From the Guidelines
Impaired diastolic dysfunction, more accurately called diastolic dysfunction, is a condition where the heart's ventricles cannot relax properly during the filling phase of the cardiac cycle, as described in the 2016 update from the American Society of Echocardiography and the European Association of Cardiovascular Imaging 1. This results in the heart requiring higher pressures to fill with blood between contractions. The condition typically affects the left ventricle and occurs when the heart muscle becomes stiff or thick, making it difficult for the chamber to fill completely. Some key points to consider about diastolic dysfunction include:
- Common causes include aging, high blood pressure, coronary artery disease, diabetes, and obesity, as noted in the 2005 ACC/AHA guideline update for the diagnosis and management of chronic heart failure in the adult 1.
- Symptoms may include shortness of breath, fatigue, swelling in the legs, and decreased exercise tolerance.
- Treatment focuses on managing underlying conditions through medications like ACE inhibitors, ARBs, beta-blockers, and diuretics, as recommended in the 2005 ACC/AHA guideline update 1.
- Lifestyle modifications are also important, including sodium restriction, regular physical activity, weight management, and blood pressure control.
- Diastolic dysfunction can lead to heart failure with preserved ejection fraction (HFpEF), where the heart pumps normally but filling is compromised, as discussed in the 1995 guidelines for the evaluation and management of heart failure 1 and 1. Early diagnosis and treatment are essential to prevent progression to more severe heart failure. Key aspects of diagnosis and evaluation include:
- Assessment of LV relaxation and filling pressures, as outlined in the 2016 update from the American Society of Echocardiography and the European Association of Cardiovascular Imaging 1.
- Use of echocardiography to evaluate LV diastolic function, including measurement of e′ velocity and annular velocity.
- Classification of diastolic dysfunction into different grades, including impaired relaxation, mildly elevated filling pressures, and restrictive filling patterns.
From the Research
Definition of Impaired Diastolic Dysfunction
Impaired diastolic dysfunction refers to a condition where the heart's ability to relax and fill with blood during diastole is compromised. This can lead to increased diastolic filling pressures, pulmonary congestion, and symptoms of heart failure 2.
Causes of Impaired Diastolic Dysfunction
The causes of impaired diastolic dysfunction can be varied, including:
- Hypertensive or valvular heart disease
- Hypertrophic or restrictive cardiomyopathy
- Tachycardia and ischemia
- Left ventricular hypertrophy
- Structural alterations of the myocardium with increased fibrosis, myocardial scarring, or infiltrative processes 2, 3
Pathophysiology of Impaired Diastolic Dysfunction
The pathophysiology of impaired diastolic dysfunction involves:
- Delayed relaxation
- Impaired LV filling
- Increased stiffness of the myocardium
- Abnormalities in diastolic function, such as abnormal relaxation or compliance 2, 4, 5
Diagnosis of Impaired Diastolic Dysfunction
Diagnosis of impaired diastolic dysfunction can be performed using various non-invasive and invasive techniques, including:
- 2D- and Doppler-echocardiography
- Color Doppler M-mode
- Doppler tissue imaging
- MR-myocardial tagging
- Radionuclide ventriculography
- Micromanometry
- Angiography
- Conductance method 2
Treatment of Impaired Diastolic Dysfunction
Treatment of impaired diastolic dysfunction is often empirical and lacks clear-cut pathophysiologic concepts. However, various medications have been shown to be beneficial, including: