Septal Dysfunction Research Articles

Hemodynamic assessment of congenital heart malformations with left to right shunt

Cardiac catheterization with direct measurements of pressure and saturation in cardiac chambers and great vessels and calculation of systemic and pulmonary blood fl ow, pulmonary and systemic resistance, and pulmonary vascular reactivity are the gold standard for assessing the hemodynamics of congenital heart malformations with a left to right shunt in both children and adults. They are the basis for determining the indications for surgical or interventional treatment. Assessment of the blood fl ow according to Fick’s principle and the resistance according to Ohm‘s law are the theoretical basis of hemodynamic calculations. The steps in assessing hemodynamics in a patient with a left-to-right shunt are presented consequently: pulmonary to systemic blood fl ow ratio, calculation of pulmonary vascular resistance (PVR) in case of pulmonary hypertension (PHy), and assessment of pulmonary vascular reactivity and their clinical signifi cance as well. Special attention is paid to the assessment of hemodynamics and indications for closure in elderly patients with atrial septal defect (ASD) and left ventricular dysfunction. The limitations and sources of errors in hemodynamic calculations are presented.

Segmental evaluation of right ventricular systolic function in atrial septal defect (ASD) type II patients

Abstract Introduction A left to right (LR) shunt in atrial septal defect (ASD) may cause right heart and pulmonary overfilling, at the expense of the systemic circulation. Purpose The study objective was to evaluate the impact of LR shunt on left (LV) and right ventricular (RV) filling, function, and myocardial strain by using cardiovascular magnetic resonance imaging (CMR). Methods Thirty-five ASD type secundum patients (42±18 y.o.) were compared to a control group (n=40). Cine imaging was used to calculate ventricular volumes and ejection fraction (EF), global longitudinal (GLS) and circumferential (GCS), free wall (FW) and interventricular septal (IVS) longitudinal strain. Phase-contrast imaging was used to calculate pulmonary flow to systemic flow ratio (Qp/Qs). Results Qp/Qs was 2.2±0.60 (range 1.3–3.6), which resulted in higher RV end-diastolic volume/BSA (EDVi, 152±42 vs. 82±11 ml/m2), lower LV EDVi (72±17 vs. 83±10 ml/m2), and higher RV/LV EDVi ratio (2.1±0.5 vs. 1±0.1) compared to controls (all p<0.001) [Figure 1]. Patients also presented with higher RV, but lower LV indexed stroke volumes (both p<0.001), and a strong trend toward lower RVEF (p=0.08). They demonstrated significantly lower RV GLS (p=0.03) and longitudinal IVS strain (p<0.001) [Figure 2]. RV FW strain or RV GCS did not differ among study groups. Shunt severity correlated with RV size and stroke volume, right atrial size and pulmonary trunk diameter (all p<0.001). In contrast, no correlation was identified with functional nor strain parameters. Conclusion Cardiac remodeling in ASD patients with long-standing LR shunt negatively affects RV systolic performance, which is likely related to longitudinal septal dysfunction. Funding Acknowledgement Type of funding sources: None. Figure 1Figure 2

Changes in mechanics of septal and lateral walls in patients with left bundle-branch block are related to extent of systolic dysfunction

Abstract Funding Acknowledgements Type of funding sources: Public Institution(s). Main funding source(s): Karolina Kupczynska was supported by research grant awarded by the Club 30 of the Polish Cardiac Society Background Left bundle branch block (LBBB) affects left ventricular (LV) mechanics and promotes systolic dysfunction. Purpose To analyse myocardial work (MW) and myocardial work efficiency (MWE) of the septal and LV lateral wall in healthy controls and LBBB patients with various degrees of LV dysfunction using non-invasive method. Methods Our study involved 102 healthy controls (mean age 41.5 ± 15.7 years, 45% male) and 58 LBBB patients without coronary artery disease (mean age 65 ± 13 years, 60% male) divided into 3 groups based on their LVEF: preserved (n= 27), mid-range (n= 16) and reduced (n= 15). Myocardial work parameters were estimated in septal and lateral wall by LV pressure-strain loop obtained by echocardiography. Results There were no differences between septal and lateral MW and MWE in healthy controls (p = NS). We found lower septal MW in comparison to lateral MW (p < 0.0001), but there were no differences in MWE (p = NS) in LBBB patients with preserved LVEF. Patients with LBBB and mid-range or reduced LVEF had lower MW (p < 0.0001 in both subgroups) and lower MWE (p = 0.002 and p = 0.0001, respectively) in septum compared with lateral wall. There was a progressive decrease in septal MW and MWE with the occurring of LBBB and the worsening of LVEF (figure A). Interestingly in healthy controls there was significantly lower lateral MW but higher MWE in comparison to group with LBBB and preserved LVEF. We did not detect differences between LBBB groups with preserved and mid-range LVEF, but patients with reduced LVEF had significant reduction in terms of lateral MW and MWE (figure B). Conclusions Impairment in septal myocardial work escalated according to the appearance of LBBB and LVEF loss. Septal dysfunction was compensated by the effective myocardial work of the lateral wall in LBBB patients with preserved and mid-range LVEF. Mechanical dysfunction of the lateral wall was associated with severely reduced LVEF. Abstract Figure.

