Miller, Fletcher A.

Echocardiography is the key tool for the diagnosis and evaluation of aortic stenosis. Because clinical decision-making is based on the echocardiographic assessment of its severity, it is essential that standards are adopted to maintain accuracy and consistency across echocardiographic laboratories. Detailed recommendations for the echocardiographic assessment of valve stenosis were published by the European Association of Echocardiography and the American Society of Echocardiography in 2009. In the meantime, numerous new studies on aortic stenosis have been published with particular new insights into the difficult subgroup of low gradient aortic stenosis making an update of recommendations necessary. The document focuses in particular on the optimization of left ventricular outflow tract assessment, low flow, low gradient aortic stenosis with preserved ejection fraction, a new classification of aortic stenosis by gradient, flow and ejection fraction, and a grading algorithm for an integrated and stepwise approach of artic stenosis assessment in clinical practice.

Background —Noninvasive assessment of diastolic filling by Doppler echocardiography provides important information about left ventricular (LV) status in selected subsets of patients. This study was designed to assess whether mitral annular velocities as assessed by tissue Doppler imaging are associated with invasive measures of diastolic LV performance and whether additional information is gained over traditional Doppler variables. Methods and Results —One hundred consecutive patients referred for cardiac catheterization underwent simultaneous Doppler interrogation. Invasive measurements of LV pressures were obtained with micromanometer-tipped catheters, and the mean LV diastolic pressure (M-LVDP) was used as a surrogate for mean left atrial pressure. Doppler signals from the mitral inflow, pulmonary venous inflow, and TDI of the mitral annulus were obtained. Isolated parameters of transmitral flow correlated with M-LVDP only when ejection fraction <50%. The ratio of mitral velocity to early diastolic velocity of the mitral annulus (E/E′) showed a better correlation with M-LVDP than did other Doppler variables for all levels of systolic function. E/E′ <8 accurately predicted normal M-LVDP, and E/E′ >15 identified increased M-LVDP. Wide variability was present in those with E/E′ of 8 to 15. A subset of those patients with E/E′ 8 to 15 could be further defined by use of other Doppler data. Conclusions —The combination of tissue Doppler imaging of the mitral annulus and mitral inflow velocity curves provides better estimates of LV filling pressures than other methods (pulmonary vein, preload reduction). However, accurate prediction of filling pressures for an individual patient requires a stepwise approach incorporating all available data.

BACKGROUND Normal Doppler hemodynamics for tricuspid prostheses have not been well characterized in a large group of patients. Therefore, we analyzed comprehensive Doppler echocardiographic examinations of 82 patients with tricuspid prostheses that were normal by clinical and two-dimensional echocardiographic examinations to establish the normal hemodynamics of various types and sizes of tricuspid prostheses. METHODS AND RESULTS The earliest complete postoperative echocardiographic study from each patient was chosen for analysis. Doppler examinations were analyzed on an off-line station from tapes or Doppler strip charts. Early velocity, atrial velocity, end-diastolic velocity, pressure half-time, and mean gradient were obtained by digitizing tricuspid velocity curves. The incidence of "physiological" tricuspid prosthetic regurgitation was noted. Ten Doppler cycles were measured for each patient, and maximal, minimal, and average measurements were recorded. The mean values +/- SD of early velocity, atrial velocity, end-diastolic velocity, mean gradient, and pressure half-time and incidence of mild prosthetic regurgitation were reported for each type of prosthesis, as were highest Doppler measurements for each valve type. Average pressure half-time was significantly lower for St Jude than for heterograft prostheses (P = .04). There were no significant differences between the valve types for mean gradient, early velocity, or incidence of prosthetic regurgitation. Increasing prosthesis size was associated with lower average pressure half-time for heterograft prostheses (P = .024). Average differences (respiratory- and cycle-length-dependent) between maximal and minimal values for 10 cardiac cycles were established for each prosthesis. CONCLUSIONS This study establishes normal ranges for Doppler hemodynamics of various tricuspid prostheses and emphasizes the importance of measuring multiple cycles for each tricuspid prosthesis, regardless of cardiac rhythm.

