Sharon Howell

Evaluation of Right Intraventricular Dyssynchrony by Two-Dimensional Strain Echocardiography in Patients With Pulmonary Arterial Hypertension

BACKGROUND Right ventricular (RV) function has major prognostic implications for patients with pulmonary arterial hypertension (PAH). Intraventricular dyssynchrony might play an important role in RV dysfunction in these patients. METHODS Thirty-six patients with PAH without right bundle branch block (mean age 44 +/- 14 yr, 24 women) and 39 controls (mean age 43 +/- 18 yr, 26 women) were evaluated. Global and segmental RV longitudinal deformation parameters were recorded by 2-dimensional strain echocardiography from apical 4-chamber views using a 6-segment RV model. The standard deviation of the heart rate-corrected intervals from QRS onset to peak strain for the 6 segments (RV-SD(6)) was used to quantify right intraventricular dyssynchrony. RESULTS RV-SD(6) was significantly higher in patients with PAH compared with controls (63 +/- 21 vs 25 +/- 15ms, P < .001). Dyssynchrony in patients with PAH was found to derive mainly from delayed contraction of the basal and mid RV free wall. In patients with PAH, RV-SD(6) was strongly correlated with RV fractional area change (beta = -.519, P = .002), RV myocardial performance index (beta = .427, P = .009), and RV global strain (beta = .512, P = .002); in models controlling for RV systolic pressure, RV size, and QRS duration, RV-SD(6) was still an independent predictor of RV fractional area change (beta = -.426, P = .005) and RV global strain (beta = .358, P = .031). RV function was significantly worse in the subgroup of patients with PAH (n = 25) with RV-SD(6) > 55 ms (the upper 95% limit in controls). CONCLUSION Right intraventricular dyssynchrony, as quantified by 2-dimensional strain echocardiography, is prevalent in PAH and is associated with more pronounced RV dysfunction. The clinical implications of these findings remain to be determined in follow-up studies.

Use of Balloon Aortic Valvuloplasty to Size the Aortic Annulus Before Implantation of a Balloon-Expandable Transcatheter Heart Valve

OBJECTIVES Our aim was to describe the use of balloon aortic valvuloplasty (BAV) to select proper transcatheter heart valve (THV) size. BACKGROUND Transesophageal echocardiogram (TEE) measurement alone of the aortic annulus may not be adequate to select a THV size. BAV can more accurately size the aortic annulus. We report our experience using this strategy in patients undergoing THV implantation. METHODS Twenty-seven patients underwent sizing of the aortic annulus by BAV and TEE. We implanted the minimal THV size that was greater than the annulus measured by BAV. RESULTS The annulus measured by TEE was 21.3 +/- 1.6 mm and by BAV was 22.6 +/- 1.8 mm (p < 0.001). The number of balloon inflations was 2.7 +/- 0.7 (range 2 to 4), and the balloon sizes used were 22.0 +/- 1.8 mm (range 20 to 25 mm). Fourteen patients (52%) required upsizing of the initial balloon suggested by TEE; rapid pacing duration was 8 +/- 1.3 s (range 6 to 11 s). No change in aortic insufficiency or hemodynamic instability occurred with BAV. Fifteen patients (56%) received a 23-mm THV; 12 patients a 26-mm THV. No coronary occlusion, annular damage, or THV embolization occurred. Paravalvular leak was grade <or=1 in all patients. In 7 patients (26%), balloon sizing resulted in selection of a specific THV size that could not be done by TEE alone. CONCLUSIONS BAV sizing of the aortic annulus is safe and is an important adjunct to TEE when selecting THV size. Implanting the minimal THV greater than the BAV annulus size resulted in no adverse events. These data suggest that use of BAV for THV selection may improve the safety and efficacy of THV implantation.

Correlates of Tricuspid Regurgitation as Determined by 3D Echocardiography: Pulmonary Arterial Pressure, Ventricle Geometry, Annular Dilatation, and Papillary Muscle Displacement

Background— While it is understood that annular dilatation contributes to tricuspid regurgitation (TR), other factors are less clear. The geometry of the right ventricle (RV) and left ventricle (LV) may alter tricuspid annulus size and papillary muscle (PM) positions leading to TR. Methods and Results— Three-dimensional echocardiographic images were obtained at Emory University Hospital using a GE Vivid 7 ultrasound system. End-diastolic area was used to classify ventricle geometry: control (n=21), isolated RV dilatation (n=17), isolated LV dilatation (n=13), and both RV and LV dilatation (n=13). GE EchoPAC was used to measure annulus area and position of the PM tips. Patients with RV dilatation had significant (P⩽ 0.05) displacement of all PMs apically and the septal PM and posterior PM away from the center of the RV toward the LV. Patients with LV dilatation had significant (P⩽0.05) apical displacement of the anterior PM. Pulmonary arterial pressure (r=0.66), annulus area (r=0.51), apical displacement of the anterior PM (r=0.26), posterior PM (r=0.49), and septal PM (r=0.40), lateral displacement of the septal PM (r=0.37) and posterior PM (r=0.40), and tenting area and height (r=0.54, 0.49), were significantly (P⩽0.05) correlated to the grade of TR. Ventricle classification (r=0.46) and RV end-diastolic area (r=0.48) also were correlated with the grade of TR. A regression analysis found ventricle classification (P=0.001), pulmonary arterial pressure (P⩽0.001) annulus area (P=0.027), and apical displacement of the anterior PM (P=0.061) to be associated with the grade of TR. Conclusions— Alterations in ventricular geometry can lead to TR by altering both tricuspid annulus size and PM position. Understanding these geometric interactions with the aim of correcting pathological alterations of the tricuspid valve apparatus may lead to more robust repairs.

Transesophageal echocardiography to help position and deploy a transcatheter heart valve.

TRANSCATHETER AORTIC VALVE IMPLANTATION (TAVI) IS A CLINICALLY ACCEPTED PRACTICE IN EUROPE for patients with high or prohibitive surgical risk and is undergoing clinical investigation in the U.S. and Canada. Some investigators have utilized transesophageal echocardiography (TEE) to select

GLOBAL LONGITUDINAL STRAIN IMPROVEMENT POST-TRANSCATHETER AORTIC VALVE REPLACEMENT CORRELATES WITH BASELINE STROKE VOLUME INDEX IN PATIENTS WITH LOW FLOW SEVERE AORTIC STENOSIS REGARDLESS LEFT VENTRICULAR EJECTION FRACTION

Severe Aortic stenosis leads to myocardial eccentric hypertrophy, remodeling and fibrosis. Speckle tracking strain imaging is reflective of myocardial deformation and is more sensitive to regional and global LV dysfunction. Changes in global longitudinal strain (GLS) of the LV post-transcatheter

DOBUTAMINE STRESS ECHOCARDIOGRAPHY RISK-STRATIFIES WOMEN WITH LOW-GRADIENT AORTIC STENOSIS UNDERGOING TRANSCATHETER AORTIC VALVE REPLACEMENT

Patients with severe aortic stenosis and low mean transvalvular gradient have poor outcomes, with an estimated 30 day post-surgical Aortic Valve Replacement (AVR) mortality of 21%. Low Dose Dobutamine Stress Echocardiography (LD-DSE) is performed in these patients for further risk stratification by