Left Ventricle Contraction diastolic function

Calcium accumulation and overload secondary to ischemia impair ventricular relaxation as well as contraction. This is apparently a result of impaired calcium uptake after systole from the myofilaments, leading to a less negative decline in the pressure in the ventricle over time. Impaired relaxation is associated with enhanced diastolic stiffness, decreased rate of wall thinning, and slowed pressure decay, producing an upward shift in the ventricular pressure-volume relationship put more simply, MVO2 is likely to be increased secondary to increased wall tension. Impairment of both diastolic and systolic function leads to elevation of the filling pressure of the left ventricle. 

Diastolic dysfunction is the most common abnormality found in patients with HCM. Approximately 80% of patients will exhibit symptoms associated with diastolic dysfunction. Studies of the left ventricle led to the realization that diastolic dysfunction is the result of abnormalities in relaxation, distensibility (compliance), and filling. The abnormalities of diastolic function can be both regional and global and lead to an incoordination of contraction and relaxation. /3-Adrenergic stimulation can aggravate these abnormalities, whereas /3-blockade may diminish them. ... 

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