RESUMO
A new echocardiographic technology, the timing of regional volumetric changes by 3-dimensional echocardiography, was applied to assess intraventricular mechanical synchronicity in 13 patients who had received cardiac resynchronization therapy (CRT). When biventricular pacing was withheld, left ventricular (LV) asynchrony occurred as reflected by these echocardiographic parameters, whereas LV volume increased and the ejection fraction decreased. Further studies are needed to explore whether this novel method can be used to select suitable candidates for CRT and to predict a favorable response.
Assuntos
Estimulação Cardíaca Artificial , Ecocardiografia Tridimensional , Insuficiência Cardíaca/diagnóstico por imagem , Insuficiência Cardíaca/terapia , Ventrículos do Coração/diagnóstico por imagem , Feminino , Insuficiência Cardíaca/fisiopatologia , Ventrículos do Coração/fisiopatologia , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
OBJECTIVE: To study the feasibility of continuous intravenous SonoVue contrast echocardiography for qualitative assessment of reversible myocardial perfusion in dipyridamole stress tests. METHODS: Eleven patients (10 male and 1 female, mean age 66 years) with a history of chest pain and a clinical indication for stress sestamibi single photon emission computed tomography (SPECT) underwent concurrent SonoVue 99mTc myocardial contrast echocardiography (MCE). RESULTS: Of the total 176 segments obtained, 53 (30%) were regarded as indeterminate, 39 (22%) as discordant, and 84 (48%) as concordant between MCE and SPECT imaging. Two patients had abnormal SPECT results. The overall feasibility and specificity of MCE were 70 and 74%, respectively. The concordant (p = 0.59) and discordant (p = 0.55) segments were comparable with either MCE technique. However, continuous low-mechanical-index imaging produced fewer indeterminate segments (17 segments, 32%) than intermittent harmonic B-mode imaging (36 segments, 68%) (p = 0.04). Significantly more indeterminate segments were found in the left anterior descending artery territory. However, the overall concordance was similar (p = 0.5) in all three coronary artery territories. The concordance and discordance rates at different left ventricular levels (i.e., basal, mid, and apical) were similar (p = 0.50 and 0.08, respectively). CONCLUSION: Continuous-infusion SonoVue contrast echocardiography is feasible, with high specificity, for detecting myocardial perfusion defects as assessed by dipyridamole SPECT.