Assessment of the right ventricle by echocardiography: a primer for cardiac sonographers

Aiming to Preserve Pulmonary Valve Function in Tetralogy of Fallot Repair: Comparing a New Approach to Traditional Management

Pulmonary valve (PV) incompetence following transannular patch (TAP) repair of tetralogy of Fallot (TOF) results in long-term morbidity and mortality. Valve-sparing repairs have recently gained recognition; however, they may be associated with residual pulmonary stenosis (PS) in patients with small PV z scores. We sought to determine whether a repair that increases the PV annulus and augments the valve leaflet with a biomaterial would result in annular growth and in longer duration of valve competence compared with TAP. Eighty patients (median age 136 days, range 4-350) who underwent surgical repair of TOF between 2010 and 2014 were included in the study. Patients were divided into three groups based on the PV intervention: balloon dilation/valvotomy (n = 29), valve-sparing transannular repair (VSTAR) (n = 19) and TAP (n = 32). Intraoperative, early postoperative and midterm follow-up echocardiographic data (median 19 months, range 1-59) were obtained. The primary outcomes were the presence and severity of pulmonary regurgitation and/or PS. Compared with TAP, VSTAR patients demonstrated significantly less severe PR with 100 % freedom of severe PR immediately post-op (vs. 0 % in TAP), 60 % at 6 months and 20 % at 20 months. There were no differences in PS between VSTAR and TAP at follow-up. A subgroup analysis of the VSTAR group was performed. PV z scores were calculated and fit to a random effects model. Patient data fit the model closely, predicting a reproducible increase in valve annulus size over time. With better short-term and comparable midterm results, VSTAR may be appropriate for TOF repair in patients with small PV that would conventionally require a TAP.

Treatment of Obstructive Sleep Apnea in Young and Middle-Aged Adults: Effects of Positive Airway Pressure and Compliance on Arterial Stiffness, Endothelial Function, and Cardiac Hemodynamics

Background

The cardiovascular effects of positive airway pressure (PAP) therapy in obstructive sleep apnea (OSA) patients are not clear because of confounding by comorbid conditions.

Methods and Results

Prospective interventional study of PAP therapy and withdrawal. Apnea Hypopnea Index (AHI; events/hour of sleep) was determined from polysomnography. Central aortic blood pressures (BPs), Aortic Augmentation Index (AAIx), and central (PWV_c‐f) and peripheral pulse wave (PWV_c‐r) velocities were determined by applanation tonometry. Echocardiography and brachial artery reactivity testing were performed at baseline, after 4 and 12 weeks of PAP therapy, and 1 week after PAP withdrawal. The 84 participants were mean (SD) 41.1 (7.6) years old and had 39.8 (24.5) AHI events/hour. After 4 weeks post‐PAP initiation and sustained after 12 weeks, subjects experienced decreases in central systolic BP (P=0.008), diastolic BP, mean BP, AAIx, and PWV_c‐r, and brachial artery dilation (all P<0.001), as well as improvements in left ventricular diastolic function and systemic and pulmonary vascular resistance. In adjusted models, PAP use (hours/night) predicted reductions in diastolic BP (β=−0.65 [SE, 0.32] mm Hg/hour; P=0.045), AAIx (β=−0.53 [0.27] %/hour; P=0.049) and PWV_c‐r (β=−0.13 [0.05] m·s⁻¹/hour; P=0.007), and improved brachial artery flow‐mediated dilation (β=0.31 [0.14] %/hour use; P=0.015). After 1 week of PAP withdrawal, brachial diameter, diastolic BP, mean BP, AAIx, and heart rate increased (P≤0.05).

Conclusions

PAP therapy reduces arterial tone and improves endothelial and diastolic function in young to middle‐aged adults. This positive effect is observed after 4 weeks and depends on hours of use, but reverts quickly with PAP withdrawal.

Clinical Trial Registration

URL: https://clinicaltrials.gov/. Unique identifier: NCT01317329.

Restrictive right ventricular performance assessed by cardiac magnetic resonance after balloon valvuloplasty of critical pulmonary valve stenosis

BACKGROUND

Little data are published about right ventricular diastolic performance in patients with critical pulmonary valve stenosis after balloon pulmonary valvuloplasty thus far.

METHODS

A total of 44 patients with isolated critical pulmonary valve stenosis who had undergone balloon valvuloplasty with haemodynamic recordings were enrolled to the study; 33 patients who came for follow-up underwent further imaging by echocardiography after 6 months and their right ventricular functional parameters were compared with 33 control patients of the same age and sex. Out of 33 patients, 21 underwent cardiac MRI with late gadolinium enhancement to assess the presence of right ventricular fibrosis.

