Decrease In End-diastolic Volume Research Articles

Challenging cardiac function post-spinal cord injury with dobutamine.

There is general consensus that spinal cord injuries (SCI) above T6 result in altered sympathetic control of the heart, which negatively influences cardiac structure and function. To by-pass disrupted circuitry and investigate cardiac responses under enhanced sympathetic activity we utilized dobutamine (DOB) stress echocardiography. Animals were divided into a T2, 25g-cm contusive SCI (SCI) or an uninjured control (CON) group. Echocardiography was performed pre-SCI and at 1, 2 and 6weeks post-SCI. Increasing doses of DOB (5, 10 & 20μg/min/kg) were infused intravenously pre-SCI and at 1 and 6weeks post-SCI. Parasternal-short axis images were used to compare group differences in systolic function and track changes in response to SCI and DOB over time. One week post-SCI, stroke volume (SV), end diastolic volume (EDV), cardiac output (CO) and ejection fraction (EF) were all reduced compared to CON and these deficits persisted to 6weeks. We also found an increase in collagen deposition at 6weeks post SCI. Pre-SCI, DOB elicited a decrease in EDV and increases in CO, EF and HR but not SV. At 6weeks following SCI, in addition to increases in CO, EF and HR, DOB also induced increases in SV. This is the first report, to our knowledge, of DOB responses in a contusive SCI model with persistent cardiac impairments. The return of CO to pre-SCI levels and the substantial increase in SV at low DOB dosages shows that impaired descending control of the heart is directly contributing to reduced resting SV after SCI.

Transapical Beating-Heart Mitral Valve Repair With an Expanded Polytetrafluoroethylene Cordal Implantation Device: Initial Clinical Experience.

Degenerative mitral valve (MV) disease is a common cause of severe mitral regurgitation (MR) and accounts for the majority of MV operations. Conventional MV surgery requires cardiopulmonary bypass, aortic cross-clamping, cardioplegia, and a thoracotomy or sternotomy and, therefore, is associated with significant disability, risks, and unpredictable rates of MV repair. Transesophageal echocardiography-guided beating-heart MV repair with expanded polytetrafluoroethylene cordal insertion has the potential to significantly reduce surgical morbidity. We report the first-in-human clinical experience with a novel preformed expanded polytetrafluoroethylene knot implantation device (Harpoon TSD-5) designed to treat degenerative MR. Through a small left thoracotomy, the device was inserted into the heart and guided by transesophageal echocardiography to the ventricular surface of the prolapsed leaflet. Multiple expanded polytetrafluoroethylene cords were anchored in the leaflet and then adjusted to the correct length to restore MV leaflet coaptation and secured at the epicardium. Eleven patients with posterior leaflet prolapse and severe MR, with mean±SD age of 65±13 years and mean ejection fraction of 69±7%, were treated with 100% procedural success. Immediate postprocedural mean MR grade was trace. At 1 month, the mean MR grade was mild with significant decreases in end-diastolic volume (139 to 107 mL; P=0.03) and left atrial volume (118 to 85 mL; P=0.04). A novel device used for beating-heart image-guided MV repair demonstrates a significant reduction in MR with favorable left ventricular and left atrial reverse remodeling. This approach has the potential to decrease invasiveness and surgical morbidity. Further follow-up is necessary to assess long-term efficacy. URL: https://clinicaltrials.gov. Unique identifier: NCT02432196.

Effect of cardiac resynchronization therapy on ventricular tachycardias in patients with dilated cardiomyopathy and severe heart failure