Elevated septal wall stress - a driver of left ventricular dysfunction in left bundle branch block?

Abstract Funding Acknowledgements Type of funding sources: Public Institution(s). Main funding source(s): The Norwegian Health Association Background Septal dysfunction is a main feature of left bundle branch block (LBBB), and increasing wall stress is a proposed mechanism of heart failure development in LBBB patients. To try to reveal the pathophysiologic pathway from dyssynchrony to heart failure, we investigated the relationship between septal and left ventricular (LV) lateral wall stress in patients with LBBB. Hypothesis Increased septal wall stress causes septal dysfunction in LBBB. Methods We included 24 LBBB-patients (65 ± 11 years, 11 males) with LV ejection fraction (EF) ranging from 18 to 67%, and 8 healthy controls (58 ± 10 years, 4 males). Wall stress was calculated at peak LV pressure (LVP) according to the law of La Place ([LVP x radius]/[wall thickness]). Wall thickness was measured using M-mode, and regional curvature was measured in mid-ventricular shortaxis from 2D echocardiographic images. We used a previously validated non-invasive method to estimate LVP from brachial blood pressure and adjusted for valvular events. Myocardial scar was ruled out by late gadolinium enhancement cardiac magnetic resonance imaging. Results Wall stress was significantly higher in septum than LV lateral wall at peak LVP (48 ± 12 vs 37 ± 11 kPa, p < 0.01) in LBBB patients, while no difference was seen in the controls (Figure A). In patients, septal wall thickening showed a strong correlation with LVEF (r = 0.77, p < 0.01) (Figure B). Similar correlation was not significant for the LV lateral wall (r = 0.13, NS). Attenuation of septal wall thickening in LBBB-patients correlated well with increasing septal wall stress (r=-0.60, p < 0.01). Wall thickening and stress did not correlate in the LV lateral wall (r=-0.14, NS). Conclusion Increased septal wall stress is associated with reduced systolic thickening in patients with LBBB. Septal wall thickening, in contrast to LV lateral wall thickening, was correlated to global LV function. These findings suggest that septal remodeling which could have normalized septal wall stress, was not achieved and heart failure may develop. Abstract Figure.

Regional myocardial work as determinant of heart failure in left bundle branch block

Abstract Funding Acknowledgements Type of funding sources: Public Institution(s). Main funding source(s): The Norwegian Health Association Background Left bundle branch block (LBBB) worsen prognosis in heart failure patients. LBBB may also cause heart failure in otherwise healthy individuals. The mechanical changes induced by LBBB are potential determinants of heart failure in these patients, but their relation to left ventricular (LV) systolic function is incompletely understood. Purpose This study investigates the contribution of regional contractile function to heart failure in patients with LBBB. Methods In 76 patients with LBBB and 11 healthy controls, myocardial strain was measured by speckle-tracking echocardiography and myocardial work by pressure-strain analysis. Patients with ischemic heart disease or myocardial scarring were excluded. LBBB patients were stratified by LV ejection fraction (EF) >50% (EFpreserved), 36-50% (EFmid), and ≤35% (EFlow). 62 LBBB patients subsequently underwent cardiac resynchronization therapy (CRT) implantation and was re-examined at 6 months. Results Septal work was significantly and successively reduced from controls, EFpreserved, EFmid, to EFlow (1977 ± 506, 1025 ± 342, 601 ± 494 and -41 ± 303 mmHg·%, respectively, all p < 0.01) (Figure 1). There was a strong correlation (R = 0.84, p < 0.01) between septal work and LVEF. In contrast, work in the LV lateral wall was preserved in both EFpreserved (2367 ± 459 mmHg·%) and EFmid (2252 ± 449 mmHg·%) vs controls (2062 ± 459 mmHg·%, all NS). In the EFlow group, however, LV lateral wall work was reduced (1473 ± 568 mmHg·%, p < 0.01 vs controls). Thus, lateral wall function was not correlated with LVEF in patients with LVEF >35% (NS). At six month CRT septal work was markedly increased (165 ± 485 vs 1288 ± 523 mmHg·%, p < 0.01) and LV lateral wall work reduced (1730 ± 620 vs 1264 ± 490 mmHg·%, p < 0.01). LVEF increased from 32 ± 8 to 47 ± 10 % (p < 0.01). Conclusions Heart failure in LBBB patients is determined by degree of septal dysfunction. LV lateral wall function, on the other hand, is preserved in the early phase of heart failure and was only reduced in patients with severe heart failure. Further clinical studies should investigate if measuring LV lateral wall function can increase precision in patient selection for CRT. Abstract Figure.

