Striking effect of left ventricular high filling pressure with mitral regurgitation on mitral annular velocity during early diastole. A study using colour M-mode tissue Doppler imaging

Pharmacotherapy of heart failure with normal ejection fraction (HFNEF)--a systematic review

AIM

The pharmacotherapy for heart failure with normal ejection fraction (HFNEF) is not as well defined as that for the treatment for heart failure with reduced ejection fraction (HFREF). Studies of the various drugs given for HFNEF have revealed conflicting results. The aim of this systematic review was to determine whether there is any benefit with pharmacotherapy in HFNEF in terms of cardiac outcomes.

METHODS

Electronic and printed sources were searched until August 2010 for randomized controlled clinical trials (RCTs) comparing drug therapy with placebo in HFNEF. Weighted mean difference and pooled odds ratio (OR) with 95% confidence intervals were calculated.

RESULTS

A total of six RCTs including 8410 patients with a mean follow-up period of 21 months were included in the analysis. Although there were no significant differences in all cause mortality between the two groups (pooled OR 0.95, 95% CI 0.79, 1.13, P= 0.55), the subgroup analysis revealed a slight but non significant advantage with the β-adrenoceptor blocker group. There was no significant difference between the two groups in terms of cardiovascular mortality, hospitalization, worsening heart failure, ejection fraction, E : A ratio, deceleration time and E : E' ratio.

CONCLUSION

There was no significant benefit of pharmacotherapy in HFNEF. This might have been because of a lack of stringent inclusion criteria for patients in the trials and lower power of the studies. Hence trials with well defined inclusion criteria, better power, longer follow-up periods and with echocardiographic parameters as endpoints are required to shed further light on this topic.

Left ventricular filling and diastolic myocardial deformation in chronic primary mitral regurgitation

AIMS

Chronic primary mitral regurgitation (MR) results in enhanced filling of the left ventricle (LV) during early diastole. Filling is impaired with the onset of LV systolic dysfunction, due to increased myocardial stiffness and reduced restoring forces. We investigated echocardiographic parameters of early diastolic function in relation to LV systolic function.

METHODS AND RESULTS

Early diastolic transmitral flow and tissue Doppler velocities, propagation velocity of early filling (V(p)), and early diastolic strain rates (SR-E) were measured in 30 patients with chronic degenerative MR and 30 age-matched controls. MR subjects were further subdivided into group 1 (14 subjects) if they had well compensated LV, and group 2 (16 subjects) if they had one or more of the following: functional limitation (> NYHA class I), LV end-systolic diameter >or=4.0 cm, and LV ejection fraction <or=60%. Group 1 had increased early diastolic transmitral flow and tissue velocities, V(p) and SR-E, compared with controls. V(p) and SR-E in group 2 (46.5 +/- 9.92 cm/s and 1.44 +/- 0.36 s(-1), respectively) decreased significantly compared with group 1 (74.4 +/- 19.9 cm/s and 1.96 +/- 0.53 s(-1), P <or= 0.002). Onset and peak of early long-axis expansion and myocardial lengthening were significantly delayed in MR, and this delay was directly correlated with preload parameters.

CONCLUSION

In chronic MR, novel echocardiographic measurements of early diastolic function exhibit a biphasic pattern depending on the state of LV systolic function, and may prove useful in the timing of surgery.

Preload dependence of the time interval between onsets of mitral inflow and early diastolic mitral annular velocity: a study in healthy subjects

The time interval (TEa-E) between onsets of early diastolic mitral annular velocity (Ea) and early mitral inflow velocity (E) has been proposed as a new index of left ventricular (LV) relaxation. We aimed to assess the influence of preload changes on this parameter by examining 25 healthy volunteers at rest, after passive leg lifting, and after administration of nitroglycerin combined with Valsalva maneuver. To obtain septal and lateral TEa-E, the time intervals between peak R-wave on electrocardiogram and the onsets of Ea and E were measured in different cardiac cycles. E and Ea were significantly changed by preload manipulations. We did not observe significant changes of TEa-E intervals after leg lifting or after nitroglycerin administration combined with Valsalva maneuver (P = NS). TEa-E was < 0 ms in several subjects using either septal or lateral Ea recordings. We conclude that TEa-E may be load independent in subjects with normal LV systolic and diastolic function as compared to other Doppler parameters. Therefore, this index could be potentially used as a reliable noninvasive parameter of LV relaxation. Nevertheless, even slight differences in cardiac cycle lengths might influence the measurements of TEa-E interval. For that reason, the clinical use of TEa-E seems to be significantly limited because of a wide margin of error in its measurement due to the inability to obtain Doppler recordings during the same cardiac cycle.

Advances in echocardiography

Echocardiography is an exceptionally useful technique for diagnosing cardiovascular disease in small animals. It is noninvasive and provides a wealth of data concerning cardiac morphology and function. For many patients, echocardiography is the definitive diagnostic tool. A well-performed study coalesces the findings of the physical examination, electrocardiogram, and radiographs into a clearly defined diagnosis on which treatment decisions can be based. More so than other diagnostic techniques, echocardiography is highly operator dependent and relies on the proper acquisition and interpretation of results by an examiner who is familiar with the principles, capabilities, and limitations of ultrasound imaging. This article reviews the basics of echocardiography, measurement of cardiac dimensions, and assessment of cardiac function. Within these sections, emerging technologies that expand the capabilities of the echocardiographic examination are introduced.