The aim of the study was to elucidate the effects of cardiac resynchronization therapy (CRT) on ventricular tachycardias in patients with dilated cardiomyopathy and to analyze the prospects of radionuclide diagnostic methods for prediction of life-threatening arrhythmias in the presence of therapy. The study included 70 patients (mean age 55 12 years) aged 32 to 75 years with dilated cardiomyopathy, NYHA FC III heart failure, left ventricular (LV) ejection fraction (EF) of 30.1 3.8%, and end-diastolic volume (EDV) of 220.7 50.9 mL. Group 1 comprised 35 patients (50%) diagnosed with paroxysms of ventricular tachycardia, while Group 2 consisted of 35 patients (50%) without episodes of ventricular tachycardia. After one year of CRT, positive clinical changes were documented in all patients: LV EF increased to 42.8 4.8% (p 0.001); functional class of heart failure decreased to II; LV EDV decreased to 197.9 47.8 mL (p 0.005). The patients whose EF increased by 14% and EDV decreased by 35 mL during one-year CRT had no episodes of ventricular tachycardia. The patients, whose paroxysms of ventricular tachycardia persisted during the entire period of the study, showed EF increase by 9% and EDV decrease by 13 mL. The second stage of the study consisted in evaluating the effects of myocardial metabolism defects (MMD). No ventricular tachycardia episodes were registered in patients whose MMD became less than 15% during CRT; if the size of DMM exceeded 15%, paroxysms of ventricular tachycardia were observed. Thus, efficacious CRT in patients with dilated cardiomyopathy results in a statistically significant reduction of the number of ventricular tachycardia episodes. The improvement of fatty acid metabolism contributes to a decrease in the number of ventricular tachycardia episodes in the course of CRT.

Ventricular function and cardiac reserve in contemporary Fontan patients

Background/objectiveTotal cavopulmonary connection (TCPC) has been the preferred treatment for patients with univentricular hearts. Current TCPC-techniques are the intra-atrial lateral tunnel (ILT) and the extracardiac conduit (ECC). We aimed to determine ventricular function during rest and stress, and to compare results for both techniques and for left (LV) versus right ventricular (RV) dominance. Methods99 patients, aged 12.5±4.0years underwent echocardiography and magnetic resonance imaging (MRI), and 69 patients underwent stress MRI. ResultsEchocardiography showed impaired systolic and diastolic function. MRI parameters were comparable between ILT and ECC at rest. During dobutamine there was a decrease in end-diastolic volume (EDVi) (91±21 vs. 80±20ml/m2 p<0.001). Ejection fraction (EF) and cardiac index (CI) during dobutamine were lower for ILT patients (59±11 (ILT) vs. 64±7% (ECC), p=0.027 and 4.2±1.0 (ILT) vs. 4.9±1.0L/min/m2 (ECC), p=0.006), whereas other parameters were comparable. TEI-index was higher in ILT-patients (0.72±0.27 (ILT) vs. 0.56±0.22 (ECC), p=0.002). Diastolic function was frequently impaired in patients with a dominant RV (67% (RV) vs. 39% (LV), p=0.011). Patients with dominant LV's had smaller end-systolic volume (ESVi) (40±13 (LV) vs. 47±16 (RV) ml/m2, p=0.030) and higher EF (55±8 (LV) vs. 49±9ml/m2 (RV), p=0.001) and contractility (2.3±0.8 (LV) vs. 1.9±0.7mmHg/ml/m2 (RV), p=0.050) during rest and higher EF during dobutamine (63±8 (LV) vs. 58±10ml/m2 (RV), p=0.043). ConclusionVentricular function is relatively well preserved in modern-day Fontan patients. With dobutamine stress there is a decrease in EDVi. ECC patients have higher CI and EF during stress. Patients with a dominant RV have lower systolic, including impaired contractility, and diastolic function.

Late percutaneous coronary intervention for an occluded infarct-related artery in patients with preserved infarct zone viability: A pooled analysis of cardiovascular magnetic resonance studies

The results of clinical trials assessing the effect of late opening of infarct-related artery (IRA) on left ventricular ejection fraction (LVEF) and size in stable patients are equivocal, which may be related to the fact that the presence of viability was not a requirement for randomization in these trials. The aim of the study was to assess the influence of late percutaneous coronary intervention (PCI) with optimal medical therapy (OMT) vs. OMT alone on cardiac function and remodeling in patients presenting infarct zone with preserved viability on cardiovascular magnetic resonance (CMR). The analysis included pooled data of 43 patients from 3 randomized studies. All patients underwent CMR before randomization, but only in 1 previously unpublished study was preserved viability required for randomization to treatment. Follow-up CMR was performed after 6-12 months. Late PCI with OMT led to improved LVEF (+5 ± 7% vs. -1 ± 6%, p = 0.005), decreased left ventricular end-systolic volume (-11 ± 19 mL vs. 12 ± 40 mL, p = 0.02) and a trend towards a decrease in end-diastolic volume (-7 ± 27 mL vs. 15 ± 47 mL, p = 0.07) in comparison to OMT alone. Increased LVEF and decreased left ventricular volumes were observed after the analysis was restricted to patients with left anterior descending artery (LAD) occlusion. In patients with the presence of infarct zone viability, OMT with late PCI for an occluded IRA (particularly LAD) is associated with improvement of left ventricular systolic function and size over OMT alone.

