Determinants of left ventricular filling dynamics: alteration in the Doppler-derived transmitral filling profile with progressive impairment of cardiac function in a dog preparation

Transmitral pulsed-Doppler echocardiography is a more accurate technique compared with two-dimensional echocardiography using dobutamine, in patients with one vessel coronary artery disease

To examine the effects of dobutamine on pulsed-Doppler left ventricular filling indices and its utility for evaluation of CAD we studied 14 patients with normal coronary arteries (Group 1) and 39 patients with significant CAD (>70% diameter stenosis). Patients with coronary artery disease (CAD) were divided into two groups: patients with one-vessel coronary disease (Group 2); and those with multivessel CAD (Group 3). After stopping cardioactive treatment, patients underwent incremental dobutamine stress (5, 10, 20, 30 and 40 microg/kg/min) during pulsed-Doppler interrogation of diastolic filling with simultaneous heart rate and blood pressure measurements. The following transmitral Doppler variables were measured at baseline and at peak-dose of dobutamine: peak early (E) and peak atrial (A) velocity; E/A ratio; acceleration time (AT) and deceleration time (DT) of E wave; isovolumic relaxation time (IVRT); and time-velocity integral (TVI). Two-dimensional echocardiography was performed to detect regional asinergy and analyzed using a 16 segment model.

RESULTS

Normals and CAD patients showed comparable changes in heart rate and blood pressure (P=NS between groups). Intergroup analysis of the changes of transmitral flow showed the significant changes for these indices (P<0.001): E velocity (-2.78+/-10.04, 12.4+/-9.4 and 16.47+/-10.65 cm/s); AT of E wave (1.66+/-2.47, -5.2+/-1.38 and -4.66+/-2.39 m/s(2)); DT of E wave (-0.23+/-0.18, 0.2+/-0.2 and 0.2+/-0.28 m/s(2)); and TVI of transmitral flow (-1.26+/-0.7, 3.5+/-1.75 and 4.1+/-1.66 cm), respectively for Groups 1, 2 and 3. All other transmitral Doppler variables showed insignificant changes (P=NS) to dobutamine between groups. It is important that the significance of these changes were the same for patients with one-vessel and those with multivessel coronary disease. In conclusion, during dobutamine stress testing, patients with CAD, had an abnormal response of these transmitral Doppler indices: E wave; AT of E wave; DT of E wave; and the TVI of transmitral flow. The abnormal responses of these Doppler indices of left ventricular filling are more accurate markers of significant single vessel CAD than new wall motion abnormalities during conventional DSE.

Transthoracic and transesophageal echocardiography in the hemodynamic assessment of patients with congestive heart failure

All methods for estimating the severity of heart failure, such as clinical and radiographic examination, measures of ventricular performance, and exercise capacity, when used independently, have major limitations. Echocardiography can be used, not only to assess left-ventricular ejection fraction but also other determinants of prognosis (i.e., left-ventricular size and shape, estimation of left atrial and pulmonary artery pressures, right side involvement). The availability of continuous-wave Doppler has permitted us to evaluate pulmonary artery systolic pressure from tricuspid regurgitation, and this contributes to additional powerful data. In long-standing heart failure, pulmonary artery wedge pressure is a predictor of survival, and aggressive therapy to reduce wedge pressure improves survival. Noninvasive estimation of left-atrial pressure and left-ventricular filling pressure have been attempted by continuous-wave Doppler echocardiography in patients with heart failure and mitral regurgitation and by tissue Doppler imaging at the mitral annulus level. A significant relation has been reported between profiles of pulmonary venous flow and left-atrial pressure, but pulmonary venous flow indexes can be better assessed by transesophageal echocardiography (TEE) in terms of detection rate. It has recently been recognized that TEE can provide valuable information on intracardiac hemodynamics and ventricular function. Two-dimensional evaluation of ventricular function and pulsed- and continuous-wave Doppler recordings from the pulmonary artery, pulmonary vein, and mitral inflow are combined to provide these data, which are both qualitative and quantitative, and permit estimation of ventricular ejection fraction, left-atrial pressure, and cardiac output. It would be important to be able to stratify patients with congestive heart failure according to groups with the highest risk for early death because heart transplantation or aggressive medical treatment could be specifically applied to this population. Serial echocardiographic evaluations of the classic variables of systolic left-ventricular function as well as Doppler transmitral flow may be useful in monitoring the progression of the disease and the effects of medical treatment. The degree of pulmonary hypertension is independently associated with the restrictive left-ventricular diastolic filling pattern and with the degree of functional mitral regurgitation. Future studies on the impact of these hemodynamic variables on the outcome of patients with left-ventricular dysfunction are desirable.