Assessment of long-term cardiac adaptation in adult patients with type II atrial septal defect : A cardiovascular magnetic resonance (CMR) study.

In type II atrial septal defect (ASD) patients, the left-to-right (LR) shunt causes adaptation of the heart and circulation. The study objective was to evaluate with cardiovascular magnetic resonance imaging (CMR) the impact of LR shunt on left (LV) and right ventricular (RV) volumes, function, and myocardial strain. Thirty-five patients (42 ± 17years, 17 male) were compared to a control group (n = 40). Cine imaging was used to calculate ventricular volumes and ejection fraction (EF), global longitudinal (GLS) and circumferential strain (GCS), and longitudinal free wall (FWS) and interventricular septal (IVS) strain. Phase-contrast imaging was used to calculate pulmonary flow to systemic flow ratio (Qp/Qs). The LR shunt (Qp/Qs 2.2 ± 0.6) resulted in larger RV end-diastolic volume (EDVi) (152 ± 42 vs 82 ± 11ml/m2), lower LV EDVi (72 ± 16 vs 83 ± 9ml/m2), and higher RV/LV EDVi ratio (2.2 ± 0.5 vs 1.0 ± 0.1) than controls (all p < 0.001). Functionally, stroke volumes were larger in RV and lower in LV (both p < 0.001) with a strong trend toward lower RV EF in patients (p = 0.08). The LR shunt negatively impacted RV GLS (p = 0.03) but not RV GCS. Longitudinal IVS but not RV FWS were significantly lower in patients, i.e., p < 0.001, of longitudinal IVS. Shunt severity correlated with RV size and stroke volume, right atrial size, and pulmonary trunk diameter (all p < 0.001), but not with functional nor strain parameters. Long-term cardiac adaptation in ASD patients, with RV overfilling and LV underfilling, has a negative impact on systolic RV performance, a phenomenon which likely can be attributed to longitudinal dysfunction of the interventricular septum. • An LR shunt in type II ASD patients causes cardiac remodeling characterized by RV overfilling and conversely underfilling of the left ventricle. • At the long term, there is evidence of systolic dysfunction of the right ventricle in this group of patients. • Septal dysfunction underlies the observed impairment in RV function.

Evaluation and Comparison of Quantitative Right Ventricular Strain Assessment by Cardiac Magnetic Resonance in Pulmonary Hypertension Using Feature Tracking and Deformable Registration Algorithms

Deformable registration algorithms (DRA) has been used to detect left ventricular myocardial changes, however, its clinical utility in right ventricular (RV) function has not been evaluated. In this study, we aim to evaluate and compare quantitative RV strain assessment by cardiac magnetic resonance in pulmonary hypertension (PH) using feature tracking (FT) and DRA. Thirty patients were confirmed to have PH using right heart catheterization, and 16 healthy controls were evaluated with cardiac magnetic resonance. Global and segmental RV strain was measured by DRA and FT methods. Intraclass correlation coefficients (ICCs), coefficient of variation, and Bland-Altman analysis were used to assess and compare the interobserver and intraobserver variability of the DRA and FT methods. DRA was more sensitive than FT in the detection of RV circumferential and septal dysfunction. The global longitudinal strain (GLS) obtained by the two methods was reduced in mild-moderate PH patients (mean pulmonary artery pressure≤45 mm Hg), and the GLS and global circumferential strain (GCS) were reduced in severe PH patients (mean pulmonary artery pressure >45 mm Hg). DRA and FT methods demonstrate similar observer agreement in global strain using ICC (ICC greater than 0.90), but RV strain derived from DRA had lower variability using COV ([8%-14%] for DRA versus [11%-39%] for FT).For segmental longitudinal strain, DRA showed higher ICC and lower COV compared with that of the FT method. Correlations between RVEF and RV global strain parameters were strong (p < 0.01):GLS-DRA, r = -0.696; GLS-FT, r = -0.832; GCS-DRA, r = -0.745; and GCS-FT, r = -0.817. GLS-DRA was weakly correlated with mPAP (r = 0.385, p < 0.05).In multiple linear regression analysis, RVEF and mPAP were independent predictors of GLS-DRA (R2 = 0.57, p < 0.01). The DRA method is more sensitive and robust for RV myocardial strain measurements than FT method.

