Kwang-Soo Cha

Relationship between Giant Negative T-Wave and Severity of Apical Hypertrophy in Patients with Apical Hypertrophic Cardiomyopathy

Objectives: This study was aimed at evaluating the usefulness of giant negative T‐wave (GNT) as an index of apical hypertrophic cardiomyopathy (ACM) severity and as a better echocardiographic index to represent apical hypertrophy. Methods: Seventy‐five patients who were recently diagnosed with ACM by echocardiography were enrolled in this study. ACM patients were divided into two groups: group 1 (ACM with GNT) and group 2 (ACM without GNT). To evaluate ACM severity, apical wall thickness (A‐WT) and apical cross‐sectional muscle area (A‐CSMA) were measured by echocardiography. Results: Twenty‐seven patients (36%) had GNT. The maximal A‐WT of groups 1 and 2 was 19.7 ± 2.4 and 18.6 ± 2.0 mm, P = 0.027, respectively. In addition, the maximal A‐CSMA differed significantly between groups 1 and 2 (14.2 ± 1.8 vs. 11.8 ± 1.9 cm2, P < 0.001). In the correlation analysis, Tmax showed a stronger correlation with A‐CSMA than with A‐WT (r = 0.599 vs. r = 0.291). Conclusions: These results indicate that the presence of GNT in ACM patients may represent more severe apical hypertrophy. Furthermore, A‐CSMA may be a more reliable ACM severity index than A‐WT. (Echocardiography 2010;27:770‐776)

Comparison of laboratory detection methods of aspirin resistance in coronary artery disease patients

Aspirin reduces the prevalence of nonfatal myocardial infarction, stroke, and death by 25.0% in high risk group of patients with cardiovascular disease. Previous studies have estimated that about 5.5–56.8% of the population are aspirin resistant. The mechanisms of aspirin resistance (AR) have not been fully understood. We compared the detection methods for AR using traditional platelet aggregometry and VerifyNow system. One hundred and seventy‐two coronary artery disease patients who had taken aspirin only or combinations with aspirin and clopidogrel for over 7u2003days were included. Of the 55 patients with aspirin only, aggregometer detected six AR (10.9%) and VerifyNow identified 10 AR (18.2%) cases. Among 117 patients with combined therapy, none (0.0%) and 10 (8.5%) of AR were detected by aggregometer and VerifyNow, respectively. There were six (3.4%) patients of AR defined by both methods and they all received aspirin monotherapy. Although the correlation between the aggregometry and VerifyNow was low, with defined criteria both methods gave 91.9% agreement to find AR. VerifyNow showed a higher sensitivity to detect AR. Further studies are required to biologically define AR and to alter therapy based on platelet function tests.

Measurement of vena contracta width for the assessment of severity of mitral stenosis

This study was designed to test whether vena contracta width (VCW) measured by color Doppler flow could be used to assess the severity of mitral stenosis (MS). A secondary objective was to determine the cut-off value of VCW for the prediction of severe MS. We studied 47 consecutive patients with MS (mean age, 50 ± 11 years; 34 females) who did not have more than mild mitral regurgitation. We compared VCW with conventional methods for determining mitral valve area (MVA). Mitral valve area was assessed by one observer using continuity equation (CE), pressure half-time (PHT), and planimetry in the parasternal short axis view. Vena contracta width was measured in the same patients by two observers (blinded to the MVA data) using the apical four-chamber view by color Doppler flow. Vena contracta width measurements were compared with MVA by CE, PHT, and planimetry. The MVA determined by CE, PHT, and planimetry was 1.19 ± 0.42, 1.31 ± 0.53, and 1.27 ± 0.43u2009cm2, respectively. The VCW in patients with MVA <1u2009cm2, 1–1.5u2009cm2, and >1.5u2009cm2 (calculated by the CE method) was 0.77 ± 0.19, 1.13 ± 0.16, and 1.36 ± 0.24u2009cm, respectively. Vena contracta width was significantly correlated to MVA by planimetry (r = 0.756, P < 0.001), PHT (r = 0.673, P < 0.001), and CE (r = 0.813, P < 0.001). The VCW of patients with MVA ≤1u2009cm2 was significantly smaller than that of patients with MVA >1u2009cm2 determined by the CE method (0.77 ± 0.19 vs 1.26 ± 0.26, P < 0.001). Vena contracta width measurement of 1u2009cm or less had a sensitivity of 88% and a specificity of 77% for the prediction of severe MS. These results demonstrate that the correlations between VCW and MVA measured by conventional methods were highly significant. In addition, these results suggest that VCW ≤1u2009cm may indicate the presence of severe mitral stenosis.