Miller, Fletcher A.

Introduction: Pulmonary valve (PV) replacement is rare, so data regarding normal hemodynamics are limited. We sought to determine the normal Doppler-derived hemodynamic profiles of various PV prostheses (PVPs) in adults. Hypothesis: Doppler-derived hemodynamic profiles of normal PVPs will vary according to prosthesis type in adult patients. Methods: We performed a retrospective review of comprehensive two dimensional and Doppler echocardiographic examinations of 327 patients (median age, 35; range 18 -83 years) with normal PVPs performed early after implantation. Data were analyzed to determine mean±SD. Results: Parasternal short axis was the most commonly used window (96%) for assessment of PVPs. For the 327 PVPs, peak instantaneous gradient was 25±11 mmHg, mean systolic gradient was 13.1±6.1 mmHg, and mean right ventricular outflow tract velocity was 0.8±0.6 m/s. Results for selected variables analyzed by prosthesis type are listed in the Table. Pericardial prostheses had significantly lower peak gradient (21±10.1 mmHg; P=0.002) compared with porcine (25±9.7 mmHg), mechanical (26±16.6 mmHg), bovine venous (34±15.5 mmHg) and homograft PVPs (35±8.4 mm Hg). Conclusions: This is the largest series reporting normal Doppler-derived hemodynamic profiles of PVPs. This study establishes normative values for Doppler-derived variables for normal PVPs implanted in adults. Pericardial prostheses had the optimal hemodynamic profile in this patient population.

Backgrounds: Left ventricular torsion (LVtor) is an integral part of systole and untwisting plays an important role in diastole. The aim of this study was to characterize LVtor and untwisting in different grades of diastolic dysfunction. Methods: We studied 135 patients with normal LV EF with various grades of diastolic dysfunction (40 group1:mild,42 group 2:moderate,and 22 group 3:severe dysfunction) and 31 controls with normal diastolic function. Apical and basal short axis rotations were measured by 2D STE. LVtor was defined as net difference between apical and basal rotation. Results: Age, gender, and EF were similar in 3 groups and control. Mitral annulus early diastolic velocity was reduced in all 3 groups (see table ). Peak LVtor was significantly greater in group 1 compared with control, group 2 and group 3. The time from peak LVtor to Mitral valve opening, and to peak early diastolic velocity were significantly delayed in group 1 compared to control (p=0.0030 and 0.0409, respectively). The twisting rate and untwisting rate were found to be highest in group 1. Conclusions: Systolic torsion and diastolic untwisting are significantly increased in patients with mild diastolic dysfunction. In patients with advanced diastolic dysfunction with increased filling pressure, torsion and untwisting are normalized. Hence, vigorous LV torsion appears to be a compensatory mechanism during an early stage of diastolic dysfunction to maintain normal filling in the setting of reduced longitudinal myocardial motion.

Background : Dyssynchrony indexes derived from time to peak systolic velocity and time to peak strain have been reported to predict left ventricular reverse remodeling (RR) after cardiac resynchronization therapy (CRT). The predictive characteristics of these indices have not been validated in a variety of clinical settings. Our objective was to determine the predictive value of strain and tissue velocity derived dyssynchrony indices for RR or clinical response to CRT in a prospective single-center CRT registry. Methods : Prospective registry of all heart failure patients (pts) undergoing CRT with echo before and 3 and 6 months after CRT. Color -coded tissue Doppler imaging in 12 segments was used to calculate the standard deviation of time to peak strain (Tϵ-SD) and time to peak systolic velocity (Tv-SD). RR was defined as a decrease in end systolic volume (ESV; biplane Simpson’s method) ≥15%. Indices were assessed with receiver-operating characteristics (ROC) analysis and the area under the curve (AUC) calculated in all pts and excluding those with atrial fibrillation at implant. Results : To date, of the first 87 patients, 4 died (classified as non-responder); 83 pts had 3 and 59 pts had 6 month echocardiography follow-up. Tϵ-SD (93%) and Tv-SD (98%) were feasible in most pts. RR occurred in 42 pts (51%) at 3 month and 32 patients (54%) at 6 month follow-up. See table . Tϵ-SD was superior to Tv-SD for prediction of RR in all pts and in those without atrial fibrillation. Findings were similar regardless of ischemic (68% of patients) or non-ischemic etiology. Neither baseline Tϵ-SD nor Tv-SD correlated with the improvement in clinical response measured by the change in six minute walk distance or peak VO 2 at 3 or 6 month after CRT (data not shown). Conclusions : In this single center experience, mechanical dyssynchrony measured by strain imaging but not tissue velocity imaging was predictive of RR. Neither index predicted clinical response.

Background: Atrial fibrillation (AF) is common in HCM yet the mechanisms are poorly understood but are likely secondary to either the consequences of left atrial structural remodeling (LASR) or myopathy, or triggers arising from pulmonary and other thoracic veins. The presence and severity of LASR as characterized by left atrial strain (LA ϵ), and its relationship to AF in HCM, has not been determined. Therefore, we measured LA ϵ and strain rate (SR) in Pts with HCM both with (AF+) and without (AF−) prior AF and compared these measures to those in age and gender matched controls without HCM or AF. Methods: Two-dimensional speckle-derived LA longitudinal peak ϵ, SR during systole (SR S ), early (SR E ) and late diastole (SR A ) were measured at the basal and mid portions of the lateral, septal, and posterior LA walls using Vector Velocity Imaging during sinus rhythm and were averaged. Results: Mean age of Pts in each of the matched groups was 56 ± 2 years (16 males; 59%). Significant left ventricular outflow tract obstruction was present in all Pts with HCM. Diastolic dysfunction was similar in both HCM groups and worse when compared to controls. Peak LA 3 , SR S , SR E , and SR A for each group is shown (table 1 ). HCM was associated with significantly lower LA ϵ and SR compared to controls. Although LA size was increased in Pts with HCM when compared to controls there was no correlation between LA size and ϵ or SR (p>0.05 for all). No differences in LA ϵ and SR were found between AF+ versus AF− Pts. Conclusion: HCM is associated with LASR as determined by decreased LA ϵ and SR. However, LA ϵ and SR were similar in AF+ versus AF− Pts suggesting that the occurrence of AF in HCM is not due to LASR alone. Table 1. Left Atrial Strain and Strain Rate in Hypertrophic Cardiomyopathy