RESULTS

The right ventricular systolic pressure (p<0.0001) and right ventricular outflow tract gradient (p<0.0001) decreased acutely (p<0.0001) after balloon valvuloplasty. During follow-up, M-mode left ventricular end diastolic dimension (p<0.001) and end systolic dimension increased (p<0.001), whereas right ventricular end diastolic dimension decreased (p<0.001). Compared with controls, patients (n=33) had significantly reduced tricuspid annular Ea and higher E/Ea (p<0.001). Right ventricular systolic dysfunction was also suggested by reduced tricuspid annular systolic velocity (p<0.001). Late gadolinium enhancement was demonstrated in 13 out of 21 patients with restrictive physiology, which involves the anterior right ventricular outflow tract, anterior wall, and inferior wall. The right ventricular late gadolinium enhancement score correlated positively with age (r=0.7, p<0.001) and right ventricular mass index (r=0.52, p<0.001).

CONCLUSION

The persistence of right ventricular diastolic dysfunction after relief of chronic pressure overload of critical pulmonary valve stenosis suggests that a factor - other than increase in afterload - is involved in this physiology. Fibrosis is the most likely factor responsible for persistence of restrictive physiology as documented by late gadolinium enhancement.

Mechanical dyssynchrony and deformation imaging in patients with functional mitral regurgitation

Chronic functional mitral regurgitation (FMR) is a frequent finding of ischemic heart disease and dilated cardiomyopathy (DCM), associated with unfavourable prognosis. Several pathophysiologic mechanisms are involved in FMR, such as annular dilatation and dysfunction, left ventricle (LV) remodeling, dysfunction and dyssynchrony, papillary muscles displacement and dyssynchrony. The best therapeutic choice for FMR is still debated. When optimal medical treatment has already been set, a further option for cardiac resynchronization therapy (CRT) and/or surgical correction should be considered. CRT is able to contrast most of the pathophysiologic determinants of FMR by minimizing LV dyssynchrony through different mechanisms: Increasing closing forces, reducing tethering forces, reshaping annular geometry and function, correcting diastolic MR. Deformation imaging in terms of two-dimensional speckle tracking has been validated for LV dyssynchrony assessment. Radial speckle tracking and three-dimensional strain analysis appear to be the best methods to quantify intraventricular delay and to predict CRT-responders. Speckle-tracking echocardiography in patients with mitral valve regurgitation has been usually proposed for the assessment of LV and left atrial function. However it has also revealed a fundamental role of intraventricular dyssynchrony in determining FMR especially in DCM, rather than in ischemic cardiomyopathy in which MR severity seems to be more related to mitral valve deformation indexes. Furthermore speckle tracking allows the assessment of papillary muscle dyssynchrony. Therefore this technique can help to identify optimal candidates to CRT that will probably demonstrate a reduction in FMR degree and thus will experience a better outcome.

Comparison of Percutaneous Mitral Valve Repair Versus Conservative Treatment in Severe Functional Mitral Regurgitation

Percutaneous mitral valve repair (PMVR) using the MitraClip System is feasible and entails clinical improvement even in patients with high surgical risk and severe functional mitral regurgitation (MR). The aim of this study was to assess survival rates and clinical outcome of patients with severe, functional MR treated with optimal medical therapy (OMT) compared with those who received MitraClip device. Sixty patients treated with OMT were compared with a propensity-matched cohort of 60 patients who underwent PMVR. Baseline demographics and echocardiographic variables were similar between the 2 groups. The mean age of patients was 75 years, and 67% were men. The median logistic EuroSCORE and EuroSCORE II were 17% and 6%, respectively, because of the presence of several co-morbidities. The mechanism of MR was functional in all cases with an ischemic etiology in 52% of patients. Median left ventricle ejection fraction was 34%. All the patients were symptomatic for dyspnea with 63% and 12% in the New York Heart Association class III and IV, respectively. In PMVR group, the procedure was associated with safety and very low incidence of procedural complications with no occurrence of procedural and inhospital mortality. After a median follow-up of 515 days (248 to 828 days), patients treated with PMVR demonstrated overall survival, survival freedom from cardiac death and survival free of readmission due to cardiac disease curves higher than patients treated conservatively (log-rank test p = 0.007, p = 0.002, and p = 0.04, respectively). In conclusion, PMVR offers a valid option for selected patients with high surgical risk and severe, functional MR and entails better survival outcomes compared with OMT.

The Prevalence and Long-Term Outcomes of Extreme Right versus Extreme Left Ventricular Hypertrophic Cardiomyopathy

OBJECTIVES

Extreme left ventricular hypertrophy (LVH) is a known risk factor for sudden cardiac death in hypertrophic cardiomyopathy (HCM). Extreme right ventricular hypertrophy (RVH) is rare, and whether it is linked to a poor outcome is unknown. This study was designed to investigate differences between HCM patients with extreme RVH and those with extreme LVH.

