Comparison of pulse wave velocity assessed by three different techniques: Arteriograph, Complior, and Echo-tracking.

Arterial stiffness estimated by pulse wave velocity (PWV) is an independent predictor of cardiovascular morbidity and mortality. Although recommended by the current guidelines, clinical applicability of this parameter is difficult, due to differences between the various techniques used to measure it and to biological variability. Our aim was to compare PWV assessed by 3 different commercially available systems. 100 subjects (51 ± 16 years, 45 men) were evaluated using the 3 methods: an oscillometric technique (Arteriograph, PWV-A); a piezo-electric method (Complior, PWV-C); and an high-resolution ultrasound technique implemented with an Echo-tracking system (Aloka, PWV-E). Conventional biological markers were measured. Correlations of PWV measured by the 3 methods were poor (r = 0.39, r = 0.39, and r = 0.31 for PWV-A vs. PWV-C, PWV-A vs. PWV-E, and PWV-C vs. PWV-E, respectively, all p < 0.05). By Bland-Altman analysis, mean difference (±SD) of PWV-A vs. PWV-C was -1.9 ± 2.0 m/s, of PWV-A vs. PWV-E -3.6 ± 1.9 m/s, and of PWV-C vs. PWV-E -2.7 ± 1.9 m/s, with a wide coefficient of variation (22.3, 25.7, and 25.7 %, respectively). As expected, PWV-A, PWV-C, and PWV-E correlated with other arterial stiffness parameters, such as intima-media thickness (r = 0.22, r = 0.22, and r = 0.36, respectively), E p (r = 0.37, r = 0.26, and r = 0.94, respectively), and augmentation index measured by Arteriograph method (r = 0.66, r = 0.35, and r = 0.26, respectively); all p < 0.05. Assessment of PWV is markedly dependent on the technique used to measure it, related to various methods for measuring traveled distance of the arterial wave. Our results suggest the urgent need to establish reference values of PWV for each of these techniques, separately, to be used in routine clinical practice.

Accuracy of fluoroscopic and electrocardiographic criteria for pacemaker lead implantation by comparison with three-dimensional echocardiography.

BACKGROUND: Fluoroscopic and electrocardiographic (ECG) criteria for the documentation of pacing lead positioning (apical and alternative sites) have been described, but data regarding their accuracy are lacking. METHODS: Fifty patients (27 men; mean age, 76 ± 9 years) with permanent right ventricular (RV) pacing leads were included. RV lead position was classified as apical, mid septal, mid RV free wall, RV outflow tract (RVOT) septal, or RVOT free wall. Exact anatomic lead position was documented using three-dimensional (3D) transthoracic echocardiography (TTE). Cohen's κ coefficient was used to assess agreement between fluoroscopic or ECG criteria and 3D TTE. RESULTS: True lead positions were as follows: 15 apical, 24 mid septal, three mid RV free wall, and eight RVOT septal wall; no leads were implanted into the RVOT free wall. Fluoroscopy (κ = 0.56; 95% confidence interval [CI], 0.37-0.76) and electrocardiography (κ = 0.43; 95% CI, 0.25-0.60) had moderate overall agreement with 3D TTE. Fluoroscopy had moderate agreement with 3D TTE for apical (κ = 0.57; 95% CI, 0.32-0.83), mid septal (κ = 0.48; 95% CI, 0.25-0.72), and mid free wall sites (κ = 0.54; 95% CI, 0.08-1.00) and moderate to good agreement for the RVOT septal wall (κ = 0.61; 95% CI, 0.30-0.90). Fluoroscopy misclassified as mid septal six of the 15 RV apical leads. ECG criteria had moderate agreement with 3D TTE for apical positions (κ = 0.55; 95% CI, 0.34-0.77) and RVOT sites (κ = 0.47; 95% CI, 0.21-0.73). Electrocardiography misclassified as apical 10 and as RVOT six of the 24 mid septal leads. CONCLUSIONS: Fluoroscopic and ECG criteria are only moderately accurate in discriminating between RV apical, mid septal, mid free wall, and RVOT pacing sites. These data suggest that both fluoroscopy and electrocardiography may not be adequate techniques for the correct documentation of RV pacing lead position for routine clinical practice or research purposes.