Strain-time curve analysis by speckle tracking echocardiography in cardiac resynchronization therapy: Insight into the pathophysiology of responders vs. non-responders.

BACKGROUND: Patients with non-ischemic heart failure etiology and left bundle branch block (LBBB) show better response to cardiac resynchronization therapy (CRT). While these patients have the most pronounced left ventricular (LV) dyssynchrony, LV dyssynchrony assessment often fails to predict outcome. We hypothesized that patients with favorable outcome from CRT can be identified by a characteristic strain distribution pattern. METHODS: From 313 patients who underwent CRT between 2003 and 2006, we identified 10 patients who were CRT non-responders (no LV end-systolic volume [LVESV] reduction) with non-ischemic cardiomyopathy and LBBB and compared with randomly selected CRT responders (n = 10; LVESV reduction ≥15%). Longitudinal strain (εlong) data were obtained by speckle tracking echocardiography before and after (9 ± 5 months) CRT implantation and standardized segmental εlong-time curves were obtained by averaging individual patients. RESULTS: In responders, ejection fraction (EF) increased from 25 ± 9 to 40 ± 11% (p = 0.002), while in non-responders, EF was unchanged (20 ± 8 to 21 ± 5%, p = 0.57). Global εlong was significantly lower in non-responders at pre CRT (p = 0.02) and only improved in responders (p = 0.04) after CRT. Pre CRT septal εlong -time curves in both groups showed early septal contraction with mid-systolic decrease, while lateral εlong showed early stretch followed by vigorous mid to late contraction. Restoration of contraction synchrony was observed in both groups, though non-responder remained low amplitude of εlong. CONCLUSIONS: CRT non-responders with LBBB and non-ischemic etiology showed a similar improvement of εlong pattern with responders after CRT implantation, while amplitude of εlong remained unchanged. Lower εlong in the non-responders may account for their poor response to CRT.

Role of temporal resolution in selection of the appropriate strain technique for evaluation of subclinical myocardial dysfunction.

OBJECTIVE: To assess the effects of frame and volume rate on the concordance between two-dimensional speckle tracking strain (2DS) and three-dimensional speckle tracking strain (3DS), and between 2DS and triplane imaging of speckle tracking (Tri-P). METHODS: Global longitudinal strains (GLSs) derived from 2DS, 3DS, and Tri-P were compared among 142 prospectively recruited patients who underwent evaluation of subclinical left ventricle (LV) function. RESULTS: Feasibility to obtain GLS of 3DS was significantly higher than that of Tri-P (76% vs. 47%, P < 0.001). The correlation between 2DS and 3DS was only modest (r = 0.47) whereas that of 2DS and Tri-P was better (r = 0.67). The difference in frame/volume rate between two methods also affected their correlation. A volume rate between 34 and 50 volumes/sec had the highest correlation between 2DS and 3DS (r = 0.72). The correlation between 2DS and Tri-P was better with a difference in frame-rate ≤20 per second than with a difference >20 per second. Likewise, there was a better correlation between 2DS and 3DS when the difference between 2D frame rate and 3D volume rate was ≤40 per second, compared to when it was >40 per second. These associations differed from segment to segment and the apical segments had the highest correlation and the basal the lowest. CONCLUSIONS: The feasibility of each means of strain calculation showed important differences, with 2DS being the most attainable. Strain values were not interchangeable among 2DS, Tri-P, and 3DS. Importantly, poor correlations seemed to be driven by differences in acquisition rate. Currently, 2DS offers the most robust measurement of subclinical myocardial dysfunction.

Dynamic change of mitral annular geometry and motion in ischemic mitral regurgitation assessed by a computerized 3D echo method.