METHODS

Among 2,413 HCM patients, 31 with extreme RVH (maximum right ventricular wall thickness ≥ 10 mm) and 194 with extreme LVH (maximum left ventricular wall thickness ≥ 30 mm) were investigated. The main clinical features and natural history were compared between the 2 groups.

RESULTS

The prevalence of extreme RVH and extreme LVH was 1.3 and 8.0%, respectively. Patients with extreme RVH tended to be younger and female (p < 0.01). Cardiovascular-related mortality and morbidity within 10 years were significantly greater in the extreme RVH group (p < 0.05). Multivariate analysis demonstrated 3 independent predictors for cardiovascular mortality - extreme RVH, left ventricular end-diastolic dimension ≥ 50 mm, and age ≤ 18 years at baseline - and 2 for morbidity - extreme RVH and presyncope.

CONCLUSIONS

Compared with extreme LVH, extreme RVH was quite uncommon in HCM and had a worse prognosis. A right ventricle examination should be performed in routine HCM evaluation.

Cardiac dysfunction in liver cirrhosis: A tissue Doppler imaging study from Egypt

BACKGROUND

Patients with liver cirrhosis suffer from various cardiac abnormalities, which may influence their outcome. Tissue Doppler recording of the mitral and tricuspid annular diastolic velocities can be used to assess diastolic function accurately. There has been very little published information regarding RV diastolic function in liver cirrhosis. This study is aimed at evaluating right and left ventricular systolic and diastolic functions in post hepatitis C liver cirrhosis patients using conventional echocardiography and tissue Doppler imaging.

METHODS

This study was conducted on 75 adults from inpatient and outpatient services of the Theodor Bilharz Research Institute (TBRI) hospital. They were divided into two groups: Group 1 included 50 patients with post hepatitis C liver cirrhosis; and Group 2 included 25 normal adults serving as a control group. All patients and normal volunteers were subjected to clinical examination, laboratory evaluation, abdominal ultrasonography and echocardiographic studies with tissue Doppler imaging for evaluation of left and right ventricular systolic and diastolic functions.

RESULTS

The mitral flow showed significant increase in A wave velocity, as well as DT and IVRT with a significant decrease in E/A ratio in Group 1 compared to Group 2 (P<0.01). The tricuspid flow also showed a significant increase in A wave velocity (P<0.01) and DT (P<0.05) in addition to a significant decrease in E wave velocity and E/A ratio (P<0.01) in Group 1 as compared to Group 2. At the mitral annulus, we found a significant increase in average Aa velocity, E/Ea ratio and average systolic wave velocity S, in addition to a statistically significant decrease in the average Ea velocity and average Ea/Aa (P<0.01) in Group 1 as compared to Group 2. At the tricuspid annulus, there were significant increases in the average Aa velocity (P<0.01), S velocity (P<0.01) and E/Ea (P<0.05) together with a statistically significant decrease in the average Ea/Aa and average Ea velocity (P<0.01) in Group 1 compared to Group 2.

CONCLUSION

It is important to evaluate the cardiovascular function in every patient with cirrhosis, especially if the patient is a candidate for any intervention that may affect haemodynamics.

Echocardiographic and Hemodynamic Predictors of Survival in Precapillary Pulmonary Hypertension: Seven-Year Follow-Up

BACKGROUND

In this study, we looked at the prognostic value of echocardiographic and hemodynamic measures in a large cohort of patients with precapillary pulmonary hypertension before and after initiation of treatment.

METHODS AND RESULTS

Data were collected prospectively in a cohort of consecutive patients with precapillary pulmonary hypertension referred between 2002 and 2011. A range of clinical and echocardiographic variables were collected and stored on a database to assess predictors of survival. Invasive hemodynamic data including pulmonary artery pressure, pulmonary vascular resistance, capillary wedge pressure, and cardiac index were also obtained at baseline in all patients. Outcome was defined as mortality because of cardiovascular-related death. The study cohort comprised 777 patients (514 women) with precapillary pulmonary hypertension. A total of 195 (25%) died. In multivariable analysis, moderate or severe tricuspid regurgitation (hazard ratio [HR], 26.537; 95% confidence interval, 11.536-61.044; P<0.001), right ventricular myocardial performance index (HR, 3.421; 95% confidence interval, 1.777-6.584; P<0.001), and the presence of pericardial effusion (HR, 1.38; 95% confidence interval, 1.023-1.862; P=0.035) were independent predictors of mortality. High pulmonary vascular resistance and right atrial pressure by invasive hemodynamic measurements were independent predictors of mortality (HR, 1.084; 95% confidence interval, 1.041-1.130, and 1.079, respectively; 95% confidence interval, 1.049-1.111; P<0.001 for both), whereas patients with a higher cardiac index had better survival overall (HR, 0.384; 95% confidence interval, 0.307-0.481; P<0.001).