A new approach for evaluation of left ventricular diastolic function: spatial and temporal analysis of left ventricular filling flow propagation by color M-mode Doppler echocardiography

OBJECTIVES

To evaluate left ventricular diastolic function and differentiate the pseudonormalized transmitral flow pattern from the normal pattern, the propagation of left ventricular early filling flow was assessed quantitatively using color M-mode Doppler echocardiography.

BACKGROUND

Because the propagation of left ventricular early filling flow is disturbed in the left ventricle with impaired relaxation, quantification of such alterations should provide useful indexes for the evaluation of left ventricular diastolic function.

METHODS

Study subjects were classified into three groups according to the ratio of early to late transmitral flow velocity (E/A ratio) and left ventricular ejection fraction: 29 subjects with an ejection fraction > or = 60% (control group); 34 with an ejection fraction < 60% and E/A ratio < 1 (group I); and 25 with ejection fraction < 60% and E/A ratio > or = 1 (group II). The propagation of peak early filling flow was visualized by changing the first aliasing limit of the color Doppler signals. The rate of propagation of peak early filling flow velocity was defined as the distance/time ratio between two sampling points: the point of the maximal velocity around the mitral orifice and the point in the mid-left ventricle at which the velocity decreased to 70% of its initial value. High fidelity manometer-tipped measurement was performed in 40 randomly selected subjects.

RESULTS

The rate of propagation decreased in groups I and II compared with that in the control group (33.8 +/- 13.8 [mean +/- SD] and 30.0 +/- 8.6 vs. 74.3 +/- 17.4 cm/s, p < 0.001, respectively) and correlated inversely with the time constant of left ventricular isovolumetric relaxation and the minimal first derivative of left ventricular pressure (peak negative dP/dt) (r = 0.82 and r = 0.72, respectively).

CONCLUSIONS

Spatial and temporal analysis of filling flow propagation by color M-mode Doppler echocardiography was free of pseudonormalization and correlated well with the invasive variables of left ventricular relaxation.

Variability of changes in Doppler transmitral filling pattern during stress echocardiography in patients with stable angina pectoris

Stress electrocardiography and echocardiography using atrial pacing together with the right-sided heart catheterization were performed in 21 patients with stable angina pectoris. Peak velocity of transmitral flow in early diastole (E) and in atrial contraction (A), deceleration time of early filling, and pulmonary artery wedge pressure were measured simultaneously at rest and immediately after each pacing frequency. Patients were divided according to their stress pulmonary artery wedge pressure changes into Group A (14 patients with an increase in pulmonary artery wedge pressure > or = 3 mmHg during stress) and into Group B (6 patients with a change in pulmonary artery wedge pressure < or = 2 mmHg during stress). One patient, T.L., with an increase in pulmonary artery wedge pressure > or = 5 mmHg after each pacing frequency was evaluated separately. In Group A patients, the non-linear course of the E/A ratio changes (from 0.78 +/- 0.06 to 0.66 +/- 0.05, P < 0.01; to 0.72 +/- 0.05, P = NS; and to 0.93 +/- 0.06, P < 0.01) and deceleration time changes (from 188.9 +/- 7.2 ms to 195.3 +/- 8.9 ms, P = NS; to 188.8 +/- 9.9 ms, P = NS; and to 154.2 +/- 6.7 ms, P < 0.01) was seen.(ABSTRACT TRUNCATED AT 250 WORDS)