Diastolic dysfunction and diastolic heart failure: diagnostic, prognostic and therapeutic aspects

Abstract

Left ventricular (LV) diastolic dysfunction (DD) and diastolic heart failure (HF), that is symptomatic DD, are due to alterations of myocardial diastolic properties. These alterations involve relaxation and/or filling and/or distensibility. Arterial hypertension associated to LV concentric remodelling is the main determinant of DD but several other cardiac diseases, including myocardial ischemia, and extra-cardiac pathologies involving the heart are other possible causes. In the majority of the studies, isolated diastolic HF has been made equal to HF with preserved systolic function (= normal ejection fraction) but the true definition of this condition needs a quantitative estimation of LV diastolic properties. According to the position of the European Society of Cardiology and subsequent research refinements the use of Doppler echocardiography (transmitral inflow and pulmonary venous flow) and the new ultrasound tools has to be encouraged for diagnosis of DD. In relation to uncertain definitions, both prevalence and prognosis of diastolic heart failure are very variable. Despite an apparent lower death rate in comparison with LV systolic HF, long-term follow-up (more than 5 years) show similar mortality between the two kinds of HF. Recent studies performed by Doppler diastolic indexes have identified the prognostic power of both transmitral E/A ratio < 1 (pattern of abnormal relaxation) and > 1.5 (restrictive patterns). The therapy of LV DD and HF is not well established but ACE-inhibitors, angiotensin inhibitors, aldosterone antagonists and beta-blockers show potential beneficial effect on diastolic properties. Several trials, completed or ongoing, have been planned to treat DD and diastolic HF.

Figure 1

In the left screen, methodological outline for the measurement of Doppler transmitral indexes of diastolic function. In the right screen, normal diastolic pattern (upper part) and pattern of abnormal relaxation (lower part). A = atrial velocity (m/s), DT = deceleration time of E velocity (ms), E = early diastolic velocity (cm/s), IVRT = isovolumic relaxation time (ms)

Figure 2

In the left screen, methodological outline for the measurement of pulmonary veins flow. In the right screen, normal pulmonary veins flow pattern (upper part) and pattern of abnormal relaxation (lower part).

Figure 3

In the left screen, methodological outline for the measurement of Tissue Doppler indexes. In the right screen, normal myocardial diastolic pattern (upper part) and pattern of abnormal myocardial relaxation (lower part). A_m = myocardial atrial velocity (cm/s), CT_m = myocardial contraction time (ms), DT_m = myocardial deceleration time of E_m(ms), E_m = myocardial early-diastolic velocity (cm/s), PCT_m = myocardial pre-contraction time (ms), RT_m = myocardial relaxation time (ms).

Figure 4

Pressure-volume loops in systolic HF (upper part) and diastolic HF (lower part). The continuous black line refers to normal, the interrupted red line to the pathologic condition.

Figure 5

Results of overall and cardiac mortality in relation to transmitral E/A ratio in the Strong Heart Study [74] (upper panel)) and classification of DD grades (I-IV) according to Mayo Clinic suggestions [21] (lower panel). It can be observed a parallel behaviour between clinic progression and prognostic value of different grade of DD: the increment of mortality in Strong Heart Study has an "U" behavior, where E/A ratio <0.6 (grade I of DD) and >1.5 (grades II, III, IV) are both main predictors of mortality DD = diastolic dysfunction, NYHA = New York Heart Association, MAP = mean atrial pressure