FRI0373 Decreased flow mediated dilatation and nailfold capillaroscopic findings can be predictors of digital ulcers in systemic sclerosis patients

BackgroundRaynaud Phenomenon (RP) is a clinical marker for microangiopathy. Systemic sclerosis is a chronic autoimmune disease characterized by widespread vasculophaty and tissue fibrosis. Vasculopathy includes vascular remodelling with progressive narrowing...

Isolated Rabbit Working Heart Function During Progressive Inhibition of Myocardial SERCA Activity

The extent to which sarcoplasmic reticulum Ca(2+)ATPase (SERCA) activity alone determines left ventricular (LV) pump function is unknown. To correlate SERCA activity with hemodynamic function of rabbit LV during thapsigargin perfusion. Isolated rabbit hearts were perfused in working heart configuration, and LV pump function was assessed using a pressure-volume catheter. Rapid and complete (>95%) inhibition of SERCA was associated with a moderate decrease in cardiac function (to 70%-85% of control). Further decrease in cardiac function to 50%-75% of control occurred over the next ≈ 30 minutes despite no detectable further inhibition of SERCA activity. Analysis of the 20 seconds prior to pump failure revealed a rapid decrease in end diastolic volume. Intermediate levels of SERCA function (≈ 50% of control) had only minor hemodynamic effects. Parallel experiments in field-stimulated isolated ventricular cardiomyocytes monitored intracellular Ca(2+) and cell shortening. On perfusion with thapsigargin, Ca(2+) transient amplitude and cell shortening fell to ≈ 70% of control followed by increased diastolic Ca(2+) concentration and diastolic cell shortening to achieve a new steady state. The relationship between SERCA activity and LV function in the rabbit is highly nonlinear. In the short term, only moderate effects on LV pump function were observed despite almost complete (>95%) reduction in SERCA activity. The terminal decline of function was associated with sudden sustained increase in diastolic tone comparable to the sustained contraction observed in isolated cardiomyocytes. Secondary increases of intracellular Ca(2+) and Na(+) following complete SERCA inhibition eventually limit contractile function and precipitate LV pump failure.

Diagnostic and prognostic value of gated myocardial perfusion single-photon emission computed tomography in low-risk patients with left bundle-branch block

The abnormal left ventricular activation pattern in patients with a left bundle-branch block (LBBB) frequently induces myocardial perfusion defects, decreasing the specificity of noninvasive coronary-risk stratification with stress testing. We assessed the diagnostic and prognostic impact of gated single-photon emission computed tomography (SPECT) in low-risk patients with LBBB. A total of 114 patients underwent dual-day protocol Tc-99m sestamibi gated SPECT and were divided into two subsets: without LBBB (group 1, n = 57) and with LBBB (group 2, n = 57). Sixty-eight (60%) patients had negative coronary angiography and 46 (40%) were at a low risk for coronary artery disease. The variables incorporating the extent and severity of perfusion defects were calculated: summed stress score, summed rest score and summed difference score, end-diastolic volume (EDV), end-systolic volume (ESV), and left ventricular ejection fraction. The mean variations in EDV and ESV were computed as follows: rest volume-poststress volume. Cardiac events were classified as major and minor. Gated SPECT was positive in eight (14%) patients of group 1 and 33 (58%) patients of group 2 (P<0.001). The summed stress score was significantly higher in group 2 than in group 1 (4.7 ± 4.8 vs. 0.9 ± 1.8, P<0.001); similarly, EDV and ESV were significantly higher in LBBB patients (P<0.05 in both). The mean variation in EDV was -2.21 ml for group 1 and 1.32 ml for group 2 (P<0.05). After a mean follow-up period of 32 ± 19 months, cardiac events occurred in 22 (23%) patients, six of group 1 and 16 of group 2 (12 vs. 35%, P<0.01). Functional and perfusion parameters obtained by gated SPECT are different between patients with and without LBBB. In LBBB patients, the decrease in EDV between rest and poststress could be considered an early marker of diastolic dysfunction that might anticipate left ventricular ejection fraction reduction and may have an impact on prognosis.