102 Different mechanics of septal and lateral walls and their effects on left ventricular ejection fraction in patients with left bundle-branch block

Abstract Funding Acknowledgements Karolina Kupczynska was supported by research grant awarded by the Club 30 of the Polish Cardiac Society Background Left bundle branch block (LBBB) impairs left ventricular (LV) mechanics and can lead to systolic dysfunction. However, LV mechanical changes that differentiate LBBB patients with preserved and reduced LV ejection fraction (LVEF) remain to be clarified. Purpose To measure myocardial work (MWI) and myocardial work efficiency (MWE) of the septal and LV lateral wall in patients with LBBB and various degrees of LV dysfunction using non-invasive strain-derived method. Methods Fifty-eight LBBB patients without coronary artery disease (mean age 65 ± 13 years, 60% male) were divided into 4 groups based on their LVEF according to current recommendations for cardiac chamber quantification (figure A): normal (n= 25), mildly (n= 16), moderately (n= 11), and severely (n= 6) reduced LVEF. Septal and lateral wall MWI and MWE were estimated by LV pressure-strain loop obtained by echocardiography. Results Both MWI (787 mmHg%, 95% CI 651-924 vs 1956 mmHg%, 95% CI 1758-2154; p &amp;lt; 0.0001) and MWE (71%, 95% CI 66-76 vs 85%, 95% CI 82-87; p = 0.0001) were lower in the septum than in the lateral wall. There was a progressive decrease in septal MWI and MWE with the worsening of LVEF (figure B). Conversely, MWI and MWE of the lateral wall were preserved in patients with normal, mildly and moderately reduced LVEF groups. A significant reduction of MWI and MWE in the lateral wall was detected only in patients with severely reduced LVEF (figure C). Conclusion In patients with LBBB, impairment in septal myocardial work escalates according to LVEF loss. Septal dysfunction was compensated by the effective myocardial work of the lateral wall in patients with normal, mildly and moderately reduced LVEF. Mechanical dysfunction of the lateral wall was associated with severe reduction of LVEF. Abstract 102 Figure.

P1535 Interventricular interaction can result in right ventricular dysfunction in interventricular septum involved myocardial infarction patient

Abstract Background Previous studies revealed that interventricular septal thickness is related to right ventricular dysfunction after anterior myocardial infarction. This finding suggest that interventricular septal function can affect right ventricular function in myocardial infarction patients. We assumed that right ventricular free wall strain values measured using dedicated software can be affected in the setting of ischemic insult on interventricular septum in long-term follow up. Methods The patients diagnosed as acute myocardial infarction due to left anterior descending artery disease who underwent successful revascularization were enrolled. Echocardiographic exams were performed at least 2 times, within 72 hours and 1 year after the revascularization. Strain values of interventricular septum and right ventricular free wall were derived from the raw-dicom images. The analysis was performed using the dedicated software for the measurement of right ventricular strain. Results Total 65 patients were enrolled. The values of global left ventricular strain were increased after the follow up. There were no changes in global longitudinal strain of the right ventricle. But longitudinal stain values acquired from right ventricular free walls were decreased even the strain values measured at left ventricle and interventricular septum were improved. Conclusion Interventricular septal dysfunction due to ischemic injury can affect long term right ventricular dysfunction. This finding suggests the interventricular dependence between cardiac chambers and can provide the development of heart failure in myocardial infarction patient even after the successful revascularization. Strain values of both ventricles Left ventricle after revascularization (n = 65) 1 year later (n = 65) P values Global longitudinal strain (%) -12.84 ± 4.50 -15.62 ± 4.45 &amp;lt;0.001 Septal longitudinal strain (%) -10.77 ± 5.96 -14.02 ± 5.26 &amp;lt;0.001 Right ventricle Global longitudinal strain (%) -19.36 ± 4.57 -19.47 ± 4.83 0.872 Septal longitudinal strain (%) -14.82 ± 4.48 -16.43 ± 6.03 0.055 Free wall longitudinal strain (%) -20.23 ± 5.33 -17.82 ± 5.70 0.010 Abstract P1535 Figure. Right ventricular segmental strain

