Transmitral flow velocities and times during stress transthoracic echocardiography in patients with myocardial ischaemia

[Evolution of the filling pattern of the left ventricle during the first year after an acute myocardial infarct. The influence of the infarct size]

OBJECTIVES

Acute myocardial infarction induces diastolic dysfunction as a result of the alteration of left ventricular relaxation and stiffness caused by ischemia and fibrosis. This study analyzes the association of infarct size with the diastolic filling pattern and the evolution of the latter during the first postinfarction year.

PATIENTS AND METHODS

The study group consisted of 68 patients with a first acute myocardial infarction treated with thrombolytic agents. A Doppler echocardiography was performed at 8 +/- 2, 32 +/- 7 and 370 +/- 23 days after infarction. Five measurements of the ratio between E and A waves peak velocities (E/A ratio) and of the E deceleration time (EDT, ms) were averaged in each echocardiographic study. The patients were divided according to infarct size into a large infarct group (creatine kinase > 1,000 U/ml; 1,913 +/- 883; n = 26) and a small infarct group (creatine kinase < 1,000 U/ml; 556 +/- 227; n = 42).

RESULTS

The large infarct group exhibited a greater E/A ratio and shorter EDT than the small infarct group in the first week (E/A ratio: 1.4 +/- 0.7 vs 0.8 +/- 0.3; p = 0.0001; EDT: 159 +/- 49 vs 192 +/- 56; p = 0.02) and at one month (E/A ratio: 1.2 +/- 0.7 vs 0.9 +/- 0.3; p = 0.01; EDT: 170 +/- 55 vs 207 +/- 40; p = 0.004); however no differences were observed between either group at one year in either E/A ratio (0.8 +/- 0.2 vs 0.9 +/- 0.4; NS) or EDT (207 +/- 44 vs 219 +/- 54; NS). In the large infarct group, E/A ratio decreased and EDT increased at one year compared to the first week (E/A ratio: p = 0.0004; EDT: p = 0.0001) and the first month (E/A: p = 0.02; EDT: p = 0.003); in contrast, in the small infarct group there were no significant differences in E/A ratio nor EDT during the first year postinfarction.

CONCLUSIONS

In the first month postinfarction, large infarcts exhibit a greater E/A ratio and shorter EDT than small infarcts. The evolution of large infarcts is characterized by an attenuation of this pattern, with a progressive reduction of E/A ratio and prolongation of EDT during the first year post-infarction.

Abnormal filling pattern of the left ventricle and outcome in acute myocardial infarction

BACKGROUND

The pattern of left ventricular filling by Doppler examination is frequently abnormal in myocardial infarction.

PURPOSE

To relate the different patterns of left ventricular filling to the clinical course of acute myocardial infarction.

PATIENTS AND METHODS

We have studied 133 patients with acute myocardial infarction. Three different patterns of mitral flow were defined by Doppler examination: Type I has an E/A ratio lesser than one, and a deceleration time of the E wave longer than 180 ms; Type II has either an E/A ratio greater than one or a deceleration time shorter than 180 ms; Type III has an E/A ratio greater than 1.6 and a deceleration time shorter than 180 ms. We also determined the pulmonary wedge pressure through a pulmonary artery catheter simultaneously with the Doppler examination on 22 occasions in 11 patients.

RESULTS

Mortality rate was 13%, 9% and 35% respectively in Type I, II and III (P=0.007). After logistic regression analysis of determinants of death, including all eight variables related with mortality on an univariate analysis, only Killip class and the presence of a Type III pattern of the mitral flow remained significant (P=0.0004 and P=0.019 respectively). Pulmonary wedge pressure was 8.4+/-6.1 mmHg in Type I, 21.0+/-7.3 mmHg in Type II, and 22.4+/-7.1 mmHg in Type III (P=0.0017).

CONCLUSION

Type III pattern of left ventricular filling is an independent predictor of death. Type I and II had no significant differences on prognosis. Type I is associated with a normal pulmonary wedge pressure.

Systolic and diastolic function in patients with chronic heart failure at rest and during exercise

In our study we tried to evaluate systolic and diastolic function in patients with chronic heart failure (CHF) by using some echocardiographic parameters and invasively measured pulmonary capillary wedge pressure (PCWP). We studied 19 patients with CHF NYHA II-III at rest, at the end of isometric exercise (handgrip) and during a bicycle stress test. Right heart catheterization and echocardiography were simultaneously performed. We measured exchange of blood gases, end diastolic volume (EDV), end systolic volume (ESV), ejection fraction (EF), peak E velocity, peak A velocity, E/A ratio, deceleration time of E wave (DT), time of mitral regurgitation (MR) and effective filling period of left ventricle (FP). We divided patients according to the median of PCWP at rest into two groups: group A with PCWP< or =11 mmHg (10 pts), group B with PCWP>11 mmHg (9 pts). In group A mean PCWP at rest was 6+/-2 mmHg, during handgrip 12+/-4 mmHg and during bicycle exercise 18+/-6 mmHg. In group B mean values of PCWP were 19+/-6 mmHg, 26+/-11 mmHg and 33+/-5 mmHg, respectively. All values were significantly higher in group B (P<0.01). There was a significant difference in pVO2: in group A 18.8+/-3.5 vs. 14.7+/-3.3 ml/kg per min in group B (P<0.03). No differences between the groups were noticed in EDV, ESV and EF. The E/A ratio in group A was less than 1, in group B greater than 1 with the restrictive pattern. No differences between the groups were observed in MR and FP at rest. During bicycle exercise, MR was significantly longer (284+/-98 vs. 164+/-79 ms; P<0.05) and FP shorter (322+/-99 vs. 421+/-74 ms; P<0.05) in group B than in group A. The functional capacity of patients with CHF is influenced not only by EF and other systolic variables, but also by filling conditions. The duration of effective diastole may be one of the most important of them.