CONCLUSIONS

Right ventricular dysfunction, moderate-severe tricuspid regurgitation, low cardiac index, and raised right atrial pressure were associated with poor survival for both pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertensive disease patients. The severity of tricuspid regurgitation, myocardial performance index, presence of pericardial effusion, pulmonary vascular resistance, cardiac index, and right atrial pressure may be used to stratify risk of death.

Peri-operative assessment of right heart function: role of echocardiography

The right heart contributes significantly to overall cardiac function. Right ventricular (RV) haemodynamics and function have been defined to be physiologically different from the left ventricle, and yet independently associated with outcomes in a spectrum of conditions. In particular, RV function has been shown to influence prognosis of patients undergoing surgery. The assessment of right heart function during the intra-operative and immediate postoperative periods plays an important role in the clinical management of patients having surgery. While a number of techniques are available for the assessment of the right heart intra-operatively, echocardiography remains the prime choice being least invasive, relatively safe, readily accessible and cost-effective. Advancements in the field of echocardiographic have improved ability to assess right heart function. This review examines the role echocardiography and advances in this imaging modality in the assessment of right heart function within the peri-operative setting.

Effect of food intake on left and right ventricular systolic tissue Doppler measurements

Systolic tissue Doppler measurements (s') have been used to measure the velocity in myocardial motion and are a valuable tool for evaluating the systolic function of the left and right ventricles. Digestion of food is known to significantly alter hemodynamics and may therefore affect s'. The effect of food intake on s' parameters has not yet been studied. We assessed whether s' is affected by food intake. Nineteen healthy subjects aged 26·2 ± 4·2 years were investigated. s' was measured with pulsed tissue Doppler imaging in the right and left ventricles before the subjects ate a standardized meal and also 30 and 110 min after the meal. Three measurements were taken in each projection, and a mean value was calculated for each. s' increased significantly (P<0·05) from fasting to 30 min after food intake in every measured site except in the left inferolateral wall (P = 0·15, NS). Several, but not all, variables returned to base value 110 min after food intake. This study shows that food intake affects the tissue Doppler variables used to evaluate systolic heart function. Further studies are needed in older healthy subjects and older subjects with various cardiovascular diseases.

Right ventricular function in preterm and term neonates: reference values for right ventricle areas and fractional area of change

BACKGROUND

Right ventricular (RV) fractional area of change (FAC) is a quantitative two-dimensional echocardiographic measurement of RV function. RV FAC expresses the percentage change in the RV chamber area between end-diastole (RV end-diastolic area [RVEDA]) to end-systole (RV end-systolic area [RVESA]). The objectives of this study were to determine the maturational (age- and weight-related) changes in RV FAC and RV areas and to establish reference values in healthy preterm and term neonates.

METHODS

A prospective longitudinal study was conducted in 115 preterm infants (23-28 weeks' gestational age at birth, 500-1,500 g). RV FAC was measured at 24 hours of age, 72 hours of age, and 32 and 36 weeks' postmenstrual age (PMA). The maturational patterns of RVEDA, RVESA, and RV FAC were compared with those in 60 healthy full-term infants in a cross-sectional study (≥37 weeks, 3.5 ± 1 kg), who underwent echocardiography at birth (n = 25) and 1 month of age (n = 35). RVEDA and RVESA were traced in the RV-focused apical four-chamber view, and FAC was calculated using the formula 100 × [(RVEDA - RVESA)/RVEDA)]. Premature infants who developed chronic lung disease or had clinically and hemodynamically significant patent ductus arteriosus were excluded (n = 55) from the reference values. Intra- and interobserver reproducibility analysis was performed.

RESULTS

RV FAC ranged from 26% at birth to 35% by 36 weeks' PMA in preterm infants (n = 60) and increased almost 2 times faster in the first month of age compared with healthy term infants (n = 60). Similarly, RVEDA and RVESA increased throughout maturation in both term and preterm infants. RV FAC and RV areas were correlated with weight (r = 0.81, P < .001) but were independent of gestational age at birth (r = 0.3, P = .45). RVEDA and RVESA were correlated with PMA in weeks (r = 0.81, P < .001). RV FAC trended lower in preterm infants with bronchopulmonary dysplasia (P = .04) but was not correlated with size of patent ductus arteriosus (P = .56). There was no difference in RV FAC based on gender or need for mechanical ventilation.

CONCLUSIONS

This study establishes reference values of RV areas (RVEDA and RVESA) and RV FAC in healthy term and preterm infants and tracks their maturational changes during postnatal development. These measures increase from birth to 36 weeks' PMA, and this is reflective of the postnatal cardiac growth as a contributor to the maturation of cardiac function These measures are also linearly associated with increasing weight throughout maturation. This study suggests that two-dimensional RV FAC can be used as a complementary modality to assess global RV systolic function in neonates and facilitates its incorporation into clinical pediatric and neonatal guidelines.