Abstract 9437: A Novel Index of Left Ventricular Contractility Loss Due to Mechanical Dyssynchrony, “Strain Rate Dispersion Index”, Predicts Responders to Cardiac Resynchronization Therapy

Background: Echocardiographic time-delay indices of left ventricular (LV) mechanical dyssynchrony cannot accurately predict responders to cardiac resynchronization therapy (CRT). It may be due to the limitation that they cannot reflect LV contractility wasted by dyssynchrony. We thus determined whether a novel index of LV contractility loss caused by dyssynchrony, “strain rate dispersion index (SRDI)”, measured by using speckle tracking method could better predict the response to CRT than time-delay indices. Methods: We studied 27 patients with NYHA class III or IV heart failure (HF) and low LV ejection fraction (&lt;35%) before and 6 months after CRT. In the apical 4-chamber view and mid-ventricular short-axis view, the standard deviation of time to segmental peak strain (St) among 6 segments (St-SD) was calculated as a time-delay index. SRDI was calculated as the average of segmental peak systolic strain rate (SR) minus global peak systolic SR, indicating the estimated global LV contractility loss caused by dyssynchrony. Longitudinal and circumferential indices were measured (L-St-SD and C-St-SD, L-SRDI and C-SRDI, respectively). Responder to CRT was defined as decrease of LV end-diastolic volume (ESV) &gt;15% or improvement of HF symptom (NYH A class≥1). Results: ESV decreased from 164±108 to 137±99 ml (p&lt;0.05) 6 months after CRT. Seventeen patients were identified as responders (63%). Although QRS duration and C-St-SD at baseline were comparable between responders and nonresponders, L-St-SD, L-SRDI, and C-SRDI were significantly higher in responders (L-St-SD: 153±61 vs 86±41 ms, p&lt;0.01; L-SRDI: 0.21±0.07 vs 0.11±0.06 s - 1 , p&lt;0.01; C-SRDI: 0.19±0.11 vs 0.10±0.05 s - 1 , p&lt;0.05). QRS duration did not correlate with the changes in ESV (ΔΕSV) whereas L-St-SD (r=-0.50), C-St-SD (r=-0.53), L-SRDI (r=-0.45), and C-SRDI (r=-0.53) significantly correlated with ΔESV. By multivariate analysis, C-SRDI was the single independent predictor of ΔESV (β=-0.53, p&lt;0.01). During the follow up, adverse events occurred in 8 out of 9 nonresponders; death in 2 patients and readmission due to worsening HF in 6 patients. In contrast, no such events occurred in the responders. Conclusions: SRDI could predict the response to CRT better than time-delay indices.

Autologous Bone Marrow Cells and Ischemic Cardiomyopathy

Evaluation of: Williams AR, Trachtenberg B, Velazquez DL et al. Intramyocardial stem cell injection in patients with ischemic cardiomyopathy: functional recovery and reverse remodeling. Circ. Res. 108, 792-796 (2011). Transcatheter, intramyocardial injections of bone marrow-derived cells produce reverse remodeling in large animal models of ischemic cardiomyopathy. A variety of adult stem and progenitor cells from different sources have already been examined for their potential to promote cardiac repair and regeneration after myocardial infarction. This article reviews a recent study by Williams et al. who test the hypothesis that transcatheter, intramyocardial injections of autologous bone marrow progenitor cells (mononuclear or mesenchymal stem cells) in left ventricular scar and border zone improve regional contractility of a chronic myocardial scar and that these changes predict subsequent reverse remodeling. All patients tolerated the procedure with no serious adverse events. At 1 year, cardiac MRI demonstrated a decrease in end diastolic volume, a trend toward decreased end systolic volume, decreased infarct size and improved regional left ventricular function. This article focuses on the findings and limitations of the study and provides an insight for future promising clinical trials.