OBJECTIVE: In patients with ischemic mitral regurgitation (IMR), we assessed dynamic changes in mitral annular geometry and motion during the cardiac cycle, and examined their association with the severity of IMR, using our computerized three-dimensional (3D) echo method. METHODS: Real-time 3D echo was performed in 12 normal controls and 25 patients with IMR. The saddle-shaped annulus was reconstructed in every 3D volume/frame during a cardiac cycle. For each 3D volume/frame, we assessed the mitral annular area (MAA) and the annular contraction that was expressed as the percentage of the largest MAA accounted for by the change in MAA from largest to smallest calculated value. RESULTS: In IMR patients, the minimum MAA occurred in late-systole, while it occurred in early-systole in the controls. IMR patients had a larger minimum MAA (6.7 ± 1.3 vs. 3.6 ± 0.8 cm², P < 0.001) and reduced annular contraction (23.0 ± 6.5 vs. 42.6 ± 7.0%, P < 0.001) when compared to controls. Both minimum MAA and annular contraction had significant correlations with IMR severity (r = 0.67 and r = 0.78, P < 0.001 for both). CONCLUSION: The contraction of the dilated mitral annulus occurred in late-systole in patients with IMR. The alterations of annular geometry and motion may be associated with the development of IMR.

Left atrial function assessed by real-time 3-dimensional echocardiography is related to right ventricular systolic pressure in chronic mitral regurgitation.

BACKGROUND: Left atrial (LA) volume is a prognostic index in chronic mitral regurgitation (MR). However, little is known about LA function in this setting. We hypothesized that LA dysfunction is related to pulmonary hypertension in chronic MR. METHODS: Seventy-one patients with organic chronic MR who underwent real-time 3-dimensional transthoracic echocardiography (RT3DE) were studied. Left atrial volumes and peak passive and active LA emptying rates were obtained. Total LA emptying fraction was calculated as follows: [(maximum - minimum LA volume)/maximum LA volume] x 100. Similarly, active and passive LA emptying fractions were calculated. From transmitral flow, the peak early (E) and late (A) diastolic filling velocities and E/A ratio were obtained. The early (E') and late (A') diastolic myocardial velocities were obtained by tissue Doppler interrogation of mitral annulus. RESULTS: Effective regurgitant orifice area (EROA) was 0.57 +/- 0.29 cm(2). Right ventricular systolic pressure (RVSP) was measured in 57 patients and averaged 37 +/- 13 mm Hg. Patients with MR and high RVSP displayed higher minimum LA volume, E/A ratio, E/E' ratio, EROA, and MR volume, and lower A' velocity, peak active LA emptying rate, active LA emptying fraction, and total LA emptying fraction than patients with MR and normal RVSP. Multiple regression analysis revealed that EROA (r = 0.51, P = .01) active LA emptying fraction (r = -0.53, P = .02), E/E' ratio (r = 0.50; P = .04), and the lateral A' velocity (r = -0.46; P = .003) were independently correlated with RVSP. CONCLUSIONS: Left atrial function determined by RT3DE had significant correlation with RVSP in chronic MR, irrespective of MR severity. Thus, pulmonary hypertension in chronic MR may depend not only on MR severity but also on LA function.

Shorter AV delays provide improved echocardiographic hemodynamics during exercise in patients receiving cardiac resynchronization therapy.

BACKGROUND: Although atrial ventricular (AV) intervals are often optimized at rest in patients receiving cardiac resynchronization therapy (CRT), there are limited data on the impact of exercise on optimal AV interval. METHODS: In 15 patients with CRT, AV intervals were serially programmed while patients were supine and at rest, and during exercise with heart rates that averaged 20 and 40 beats per minute above their resting rates. Echocardiographic Doppler images were acquired at each programmed AV interval and each rate. Three independent echocardiographic criteria were retrospectively used to determine each patient's optimal AV interval as a function of exercise-induced increased heart rates: the duration of left ventricular filling, stroke volume, and a clinical assessment of left ventricular function. RESULTS: A negative correlation between the optimal AV interval and heart rate was observed across all patients using all three independent criterion: the maximum left ventricular filling time (slope =-0.77, intercept = 151.9, r = 0.55, P < 0.001), maximum stroke volume (slope =-0.93, intercept = 183.3, r = 0.50, P = 0.002), or the subjective clinical assessment (slope =-1.06, intercept = 182.0, r = 0.72, P < 0.001). Consistent trends were observed between all three parameters for 12 out of the 15 patients. CONCLUSIONS: These results suggest that in patients indicated for CRT, rate-adaptive functions may be useful to shorten AV intervals with increased rate, in order to maximize left ventricular filling, stroke volume, and clinical left ventricular function. Further studies are necessary to determine the clinical impact of these rate-adaptive algorithms.