Accuracy and Test-Retest Reproducibility of Two-Dimensional Knowledge-Based Volumetric Reconstruction of the Right Ventricle in Pulmonary Hypertension

Background

Right heart function is the key determinant of symptoms and prognosis in pulmonary hypertension (PH), but the right ventricle has a complex geometry that is challenging to quantify by two-dimensional (2D) echocardiography. A novel 2D echocardiographic technique for right ventricular (RV) quantitation involves knowledge-based reconstruction (KBR), a hybrid of 2D echocardiography–acquired coordinates localized in three-dimensional space and connected by reference to a disease-specific RV shape library. The aim of this study was to determine the accuracy of 2D KBR against cardiac magnetic resonance imaging in PH and the test-retest reproducibility of both conventional 2D echocardiographic RV fractional area change (FAC) and 2D KBR.

Methods

Twenty-eight patients with PH underwent same-day echocardiography and cardiac magnetic resonance imaging. Two operators performed serial RV FAC and 2D KBR acquisition and postprocessing to assess inter- and intraobserver test-retest reproducibility.

Results

Bland-Altman analysis (mean bias ± 95% limits of agreement) showed good agreement for end-diastolic volume (3.5 ± 25.0 mL), end-systolic volume (0.9 ± 19.9 mL), stroke volume (2.6 ± 23.1 mL), and ejection fraction (0.4 ± 10.2%) measured by 2D KBR and cardiac magnetic resonance imaging. There were no significant interobserver or intraobserver test-retest differences for 2D KBR RV metrics, with acceptable limits of agreement (interobserver end-diastolic volume, −0.9 ± 21.8 mL; end-systolic volume, −1.3 ± 25.8 mL; stroke volume, −0.2 ± 24.2 mL; ejection fraction, 0.7 ± 14.4%). Significant test-retest variability was observed for 2D echocardiographic RV areas and FAC.

Conclusions

Two-dimensional KBR is an accurate, novel technique for RV volumetric quantification in PH, with superior test-retest reproducibility compared with conventional 2D echocardiographic RV FAC.

Pressure Overload Creates Right Ventricular Diastolic Dysfunction in a Mouse Model: Assessment by Echocardiography

BACKGROUND

Noninvasive diagnostic tools for right ventricular (RV) dysfunction measurements are increasingly being used, although their association with the pathologic mechanisms of dysfunction is poorly understood. Although investigations have focused mainly on RV systolic function, RV diastolic function remains mostly neglected. The aim of this study was to test which echocardiographic parameters best reflect RV diastolic function in mice.

METHODS

Pulmonary artery banding (PAB) was used to induce RV pressure overload in mice. Transthoracic echocardiography and invasive hemodynamic measurements were performed after 3 weeks in PAB and sham-operated mice. Subsequently, the hearts were investigated by histology and analyzed for gene expression.

RESULTS

PAB-induced pressure overload (RV systolic pressure PAB 52.6 ± 11.8 mm Hg vs sham 27.0 ± 2.7 mm Hg) resulted in RV hypertrophy and remodeling, as reflected by increased Fulton index (PAB 0.37 ± 0.05 vs sham 0.25 ± 0.02, P = .001). Masson's trichrome staining revealed increased interstitial fibrosis (PAB 12.25 ± 3.12% vs sham 3.97 ± 1.58%, P = .002). This was associated with significant systolic RV dysfunction as demonstrated by reduced contractility index and diastolic dysfunction as demonstrated by end-diastolic pressure (PAB 2.66 ± 0.83 mm Hg vs sham 1.49 ± 0.50 mm Hg, P < .001) and τ (PAB 40.0 ± 16.1 msec vs sham 13.0 ± 3.5 msec, P < .001). Messenger ribonucleic acid expression of β-myosin heavy chain, atrial and brain natriuretic peptides, collagen family members was elevated, and the sarco/endoplasmic reticulum Ca(2+)-ATPase was decreased. Echocardiography revealed significant increases in RV free wall thickness and isovolumic relaxation time and a decrease in left ventricular eccentricity index, E', and tricuspid annular plane systolic excursion. Isovolumic relaxation time and E' were significantly correlated with end-diastolic pressure (rs = 0.511 and -0.451) and τ (rs = 0.739 and -0.445, respectively). Moreover, E' was negatively correlated with the degree of RV fibrosis (rs = -0.717).

