Evaluation of myocardial perfusion with grey-scale ultra-harmonic and multiple-frame triggering. The need for quantification.

BACKGROUND AND OBJECTIVE: Contrast echocardiography has been recently introduced as a new technique for evaluating myocardial perfusion in a qualitative basis. The objective of this study was to test whether a visual subjective evaluation of myocardial perfusion by myocardial contrast echocardiography adequately matches the data obtained with an off-line quantification of myocardial perfusion. METHODS: Sixty-one myocardial segments were evaluated by myocardial contrast echocardiography with Ultra-harmonic and Multiframe Triggering in 11 patients 3-7 days after an anterior myocardial infarction, using SH-U 563A (Levovistâ, Schering AG, Berlin, Germany) as contrast agent. Myocardial perfusion was classified as grade 1 (absent), 2 (patchy or incomplete) and 3 (complete) in each segment. The quantitative analysis was performed off-line by a different investigator blinded to the qualitative evaluation, using a commercially available software. The quantitative data on grey-scale obtained were compared between grade 1, 2 and 3 segments. RESULTS: Of the 61 segments, 45 (73.8%) were classified as grade 3, whereas the remaining 16 (26.2%) were considered to be abnormally perfused (grade 2: n=12, 19.6%; grade 1: n=4, 6.6%). Segments with grade 1 perfusion had a significantly higher grey-scale value (123.6 +/- 41.3 vs. 70.1 +/- 34.3, p=0.004). However, there were no significant differences between segments with perfusion grade 2 and 3 (76.8 +/- 33.2 vs. 68.3 +/- 34.8, p=0.452). CONCLUSION: Qualitative assessment of myocardial perfusion by Ultra-harmonic and Multiframe Triggering is of limited value, since only myocardial segments with absent perfusion may be reliably identified. This findings support the need of quantification in the evaluation of myocardial perfusion by contrast echocardiography.

Myocardial perfusion in real-time using power modulation. In vivo evidence for microcirculatory damage after acute myocardial infarction.

BACKGROUND AND OBJECTIVES: In addition to the myocardium, the microvasculature may be also damaged in acute myocardial infarction. The aim was to evaluate the capability of myocardial contrast echocardiography in the detection of microvasculature damage after myocardial infarction. PATIENTS AND METHODS: Twelve patients with recent acute myocardial infarction and five control subjects with normal coronary arteries and without history of myocardial infarction were studied. Myocardial contrast echocardiography with power modulation was performed, and quantitative data were measured off-line. Power modulation uses a combination of low (0.1) and high (1.7) mechanical indexes, allowing a real-time evaluation of myocardial perfusion. Contrast agent was administered as a 3-min bolus. The quantitative analysis was performed off-line by a different blinded investigator. The refilling velocity was calculated as the difference between the peak myocardial refilling value and the value at 1 s after the impulse divided by the time from the first second after the impulse to the peak refilling value. RESULTS: Eighty-one myocardial segments (75%) were analysed qualitatively and quantitatively in AMI patients, and 18 (60%) in control subjects (P=NS). The peak refilling intensity was not significantly different in patients and control subjects (6.62+/-5.85 vs. 7.53+/-4.06 dB, respectively). However, time to peak refilling intensity was significantly longer (5.25+/-1.57 vs. 4.00+/-0.53, P=0.004) and the velocity of refilling was significantly lower (2.74+/-5.34 vs. 6.58+/-8.02, P=0.028) in patients with myocardial infarction. CONCLUSION: There is microvasculature damage after myocardial infarction that is reflected as a delayed velocity of refilling in myocardial contrast echocardiography.

Value of automated segmental motion analysis in the assessment of aortic stenosis severity.

BACKGROUND AND AIMS OF THE STUDY: Left ventricular (LV) contraction is slowed in patients with aortic stenosis (AS). Although the possible role of LV systolic function abnormalities in the assessment of AS severity has been evaluated, current echocardiographic techniques cannot offer precise quantification of LV motion velocity. The study aim was to evaluate an automated segmental motion analysis (ASMA) system to assess AS severity. METHODS: Twenty-two patients with AS, sinus rhythm and preserved LV ejection fraction were studied prospectively. Patients underwent both conventional Doppler echocardiography to measure transaortic gradient and aortic valve area by the continuity equation, and ASMA of the interventricular septum. The ASMA line graph mode displays changes in area through the cardiac cycle. The RR interval and time from the R-wave to peak maximum area shortening were measured, and an ASMA index was calculated. RESULTS: A significant and strong inverse correlation was found between aortic valve area and ASMA index (r = -0.78; 95% CI -0.90 to -0.55; p <0.001). The area under the ROC curve in the diagnosis of severe AS (aortic valve area < or =0.8 cm2) was 0.97 (95% CI 0.90-1.0). Sensitivity, specificity, positive and negative predictive values and overall accuracy for an ASMA index >0.40 were 100, 91.7, 92.3, 100 and 95.8%, respectively. CONCLUSION: The ASMA system may be valuable in evaluating AS, as it offers a strong correlation with aortic valve area calculated by the continuity equation, and very high sensitivity and specificity in the diagnosis of severe AS.

Influence of diabetes mellitus on short- and long-term outcome in patients with active infective endocarditis.

BACKGROUND AND AIM OF THE STUDY: The incidence and severity of certain infections appear to be increased in patients with diabetes mellitus (DM). The study aim was to evaluate the effect of DM on short- and long-term outcome in patients with active infective endocarditis (IE). METHODS: A total of 151 patients with IE was included and followed up for a mean of 3.1 years. Of these patients, 13 (9%) were diabetics. The outcome of patients with or without DM was compared at short-term (in-hospital) and long-term follow up. RESULTS: Patients with DM were older (66 +/- 11 versus 50 +/- 19 years, p < 0.01) and had a lower frequency of intravenous drug abuse (0 versus 30%, p <0.01) and tricuspid valve involvement (0 versus 20%, p = 0.02) than non-DM patients. Mortality was higher in DM patients both in hospital (31% versus 15%, p = NS) and at a mean follow up of 3.1 years (54% versus 31%, p = 0.002). DM patients also had a significantly higher rate of cardiac failure (69% versus 38%, p = 0.03) and renal failure (62% versus 20%, p <0.01) during hospitalization. Incidences of anatomic complications (abscess, pseudoaneurysm) (15.4% versus 20.3%), valve rupture or perforation (7.7% versus 16.7%) and need for surgical repair (46.2% versus 45.7%) were similar in both DM and non-DM patients. DM, without secondary pathology like renal failure, did not appear to be an independent risk factor for mortality at either short- or long-term follow up. CONCLUSION: Although mortality and morbidity in IE were greater in DM than in non-DM patients, diabetes itself does not constitute an independent risk factor.