BACKGROUND Maroteaux-Lamy syndrome is a lysosomal storage disease of mucopolysaccharide metabolism (MPS type VI) that may involve the mitral and aortic valves. Affected patients have other skeletal and oropharyngeal malformations that complicate anesthetic and surgical management. METHODS AND RESULTS The present report describes the clinical, echocardiographic, and pathological findings in four patients with Maroteaux-Lamy syndrome. Two of three siblings underwent successful double-valve replacement for aortic and mitral valve stenoses. The third sibling, whose aortic and mitral valves were thick and fibrotic, died from septicemia after hip surgery. A fourth, unrelated patient also had successful double-valve replacement. CONCLUSIONS Our experience emphasizes the potential difficulties in preoperative assessment and surgical treatment as well as the unique problems related to airway management in patients with this syndrome.

BACKGROUND Transthoracic Doppler echocardiography examination has become an integral part of the investigations performed in patients with mitral valve prostheses. The limitations of the transthoracic approach are well documented. Transesophageal echocardiography provides a unique window for achieving a clear view of the mitral prosthesis. METHODS AND RESULTS This study shows the usefulness of transesophageal echocardiography in clinical practice for assessment of patients with a mitral valve prosthesis. This technique demonstrated an abnormality in 48% of patients who had normal results on transthoracic examination. The overall sensitivity of transesophageal echocardiography was 96%. CONCLUSIONS Transesophageal echocardiography constitutes an essential part of a comprehensive two-dimensional/Doppler echocardiographic examination in patients with suspected malfunction of mitral prostheses.

Background— Whether mechanical dyssynchrony indices predict reverse remodeling (RR) or clinical response to cardiac resynchronization therapy (CRT) remains controversial. This prospective study evaluated whether echocardiographic dyssynchrony indices predict RR or clinical response after CRT. Methods and Results— Of 184 patients with heart failure with anticipated CRT who were prospectively enrolled, 131 with wide QRS and left ventricular ejection fraction <35% had 6-month follow-up after CRT implantation. Fourteen dyssynchrony indices (feasibility) by M-mode (94%), tissue velocity (96%), tissue Doppler strain (92%), 2D speckle strain (65% to 86%), 3D echocardiography (79%), and timing intervals (98%) were evaluated. RR (end-systolic volume reduction ≥15%) occurred in 55% and more frequently in patients without (71%) than in patients with (42%) ischemic cardiomyopathy ( P =0.002). Overall, only M-mode, tissue Doppler strain, and total isovolumic time had a receiver operating characteristic area under the curve (AUC) greater than the line of no information, but none of these were strongly predictive of RR (AUC, 0.63 to 0.71). In nonischemic cardiomyopathy, no dyssynchrony index predicted RR. In ischemic cardiomyopathy, M-mode (AUC, 0.67), tissue Doppler strain (AUC, 0.79), and isovolumic time (AUC, 0.76) -derived indices predicted RR ( P <0.05 for all), although the incremental value was modest. No indices predicted clinical response assessed by Minnesota Living with Heart Failure Questionnaire, 6-minute walk distance, and peak oxygen consumption. Conclusions— These findings are consistent with the Predictors of Response to CRT study and do not support use of these dyssynchrony indices to guide use of CRT.

Background— Mitral annulus is a complex structure of poorly understood physiology. Full-volume real-time 3-dimensional transesophageal echocardiography offers a unique opportunity to completely image and quantify mitral annulus size and motion. Methods and Results— Real-time 3-dimensional transesophageal echocardiography of the mitral valve was acquired in 32 patients with myxomatous valve disease (MVD) and moderate to severe regurgitation, 15 normal control subjects, and 10 patients with ischemic mitral regurgitation of identical body surface area. Mitral annular dimensions (circumference, area, anteroposterior and intercommissural diameters, height, and ratio of height to intercommissural diameter ratio, which appraises annular saddle-shape depth) were measured throughout the cardiac cycle with dedicated quantification software. Compared with direct surgical measurement, 3-dimensional anterior annular dimension provided reliable measurements (mean difference, 0.1±0.1 mm; P =0.73; 95% confidence interval, ±4.4 mm). Annular dimensions were larger in MVD patients compared with control subjects in diastole (all P <0.05). Normal annulus displayed early-systolic anteroposterior ( P <0.001) and area ( P =0.04) contraction, increased height ( P <0.001), and deeper saddle shape (ratio of height to intercommissural diameter, 15±1% to 21±1%; P <0.001), whereas intercommissural diameter was unchanged ( P =0.30). In contrast, MVD showed early-systolic intercommissural dilatation ( P =0.02) and no area contraction ( P =0.99), height increase ( P =0.11), or saddle-shape deepening ( P =0.35). Late-systolic MVD annular saddle shape deepened but annular area excessively enlarged ( P <0.04) as a result of persistent intercommissural widening ( P <0.02). MVD annulus also contrasts with ischemic mitral regurgitation annulus, which, despite similar anteroposterior enlargement, is narrower and essentially adynamic. After MVD repair, the annulus remained dynamic without systolic saddle-shape accentuation ( P =0.30). Conclusions— Real-time 3-dimensional transesophageal echocardiography provides insights into normal, dynamic mitral annulus function with early-systolic area contraction and saddle-shape deepening contributing to mitral competency. MVD annulus is also dynamic but considerably different with loss of early-systolic area contraction and saddle-shape deepening despite similar magnitude of ventricular contraction, suggestive of ventricular-annular decoupling. Subsequent area enlargement may contribute to mitral incompetence. After mitral repair, MVD annulus remains dynamic without systolic saddle-shape accentuation. Thus, real-time 3-dimensional transesophageal echocardiography provides new insights that allow the refining of mitral pathophysiology concepts and repair strategies.