CONCLUSIONS

Within 3 weeks, PAB causes pressure overload-induced RV hypertrophy and remodeling with compensated systolic and diastolic dysfunction in mice. RV free wall thickness, tricuspid annular plane systolic excursion, E', E/E' ratio, and isovolumic relaxation time appear to be the most reliable echocardiographic parameters for the assessment of RV dysfunction.

Design of an Experimental Test System to Investigate Parameters Affecting Distal Tip Loads of Pacemaker and Defibrillator Leads

The purpose of this study was to design and evaluate a system to test the mechanical behavior of pacemaker and defibrillator leads. Over 300,000 pacemaker and implantable cardioverter defibrillator (ICD) procedures are performed every year in the U.S. for the treatment of cardiac arrhythmias, ventricular dysrhythmias, and congestive heart failure. These procedures require implanting transvenous leads into the interior wall of the heart. A serious and sometimes fatal complication that may occur during or after lead implantation is perforation of the lead tip through the heart wall. The factors that lead to perforation are not fully understood. This illustrates that the mechanical interactions between the lead tip and the cardiac tissue need to be further investigated to improve the outcome for pacemaker and ICD patients. To improve the performance of lead tips, the testing protocols must reproduce physiological and clinically relevant tip-tissue interactions. As a first step toward this goal, testing parameters that influence those interactions must be identified. We investigated the effect of test system parameters, which reproduce potentially critical physiological constraints, on the load experienced at the distal tip of thirteen pacemaker and defibrillator active-fixation leads. We evaluated the use of a constraint to simulate the effect of the right ventricle (RV constraint) in vivo, how and where the lead was fixed in the test configuration, location of the load cell in the test system, rotation and frequency of the test protocol, and the effect of stylets. Results showed the RV constraint and load cell placement had the largest impact on lead tip load, while rotation of the test setup and test frequency had a minimal impact. Recommendations are made for a test system and protocol for in vitro testing of leads that take into consideration in vivo conditions. Better approximations of the in vivo environment may lead to improved product development. The potential of this system to more effectively evaluate new pacemaker and defibrillator lead designs will require further study.

Right ventricular strain analysis from three-dimensional echocardiography by using temporally diffeomorphic motion estimation

PURPOSE

Quantitative analysis of right ventricle (RV) motion is important for study of the mechanism of congenital and acquired diseases. Unlike left ventricle (LV), motion estimation of RV is more difficult because of its complex shape and thin myocardium. Although attempts of finite element models on MR images and speckle tracking on echocardiography have shown promising results on RV strain analysis, these methods can be improved since the temporal smoothness of the motion is not considered.

METHODS

The authors have proposed a temporally diffeomorphic motion estimation method in which a spatiotemporal transformation is estimated by optimization of a registration energy functional of the velocity field in their earlier work. The proposed motion estimation method is a fully automatic process for general image sequences. The authors apply the method by combining with a semiautomatic myocardium segmentation method to the RV strain analysis of three-dimensional (3D) echocardiographic sequences of five open-chest pigs under different steady states.

RESULTS

The authors compare the peak two-point strains derived by their method with those estimated from the sonomicrometry, the results show that they have high correlation. The motion of the right ventricular free wall is studied by using segmental strains. The baseline sequence results show that the segmental strains in their methods are consistent with results obtained by other image modalities such as MRI. The image sequences of pacing steady states show that segments with the largest strain variation coincide with the pacing sites.

CONCLUSIONS

The high correlation of the peak two-point strains of their method and sonomicrometry under different steady states demonstrates that their RV motion estimation has high accuracy. The closeness of the segmental strain of their method to those from MRI shows the feasibility of their method in the study of RV function by using 3D echocardiography. The strain analysis of the pacing steady states shows the potential utility of their method in study on RV diseases.

Relationship between endothelin-1 levels and pulmonary arterial hypertension in HIV-infected patients

OBJECTIVE

Pulmonary arterial hypertension (PAH) is a progressive, fatal disease with average survival of less than 3 years if left untreated. It is most common in patients infected with HIV. Although the pathogenesis in this population is not fully understood, it is thought that HIV infection, through the immune response and release of different inflammatory mediators such as endothelin-1, may contribute directly to endothelial damage. Our objective was to quantify endothelin-1 levels in HIV-infected patients and determine whether or not there is an association between this marker and PAH.

DESIGN

A case-control study in patients attending an infectious diseases clinic.

METHODS

The sample was composed of 79 patients divided into three groups: 23 HIV patients with PAH (HIV+/PAH+), 45 HIV patients without PAH (HIV+/PAH-) and a control group of 11 healthy individuals. The ratio between the HIV+/PAH- and HIV+/PAH+ groups was 2 : 1. Patients were matched by age, sex, risk group and viral load; the control group by age and sex. All patients had blood taken for endothelin-1 plasma quantification.

