Regional response of myocardial acceleration during isovolumic contraction during dobutamine stress echocardiography: a color tissue Doppler study and comparison with angiocardiographic findings.

BACKGROUND: Color tissue Doppler imaging permits noninvasive quantitation of regional wall motion. In experimental studies, a new marker, the slope of the isovolumic contraction wave, isovolumic acceleration (IVA) was more insensitive to ventricular loading conditions than myocardial velocities. This study compared the regional response IVA to dobutamine stress echocardiography to angiographic findings. METHODS: The Myocardial Doppler in Stress Echocardiography (MYDISE) study prospectively recruited 149 consecutive patients with chest pain for dobutamine stress tissue Doppler echocardiography prior to coronary angiography. This color tissue Doppler database was analyzed for IVA in 1,192 basal and mid segments at rest and again at peak stress. Angiographic findings were compared to IVA and peak systolic velocities (PSV) in corresponding cardiac segments. The diagnostic accuracy of IVA to predict coronary artery stenosis was determined using cut-off values for three representative segments and with the MYDISE diagnostic model including eight segments. RESULTS: Regional IVA increased in a dose-dependent manner during dobutamine infusion. The response was blunted in the supply territory of stenosed coronary artery branches. IVA performed slightly better than PSV as single marker for coronary artery stenosis. A diagnostic model incorporating IVA and PSV was 85-95% accurate (area under receiver operating characterstic curves). CONCLUSIONS: Regional changes of isovolumic acceleration during dobutamine stress echocardiography reflect regional wall motion and can be used to predict coronary artery stenosis with similar accuracy as a model based on systolic myocardial velocities. As a single marker, IVA performed better than myocardial velocities.

Subclinical cardiac involvement in myotonic dystrophy manifesting as decreased myocardial Doppler velocities.

To assess subendocardial (long-axis) and mid-wall (short-axis) left ventricular (LV) function in patients with type 1 myotonic dystrophy (MD1), with no symptoms or clinical signs of heart disease, to investigate if they have subclinical cardiac involvement, 28 subjects (14 with MD1, and 14 age- and sex-matched normals) had conventional and tissue Doppler echocardiography. Myocardial velocities and timings to peak systolic contractions were measured. LV wall thickness, diameters, and ejection fraction were not different between the groups. 4/14 of the MD1 patients (29%) had global diastolic dysfunction. Both long-axis and short-axis systolic and early diastolic myocardial velocities were lower in patients with MD1, whereas time-to-peak myocardial contraction was longer; mean longitudinal systolic velocity was 5.5+/-1.7 cm/s in patients with MD1, compared with 7.8+/-1.3 cm/s in normal subjects (P<0.001) 10/14 of the patients (71%) had reduced longitudinal systolic function. Longitudinal systolic and diastolic velocities were inversely related to the duration of the QRS complex ( r=-0.86 and r=-0.63 respectively, both P<0.01), but they did not correlate with the CTG-repeat size. Patients with MD1 have subclinical cardiac impairment revealed by measurement of myocardial velocities using tissue Doppler echocardiography.

Subclinical left ventricular dysfunction in asymptomatic patients with Type II diabetes mellitus, related to serum lipids and glycated haemoglobin.

The aim of the present study was to measure regional ventricular function at rest and during stress in order to assess if patients with Type II diabetes have subclinical myocardial dysfunction and if it is related to risk factors. Seventy subjects (35 patients with Type II diabetes with no symptoms, signs or history of heart disease, and 35 age- and sex-matched healthy controls) had echocardiography at rest and during dobutamine stress. Myocardial velocities were measured off-line from digital loops of colour tissue Doppler. Subendocardial function was assessed from the mean longitudinal velocities of four basal segments (apical views) and radial function from the velocities of the basal posterior wall (parasternal view). Systolic functional reserve was calculated as the increase in velocity from baseline. Longitudinal peak systolic velocity was lower in patients with diabetes, at rest (5.6 +/- 1.4 compared with 6.5 +/- 1.1 cm/s) and at peak stress (10.9 +/- 2.8 compared with 14.3 +/- 2.1 cm/s) (both P <0.01). Functional reserve was impaired in patients with diabetes (+5.4 +/- 2.0 compared with +7.7 +/- 1.7 cm/s; P <0.01). Radial systolic velocity was higher in patients with diabetes (5.4 +/- 1.3 compared with 4.7 +/- 1.4 cm/s; P <0.05). Resting longitudinal systolic function correlated inversely with low-density lipoprotein-cholesterol ( r =-0.53), glycated haemoglobin ( r =-0.48), age ( r =-0.41) and diastolic blood pressure ( r =-0.38) (all P < 0.05). Peak stress systolic velocity correlated inversely with glycated haemoglobin ( r =-0.46) and age ( r =-0.44) (both P < 0.01). In conclusion, patients with Type II diabetes and no clinical heart disease have impaired subendocardial function of the left ventricle at rest and peak stress, which is related to glycated haemoglobin and serum low-density lipoprotein-cholesterol.