Intramyocardial Stem Cell Injection in Patients With Ischemic Cardiomyopathy

Rationale: Transcatheter, intramyocardial injections of bone marrow–derived cell therapy produces reverse remodeling in large animal models of ischemic cardiomyopathy. Objective: We used cardiac MRI (CMR) in patients with left ventricular (LV) dysfunction related to remote myocardial infarction (MI) to test the hypothesis that bone marrow progenitor cell injection causes functional recovery of scarred myocardium and reverse remodeling. Methods and Results: Eight patients (aged 57.2±13.3 years) received transendocardial, intramyocardial injection of autologous bone marrow progenitor cells (mononuclear or mesenchymal stem cells) in LV scar and border zone. All patients tolerated the procedure with no serious adverse events. CMR at 1 year demonstrated a decrease in end diastolic volume (208.7±20.4 versus 167.4±7.32 mL; P =0.03), a trend toward decreased end systolic volume (142.4±16.5 versus 107.6±7.4 mL; P =0.06), decreased infarct size ( P &lt;0.05), and improved regional LV function by peak Eulerian circumferential strain in the treated infarct zone (−8.1±1.0 versus −11.4±1.3; P =0.04). Improvements in regional function were evident at 3 months, whereas the changes in chamber dimensions were not significant until 6 months. Improved regional function in the infarct zone strongly correlated with reduction of end diastolic volume ( r 2 =0.69, P =0.04) and end systolic volume ( r 2 =0.83, P =0.01). Conclusions: These data suggest that transcatheter, intramyocardial injections of autologous bone marrow progenitor cells improve regional contractility of a chronic myocardial scar, and these changes predict subsequent reverse remodeling. The findings support the potential clinical benefits of this new treatment strategy and ongoing randomized clinical trials.

Cardiac support device, restrictive mitral valve annuloplasty, and optimized medical treatment: A multimodality approach to nonischemic cardiomyopathy

Nonischemic dilated cardiomyopathy with functional mitral regurgitation carries a poor prognosis. Mitral valve surgery with implantation of a cardiac support device can treat mitral regurgitation and promote left ventricular reverse remodeling. This observational study evaluates clinical and echocardiographic outcomes of an individualized medico-surgical approach, focusing on mitral regurgitation recurrence and left ventricular reverse remodeling. Sixty-nine consecutive patients with heart failure (New York Heart Association class III/IV) with functional mitral regurgitation (grade 3+/4+) and left ventricular remodeling (end-diastolic volume 227 ± 73 mL, ejection fraction 26% ± 8%) underwent restrictive mitral annuloplasty (median ring size 26), with (n = 41) or without (n = 28) a cardiac support device and optimal postoperative medical treatment. Patients were clinically and echocardiographically evaluated at up to 3.1 years' median follow-up. Early mortality was 5.8%. Actuarial survival at 1, 2, and 5 years was 86% ± 4%, 79% ± 5%, and 63% ± 7%. New York Heart Association class improved from 3.1 ± 0.4 to 2.0 ± 0.5 (P < .01). Cardiac support device implantation in addition to mitral valve surgery, applied in patients with more advanced left ventricular remodeling, resulted in similar clinical outcome, greater left ventricular end-diastolic volume decrease (33% vs 18%; P = .007), and in a trend toward less recurrent mitral regurgitation of grade 2+ or more (actuarial freedom at 3 years 89% ± 8% vs 63% ± 11%; P = .067). An individualized medico-surgical approach to nonischemic cardiomyopathy combining restrictive mitral annuloplasty, cardiac support device implantation, and optimal medical management leads to favorable survival and improved functional status, low incidence of significant recurrent mitral regurgitation, and sustained left ventricular reverse remodeling.