Geometry of the proximal isovelocity surface area in mitral regurgitation by 3-dimensional color Doppler echocardiography: difference between functional mitral regurgitation and prolapse regurgitation.

BACKGROUND: The geometry of the proximal isovelocity surface area (PISA) of functional mitral regurgitation (MR), which is conventionally assumed to be a hemisphere, remains to be clarified. We investigated the 3-dimensional (3D) geometry of PISA of functional MR as opposed to that of MR due to mitral valve prolapse (MVP) by real-time 3D echocardiography with color Doppler capability. METHODS: Twenty-seven patients with functional MR and 27 patients with MVP were examined. The horizontal PISA length in the commissure-commissure plane and each PISA radius in 3 anteroposterior planes (medial, central, and lateral) were measured by real-time 3D echocardiography with 3D software. The effective regurgitant orifice (ERO) area was calculated with the maximum PISA radius and compared to that by 2D quantitative Doppler method. RESULTS: En-face 3D color Doppler images showed an elongated and slightly curved PISA geometry along the leaflet coaptation in functional MR, whereas the geometry was rounder in MVP. The PISA horizontal length in functional MR was longer than that in MVP (2.3 +/- 0.4 vs 1.2 +/- 0.2 cm, P < .001). The PISA method with the maximum radius underestimated the ERO area by 2D quantitative Doppler method (by 24%) in functional MR, but not in MVP. CONCLUSIONS: The geometry of PISA in functional MR was elongated, distinctly different from the more focal pathology of MVP, leading to underestimation of the ERO area by PISA method.

Tissue synchronization imaging and optimal left ventricular pacing site in cardiac resynchronization therapy.

The optimal pacing site in cardiac resynchronization therapy (CRT) remains controversial. Tissue synchronization imaging is a novel echocardiographic technique that color-codes for areas of maximal delay in myocardial velocities. This study aimed to identify whether the left ventricular (LV) pacing lead position in CRT should be guided by a patient's area of maximal mechanical delay. Fifty-four patients with advanced heart failure were assessed echocardiographically before and 6 months after CRT. Response was analyzed according to the relation between the LV lead position and the area of maximal delay to peak velocity by tissue synchronization imaging in the first half of the ejection phase: group 1 (n = 22) had lead placement corresponding to the segment of maximal delay; group 2 (n = 13) had lead placement 1 segment adjacent; and group 3 (n = 19) had lead placement remote from this site. Evidence of LV reverse remodeling and improved systolic function was documented in group 1 (mean percentage decrease in end-systolic volume 23%) more than in group 2 (mean decrease 15%), and more than in group 3 (mean increase 8.9%, p <0.0001 compared with groups 1 and 2). In group 1, 16 of 22 patients had reverse remodeling (>15% decrease in end-systolic volume); reverse remodeling was seen in 7 of 13 patients in group 2 and 1 of 19 in group 3. The placing of the lead position proximal to the site of maximal delay by tissue synchronization imaging was correlated with reverse remodeling (r = 0.449, p = 001). Of 7 patients with delay confined to the septum and anterior wall only, none had evidence of reverse remodeling after CRT. In conclusion, pacing at the site of maximal mechanical delay was associated with reverse remodeling. Individually tailored LV lead positioning should be considered before CRT.

Importance of mitral valve repair associated with left ventricular reconstruction for patients with ischemic cardiomyopathy: a real-time three-dimensional echocardiographic study.