P602Septal function and viability determine response to cardiac resynchronization therapy

Abstract Introduction Cardiac resynchronization therapy (CRT) has evolved as an important treatment in patients with symptomatic heart failure, reduced left ventricular (LV) ejection fraction and wide QRS. However, as one third of patients do not benefit from the therapy, there is need for better selection criteria. Previous studies have shown an association between recovery of septal function and response to CRT. Purpose To test the hypothesis that septal dysfunction in the absence of scar predicts response to CRT. Methods In 121 patients undergoing CRT implantation according to current European Society of Cardiology guidelines, we performed speckle-tracking echocardiography and estimated LV pressure non-invasively based on a method recently innovated in our lab. Pressure-strain analysis was used to calculate myocardial work. Septal dysfunction with asymmetric LV workload was calculated as the difference between LV lateral wall and septal work. Late gadolinium enhancement cardiac magnetic resonance imaging (LGE-CMR) was performed to assess septal scar. CRT response was defined as ≥15% reduction of LV end systolic volume by echocardiography at 6 months follow-up. Results Eighty-eight patients (73%) responded to CRT at 6 months follow-up. Multivariate logistic regression analysis including lateral-to-septal work difference, septal scar, QRS duration and QRS morphology found that only lateral-to-septal work difference and septal scar were significant predictors of CRT response (both p&lt;0.005). Using logistic regression and receiver operating characteristic (ROC) curve analysis, we found that the combined approach of these two parameters identified CRT responders with a sensitivity of 86% and a specificity of 82%. The area under the curve (AUC) for CRT response prediction was 0.85 (95% CI: 0.76–0.94) (Figure). In comparison, the AUC value for QRS duration was 0.63 (95% CI: 0.52–0.75). Furthermore, for the subgroup of patients with QRS duration 120–150 ms (n=27), the AUC value for lateral-to-septal work difference in combination with septal scar was 0.90 (95% CI: 0.78–1.00). Conclusions A multimodality approach with strain echocardiography and LGE-CMR was able to detect CRT responders with high accuracy, also in the subset of patients with intermediate QRS duration. A dysfunctional but viable septum appears to be an ideal target for CRT.

Interventricular Septal Dysfunction Due to Myocardial Infraction Can Result in Right Ventricular Failure in Long Term Follow Up

Background Diastolic functional parameters and interventricular septal thickness are related to right ventricular dysfunction after anterior myocardial infarction. This finding suggest that interventricular septal function can affect right ventricular function in myocardial infarction patients. We measured right ventricular free wall strain using dedicated software whether the ischemic insult on interventricular septum can affect the long-term right ventricular function, which is important parameter for the development of heart failure. Methods The patients diagnosed as acute myocardial infarction due to left anterior descending artery disease who underwent successful revascularization were enrolled. Echocardiographic exams were performed 2 times, within 72 hours and 1 year after the revascularization. Strain values of interventricular septum and right ventricular free wall were derived from the Dicom images. And the analysis was performed using the dedicated software for the measurement of right ventricular strain. Results Total 53 patients were enrolled. The values of global left ventricular strain were increased after the follow up. There were no changes in global longitudinal strain of the right ventricle. But longitudinal stain values acquired from right ventricular free walls were decreased even the improved left ventricular strain values. Conclusions Interventricular septal dysfunction due to ischemic injury resulted from anterior myocardial infarction can affect long term right ventricular dysfunction. This finding suggests the interventricular dependence between cardiac chambers and can provide the development of heart failure in myocardial infarction patient after the successful revascularization.

Myocardial protection: a forgotten modality.

