47 research outputs found
New non-invasive imaging techniques to quantify ventricular function: reappraisal of dobutamine stress echocardiography
This thesis is an insight investigation in some recently developed noninvasive
imaging advances to quantitatively assess left or right ventricular function. The
focus is on dobutamine stress echocardiography, with some reference to a
recently developed nuclear imaging technique: Technetium-tetrofosmin-fluorodeoxyglucose-
single photon emission computcd tomography (FDGSPECT). Among many attempts to pass from a subjective and qualitative to
an objective and quantitative evaluation of ventricular function we analyzed
Doppler tissue imaging. Left vcntricular ftmction, as stimulated by dobutaminc,
was studied by applying Doppler tissue imaging as a test on myocardial
ischemia and contractile reserve, the latter being even more subjected to interobserver
variability, than the assessment of myocardial ischemia
Quantification of regional left ventricular function in Q wave and non-Q wave dysfunctional regions by tissue Doppler imaging in patients with ischaemic cardiomyopathy
OBJECTIVE: To quantify regional left ventricular (LV) function and
contractile reserve in Q wave and non-Q wave regions in patients with
previous myocardial infarction. DESIGN: An observational study. SETTING:
Tertiary care centre. PATIENTS: 81 patients with previous myocardial
infarction and depressed LV function. INTERVENTIONS: All patients
underwent surface ECG at rest and pulsed wave tissue Doppler imaging at
rest and during low dose dobutamine infusion. The left ventricle was
divided into four major regions (anterior, inferoposterior, septal, and
lateral). Severely hypokinetic, akinetic, and dyskinetic regions on two
dimensional echocardiography at rest were considered dysfunctional. MAIN
OUTCOME MEASURES: Regional myocardial systolic velocity (Vs) at rest and
the change in Vs during low dose dobutamine infusion (DeltaVs) in
dysfunctional regions with and without Q waves on surface ECG. RESULTS:
220 (69%) regions were dysfunctional; 60 of these regions corresponded to
Q waves and 160 were not related to Q waves. Vs and DeltaVs were lower in
dysfunctional than in non-dysfunctional regions (mean (SD) Vs 6.2 (1.9)
cm/s v 7.1 (1.7) cm/s (p < 0.001), and DeltaVs 1.9 (1.9) cm/s v 2.6 (2.5)
cm/s (p = 0.009), respectively). There were no significant differences in
Vs and DeltaVs among dysfunctional regions with and without Q waves (Q
wave regions: Vs 6.2 (1.8) cm/s, DeltaVs 1.6 (2.2) cm/s; non-Q wave
regions: Vs 6.3 (1.9) cm/s, DeltaVs 2.0 (2.0) cm/s). CONCLUSIONS:
Quantitative pulsed wave tissue Doppler demonstrated that, among
dysfunctional regions, Q waves on the ECG do not indicate more severe
dysfunction, and myocardial contractile reserve is comparable in Q wave
and non-Q wave dysfunctional myocardium