BACKGROUND: Left ventricular (LV) reconstruction surgery leads to early improvement in LV function in ischemic cardiomyopathy (ICM) patients. This study was designed to evaluate the impact of mitral valve (MV) repair associated with LV reconstruction on LV function 1-year after surgery in ICM patients assessed by real-time 3-dimensional echocardiography (3DE). METHODS AND RESULTS: Sixty ICM patients who underwent the combination surgery (LV reconstruction in 60, MV repair in 30, and revascularization in 52 patients) were studied. Real-time 3DE was performed and LV volumes were obtained at baseline, discharge, 6-month and >or=12-month follow-up. Reduction in end-diastolic volumes (EDV) by 29% and in end-systolic volumes by 38% were demonstrated immediately after surgery and remained at subsequent follow-up (P<0.0001). The LV ejection fraction significantly increased by about 10% at discharge and was maintained >or=12-month (P<0.0001). Although the LV volumes were significantly larger in patients with MV repair before surgery (EDV, 235+/-87 mL versus 193+/-67 mL, P<0.05), they were similar to LV volumes of the patients without MV repair at subsequent follow-ups. However, the EDV increased from 139+/-24 mL to 227+/-79 mL (P<0.01) in 7 patients with recurrent mitral regurgitation (MR). Improvement in New York Heart Association functional class occurred in 81% patients during late follow-up. CONCLUSIONS: Real-time 3DE demonstrates that LV reconstruction provides significant reduction in LV volumes and improvement in LV function which is sustained throughout the 1-year follow-up with 84% cardiac event free survival. If successful, MV repair may prevent LV redilation, while recurrent MR is associated with increased LV volumes.

Geometric differences of the mitral apparatus between ischemic and dilated cardiomyopathy with significant mitral regurgitation: real-time three-dimensional echocardiography study.

BACKGROUND: This study was conducted to elucidate the geometric differences of the mitral apparatus in patients with significant mitral regurgitation caused by ischemic cardiomyopathy (ICM-MR) and by idiopathic dilated cardiomyopathy (DCM-MR) by use of real-time 3D echocardiography (RT3DE). METHODS AND RESULTS: Twenty-six patients with ICM-MR caused by posterior infarction, 18 patients with DCM-MR, and 8 control subjects were studied. With the 3D software, commissure-commissure plane and 3 perpendicular anteroposterior (AP) planes were generated for imaging the medial, central, and lateral sides of the mitral valve (MV) during mid systole. In 3 AP planes, the angles between the annular plane and each leaflet (anterior, Aalpha; posterior, Palpha) were measured. In ICM-MR, Aalpha measured in the medial and central planes was significantly larger than that in the lateral plane (39+/-5 degrees, 34+/-6 degrees, and 27+/-5 degrees, respectively; P<0.01), whereas Palpha showed no significant difference in any of the 3 AP planes (61+/-7 degrees, 57+/-7 degrees, and 56+/-7 degrees, P>0.05). In DCM-MR, both Aalpha (38+/-8 degrees, 37+/-9 degrees, and 36+/-7 degrees, P>0.05) and Palpha (59+/-6 degrees, 58+/-5 degrees, and 57+/-6 degrees, P>0.05) revealed no significant differences in the 3 planes. CONCLUSIONS: The pattern of MV deformation from the medial to the lateral side was asymmetrical in ICM-MR, whereas it was symmetrical in DCM-MR. RT3DE is a helpful tool for differentiating the geometry of the mitral apparatus between these 2 different types of functional mitral regurgitation.

Impact of left ventricular outflow tract area on systolic outflow velocity in hypertrophic cardiomyopathy: a real-time three-dimensional echocardiographic study.