Background: Effect of CRT on the timing of regional myocardial strain is not fully described. We aimed to explore the effect of CRT on the timing of regional myocardial strain using speckle tracking echocardiography (STE). Methods: STE and tissue Doppler imaging were performed in 91 patients before and 6 month after CRT. Time to peak longitudinal strain (Tϵ) from the onset of QRS was measured in 16 segments from three apical views. Time to peak systolic tissue velocity (Tv) was also measured in 12 basal and mid segments. Reverse remodeling was defined as 10% reduction in end-systolic volume. Results: At baseline, Tϵ and Tv demonstrated specific pattern with earlier septal and delayed lateral contraction (Figure ). Tϵ in responders showed significantly earlier timing in mid inferoseptal (p=0.003) and anteroseptal segments (base, P=0.005, mid P=0.007) than in nonresponders, whereas the timing of free wall did not differ between responders and non-responders. After CRT, Tϵ in earlier segments (inferoseptal, anteroseptal and inferior wall) prolonged significantly (p<0.001), whereas other segments did not change timing. Accordingly, SD of Tϵ in 12 segments reduced after CRT (110±46 ms vs. 81±36 ms, p<0.001). Tv did not change in all segments and SD of Tv did not improve after CRT (43±16 vs. 46±16 ms, p=0.20). Conclusions: Simultaneous electrical activation of LV free wall and septum with CRT achieves mechanical synchronization by delaying the timing of earlier contracting segment rather than directly shortening the timing in lateral wall. This could be explained by the increased wall stress on the septum as it contracts simultaneously with the opposing LV free wall. Figure. Change in Regional Timing in Strain and Peak Velocity

Background: Cardiac resynchronization therapy (CRT) improves global systolic function in left ventricle. However, the impact of CRT on regional myocardial function is less clear. The aim of this study, therefore, is to evaluate regional changes in myocardial strain after CRT. Methods: Speckle tracking echocardiography (STE) was performed in 91 patients before and 6 month after CRT. Peak longitudinal strain was measured in 18 segments at base, mid and apex in three apical views. Left ventricular end-systolic volume (ESV) was measured by biplane Simpson’s method and reverse remodeling was defined as 10 % reduction in ESV at 6 month after CRT. Results: Peak strain improved in basal and mid segments of medial walls (basal inferoseptal, anteroseptal and inferior segments, p<0.05, mid inferoseptal and inferior segments: p<0.01) in entire group after CRT, with a greater degree of improvement in CRT responders than in nonresponders (Figure ). There was no significant improvement in free wall strain, with significant reduction in basal inferolateral segment after CRT (P=0.047) in entire group. Nonresponders had significant reduction in strain at the mid anterolateral segment (P=0.004) (Figure ). Strain of the apical segments also did not improve. Conclusions: CRT induces reverse remodeling by enhancing regional myocardial function in the septum, but suppresses the function in the free wall. Lack of reverse remodeling after CRT was characterized by the reduced function in lateral segments without improvement in septal function..

Abstract Background: Left atrial (LA) function can be impaired by the atrial fibrillation (AF) ablation and might be associated with the risk of recurrence. We sought to determine whether the post-procedural changes in LA function impact the risk of recurrence following AF ablation. Methods: We retrospectively reviewed patients who underwent AF ablation between 2009 and 2011 and underwent transthoracic echocardiography before ablation, 1-day and 3-month after ablation. Peak left atrial contraction strain (PACS) and left atrial emptying fraction (LAEF) were evaluated during sinus rhythm and compared across the three time points. The primary endpoint was atrial tachyarrhythmia recurrence after ablation. Results: Out of 144 patients were enrolled (mean age 61±11 years, 77% male, 46% persistent AF). PACS and LAEF initially decreased 1-day following ablation but partially recovered within 3 months in PAF patients, with a similar trend in the PerAF patients. After median 24 months follow-up, 68 (47%) patients had recurrence. Patients with recurrence had higher PACS1-day than that in non-recurrence subjects (-10.9±5.0%%vs. -13.4±4.7, p=0.003). PACS1-day -12% distinguished recurrence cases with a sensitivity of 67.7% and specificity of 60.5%. The Kaplan-Meier curves showed significant difference in 5-year cumulative probability of recurrence between those with PACS≥ -12 % and PACS < -12% (log rank p<0.0001). Multivariate regression showed that PACS1-day was an independent risk factor of arrhythmia recurrence. Conclusions: Left atrial function deteriorates immediately following AF ablation and partially recovers in 3 months but remains abnormal in the majority of patients. PACS1-day post procedure predicts arrhythmia recurrence at long-term follow-up.

AbstractWe describe a case of a mass‐like echocardiographic density on a mechanical prosthetic aortic valve. We initially suspected a thrombus vs vegetation on transthoracic echocardiography, but after transesophageal echocardiography, the density was subsequently determined to be cavitation by reviewing the initial images in slow motion.