Simultaneous Doppler tracing of transmitral inflow and mitral annular velocity as an estimate of elevated left ventricular filling pressure in patients with atrial fibrillation.

BACKGROUND: The time interval between the onset of early transmitral flow velocity (E) and that of early diastolic mitral annular velocity (e') (T(E-e')) is a good predictor of elevated left ventricular (LV) filling pressure in patients with sinus rhythm. Although the evaluation of LV filling pressure using E/e' has been challenging in atrial fibrillation (AF), the usefulness of T(E-e') is unknown. METHODS AND RESULTS: E and e' were simultaneously recorded using dual Doppler echocardiography in 45 AF patients (30 men; mean age, 69 ± 9 years). E/e' and T(E-e') were calculated and compared with the pulmonary capillary wedge pressure (PCWP), which was measured invasively. E/e' and T(E/e') correlated with PCWP (E/e', r=0.57, P<0.001; T(E-e'), r=0.77, P<0.001). Using receiver operating characteristic analysis, the optimal cut-off for T(E-e') was 34 ms (sensitivity, 95%; specificity, 88%) and that for E/e' was 14.6 (sensitivity, 50%; specificity, 84%) in order to predict >12-mmHg PCWP. When the combined cut-offs of T(E-e') >34 ms and E/e' >14.6 were used, the sensitivity and specificity of predicting elevated PCWP were improved to 100% and 88%, respectively. CONCLUSIONS: In AF patients, the simultaneous recording of E and e' using dual Doppler echocardiography and the analysis of T(E-e'), in addition to E/e', improved the accuracy of evaluation of LV filling pressure.

Right ventricular dysfunction in patients with Brugada-like electrocardiography: a two dimensional strain imaging study.

BACKGROUND: Sodium channel blockers augment ST-segment elevation in the right precordial leads in patients undergoing Brugada-type electrocardiography (ECG). However, their effect on echocardiographic features is not known. We address this by assessing global and regional ventricular function using conventional Doppler and two- dimensional (2D) speckle tracking techniques. METHODS: Thirty-one patients with Brugada-type ECG were studied. A pure sodium channel blocker, pilsicainide, was used to provoke an ECG response. The percentage longitudinal systolic myocardial strain at the base of both the right ventricular (RV) free wall and the interventricular septum wall was measured using 2D speckle tracking. Left ventricular (LV) and RV myocardial performance (TEI) indices were also measured. RESULTS: The pilsicainide challenge provoked a positive ECG response in 13 patients (inducible group). In the inducible group, longitudinal strain was significantly reduced only at the RV (-27.3 ± 5.4% vs -22.1 ± 3.6%, P < 0.01), and both RV and LV TEI indices increased (RV: 0.19 ± 0.09 vs 0.27 ± 0.11, P < 0.05; LV: 0.30 ± 0.10 vs 0.45 ± 0.10, P < 0.01) after pilsicainide administration. CONCLUSIONS: Temporal and spatial analysis using the TEI index and 2D strain imaging revealed the deterioration of global ventricular function associated with conduction disturbance and RV regional function in patients with Brugada-type ECG and coved type ST elevation due to administration of a sodium channel blocker.

Usefulness of mitral annular velocity in predicting exercise tolerance in patients with impaired left ventricular systolic function.

Left ventricular (LV) diastolic function is 1 of the determinants of exercise tolerance. However, the relation between early diastolic velocity of the mitral annulus (Ea) obtained by tissue Doppler imaging and exercise tolerance is unknown in patients with impaired LV systolic function. To investigate the feasibility of evaluating exercise tolerance using tissue Doppler imaging, we studied 53 consecutive patients (mean age 58 +/- 14 years) with a LV ejection fraction of <50% (mean 37 +/- 9%). We measured the peak early diastolic velocity of transmitral flow (E) and Ea at the lateral border of the mitral annulus and then calculated the E/Ea ratio. After echocardiography, we measured the peak oxygen consumption and anaerobic threshold (AT) by cardiopulmonary exercise testing. Of all the echocardiographic parameters, the best correlation for AT was the E/Ea ratio (r = -0.74, p <0.001). Peak oxygen consumption correlated well with Ea and the E/Ea ratio (r = 0.64 and r = -0.68, respectively, p <0.001). The AT and peak oxygen consumption did not correlate with conventional Doppler indexes. Using an AT of 8 ml/min/kg as the cutoff to separate severe exercise intolerance from normal, mild, or moderate exercise intolerance, a receiver-operating characteristic curve showed that an E/Ea ratio of >11.3 had the best combination of sensitivity (88%) and specificity (86%). Exercise tolerance correlated with the E/Ea ratio in patients with impaired LV systolic function. In conclusion, the evaluation of LV diastolic function using tissue Doppler imaging is useful for predicting exercise tolerance in patients with heart failure.

Heterogeneity of apex-to-base dispersion in diastolic lengthening is related to impaired global left ventricular relaxation in patients with hypertrophic cardiomyopathy.