OBJECTIVES: The aim of this study was to use real-time three-dimensional echocardiography (3DE) to investigate the quantitative relation between minimal left ventricular (LV) outflow tract area (A(LVOT)) and maximal LV outflow tract (LVOT) velocity in patients with hypertrophic obstructive cardiomyopathy (HCM). BACKGROUND: In patients with HCM, LVOT velocity should change inversely with minimal A(LVOT) unless LVOT obstruction reduces the pumping capacity of the ventricle. METHODS: A total of 25 patients with HCM with systolic anterior motion (SAM) of the mitral valve leaflets underwent real-time 3DE. The smallest A(LVOT) during systole was measured using anatomically oriented two-dimensional "C-planes" within the pyramidal 3DE volume. Maximal velocity across LVOT was evaluated by two-dimensional Doppler echocardiography (2DE). For comparison with 3DE A(LVOT), the SAM-septal distance was determined by 2DE. RESULTS: Real-time 3DE provided unique information about the dynamic SAM-septal relation during systole, with A(LVOT) ranging from 0.6 to 5.2 cm(2) (mean: 2.2 +/- 1.4 cm(2)). Maximal velocity (v) correlated inversely with A(LVOT) (v = 496 A(LVOT)(-0.80), r = -0.95, p < 0.001), but the exponent (-0.80) was significantly different from -1.0 (95% confidence interval: -0.67 to -0.92), indicating a significant impact of small A(LVOT) on the peak LVOT flow rate. By comparison, the best correlation between velocity and 2DE SAM-septal distance was significantly (p < 0.01) poorer at -0.83, indicating the superiority of 3DE for assessing A(LVOT). CONCLUSIONS: Three-dimensional echocardiography-measured A(LVOT) provides an assessment of HCM geometry that is superior to 2DE methods. These data indicate that the peak LVOT flow rate appears to be significantly decreased by reduced A(LVOT). Real-time 3DE is a potentially valuable clinical tool for assessing patients with HCM.

Evaluation of left ventricular outflow tract area after septal reduction in obstructive hypertrophic cardiomyopathy: a real-time 3-dimensional echocardiographic study.

BACKGROUND: The comparative impact of percutaneous alcohol septal reduction (ASR) and surgical myectomy on the left ventricular outflow tract (LVOT) area in patients with obstructive hypertrophic cardiomyopathy (HC) is not well defined. Real-time 3-dimensional echocardiography (RT3DE) provides accurate information about the LVOT geometry and shape. We aimed to analyze the change in LVOT area after septal reduction interventions in patients with obstructive HC using RT3DE. METHODS: Thirty-one HC patients (mean age 53 +/- 17 years) undergoing ASR (n = 14) or myectomy (n = 17) were studied at baseline and during follow-up with RT3DE. LVOT area was measured after observing the LVOT in the 3D space as the smallest area during midsystole. LVOT pressure gradients were determined by conventional continuous wave Doppler. RESULTS: Overall, LVOT area increased from 0.86 +/- 0.20 to 2.50 +/- 0.88 cm2 (P < .01), and the resting LVOT pressure gradient decreased from 64 +/- 41 to 16 +/- 10 mm Hg (P < .01) after a median follow-up of 3 months after intervention (range 1-24 months). A similar significant decrease in LVOT pressure gradients was seen in myectomy and ASR groups (from 62 +/- 39 to 12 +/- 5 mm Hg and from 67 +/- 43 to 21 +/- 14 mm Hg, respectively, P < .01 in between each group, and P = NS between both groups). However, the increase in LVOT area was greater in myectomy than in ASR group (from 0.81 +/- 0.22 to 2.90 +/- 0.64 cm2 and 0.93 +/- to 0.16 to 2.02 +/- 0.92 cm2, respectively, P < .01 between both groups). CONCLUSION: RT3DE demonstrated an effective increase in LVOT area after both ASR and myectomy. This technique may be useful for assessing the results of septal reduction in patients with obstructive HC.

Automated mitral annular tracking: a novel method for evaluating mitral annular motion using two-dimensional echocardiography.

We developed an automated mitral annular tracking method based on a digital processing of high frame rate cineloop images of 2-dimensional echocardiography. In this study, its feasibility and accuracy was validated in 11 healthy volunteers and 16 patients with left ventricular (LV) dysfunction. The mitral annular excursion measured by automated mitral annular tracking agreed well with that measured by 3-dimensional echocardiography and correlated with LV ejection fraction. The longitudinal mitral annular excursion was reduced whereas the radial one was preserved for patients with LV dysfunction compared with control subjects. The novel automated mitral annular tracking method is clinically feasible and has potential capability to quantify the comprehensive mitral annular motion for evaluating LV function in a clinical setting.

Left Ventricular Outflow Tract Obstruction in Hypertrophic Cardiomyopathy Patients Without Severe Septal Hypertrophy: Implications of Mitral Valve and Papillary Muscle Abnormalities Assessed Using Cardiac Magnetic Resonance and Echocardiography.