On-line quantitative assessment of left ventricular filling during dobutamine stress echocardiography: a useful addition to conventional wall motion scoring

In order to determine whether the diastolic rate of ventricular volume change obtained on-line with an automatic border detection (ABD) system during dobutamine stress echocardiography (DSE) would provide an interpretation of the diastolic ventricular response to the drug in quantitative terms in the assessment of coronary artery disease, we studied, with ABD and DSE, 59 patients who underwent coronary arteriography within 2 months of the stress test. Eleven patients had normal coronary findings or non-significant coronary lesions. Significant (> or =70% diameter stenosis) coronary artery disease (CAD) was present in 48 patients (81%). Dobutamine stress echocardiography (DSE) to a maximal dose of 50 microg/kg per min was performed in all patients. ABD images were acquired at rest and at the peak of infusion along with conventional two-dimensional images. The following measurements were evaluated: left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV), left ventricular ejection fraction (LVEF), slope of rapid filling segment (RFS), peak filling rate (PFR), rapid filling phase fractional change (RFFC). Patients with non-significant coronary artery lesions exhibited a hyperdynamic response with an LVEF increment of at least 20% from baseline to peak drug infusion. In these patients the effect of dobutamine produced an increase of RFS from 35.5+/-5.6 to 86.5+/-10.5 ml/s, an increase of PFR from 4.4+/-0.6 to 6.8+/-0.6 EDV/s, and an increase of RFFC from 74+/-8 to 92+/-5% (P<0.001). Of the 48 patients with coronary artery disease, 27 had <20% LVEF increase at peak dobutamine infusion. Four of 22 patients with single vessel disease and 23 of 26 patients with multivessel disease had an abnormal systolic response. After dobutamine infusion single vessel CAD patients showed a decrease of RFS from 33.4+/-5.3 to 26.7+/-5.9 ml/s, a decrease of PFR from 3.8+/-0.7 to 3.0+/-0.7 EDV/s, and a decrease of RFFC from 73+/-6 to 59+/-4% (P<0.001). Multivessel CAD patients showed a decrease of RFS from 32.0+/-5.9 to 23.1+/-4.1 ml/s, a decrease of PFR form 3.8+/-0.6 to 2.8+/-0.6 EDV/s, and a decrease of RFFC from 71+/-5 to 54+/-8% (P<0.001). The overall sensitivity of detecting CAD was 85% for conventional DSE and 90% for ABD-DSE (P=NS). The sensitivities of detecting patients with single vessel and multivessel CAD with conventional DSE were 68 and 92%, respectively, and with ABD-DSE were 91% (P<0.01) and 96% (P=NS), respectively. Our results show that an abnormal diastolic as well as systolic response during on-line quantitative assessment of dobutamine stress echocardiography is a sensitive marker of coronary artery disease and is predictive for the detection of extensive lesions. The described measurements can be utilized to improve the DSE sensitivity in identifying coronary artery disease. On-line quantitation of diastolic indexes with ABD can represent another step toward obtaining uniform results after stress echocardiography.

[E wave deceleration time predicts left ventricular telediastolic pressure in acute myocardial infarction in patients with systolic dysfunction]

OBJECTIVES

Left ventricular end-diastolic pressure (LVEDP) is a useful parameter for the management of postinfarction patients. As the current methods of estimating LVEDP are invasive, the existence of non-invasive methods would be of great practical value. This study investigates the relation between LVEDP and Doppler parameters such as E wave deceleration time (EDT) and E/A ratio, at one month following an acute myocardial infarction.

METHODS

Eighty-nine patients with a first acute myocardial infarction treated with thrombolytic agents were studied. Doppler-echocardiography at 29 +/- 3 days and cardiac catheterization at 30 +/- 4 days postinfarction were performed. According to the ejection fraction (EF), the patients were divided into group 1 (n = 17) with EF < 45%, and group 2 (n = 72) with EF > 45%.

RESULTS

Overall, the E/A ratio showed a weak correlation with LVEDP (r = 0.32; p = 0.007), and EDT did not correlate with LVEDP. When patients from group 2 were analyzed, no correlation was found between LVEDP and either E/A or EDT. However, in patients from group 1, LVEDP strongly correlated with both EDT (r = -0.83; p = 0.00001) and E/A (r = 0.70; p = 0.003). Moreover, the sensitivity and specificity of an EDT of less than 150 ms in predicting a LVEDP > 20 mmHg was 100%.

CONCLUSIONS

We conclude that at the first month after a myocardial infarction EDT provides a non-invasive and useful parameter for estimating LVEDP in patients with systolic dysfunction.

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)