Background— Various dyssynchrony indexes derived from tissue velocity and strain imaging have been proposed to predict the effectiveness of cardiac resynchronization therapy (CRT). We sought to compare the effect of CRT on dyssynchrony indexes derived by tissue velocity and strain and to determine which baseline intraventricular dyssynchrony parameters correlate with improvement in left ventricular volume after CRT. Methods and Results— Echocardiography with tissue Doppler imaging was performed in 45 patients with systolic heart failure at baseline, 1 day after CRT, and a median of 6 months after CRT. We calculated septal–lateral delay and anteroseptal–posterior delay and standard deviation of time to peak systolic velocity in the 12 basal and mid-left ventricular segments (Tv-SD). The standard deviation for time to peak strain in the 12 basal and mid-left ventricular segments (Tε-SD) was calculated as a strain-derived dyssynchrony index. None of the tissue velocity–derived dyssynchrony indexes improved after CRT (septal–lateral delay, P =0.39; anteroseptal–posterior delay, P =0.46; Tv-SD, P =0.30), whereas Tε-SD decreased significantly after CRT ( P <0.001). Improvement in Tε-SD 1 day after CRT correlated with the reduction in end-systolic volume at follow-up ( r =0.66; P <0.001). Baseline Tε-SD demonstrated significant correlation with the reduction of end-systolic volume at follow-up ( r =0.57; P <0.001); however, baseline tissue velocity–derived dyssynchrony indexes failed to predict the effect of CRT. Conclusions— The strain-derived dyssynchrony index is a better measurement than the tissue velocity dyssynchrony index for monitoring changes in mechanical dyssynchrony after CRT and for predicting reduction in left ventricular volume after CRT.

Background— Several echocardiographic dyssynchrony indexes have been proposed to identify responders to cardiac resynchronization therapy using tissue velocity and strain. The present study aimed to compare tissue velocity–derived and strain-derived dyssynchrony indexes in patients with or without systolic dysfunction and left bundle-branch block. Methods and Results— Tissue Doppler imaging was performed in 120 subjects divided into 4 groups: group 1 (n=40), normal subjects; group 2 (n=20), normal left ventricular ejection fraction and left bundle-branch block; group 3 (n=20), left ventricular ejection fraction <35% and normal conduction; and group 4 (n=40), left ventricular ejection fraction <35% and left bundle-branch block. Dyssynchrony indexes based on time to peak tissue velocity (septal-lateral delay, anteroseptal-posterior delay, and SD in time to peak systolic velocity in the 12 left ventricular segments) and strain (SD of time to peak strain in 12 segments) were measured. The SD in time to peak systolic velocity in the 12 left ventricular segments was greater in group 4 (54 ms; 25th and 75th percentiles, 46 to 64 ms) than group 1 (44 ms; 25th and 75th percentiles, 28 to 53 ms; P =0.006), but there was a considerable overlap of all tissue velocity–derived indexes among 4 groups, with 40% to 68% of group 1 having values proposed for predicting the responders of cardiac resynchronization therapy. The SD of time to peak strain in 12 segments distinguished these groups with much less overlap ( P <0.01 for all pairwise comparisons). Conclusions— A substantial proportion of normal subjects have tissue velocity–derived dyssynchrony indexes higher than the cutoff value proposed for predicting beneficial effect of cardiac resynchronization therapy. Strain-derived timing index appears to be more specific for dyssynchrony in patients with systolic dysfunction and left bundle-branch block. Identifying an optimal tissue velocity– or strain-derived dyssynchrony index requires a large prospective clinical trial.