BACKGROUND: In patients with hypertrophic cardiomyopathy and left ventricular outflow tract (LVOT) obstruction, but without basal septal hypertrophy, we sought to identify mitral valve (MV) and papillary muscle (PM) abnormalities that predisposed to LVOT obstruction, using echo and cardiac magnetic resonance. METHODS AND RESULTS: We studied 121 patients with hypertrophic cardiomyopathy hypertrophic cardiomyopathy (age, 49±17 years; 60% men; 57% on ß-blockers) with a basal septal thickness of ≤1.8 cm who underwent echocardiography (rest+stress) and cine cardiac magnetic resonance. Echo measurements included maximal LVOT gradient (rest/provocable), MV leaflet length (parasternal long, 4 and 3-chamber views), and abnormal chordal attachment to mid/base of anterior MV. Cine cardiac magnetic resonance measurements included basal septal thickness, number/area of PM heads, and bifid PM mobility (in systole and diastole). Mean basal septal thickness, LVOT gradient, and LV ejection fraction were 1.5±0.3 cm, 72±54 mm Hg, and 61±6%, respectively. The number of anterolateral and posteromedial PM heads was 2.7±0.7 and 2.6±0.7, respectively. Anterolateral and posteromedial PM areas were 19.9±7 cm(2) and 17.1±6 cm(2), respectively. PM mobility was 11±6°. On multivariable analysis, predictors of maximal LVOT gradient were basal septal thickness, bifid PM mobility, anterior mitral leaflet length, and abnormal chordal attachment to base of anterior mitral leaflet. Forty-five patients underwent surgery to relieve LVOT obstruction, of which 52% needed an additional nonmyectomy (MV repair/replacement or PM reorientation) approach. CONCLUSIONS: In hypertrophic cardiomyopathy patients without significant LV hypertrophy, in addition to basal septal thickness, anterior MV length, abnormal chordal attachment, and bifid PM mobility are associated with LVOT obstruction. In such patients, additional procedures on MV and PM (±myectomy) could be considered.

Usefulness of real-time three-dimensional echocardiography for evaluation of myectomy in patients with hypertrophic cardiomyopathy.

Real-time 3-dimensional echocardiography was performed in 10 patients with obstructive hypertrophic cardiomyopathy (HC) before and after myectomy and in 6 controls. The exact location of systolic anterior motion of the mitral leaflet was shown in all patients with HC with a predominant involvement of the medial portion in 4 patients and the middle portion in 6 patients. The smallest area of the left ventricular outflow tract was significantly smaller in patients with HC than in controls (1.4 +/- 0.7 vs 5.1 +/- 1.2 cm(2), p <0.01), significantly increased after myectomy (4.8 +/- 1.8 cm2, p <0.01) and was associated with a reduction of the pressure gradient at rest from 63 +/- 41 to 15 +/- 5 mm Hg (p <0.01).

Conduction system abnormalities in patients with obstructive hypertrophic cardiomyopathy following septal reduction interventions.

We observed the impact of percutaneous transluminal septal myocardial ablation (PTSMA) and myectomy on the conduction system in patients with obstructive hypertrophic cardiomyopathy (HC). Septal reduction intervention is capable of eliminating the left ventricular outflow tract obstruction in patients with obstructive HC; however, conduction system abnormalities are frequent consequences of these procedures. A standard 12-lead electrocardiogram and Doppler echocardiogram were obtained in 204 patients who underwent PTSMA (n = 70) or myectomy (n = 134) before and at average of 3 months after intervention. Of 146 patients who had normal conduction systems before intervention, the duration of the QRS complex was significantly prolonged from 98 +/- 15 to 130 +/- 25 ms (p <0.0001), with right bundle branch block (RBBB) developing in 62% patients after PTSMA, and from 100 +/- 13 to 154 +/- 20 ms (p <0.0001), with left bundle branch block (LBBB) developing in 93% patients after myectomy. No significant difference in the QRS duration was found in the remaining 58 patients who had preexisting conduction abnormalities after intervention. In 174 patients without a preexisting permanent pacemaker, a pacemaker was implanted in 22% versus 13% of patients who underwent PTSMA (overall and without preexisting conduction block, respectively) and 10% versus 2% of patients with myectomy. The duration of baseline QRS was an independent predictor for the requirement of a permanent pacemaker (p <0.0001). Thus, RBBB often develops after PTSMA and LBBB is very frequently produced by myectomy. A possible requirement of a permanent pacemaker should always be considered before intervention when patients have preexisting RBBB or LBBB.