Lessons from a mathematical hypothesis — modification of the endoventricular circular patch plasty

Surgical ventricular restoration has been the bailout therapy for end-stage heart failure due to ischemic cardiomyopathy in patients not suitable for cardiac transplantation. The recently concluded STICH trial has stated that surgical restoration of the left ventricle does not benefit this subgroup of patients clinically as compared with revascularization alone. The reasons for failure of this trial are multifactorial. The technique of surgical ventricular restoration employed in the STICH trial was circular endoventricular patch plasty. The various drawbacks related to this technique can be offset by a modification based on a mathematical hypothesis, which should result in a more physiological ventricular geometry, with consequent late reverse remodeling and improved left-ventricular performance. A total of 54 consecutive patients out of 102 patients with post-infarction left-ventricular aneurysms were studied before and 2 years after surgical ventricular restoration by linear endoventricular patch plasty using two-dimensional (2D) echocardiography and contrast ventriculography. Linear endoventricular patch plasty resulted in a decrease in end-diastolic volume (EDV) of 40.2 ml (95% confidence interval (CI): 33.6, 46.7) and stroke volume (SV) of 10.0 ml (95% CI: 6.6, 13.5) and increase in ejection fraction (EF) of 6.7% (95% CI: 5.5, 7.9). There was a further 14% decrease in EDV and SV (30%) at 2 years with increase in EF (20%). There was a persistent significant improvement in sphericity index. The changes in EDV and SV were linearly related (r=0.72, p<0.001) and persisted at 2 years following surgery. The change in EDV was linearly related to the EF (r=0.35, p=0.02). The left-ventricular shape analysis showed improvements in the anterior and anterolateral segments (effect size=1.1, p<0.001) with nonsignificant changes in the inferior segments, conforming to an ellipsoid geometry. Linear endoventricular patch plasty restored a physiological elliptical ventricular geometry with persistent late reverse remodeling. The decreases in EDVs following surgery were significantly linearly proportional to the decreases in SVs at rest, which conforms to the normal left-ventricular geometry.

Impact of pericardial adhesions on diastolic function as assessed by vortex formation time, a parameter of transmitral flow efficiency

BackgroundPericardial adhesions are a pathophysiological marker of constrictive pericarditis (CP), which impairs cardiac filling by limiting the total cardiac volume compliance and diastolic filling function. We studied diastolic transmitral flow efficiency as a new parameter of filling function in a pericardial adhesion animal model. We hypothesized that vortex formation time (VFT), an index of optimal efficient diastolic transmitral flow, is altered by patchy pericardial-epicardial adhesions.MethodsIn 8 open-chest pigs, the heart was exposed while preserving the pericardium. We experimentally simulated early pericardial constriction and patchy adhesions by instilling instant glue into the pericardial space and using pericardial-epicardial stitches. We studied left ventricular (LV) function and characterized intraventricular blood flow with conventional and Doppler echocardiography at baseline and following the experimental intervention.ResultsSignificant decreases in end-diastolic volume, ejection fraction, stroke volume, and late diastolic filling velocity reflected the effects of the pericardial adhesions. The mean VFT value decreased from 3.61 ± 0.47 to 2.26 ± 0.45 (P = 0.0002). Hemodynamic variables indicated the inhibiting effect of pericardial adhesion on both contraction (decrease in systolic blood pressure and +dP/dt decreased) and relaxation (decrease in the magnitude of -dP/dt and prolongation of Tau) function.ConclusionPatchy pericardial adhesions not only negatively impact LV mechanical functioning but the decrease of VFT from normal to suboptimal value suggests impairment of transmitral flow efficiency.

Effect of Cardiac Resynchronization Therapy on Reverse Remodeling and Relation to Outcome

Cardiac resynchronization therapy (CRT) plus implantation of an implantable cardioverter defibrillator (ICD) reduced the risk of death or heart failure event in patients with mildly symptomatic heart failure, left ventricular dysfunction, and wide QRS complex compared with an ICD only. We assessed echocardiographic changes in patients enrolled in the MADIT-CRT trial (Multicenter Automatic Defibrillator Implantation Trial: Cardiac Resynchronization Therapy) to evaluate whether the improvement in outcomes with CRT plus an ICD was associated with favorable alterations in cardiac size and function. A total of 1,820 patients were randomly assigned to CRT plus an ICD or to an ICD only in a 3:2 ratio. Echocardiographic studies were obtained at baseline and 12 months later in 1,372 patients. We compared changes in cardiac size and performance between treatment groups and assessed the relationship between these changes over the first year, as well as subsequent outcomes. Compared with the ICD-only group, the CRT-plus-ICD group had greater improvement in left ventricular end-diastolic volume index (-26.2 versus -7.4 mL/m(2)), left ventricular end-systolic volume index (-28.7 versus -9.1 mL/m(2)), left ventricular ejection fraction (11% versus 3%), left atrial volume index (-11.9 versus -4.7 mL/m(2)), and right ventricular fractional area change (8% versus 5%; P<0.001 for all). Improvement in end-diastolic volume at 1 year was predictive of subsequent death or heart failure, with adjustment for baseline covariates and treatment group; each 10% decrease in end-diastolic volume was associated with a 40% reduction in risk (P<0.001). CRT resulted in significant improvement in cardiac size and performance compared with an ICD-only strategy in patients with mildly symptomatic heart failure. Improvement in these measures accounted for the outcomes benefit. Clinical Trial Registration Information- URL: http://www.clinicaltrials.gov. Unique identifier: NCT00180271.