The goals of a cardiac surgical procedure are both technical excellence and complete protection of cardiac function. Cardioplegia is used almost universally to protect the heart and provide a quiet bloodless field for surgical accuracy. Yet, despite the importance of myocardial protection in cardiac surgery, manuscripts or dedicated sessions at major meetings on this subject have become relatively rare, as though contemporary techniques now make them unnecessary. Nevertheless, septal dysfunction and haemodynamic support (inotropes, intra-aortic balloon pump, assist devices) are common in postoperative patients, indicating that myocardial damage following cardiac surgery is still prevalent with current cardioplegic techniques and solutions. This article first describes why cardiac enzymes and septal function are the ideal markers for determining the adequacy of myocardial protection. It also describes the underappreciated consequences of postoperative cardiac enzyme release or septal dysfunction (which currently occurs in 40-80% of patients) from inadequate protection, and how they directly correlate with early and especially late mortality. Finally, it reviews the various myocardial protection techniques available to provide a detailed understanding of the cardioplegic methods that can be utilized to protect the heart. This will allow surgeons to critically assess their current method of protection and, if needed, make necessary changes to provide their patients with optimal protection.

Ventricular interactions and electromechanical dyssynchrony after Ross and Ross-Konno operations

ObjectivesRoss and Ross-Konno operations are associated with the inherent risk of residual ventricular septal dysfunction and injury to the conduction system. However, comprehensive biventricular functional outcomes on magnetic resonance imaging after Ross and Ross-Konno procedures are unknown. The purpose of this study was to evaluate and compare the degree of electrical and mechanical dyssynchrony using cardiac magnetic resonance imaging in patients late after Ross and Ross-Konno operations. MethodsPatients following Ross operation (n = 16), Ross-Konno operation (n = 13), and healthy controls (n = 12) underwent cardiac magnetic resonance imaging strain deformation analysis to quantify left ventricular (LV) intraventricular dyssynchrony and right ventricular (RV)–LV interventricular dyssynchrony. Mechanical dyssynchrony indices were correlated with the degree of electrical dyssynchrony as assessed by QRS duration, as well as with magnetic resonance imaging-derived biventricular and autograft regurgitation parameters. ResultsPatients in the Ross and Ross-Konno groups had reduced LV global longitudinal strain when compared with controls (both P values < .01). Both Ross (P < .05) and Ross-Konno (P < .01) groups demonstrated increased RV–LV interventricular dyssynchrony compared with controls. Patients in the Ross-Konno group also had increased septal LV intraventricular dyssynchrony when compared with control and Ross groups (both P values < .01). The global LV intramechanical dyssynchrony strongly correlated with QRS duration (R = 0.716; P < .001). There was no association between mechanical dyssynchrony and aortic regurgitation fraction. ConclusionsLong-term follow-up of patients who underwent Ross and Ross-Konno operations demonstrates reduced LV global longitudinal strain suggestive of chronically increased afterload independent of autograft function. Additionally, Ross-Konno operation is associated with impaired LV intraventricular mechanics and electrical dyssynchrony.

Effect of ingesting carbohydrate only or carbohydrate plus casein protein hydrolysate during a multiday cycling race on left ventricular function, plasma volume expansion and cardiac biomarkers

Multiday racing causes mild left ventricular (LV) dysfunction from day 1 that persists on successive days. We evaluated ingesting casein protein hydrolysate-carbohydrate (PRO) compared with carbohydrate-only (CHO) during a 3-day mountain bike race. Eighteen male cyclists were randomly assigned to ingest 6.7% carbohydrate without (CHO) or with 1.3% casein hydrolysate (PRO) during racing (~ 4-5h/day; 68/71/71km). Conventional LV echocardiography, plasma albumin content, plasma volume (PV) and blood biomarkers were measured before day 1 and post race on day 3. Fourteen cyclists (n = 7 per group) completed the race. PV increased in CHO (mean increase (95% CI), 10.2% (0.1to 20.2)%, p = 0.045) but not in PRO (0.4% (- 6.1 to 6.9)%). Early diastolic transmitral blood flow (E) was unchanged but deceleration time from peak E increased post race (CHO: 46.7 (11.8to 81.6)ms, p = 0.019; PRO: 24.2 (- 0.5 to 48.9)ms, p = 0.054), suggesting impaired LV relaxation. Tissue Doppler mitral annular velocity was unchanged in CHO, but in PRO septal early-to-late diastolic ratio decreased (p = 0.016) and was compensated by increased lateral early (p = 0.034) and late (p = 0.012) velocities. Systolic function was preserved in both groups; with increased systolic lateral wall velocity in PRO (p = 0.002). Effect size increase in serum creatine kinase (CK) activity, CK-MB and C-reactive protein concentrations was less in PRO than CHO (Cohen's d mean ± SD, PRO: 2.91 ± 2.07; CHO: 7.56 ± 4.81, p = 0.046). Ingesting casein hydrolysate with carbohydrate during a 3-day race prevented secondary hypervolemia and failed to curb impaired LV relaxation despite reducing tissue damage and inflammatory biomarkers. Without PV expansion, systolic function was preserved by lateral wall compensating for septal wall dysfunction.