Comparison of left ventricular diastolic function in obstructive hypertrophic cardiomyopathy in patients undergoing percutaneous septal alcohol ablation versus surgical myotomy/myectomy.

Both percutaneous transcoronary alcohol septal reduction (ASR) and surgical myectomy are effective treatments to relieve left ventricular (LV) outflow tract obstruction in obstructive hypertrophic cardiomyopathy (HC). LV diastolic function was assessed by echocardiography in 57 patients with obstructive HC at baseline and 5 +/- 4 months after ASR (n = 37) or surgical myectomy (n = 20). LV outflow tract pressure gradient decreased from 65 +/- 40 to 23 +/- 21 mm Hg (p <0.01) after treatment. The ratio of the early-to-late peak diastolic LV inflow velocities, and the ratio of the early peak diastolic LV inflow velocity to the lateral mitral annulus early diastolic velocity determined by tissue Doppler imaging significantly decreased after the procedures (1.6 +/- 1.7 vs 1.0 +/- 0.7 and 15 +/- 8 vs 11 +/- 5, respectively), whereas LV inflow propagation velocity significantly increased (60 +/- 24 vs 71 +/- 36 cm/s). Left atrial size decreased from 29 +/- 7 to 25 +/- 6 cm(2) (p <0.05). Patients had a significant improvement in New York Heart Association functional class and in exercise performance. When comparing ASR with myectomy, no difference was found in the degree of change in any parameter of diastolic function. Thus, diastolic function indexes obtained by echocardiography changed after septal reduction interventions in patients with obstructive HC; this change was similar to that after surgical myectomy and ASR.

Geometric changes of mitral annulus assessed by real-time 3-dimensional echocardiography: becoming enlarged and less nonplanar in the anteroposterior direction during systole in proportion to global left ventricular systolic function.

OBJECTIVE: We sought to investigate the geometric changes of the mitral annulus during systole in relation to global left ventricular (LV) systolic function using real-time 3-dimensional (3D) echocardiography. METHODS: Real-time 3D echocardiography was performed in 23 patients with global LV systolic dysfunction with ejection fraction of 37 +/- 19% and 9 control subjects with ejection fraction of 62 +/- 4%. Volumetric data were divided into 9 rotational apical planes (angle increment = 20 degrees) using 3D software. Nine rotational annular dimensions (ADs) were measured in all planes in early and late systole. Nonplanar angle (NPA) of the annulus between two vectors from two hinge points of the annulus in the anteroposterior plane to the center between two commissures in the commissure-commissure plane was measured during early and late systole. Fractional changes of NPA and AD were defined as changes in percentage during systole. RESULTS: NPA significantly increased during systole (early, 145 +/- 12 degrees; late, 160 +/- 9 degrees; P < .01). Among 9 ADs, 3 anteroposteriorly directed ADs showed the most prominent fractional increases during systole in all patients. Both fractional changes of NPA ( R 2 = 0.87, P < .01) and the anteroposterior dimension, AD 1 ( R 2 = 0.85, P < .01) showed significant positive correlation with global LV systolic function. CONCLUSIONS: Real-time 3D echocardiography demonstrated that saddle shape of the mitral annulus was getting enlarged and less nonplanar mainly in the anteroposterior direction during systole. These geometric changes were proportional to the global LV systolic function.

In vivo short-term Doppler hemodynamic profiles of 189 Carpentier-Edwards Perimount pericardial bioprosthetic valves in the mitral position.