BACKGROUND: The presence of apex-to-base disparity in diastolic left ventricle (LV) endocardial lengthening, based on an electromechanical activation sequence, has been recognized as an important determinant of LV diastolic properties. However, the behavior of LV apical and basal diastolic lengthening and its relationship to LV filling in hypertrophic cardiomyopathy (HCM) are unknown. METHODS: We obtained basal and apical LV short-axis views in 27 patients with non-obstructive HCM and 25 healthy volunteers. The patients with HCM were subdivided into two groups; those with apical hypertrophy [APH(+)] or those without apical hypertrophy [APH(-)]. Eight equiangular points on the endo-myocardium at end diastole were placed in each view, and the movements of these points were automatically tracked using a two-dimensional echocardiographic tissue tracking system. Time-LV internal diameter curves were obtained and averaged. The time intervals from the aortic valve closure to the point of the first 40% of peak diastolic lengthening (T 40) were measured in each view. The standard deviation of the time to peak systolic circumferential shortening at the base and apex were calculated to assess the heterogeneity of LV contraction. RESULTS: The time difference in the T 40 between the apex and base (dt-T 40) in the HCM-APH(+) and HCM-APH(-) groups was greater than that in the control group. The heterogeneities in LV apical systolic shortening in the HCM groups were greater than those in the control group. There were good linear correlations between the dt-T 40 and the LV early diastolic echo-parameters and the LV mass index. CONCLUSIONS: Delayed apical relaxation and filling in patients with HCM is related to LV diastolic dysfunction and systolic dyssynchronous contraction.

The impact of intermittent pneumatic compression devices on deep venous flow velocity in patients with congestive heart failure.

BACKGROUND: Intermittent pneumatic compression (IPC) has been used to prevent deep venous thrombosis (DVT), but the effects of IPC on the hemodynamics of popliteal and soleal veins, especially in patients with congestive heart failure (CHF) have not been evaluated. The aim of this study was to evaluate the effects of IPC on the flow velocity of deep veins in the lower extremities and to compare the efficacy of two different types of IPC in deep venous flow enhancement in patients with CHF. METHODS: Flow velocities of popliteal and soleal veins were recorded in 19 patients with CHF and in 19 control subjects using a high-resolution linear probe. Peak and mean flow velocities were measured (1) at rest, (2) with sequential foot and calf IPC (SFC-IPC) which consists of an electrically driven air compressor and four air chambers, and (3) with impulse foot IPC (IF-IPC) which consists of a pneumatic impulse generator operated at an applied pressure of 130 mmHg. RESULTS: In the resting condition, popliteal venous flow velocity in the CHF group was attenuated (12.8+/-4.7 cm/s vs. 21.1+/-13.5 cm/s; p<0.05). Both SFC-IPC and IF-IPC increased venous velocity, but the increase with IF-IPC in CHF patients was lower than that in control subjects. In the soleal veins, after applying SFC-IPC, the peak and mean velocity in CHF increased to the same extent as in the control group. IF-IPC increased soleal venous velocity in control subjects, but there was no increase in CHF patients. CONCLUSION: Two-dimensional Doppler scanning revealed a significant increase in the mean and peak velocities in the soleal and popliteal veins with SFC-IPC but not with IF-IPC in patients with CHF. These results indicate that SFC-IPC could have favorable effects in preventing DVT in patients with CHF.

Impact of intraoperative transesophageal echocardiography in cardiac and thoracic aortic surgery: experience in 1011 cases.

BACKGROUND: Although intraoperative transesophageal echocardiography (IOTEE) has been widely used in cardiovascular surgery, the exact incidence of abnormalities detected by IOTEE in each type of surgical procedure is still unclear. The aim of this study was to review our experiences of IOTEE, in patients who underwent different types of cardiovascular surgery and to evaluate the clinical usefulness of IOTEE. METHODS AND RESULTS: Our database of 1011 consecutive patients, who underwent cardiovascular surgery and IOTEE monitoring was reviewed. The incidence of abnormal findings was 115 of 1011 patients (11.4%), and the highest incidence was the appearance of new wall motion abnormalities after cardiopulmonary bypass. These findings influenced surgical decision-making in 59 of the evaluated 1011 patients (5.8%). CONCLUSIONS: IOTEE provides important intraoperative and postoperative information that may influence surgical decision-making in various cardiovascular surgeries.

Augmentation of left ventricular apical endocardial rotation with inotropic stimulation contributes to increased left ventricular torsion and radial strain in normal subjects: quantitative assessment utilizing a novel automated tissue tracking technique.

BACKGROUND: The difference in the left ventricular (LV) torsion of the endo- and epicardium (Endo, Epi) with inotropic stimulation and its relation to radial strain (RS) remain unclear. METHODS AND RESULTS: LV basal and apical short-axis images were recorded in 13 normal subjects at rest and during dobutamine infusion (5, 10 microg x kg (-1) x min(-1)). A total of 8 points (anterior, lateral, posterior and septum in both Endo and Epi) were manually placed by 2-dimensional tissue tracking technique and the movement of these points during a cardiac cycle was tracked, after which the rotation angles and RS were calculated. LV torsion was defined as the net difference between the basal and apical rotations. In the LV apex, Endo-rotation increased (7.8+/-2.7 to 14.1+/-4.6 degrees, p<0.01), whereas Epi-rotation was unchanged, with dobutamine. The apical Endo-rotation was significantly greater than the Epi-rotation, although no difference was seen between the Endo and Epi in the LV base throughout the study. During dobutamine infusion, the LV Endo-torsion increased (9.5+/-2.8 to 19.3+/-4.8 degrees, p<0.01) and these values were greater than those for Epi. The apical RS increased with the dobutamine dose (39.0+/-9.3 to 61.9+/-15.5%, p<0.01), whereas basal RS initially increased at 5 microg x kg(-1) x min(-1), but thereafter showed no further increase at 10 microg x kg(-1) x min(-1) of dobutamine. CONCLUSIONS: Augmentation of LV rotation with inotropism was clearly observed in the apical Endo, thus causing increased LV endo-torsion and apical RS.