M-mode analysis of mitral annulus motion for detection of pseudonormalization of the mitral inflow pattern

Validity of N-terminal propeptide of the brain natriuretic peptide in predicting left ventricular diastolic dysfunction diagnosed by tissue Doppler imaging in patients with chronic liver disease

BACKGROUND AND AIMS

Left ventricular diastolic dysfunction has been reported in patients with liver cirrhosis. Although conventional Doppler echocardiography has been used to assess diastolic filling dynamics, this technique is limited in diagnosing left ventricular diastolic dysfunction. The aim of the study was to validate the N-terminal propeptide of the brain natriuretic peptide (NT-proBNP) in predicting left ventricular diastolic dysfunction diagnosed by tissue Doppler imaging in patients with chronic liver disease.

METHODS

In 64 patients, left ventricular diastolic dysfunction was classified using tissue Doppler imaging and serum levels of NT-proBNP were measured.

RESULTS

Left ventricular diastolic dysfunction was found in 25 of 31 (80.6%) patients with severe liver fibrosis/cirrhosis versus 2 of 8 (25.0%) patients with moderate and 6 of 25 (24.0%) patients with mild liver fibrosis (P<0.001). Mean NT-proBNP levels were 407.1+/-553.4 pg/ml in patients with severe fibrosis/cirrhosis as compared with 60.8+/-54.9 pg/ml and 55.4+/-41.4 pg/ml in patients with mild and moderate fibrosis (P=0.001). NT-proBNP was most accurate in predicting advanced left ventricular diastolic dysfunction with an area under the receiver-operating characteristic curve of 0.90 (95% confidence interval, 0.77-1.0; P<0.001). A cutoff value of greater than 290 pg/ml was highly predictive of advanced left ventricular diastolic dysfunction.

CONCLUSION

NT-proBNP is a useful marker in detecting advanced left ventricular diastolic dysfunction in patients with chronic liver disease. Patients with severe liver fibrosis/cirrhosis and NT-proBNP levels exceeding 290 pg/ml should undergo further cardiac evaluation.

Protein kinase C epsilon induces systolic cardiac failure marked by exhausted inotropic reserve and intact Frank-Starling mechanism

Myofilament dysfunction is a common point of convergence for many forms of heart failure. Recently, we showed that cardiac overexpression of PKC epsilon initially depresses myofilament activity and then leads to a progression of changes characteristic of human heart failure. Here, we examined the effects of PKC epsilon on contractile reserve, Starling mechanism, and myofilament activation in this model of end-stage dilated cardiomyopathy. Pressure-volume loop analysis and echocardiography showed that the PKC epsilon mice have markedly compromised systolic function and increased end-diastolic volumes. Dobutamine challenge resulted in a small increase in contractility in PKC epsilon mice but failed to enhance cardiac output. The PKC epsilon mice showed a normal length-dependent tension development in skinned cardiac muscle preparations, although Frank-Starling mechanism appeared to be compromised in the intact animal. Simultaneous measurement of tension and ATPase demonstrated that the maximum tension and ATPase were markedly lower in the PKC epsilon mice at any length or Ca2+ concentration. However, the tension cost was also lower indicating less energy expenditure. We conclude 1) that prolonged overexpression of PKC epsilon ultimately leads to a dilated cardiomyopathy marked by exhausted contractile reserve, 2) that PKC epsilon does not compromise the Frank-Starling mechanism at the myofilament level, and 3) that the Starling curve excursion is limited by the inotropic state of the heart. These results reflect the significance of the primary myofilament contractilopathy induced by phosphorylation and imply a role for PKC epsilon-mediated phosphorylation in myofilament physiology and the pathophysiology of decompensated cardiac failure.

Doppler tissue echocardiographic features of cardiac amyloidosis

The purpose of the study was to assess whether quantification of myocardial involvement by Doppler tissue echocardiography (DTE) enhances the accuracy of echocardiographic characterization of cardiac amyloidosis (CA). A group of 36 patients with CA (mean age 58 +/- 13 years; 22 male) and 40 age-matched control patients were studied. Patients with CA were divided into CA-1 subgroup with nonrestrictive (n = 22) and CA-2 with restrictive left ventricular (LV) filling pattern (n = 14). Peak lateral and medial mitral annulus velocities by pulsed wave DTE were measured in systole, early diastole, and late diastole. Using color M-mode DTE of the LV posterior wall, mean myocardial velocities (MMV) and myocardial velocity gradient (MVG) were measured during ventricular ejection, early and late isovolumic relaxation (IVR), rapid ventricular filling, and atrial contraction. In both CA-1 and CA-2 groups, mitral annulus velocities, MMV, and all MVG were lower than those measured in control patients, with the exception of peak late diastolic annulus velocities at lateral side and MMV in atrial contraction. MVGs in both early IVR and rapid ventricular filling were lower in the CA-1 as compared with the CA-2 group. Late IVR-MVG was negative in control patients and positive in patients with CA indicating a faster movement of the subendocardium rather than the subepicardium during late IVR in patients with CA (0.88 +/- 0.50 s(-1) vs -0.40 +/- 1.59 s(-1); P <.001). The following parameters: peak early diastolic annulus velocities at lateral side < or = -12 cm/s, peak early diastolic annulus velocities at medial side < or = -10 cm/s, early IVR-MMV < or = -2.5 cm/s, early IVR-MVG < or = -0.7 s(-1), and late IVR-MVG > or = 0.5 s(-1) differentiated patients with CA from control patients with an overall accuracy of 0.82, 0.83, 0.81, 0.87, and 0.81, respectively. In patients with CA, reduction in early IVR-MMV was independent of patients' age and LV mass. DTE indices proved helpful in differentiating patients with CA from control patients including those patients with CA who had borderline conventional echocardiographic features and nonrestrictive LV filling pattern.

How should we assess diastolic function in hypertension?

OBJECTIVE

the aim of our study was to assess the relative merits of three indices of diastolic LV function in a group of patients with hypertension and normal systolic function and a group of healthy controls.

DESIGN

In this echocardiographic study, diastolic LV function was assessed by E/A ratio using pulsed Doppler recording and by atrial to total mitral annulus motion (AC) and maximal longitudinal LV relaxation velocity (RVm) by M-mode recordings from apical views. The study took place in the Department of Clinical Physiology in a secondary referral centre. Nineteen consecutive patients with uncomplicated hypertension referred to echocardiographic examination and 20 age- and sex-matched controls were included in the study.

RESULTS

All three measures of diastolic function, E/A ratio, AC and RVm indicated impaired diastolic function in the hypertensive group, compared to the healthy controls. However, E/A ratio and AC showed a considerable overlap between the groups, whereas there was a highly significant difference in RVm between the hypertensive group and the controls, with much less of an overlap.

CONCLUSION

The results indicate that of these three indices of diastolic function, RVm may be the most appropriate in patients with hypertension and normal systolic LV function.