We sought to determine the hemodynamic performance of the Carpentier-Edwards Perimount pericardial valve in the mitral position. We reviewed the Doppler echocardiographic data on 189 patients (110 women; 68 +/- 12 years of age) who were implanted with this valve (7.6 days +/- 13 postoperatively) at our institution between September 2000 and May 2002. The average ejection fraction was 47%. For all valves, the peak velocity was 1.9 +/- 0.3 m/s, peak gradient was 15 +/- 4.8 mm Hg, and mean gradient was 5.8 +/- 2 mm Hg. The pressure half-time was 93 +/- 24 milliseconds, with a calculated effective orifice area of 2.5 +/- 0.6 cm2. The average effective orifice area by continuity equation (83 valves) was 1.5 +/- 0.5 cm2. The mitral regurgitation was graded mild or less in 97.5% of all valves. This is the largest series establishing the favorable hemodynamic behavior of the different sizes of a new Perimount mitral valve, and the reported data could serve as a reference.

The pseudorestrictive pattern of transmitral Doppler flow pattern after conversion of atrial fibrillation to sinus rhythm: is atrial or ventricular dysfunction to blame?

Patients with paroxysmal atrial fibrillation (AF) who have recently converted from AF to sinus rhythm often exhibit a restrictive Doppler pattern in the transmitral flow (TMF) velocity. However, the mechanism of this phenomenon has not been well defined. We evaluated the temporal change of TMF pattern and hemodynamics after conversion of AF to in sinus rhythm in an animal model. Eight open-chest dogs underwent 3 hours of pacing-induced AF. TMF velocities and pressure data were acquired at baseline (sinus rhythm), immediately after conversion of AF, and every 10 minutes thereafter. Early diastolic TMF velocity was increased immediately after conversion and recovered to the baseline value in 20 minutes. Atrial systolic TMF velocity was reduced after AF and recovered to baseline value in 20 to 30 minutes. Early diastolic/atrial systolic TMF velocity was increased after conversion, and recovered to baseline value in 20 to 30 minutes. The mean left atrial (LA) pressure increased immediately, 10 and 20 minutes after the conversion of AF to sinus rhythm. The left ventricular end-diastolic pressure was increased and positive left ventricular dP/dt and tau were decreased immediately after AF, whereas they recovered within 10 minutes. In conclusion, a pseudorestrictive pattern of TMF after AF occurred as a result of transient LA mechanical functional impairment and increased LA pressure caused by LA stunning. Transient left ventricular diastolic dysfunction also effected the TMF velocity immediately after the conversion from AF to sinus rhythm, although it recovered faster than LA mechanical dysfunction.

Real-time three-dimensional color doppler evaluation of the flow convergence zone for quantification of mitral regurgitation: Validation experimental animal study and initial clinical experience.

BACKGROUND: Pitfalls of the flow convergence (FC) method, including 2-dimensional imaging of the 3-dimensional (3D) geometry of the FC surface, can lead to erroneous quantification of mitral regurgitation (MR). This limitation may be mitigated by the use of real-time 3D color Doppler echocardiography (CE). Our objective was to validate a real-time 3D navigation method for MR quantification. METHODS: In 12 sheep with surgically induced chronic MR, 37 different hemodynamic conditions were studied with real-time 3DCE. Using real-time 3D navigation, the radius of the largest hemispherical FC zone was located and measured. MR volume was quantified according to the FC method after observing the shape of FC in 3D space. Aortic and mitral electromagnetic flow probes and meters were balanced against each other to determine reference MR volume. As an initial clinical application study, 22 patients with chronic MR were also studied with this real-time 3DCE-FC method. Left ventricular (LV) outflow tract automated cardiac flow measurement (Toshiba Corp, Tokyo, Japan) and real-time 3D LV stroke volume were used to quantify the reference MR volume (MR volume = 3DLV stroke volume - automated cardiac flow measurement). RESULTS: In the sheep model, a good correlation and agreement was seen between MR volume by real-time 3DCE and electromagnetic (y = 0.77x + 1.48, r = 0.87, P <.001, delta = -0.91 +/- 2.65 mL). In patients, real-time 3DCE-derived MR volume also showed a good correlation and agreement with the reference method (y = 0.89x - 0.38, r = 0.93, P <.001, delta = -4.8 +/- 7.6 mL). CONCLUSIONS: real-time 3DCE can capture the entire FC image, permitting geometrical recognition of the FC zone geometry and reliable MR quantification.