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Color Doppler Tissue Imaging to Evaluate Left Atrial Appendage Function in Patients With Mitral Stenosis in Sinus Rhythm

Two‐dimensional color Doppler tissue imaging (CDTI) has so far been used, in general, to evaluate ventricular function. In this study, the left atrial appendage (LAA) tissue velocity was measured by CDTI. LAA function in 38 patients with mitral stenosis in sinus rhythm (SR) and 19 healthy subjects undergoing transesophageal echocardiography were examined by CDTI. Systolic tissue appendage velocity (SaV, m/s) was measured at the tip of the LAA in the basal short‐axis view. LAA emptying (LAAEV) and filling (LAAFV) velocities (m/s) were also recorded 1 cm below the orifice of the appendage. LAA ejection fraction was also measured. In addition, two‐dimensional imaging was used to determine the presence of thrombus and/or spontaneous echo contrast (SEC). Patients with mitral stenosis in SR had significantly decreased LAAEV, LAAFV, SaV, and LAA ejection fraction compared to controls (0.34 ± 0.15 vs 0.72 ± 0.17, 0.37 ± 0.13 vs 0.63 ± 0.19, 0.050 ± 0.015 vs 0.071 ± 0.093, and 39 ± 14% vs 69 ± 13%, respectively, P < 0.001, P < 0.001, P < 0.001, and P < 0.001). Among the patients with mitral stenosis in SR, 10 patients had SEC and one had LAA thrombus. Compared with patients without SEC, patients with SEC had decreased LAAEV, LAAFV, SaV, and LAA ejection fraction (0.24 ± 0.05 vs 0.37 ± 0.16, 0.29 ± 0.05 vs 0.39 ± 0.14, 0.039 ± 0.087 vs 0.055 ± 0.015, and 28 ± 14% vs 43 ± 12%, respectively, P = 0.01, P = 0.02, P = 0.01, and P = 0.006). In conclusion, these results suggest that the LAA dysfunction may occur in patients with mitral stenosis in SR and CDTI can successfully be used for the quantification of contraction at the tip of the LAA. (ECHOCARDIOGRAPHY, Volume 21, April 2004)

Color Doppler tissue imaging to evaluate left atrial appendage function in mitral stenosis.

Two‐dimensional color Doppler tissue imaging (CDTI) has so far been used, in general, to evaluate ventricular function. This study examined if the left atrial appendage tissue velocity could reproducibly be measured with CDTI and if they have any predictive value for left atrial appendage (LAA) function and former thromboembolism. Thirty‐six patients (24 women, 12 men; mean age 45 ± 12 years; 18 AF; 11 former thromboembolic stroke) with mitral stenosis undergoing transesophageal echocardiography were examined with CDTI. Peak systolic tissue velocity (m/sec, peak systolic velocity [PSV]) was measured at the tip of the LAA in the basal short‐axis view. LAA flow emptying (LAAEV) and filling (LAAFV) velocities (m/sec) were also recorded 1 cm immediately below the orifice of the appendage. Interobserver and intraobserver variabilities were determined for the PSV. LAA ejection fraction was measured by Simpsons method. Mitral regurgitation, AF, transmitral mean gradient, left ventricular ejection fraction, mitral valve area, and left atrial diameter were used as a covariant for adjustment. The intraobserver and interobserver correlation coefficients for the PSV using CDTI was 0.64 and 0.60, respectively (both P = 0.01 ). LAAEV (0.29 ± 0.09 vs 0.19 ± 0.04, P = 0.001) and LAA ejection fraction (44 ± 12 vs 29 ± 14, P = 0.004) were found to be significantly decreased in the patients with decreased PSV (<0.05 m/sec), even after adjustment. The decreased PSV was positively correlated with the low LAAEV (<0.25 m/sec) and history of thromboembolism ( r = 0.59, r = 0.38 , respectively), and remained a significant determinant of the low LAAEV (OR 50.03, CI 1.46–1738.11, P = 0.02 ), but not of history of thromboembolism (OR 4.29, CI 0.52–35.01, P = 0.08 ) after adjustment. In conclusion, these results suggest that CDTI provides a reproducible method for quantification of contraction at the tip of the LAA. Decreased PSV may be predictive of poor LAA function. (ECHOCARDIOGRAPHY, Volume 20, January 2003)

A new definition of aspirin non-responsiveness by platelet function analyzer-100 and its predictors.