Dysfunction of the systemic right ventricle after atrial switch: physiological implications of altered septal geometry and load.

Atrial switch operation in patients with transposition of the great arteries (TGA) leads to leftward shift and changes the geometry of the interventricular septum. By including the implications of regional work and septal curvature, this study investigates if changes in septal function and geometry contribute to reduced function of the systemic right ventricle (RV) in adult TGA patients. Regional myocardial work estimation has been possible by applying a recently developed method for noninvasive work calculation based on echocardiography. In 14 TGA patients (32 ± 6 yr, means ± SD) and 14 healthy controls, systemic ventricular systolic strains were measured by speckle tracking echocardiography and regional work was calculated by pressure-strain analysis. In TGA patients, septal longitudinal strain was reduced to -14 ± 2 vs. -20 ± 2% in controls ( P < 0.01) and septal work was reduced from 2,046 ± 318 to 1,146 ± 260 mmHg·% ( P < 0.01). Septal circumferential strain measured in a subgroup of patients was reduced to -11 ± 3 vs. -27 ± 3% in controls ( P < 0.01), and a reduction of septal work (540 ± 273 vs. 2,663 ± 459 mmHg·%) was seen ( P < 0.01). These reductions were in part attributed to elevated afterload due to increased radius of curvature of the leftward shifted septum. To conclude, in this mechanistic study we demonstrate that septal dysfunction contributes to failure of the systemic RV after atrial switch in TGA patients. This is potentially a long-term response to increased afterload due to a flatter septum and suggests that medical therapy that counteracts septal flattening may improve function of the systemic RV. NEW & NOTEWORTHY We have demonstrated that transposition of the great arteries patients with systemic right ventricles (RVs) have reduced function of the interventricular septum (IVS). Since the IVS is constructed to eject into the systemic circulation, it may seem unexpected that it does not maintain function when being part of the systemic RV. By applying the principles of regional work, wall tension, and geometry, we have identified unfavorable working conditions for the IVS when the RV adapts to systemic pressures.

ALTERED RIGHT VENTRICULAR CONTRACTILE PATTERN AFTER CARDIAC SURGERY: A RETROSPECTIVE STUDY

Diminished right ventricular (RV) longitudinal contraction and septal dysfunction after cardiac surgery are well-known phenomenon, but they are not well understood. We hypothesized that reduction in RV longitudinal contraction, assessed by tricuspid annular plane systolic excursion (TAPSE) or

Current topics in surgery for multiple ventricular septal defects.

In this review article, we describe several topics, including the sandwich technique, the transatrial re-endocardialization technique, the limited apical left ventriculotomy approach and device closure. The sandwich technique was introduced for the closure of muscular ventricular septal defects (VSD) by sandwiching the septum between two felt patches placed in the left and right ventricle. This technique requires neither the transection of muscular trabeculae nor ventriculotomy. Although the sandwich technique has resulted in the improvement of surgical outcomes, cases of postoperative cardiac dysfunction have been reported. Multiple smaller VSDs have been closed with transatrial re-endocardialization. Septal dysfunction may be avoided through this technique, in which the septal trabeculae are approximated in two layers of superficial, endocardial running sutures. Recently, a number of reports have recommended a limited apical left ventriculotomy approach. With this technique, a much shorter incision of around 1cm at the apex of the left ventricle may be sufficient for achieving the complete closure of apical muscular VSDs. The transcatheter or perventricular device closure of muscular VSDs has increasingly been performed with good results. Although favorable early and mid-term results of device closure have been reported, this method is not always safer or less invasive than surgical closure. Long-term evaluations should be performed to determine whether the right and left ventricular functions are affected by treatment with relatively large devices in the heart.

Altered right ventricular contractile pattern after cardiac surgery: monitoring of septal function is essential.

