Time to peak velocity measurements by pulsed wave Doppler tissue imaging to quantify ischemia-related regional myocardial asynchrony

Evaluation of a novel index by tissue Doppler imaging in patients with advanced heart failure: relation to functional class and prognosis

BACKGROUND

Despite the ability of tissue Doppler imaging (TDI) to detect left ventricular (LV) systolic and diastolic myocardial functions in patients with heart failure, the added value of TDI to clinical variables and conventional echocardiography in predicting the symptoms and outcome of advanced heart failure has not been clearly defined.

METHODS AND RESULTS

Two hundred and thirty adult patients diagnosed with congestive heart failure were assigned to study groups based on the New York Heart Association functional classes. Pulsed-wave TDI (PWTDI), including average of peak systolic (Sm), early (Em) and late diastolic (Am) velocities from six mitral annular sites was evaluated. PWTDI was also calculated to create a combined index (EAS index) of diastolic and systolic performances. All patients were followed up for cardiac-related death and hospitalisation as a result of heart failure. Patients with functional class III-IV had a significantly higher EAS index (0.21 ± 0.19 vs. 0.13 ± 0.08, p < 0.05) than those with class I-II and the control (0.10 ± 0.04, p < 0.05). Except for Sm and Em, all conventional echocardiographic Doppler parameters and TDI variables significantly correlated with functional class. Moreover, according to multiple stepwise analysis, EAS index and percentage of chronic renal insufficiency (CRF) were the only two independent predictors of functional class (EAS index, p = 0.006; CRF, p = 0.019). During follow-up (median, 30 months), 93 participants had cardiac events. EAS index, LV mass index and CRF were significant predictors of cardiac mortality and hospitalisation [EAS index, hazard ratio (HR) 4.962, p = 0.006; LV mass index, HR 1.007, p = 0.003; CRF, HR 1.616, p = 0.040].

CONCLUSIONS

The EAS index, which reflects systolic and diastolic performances, is a highly effective means of differentiating between patients with functional class I-II and those with III-IV. The index also correlates with cardiac mortality and hospitalisation for worsening heart failure, thus providing additional value to conventional echocardiographic measures.

Left ventricular systolic and diastolic dyssynchrony in coronary artery disease with preserved ejection fraction

The present study aims to evaluate LV (left ventricular) mechanical dyssynchrony in CAD (coronary artery disease) with preserved and depressed EF (ejection fraction). Echocardiography with TDI (tissue Doppler imaging) was performed in 311 consecutive CAD patients (94 had preserved EF > or =50% and 217 had depressed EF <50%) and 117 healthy subjects to determine LV systolic and diastolic dyssynchrony by measuring Ts-SD (S.D. of time to peak myocardial systolic velocity during the ejection period) and Te-SD (S.D. of time to peak myocardial early diastolic velocity during the filling period) respectively, using a six-basal/six-mid-segmental model. In CAD patients with preserved EF, both Ts-SD (32.2+/-17.3 compared with 17.7+/-8.6 ms; P<0.05) and Te-SD (26.2+/-13.6 compared with 20.3+/-8.1 ms; P<0.05) were significantly prolonged when compared with controls, although they were less prolonged than CAD patients with depressed EF (Ts-SD, 37.8+/-16.5 ms; and Te-SD, 36.0+/-23.9 ms; both P<0.005). Patients with preserved EF who had no prior MI (myocardial infarction) had Ts-SD (32.9+/-17.5 ms) and Te-SD (28.6+/-14.8 ms) prolonged to a similar extent (P=not significant) to those with prior MI (Ts-SD, 28.4+/-16.8 ms; and Te-SD, 25.5+/-15.0 ms). Patients with class III/IV angina or multi-vessel disease were associated with more severe mechanical dyssynchrony (P<0.05). Furthermore, the majority of patients with mechanical dyssynchrony had narrow QRS complexes in those with preserved EF. This is in contrast with patients with depressed EF in whom systolic and diastolic dyssynchrony were more commonly associated with wide QRS complexes. In conclusion, LV mechanical dyssynchrony is evident in CAD patients with preserved EF, although it was less prevalent than those with depressed EF. In addition, mechanical dyssynchrony occurred in CAD patients without prior MI and narrow QRS complexes.

Predictive accuracy of tissue Doppler imaging for assessment of noninfarct myocardial region in patients with acute myocardial infarction

OBJECTIVES

To investigate the value of pulsed tissue Doppler imaging (TDI) in order to predict significant coronary artery stenosis supplying the noninfarct region in patients after acute anterior myocardial infarction.

SUBJECTS AND METHODS

Transthoracic echocardiography and coronary angiography were performed on 220 patients with acute anterior myocardial infarction. The TDI-derived variables of the mitral valve annulus in the noninfarct region, systolic velocity (Sm), early diastolic velocity (Em) and late diastolic velocity (Am), were estimated in centimeters per second, and the Em/Am ratio was calculated.

RESULTS

Predictive indices revealed that the impaired TDI-derived variables, Sm, Em, Am and the Em/Am ratio, were an indicator for predicting significant coronary stenosis in the noninfarct region. Multivariate analysis revealed that the impaired Sm and Em velocities were significantly associated with age of the patients, coronary collaterals and infarct-related artery stenosis (p < 0.05). Receiver-operating characteristic curve data of TDI-derived variables for prediction of significant coronary stenosis revealed that the cut-off values of Sm, Em, Am and Em/Am ratio were 7.2 cm/s, 6.4 cm/s, 12.1 cm/s and 0.56, respectively. The kappa coefficient value indicated that there was an agreement between coronary angiography and the TDI-derived variables Sm, Em, Am and Em/Am ratio in noninfarct regions (kappa = 0.770, 0.731, 0.693 and 0.679, respectively). There was a significant correlation between the severity of coronary artery stenosis (independent variable) and impaired Sm and Em/Am ratio (dependent variables), y = 11.5 - 0.05x, r = -0.902, (p < 0.05), and y = - 0.14x + 1.87, r = -0.754, (p < 0.05), respectively.

CONCLUSION

TDI can be used to identify patients with significant stenosis of the coronary arteries supplying the noninfarct region and consequently may be helpful in considering patients for coronary angiography in the early postinfarction period.