Analysis of LV Lead Position in Cardiac Resynchronization Therapy Using Different Imaging Modalities

This study sought to evaluate whether left ventricular (LV) lead position in cardiac resynchronization therapy (CRT) can be determined by myocardial deformation imaging during LV pacing and to compare imaging techniques for analysis of LV lead position. LV lead position has a significant impact on effectiveness of CRT, but clinically applicable methods to determine LV lead position are less defined. In 56 patients (53 +/- 5 years, 34 men) undergoing CRT, fluoroscopy and 2 myocardial deformation imaging-based approaches were applied to determine the LV lead position. Myocardial deformation imaging-based techniques were used to determine 1) the segment with maximal temporal difference of peak circumferential strain before and while on biventricular CRT; and 2) the segment with earliest peak systolic circumferential strain during pure LV pacing. Twelve-month echocardiography was performed to determine LV remodeling and improvement in function. Optimal LV lead position was defined as concordance or immediate neighboring of the determined LV lead position to the segment with latest systolic strain prior to CRT. LV lead position determined during LV pacing correlated to the position determined by fluoroscopy (kappa = 0.761). Patients with optimal LV lead position had greater improvement in LV ejection fraction and decrease in end-diastolic volume than those with nonoptimal LV lead position (12 +/- 4% vs. 7 +/- 3%, p < 0.001, and 28 +/- 13 ml vs. 14 +/- 8 ml, p < 0.001, respectively). Determination of the LV lead position based on myocardial deformation imaging during LV pacing showed greater discriminatory power for improvement of ejection fraction (difference optimal vs. nonoptimal lead position group: 4.64 +/- 1.01 ml; p < 0.001) than deformation imaging with biventricular pacing (3.03 +/- 1.08 ml; p = 0.007) and fluoroscopy (2.22 +/- 1.12 ml; p = 0.053). Myocardial deformation imaging during LV pacing allows determination of the LV lead position in CRT. Improvement in LV function and remodeling as indicators of optimal LV lead position can be best predicted by LV lead position analysis during LV pacing. (Left Ventricular Lead Position in Cardiac Resynchronization Therapy; NCT00748735).

Direct imaging of viable myocardium by gated SPECT in patients with ischaemic left ventricular dysfunction

The aim of the study was to evaluate a novel polar map of myocardial viability obtained by gated SPECT imaging to predict functional recovery after revascularization in patients with ischaemic left ventricular (LV) dysfunction. The study group comprised 17 patients (15 men, mean age 58 +/- 9 years) with ischaemic LV dysfunction (ejection fraction <or=40%) who underwent nitrate-enhanced gated SPECT before and 6 months after coronary revascularization. A parametric image of viable myocardium (VIA) was obtained using a semiautomated method to subtract the point-to-point motion polar map from the perfusion polar map. A parametric image of segments with functional recovery (REC) was obtained by subtracting the baseline motion polar map from the motion polar map after revascularization. Of the total 340 segments, 248 (73%) were considered viable on the basis of the VIA map. After revascularization, of 248 dysfunctional viable segments 186 (75%) showed an improvement in LV function. An increase in LV ejection fraction (from 30 +/- 10% to 42 +/- 11%, p < 0.01) and a decrease in end-diastolic volume (from 207 +/- 74 ml to 174 +/- 74 ml, p < 0.01) were observed after revascularization. Overall concordance between the VIA map and the REC map was 85%, with a k value of 0.63. Sensitivity, specificity, and positive and negative predictive values of the VIA map for predicting functional recovery were 89%, 75%, 91% and 71%, respectively. The proposed polar map of myocardial viability obtained by gated SPECT imaging accurately predicts functional recovery after coronary revascularization. Thus, a direct quantitative image of viability obtained from perfusion/function matching may be helpful for clinical decision-making in patients with ischaemic LV dysfunction.