RESULTS

We found lower endothelin-1 levels in the controls than in the HIV+/PAH- group [0.71 pg/ml (interquartile range, IQR 0.54-0.94) vs. 1.13 pg/ml (IQR 0.87-1.38); P = 0.005] and the HIV+/PAH+ cohort [1.16 pg/ml (IQR 0.86-2.37); P = 0.003]. Patients with severe PAH had higher endothelin-1 levels [2.94 pg/ml (IQR 1.81-6.33)] than patients with mild and moderate PAH.

CONCLUSION

Plasma endothelin-1 levels are higher in HIV patients with PAH than in the HIV-noninfected population and levels increase with the severity of the PAH.

Quantification of right ventricular volume in dogs: a comparative study between three-dimensional echocardiography and computed tomography with the reference method magnetic resonance imaging

Background

Right ventricular (RV) volume and function are important diagnostic and prognostic factors in dogs with primary or secondary right-sided heart failure. The complex shape of the right ventricle and its retrosternal position make the quantification of its volume difficult. For that reason, only few studies exist, which deal with the determination of RV volume parameters. In human medicine cardiac magnetic resonance imaging (CMRI) is considered to be the reference technique for RV volumetric measurement (Nat Rev Cardiol 7(10):551-563, 2010), but cardiac computed tomography (CCT) and three-dimensional echocardiography (3DE) are other non-invasive methods feasible for RV volume quantification. The purpose of this study was the comparison of 3DE and CCT with CMRI, the gold standard for RV volumetric quantification.

Results

3DE showed significant lower and CCT significant higher right ventricular volumes than CMRI. Both techniques showed very good correlations (R > 0.8) with CMRI for the volumetric parameters end-diastolic volume (EDV) and end-systolic volume (ESV). Ejection fraction (EF) and stroke volume (SV) were not different when considering CCT and CMRI, whereas 3DE showed a significant higher EF and lower SV than CMRI. The 3DE values showed excellent intra-observer variability (<3%) and still acceptable inter-observer variability (<13%).

Conclusion

CCT provides an accurate image quality of the right ventricle with comparable results to the reference method CMRI. CCT overestimates the RV volumes; therefore, it is not an interchangeable method, having the disadvantage as well of needing general anaesthesia. 3DE underestimated the RV-Volumes, which could be explained by the worse image resolution. The excellent correlation between the methods indicates a close relationship between 3DE and CMRI although not directly comparable. 3DE is a promising technique for RV volumetric quantification, but further studies in awake dogs and dogs with heart disease are necessary to evaluate its usefulness in veterinary cardiology.

Right ventricular function assessment using tissue Doppler imaging and speckle tracking echocardiography

Modern echocardiographic techniques, i.e. tissue Doppler imaging and speckle tracking echocardiography, allow for an assessment of global and regional right ventricular function. The right ventricular myocardial performance index and tricuspid annulus motion are used in the assessment of global right ventricular function, whereas duration of the cardiac cycle phases and myocardial velocities are used in the assessment of regional function. Strain and strain rate allow for an evaluation of both regional and global myocardial function. Literature reports provide data on the usefulness of these methods in patients with pressure and volume overload as well as with direct myocardial damage involving the right ventricle. In pulmonary hypertension, S' wave assessment may be used for therapeutic efficacy evaluation. Longitudinal strain reduction indicates an increased risk of vascular events, while an increased value of myocardial performance index is a predictor for a survival in pulmonary hypertension. A decreased S' wave velocity is associated with limited pulmonary vascular flow in patients with pulmonary embolism. In patients after atrial baffle repair for transposition of the great arteries, decreased longitudinal strain was an independent predictor for heart failure. A statistically significant decrease in both the S' wave as well as acceleration during isovolumic contraction were observed in arrhythmogenic right ventricular cardiomyopathy. S' wave and global right ventricular longitudinal strain values were lower in patients in the acute phase of myocardial infarction involving the right ventricle compared to the corresponding parameters in healthy individuals. In the case of tetralogy of Fallot correction, the evaluation of S' wave velocity may prove useful in identifying patients with reduced cardiac systolic reserve; a good correlation was also found between the global right ventricular longitudinal strain and right ventricular ejection fraction in MRI.

Right ventricular cardiomyopathies: a multidisciplinary approach to diagnosis

The physiological importance of the right ventricle (RV) has been underestimated over the past years. Finally in the early 1950s through the 1970s, cardiac surgeons recognized the importance of RV function. Since then, the importance of RV function has been recognized in many acquired cardiac heart disease. RV can be mainly or together with left ventricle (LV) affected by inherited or acquired cardiomyopathy. In fact, RV morphological and functional remodeling occurs more common during cardiomyopathies than in ischemic cardiomyopathies and more closely parallels LV dysfunction. Moreover, there are some cardiomyopathy subtypes showing a predominant or exclusive involvement of the RV, and they are probably less known by cardiologists. The clinical approach to right ventricular cardiomyopathies is often challenging. Imaging is the first step to raise the suspicion and to guide the diagnostic process. In the differential diagnosis, cardiologists should consider athlete's heart, congenital heart diseases, multisystemic disorders, and inherited arrhythmias. However, a multiparametric and multidisciplinary approach, involving cardiologists, experts in imaging, geneticists, and pathologists with a specific expertise in these heart muscle disorders is required.