Background: Aspirin non-responsiveness has been described as having a normal closure time (CT) by platelet function analyzer (PFA)-100 assay despite confirmed treatment with aspirin. There is no standard definition of aspirin non-responsiveness by PFA-100, with a variety of cut-off values having been used. We proposed an alternative definition of aspirin non-responsiveness by PFA-100 assay. Methods: One hundred eighty-four patients with diagnosis of stable coronary artery disease or diabetes mellitus were included in the study. Blood samples were drawn before and after the 7 days of aspirin therapy. An individual was labelled as aspirin non-responder if his/her post-aspirin CT was not 2SD above his/her baseline CT, where SD was calculated from the baseline CTs of the study population. Aspirin non-responsiveness was also defined as having a normal post-aspirin CT (≤193 s) regardless of pre-aspirin CT. Results: The baseline CT ranged 82–187 s (mean 129.1 ± 27.5, median 128 s) in the study population. At the end of 1 week of aspirin administration, CT increased to a mean of 260.7 ± 63.6 s (range 102–301). According to our definition, 28 (15.2%) of 184 patients were aspirin non-responders. Univariate analysis indicated that aspirin non-responsiveness was closely associated with gender (P = 0.012) diabetes (P = 0.006), smoking (P = 0.0496) and hypertension (P = 0.021). Multivariate analysis identified diabetes (P = 0.016) as the only significant independent predictor for the presence of aspirin non-responsiveness. Thirty-four of 184 patients (18.5%) classified as aspirin non-responders according to the second criteria. Seven patients with prolongation of post-aspirin CT more than 2SD were classified as aspirin non-responders by the second criteria. Only 1 patient without prolongation of CT more than 2SD was classified as aspirin responsive by the second criteria. Conclusion: Definition of aspirin non-responsiveness as post-aspirin CTs ≤193 s might overestimate the prevalence of aspirin non-responsiveness. Nevertheless, definition of aspirin non-responsiveness by PFA-100 must be standardized and its utility as a predictor of cardiovascular events needs to be further investigated.

Pharmacological profile of survivors of acute myocardial infarction at Turkish academic hospitals

AIM The purpose of this study was to document treatment profiles in 850 patients surviving acute myocardial infarction at 17 academic hospitals in Turkey. METHODS AND RESULTS Pharmacological management data of acute myocardial infarction survivors were collected and divided into three categories: drugs which patients received before hospitalization, during the hospitalization, and at hospital discharge. Data regarding medical history, complications during hospitalization, MI extent (Q wave or non-Q wave), infarct location and diagnostic and revascularization procedures were also recorded. This study is based on the 850 patients who met the diagnostic criteria for initial acute MI in the period examined. Among 850 patients with myocardial infarction enrolled 408 (48%) received thrombolytic therapy. The median time interval from symptom onset to initiation of thrombolytic therapy was 196 min. The most commonly used thrombolytic agent was streptokinase (93%). Thrombolytic recipients were younger, and presented sooner after onset of symptoms. Among patients receiving thrombolytic therapy, concomitant pharmacotherapy included aspirin (95%), intravenous heparin (93%), intravenous nitroglycerin (91%), oral beta-blockers (44%), calcium channel antagonists (13%), and angiotensin converting enzyme inhibitors (41%). The lipid lowering therapy was only used in 4% of all patients, and was given to 18% of patients with hyperlipidemia. CONCLUSION Current usage rates of thrombolytic therapy in Turkey are lower than expected, but when compared with previous reports it increased. Although adjunctive treatment with intravenous heparin and intravenous nitroglycerin is usually used, beta-blockers appear to be underused and calcium channel blockers appear to be overused. The lipid reducing therapies were infrequently prescribed.

Application of the Vena contracta Method for the Calculation of the Mitral Valve Area in Mitral Stenosis

Objectives: The vena contracta is the narrowest region of the regurgitant or stenotic jet just downstream the orifice and reflects the size of that orifice. This study was performed to assess the accuracy of the vena contracta width (VCW) in evaluating the severity of mitral stenosis (MS) and to compare the mitral valve area (MVA) determined by VCW with MVAs obtained by other more traditional echocardiographic methods. Methods: We studied 59 patients (43 females, 42 ± 14 years) with MS. VCW was measured in the apical four chamber view by Doppler color flow mapping. The largest diameter of the VCW during diastole was measured for at least three cardiac cycles and averaged. MVA was calculated from the following equation: πr2, where r = VCW/2. MVA was also determined by planimetry, the pressure half-time method, and by the Gorlin formula. Results: In this study, the width of the vena contracta ranged from 0.89 to 1.73 cm (mean 1.30 ± 0.21). MVA, calculated based on the VCW, ranged from 0.63 to 2.35 cm2 (mean 1.36 ± 0.41). MVA by VCW (1.36 ± 0.41 cm2) showed good correlations with three comparative techniques: (1) the cross-sectional area by planimetry (1.35 ± 0.36 cm2, mean difference = 0.21 ± 0.16 cm2, y = 0.91x + 0.14, r = 0.79, SEE = 0.26 cm2, p < 0.001); (2) the area derived from the Doppler pressure half-time (1.27 ± 0.32 cm2, mean difference = 0.22 ± 0.19 cm2, y = 0.97x + 0.13, r = 0.76, SEE = 0.27 cm2, p < 0.001), and (3) the area derived from the Gorlin equation in the 18 patients who underwent catheterization (1.27 ± 0.35 cm2, mean difference = 0.19 ± 0.16, y = 0.98x + 0.05, r = 0.81, SEE = 0.26 cm2, p < 0.001). Conclusions: These findings suggest that Doppler color flow imaging of the MS jet in the vena contracta can provide an accurate estimation of MVA and appears to be potentially applicable in the assessment of the severity of MS.

Is the Change of Late Potential Over Time Related to Enzyme Levels?Ichemic Burden in Acute Myocardial Infarction

Background: The ventricular late potential (VLP) detected using the technique of signal average electrocardiography (SAECG) interacts with several factors, primarily time.