Quantification of Left Ventricular Twisting Mechanics by Velocity Vector Imaging in an Animal Model of Pericardial Adhesions

Diagnosis of constrictive pericarditis remains clinically challenging. Untwisting of the left ventricle (LV) is essential for normal LV diastolic function. Echocardiography is able to measure LV twisting mechanics. We designed an animal model of constrictive pericarditis to determine how pericardial-epicardial adhesions impair LV twisting mechanics. In eight open-chest pigs, the heart was exposed while preserving the pericardium. We simulated early constrictive pericarditis by pericardial constriction and patchy adhesions induced with instant glue and pericardial-epicardial stitches. Using Velocity Vector Imaging™ (VVI), LV magnitudes of twisting and untwisting were measured along with hemodynamic data at baseline and after the experimental intervention. Significant decreases in end-diastolic volume, ejection fraction, stroke volume, and late diastolic filling velocity reflected the effects of the pericardial adhesions. Magnitude of LV untwisting rate decreased from –80 ± 23°/s to –26 ± 10 °/s ( p = 0.0009). LV twisting rate dropped from 78 ± 20°/s to 40 ± 8°/s ( p = 0.0039) and LV twist magnitude decreased from 9 ± 2° to 5 ± 2 ° ( p = 0.0081). Patchy pericardial adhesions are associated with reductions in LV untwisting rate and twisting magnitude, consistent with a negative impact of constrictive pericarditis on systolic and diastolic function. Impairments in LV twisting mechanics may have a diagnostic role in the detection of early stages of constrictive pericarditis. (E-mail: belohlavek.marek@mayo.edu)

Hemodynamic effects of PEEP in a porcine model of HCl‐induced mild acute lung injury

Positive end-expiratory pressure (PEEP) and sustained inspiratory insufflations (SI) during acute lung injury (ALI) are suggested to improve oxygenation and respiratory mechanics. We aimed to investigate the hemodynamic effects of PEEP with and without alveolar recruiting maneuver in a mild ALI model induced by inhalation of hydrochloric acid. Thirty-two pigs were randomly allocated into four groups (Control-PEEP, Control-SI, ALI-PEEP and ALI-SI). ALI was induced by intratracheal instillation of hydrochloric acid. PEEP values were progressively increased and decreased from 5, 10, 15 and 20 cmH2O in all groups. Three SIs maneuvers of 30 cmH2O for 20 s were applied to the assignable groups between each PEEP level. Transesophageal echocardiography (TEE), global hemodynamics, oxygenation indexes and gastric tonometry were measured 5 min after the maneuvers had been concluded and at each established value of PEEP (5, 10, 15 and 20 cmH2O). The cardiac index, ejection fraction and end-diastolic volume of right ventricle were significantly (P < 0.001) decreased with PEEP in both Control and ALI groups. Left ventricle echocardiography showed a significant decrease in end-diastolic volume at 20 cmH2O of PEEP (P < 0.001). SIs did not exert any significant hemodynamic effects either early (after 5 min) or late (after 3 h). In a mild ALI model induced by inhalation of hydrochloric acid, significant hemodynamic impairment characterized by cardiac function deterioration occurred during PEEP increment, but SI, probably due to low applied values (30 cmH2O), did not exert further negative hemodynamic effects. PEEP should be used cautiously in ALI caused by acid gastric content inhalation.

Response to Letter Regarding Article, “Role of Left Ventricular Stiffness in Heart Failure With Normal Ejection Fraction”

We would like to thank Dr Kass for his interest in our study, which investigated hemodynamic characteristics of patients with heart failure and normal ejection fraction (HFNEF).1 An important finding in our study was that with increased paced heart rates the patients in the HFNEF group showed a decrease in end-diastolic volume leading to reduced stroke volume, which limited their ability to increase cardiac output and may explain their exertional limitations. These results were in contrast to those in the control group where end-diastolic volumes and stroke …