Assessment of right ventricular (RV) function is important in the management of various forms of cardiovascular disease. Accurately assessing RV volume and systolic function is a challenge in day-to-day clinical practice due to its complex geometry. Tricuspid annular plane systolic excursion (TAPSE) and systolic excursion velocity (S') have been reviewed to further assess their suitability and objectivity in evaluating RV function. Multiple studies have validated their diagnostic and prognostic values in numerous pathologic conditions. Diminished longitudinal contraction after cardiothoracic surgery is a well-known phenomenon, but it is not well validated. Despite significant reduction in RV performance along the long-axis assessed by TAPSE and S' after cardiac surgery, RV ejection fractions did not change as well as the left ventricular parameters and exercise capacity. RV contractile patterns were markedly altered with decreased longitudinal shortening and increased transverse shortening, which are likely resulted from the septal damage during cardiac surgery. The septum is essential for RV performance due to its oblique fiber orientation. This allows ventricular twisting, which is a vital mechanism against increased pulmonary vascular resistance. The septum function along with TAPSE and S' should be adequately assessed during cardiac surgery, and evidence of septal dysfunction should lead to reevaluation of myocardial protection methods.

Comprehensive Assessment of Right Ventricular Function in Patients with Pulmonary Hypertension with Global Longitudinal Peak Systolic Strain Derived from Multiple Right Ventricular Views

Right ventricular (RV) function is a strong predictor of mortality in pulmonary hypertension (PH), but two-dimensional (2D) echocardiography-derived assessments of RV function that could aid in risk assessment and management of patients with PH are of limited utility. RV longitudinal peak systolic strain (RVLS) derived from 2D speckle-tracking echocardiography is a relatively novel method for quantifying RV function but typically is derived from a single apical four-chamber view of the right ventricle and may have inherent limitations. The objective of this study was to determine the utility of regional and global RVLS calculated from multiple views of the right ventricle to comprehensively assess RV function in a cohort of patients with PH. Regional and global RVLS were obtained from multiple views of the right ventricle (centered on the right ventricle-focused apical position) in 40 patients with PH, defined as a mean pulmonary artery pressure ≥25 mm Hg, most of whom also had pulmonary capillary wedge pressures ≤ 15 mm Hg and were thus defined as having pulmonary arterial hypertension. This was compared with other 2D echocardiography-derived parameters of RV function and functional parameters. Global RVLS calculated from multiple views had a superior correlation with 6-min walk distance compared with other parameters of RV function, including tricuspid annular plane systolic excursion, RV myocardial performance index, and fractional area change. Although global RVLS calculated from multiple views displayed a similar correlation with 6-min walk distance as global RVLS calculated from a single four-chamber view, analysis of regional strains provided by multiple views identified distinct patterns of RV dysfunction, consisting of global, free wall, or septal dysfunction, that were associated with specific clinical characteristics. Global RVLS derived from multiple right ventricle-focused views yields a comprehensive quantitative assessment of regional and global RV function that correlates moderately with functional parameters and may be useful in the assessment of PH. Distinct patterns of regional RV dysfunction are associated with different clinical characteristics.

Ventricular Septal Dysfunction After Surgical Closure of Multiple Ventricular Septal Defects

We assessed the global and regional ventricular septal functions using conventional echocardiography and two-dimensional speckle tracking imaging in children with postoperative multiple ventricular septal defects. Thirty-six children were studied: 16 with postoperative multiple ventricular septal defects and 20 normal control subjects. In children with multiple ventricular septal defects, 60 ventricular septal defects were closed using one of three different techniques (patch closure, the sandwich technique, direct closure). Speckle tracking imaging was applied to three short-axis echocardiographic images. The total patch area used in the multiple ventricular septal defects group was correlated with the postoperative ejection fraction (r=0.703) and Tei index (r=0.778). The global septal peak systolic radial displacement and global septal peak systolic radial strain in the multiple ventricular septal defects group were significantly lower than those observed in the control subjects. The peak systolic radial strain in the segments closed with patches and the peak systolic radial displacement in the segments closed with the felt sandwich technique were significantly lower than those observed in the intact septal segments. No significant regional functional depressions were identified in the segments that were closed directly. The postoperative ventricular global and septal functions were significantly reduced in children with multiple ventricular septal defects, especially in the cases with complex congenital heart disease and that were closed with large prosthetic materials. These results suggest that an effort to minimize the use of patch materials may lead to preserved postoperative ventricular function.