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In recent years diastolic function has received greater recognition for its impact on overall cardiac performance. Diastole is no longer regarded as a passive phase of the cardiac cycle, but rather as a complex sequence of interrelated events, which are dependent upon loading conditions, heart rate, and contractility, and ultimately influence the systolic function of the left ventricle (LV). Studies have suggested that patients with diastolic dysfunction presenting for cardiac surgery are prone to hemodynamic instability and potentially worse outcomes,1 and that patients with diastolic heart failure are at increased risk for decompensation in the perioperative period.2 Therefore, the perioperative echocardiographer should be familiar with the pathophysiology of diastolic heart failure and understand how to monitor and optimize diastolic function. Although advances in ultrasound technology have rendered Doppler echocardiography as the clinician's “Rosetta Stone” for diastolic function evaluation, this chapter will familiarize the readers with all the echocardiographic techniques routinely employed to assess LV diastolic function, explain the significance of these diastolic indices, and provide a diagnostic algorithm to evaluate diastolic dysfunction.

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Diastolic dysfunction is defined as the inability of the LV to fill at normal left atrial (LA) pressure and represents a mechanical dysfunction of the LV, characterized by delayed LV relaxation and/or decreased compliance. Diastolic dysfunction may be present in the absence of signs and symptoms of heart failure, but when these symptoms occur, the diagnosis of diastolic heart failure can be made. Therefore, while diastolic dysfunction describes a cardiac mechanical abnormality, diastolic heart failure represents a clinical syndrome. Heart failure is the most common cause of hospital admission in patients over 65 years of age, accounting for approximately 1 million admissions annually in the United States and more then $15 billion in costs.3 Nearly half of these patients, however, have a preserved ejection fraction and are defined as having diastolic heart failure.4 The prevalence of diastolic heart failure is age dependent, increasing from less than 15% in patients younger than 45 years of age to 35% in those between the ages of 50 and 70 years, and more then 70% in patients older than 70 years.5 The increased prevalence of diastolic dysfunction in the elderly appears to be related to the coexistence of diseases associated with aging such as hypertension, coronary artery disease, aortic stenosis, and cardiomyopathies that alter the normal LV structure and lead to deterioration of the LV diastolic properties. Morbidity from diastolic heart failure is high and the 1-year readmission rate approaches 50%.5 The annual mortality rate for patients with diastolic heart failure (5% to 8%) is lower than that for those with systolic heart failure, except in patients 70 years or older, where the mortality rates are similar.5

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From a clinical standpoint, the cardiac cycle has been divided into systole and diastole. Systole starts with closure of the atrioventricular valves and encompasses isovolumic contraction and ejection, finishing with the closure of the semilunar valves. At this point, ...

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