma or hyperreflexia. When the condition is defined in this way, a number of other features are commonly but not always found: among these are weakness of the limbs, the face, and/or the bulbar muscles; abnormalities of the pupils; and absent reflexes.Like some other autoimmune diseases, the condition usually follows a minor infection, such as a respiratory tract infection or gastroenteritis. Pathophysiology
The clinical features and course of the condition, the associated auto-antibodies against relevant antigens, and the response to treatment, all suggest that Bickerstaff brainstem encephalitis is an autoimmune disease. However, each of these criteria fails to fit a substantial proportion of patients, and there is no single test or feature which is diagnostic of Bickerstaff brainstem encephalitis. It is, therefore, possible that a proportion of cases are due to other causes, such as infection or lymphoma, but remain undiagnosed. It is also possible that there is more than one autoimmune disease that can cause an illness that would currently be diagnosed as Bickerstaffs.