Neutrophil/lymphocyte ratio is related to the severity of idiopathic dilated cardiomyopathy

OBJECTIVES

The aim of this study was to assess whether NLR levels are associated with echocardiographic parameters, New York Heart Association (NYHA) functional class, or B- type natriuretic peptide (BNP) levels in patients with idiopathic dilated cardiomyopathy (DCM).

DESIGN

Eighty-seven patients with idiopathic DCM were included prospectively from 2009 to 2014. Patients with acute decompensated heart failure and conditions that alter the total or differential white blood cell counts were excluded. Blood samples were collected before echocardiographic investigation on admission.

RESULTS

There was a statistically significant correlation between neutrophil/lymphocyte ratio (NLR) and NYHA functional class (r = 0.68, p < 0.001), BNP levels (r = 0.61, p < 0.001) and various echocardiographic parameters. NLR was significantly higher in patients in NYHA functional class III or IV (n = 39) than among those categorized as NYHA class I or II (n = 48), (3.3 ± 1.0 vs 2.1 ± 0.6; p < 0.001). The NLR cutoff value predicting severe chronic HF was 2.25 with 82% sensitivity and 65% specificity (p < 0.001). On multivariate linear regression analysis NLR (p = 0.025), left ventricular end-diastolic volume (p = 0.041) and left atrial volume index (LAVI) (p = 0.001) were found to be independent positive predictors of BNP levels.

CONCLUSION

Neutrophil/Lymphocyte ratio is associated with the severity of chronic heart failure in patients with idiopathic DCM.

Right ventricle chamber of young trained athletes: morphology and function

Purpose

The study of the right ventricular (RV) chamber has been recently improved by use of the 3D method. In young asymptomatic trained athletes, RV is not routinely investigated if not in suspected disease. This study is designed to test if the 3D method compared to 2D, adds information to study of RV morphology and function, in the early stages of myocardial remodeling of a group of young athletes.

Methods

The RV chamber function was assessed in 25 young trained athletes (20 soccer and 5 basketball) aged 20±3 yrs and compared to 20 sedentary controls by 2D-AC and 3D-RV methods (TomTec), measuring RV diastolic (RVDV) and systolic (RVSV) volumes or ejection fraction (EF).

Results

3D RV volumes were slightly higher in athletes than the 2D volumes in presence of lower EF values, but not significantly higher than in sedentary. Significant differences were conversely found comparing 3D systolic and diastolic RV volumes and 2D-AC volumes within each group with higher values in athletes (RVDV: P=0.001 for athletes and P<0.001 for sedentary, and RVSV: P<0.04 for athletes and P<0.001 for sedentary).

Conclusion

Although the found EF values were substantially similar, the morphological assessment of the initial modifications of this chamber of the young “athlete's heart”, results seem to be more accurate using the 3D method than 2D. The clinical implication of this aspect could be of interest in case of difficulty in drawing a clear diagnosis of any RV chamber disease in young athletes.

Right ventricular global longitudinal strain provides prognostic value incremental to left ventricular ejection fraction in patients with heart failure

BACKGROUND

Right ventricular (RV) global longitudinal strain (RV strain) is a sensitive measure of RV mechanics. Its relationship with standard clinical markers and long-term events in chronic systolic heart failure is not well established. The aim of this study was to examine the ability of RV strain to provide incremental prognostic value to left ventricular (LV) ejection fraction (LVEF) in patients with chronic systolic heart failure.

METHODS

In 171 patients with chronic systolic heart failure (LVEF ≤ 35%), a retrospective substudy of RV strain was performed using Velocity Vector Imaging to analyze previously recorded, comprehensive echocardiographic images. Death, cardiac transplantation, and heart failure hospitalization were tracked for 5 years.

RESULTS

In this study cohort (mean age, 57 ± 14 years; mean LVEF, 25 ± 6%), mean RV strain was -11.6 ± 5.4%. More impaired RV strain was associated with increasing New York Heart Association class (rank-sums P < .0001) and greater LV volume (LV end-systolic volume index: r = 0.35, P < .0001). Worse RV strain was associated with reduced LVEF (r = -0.45, P < .0001), worse LV diastolic dysfunction (E/e' septal: r = 0.19, P = .017; left atrial volume index: r = 0.18, P = .031), and standard indices of RV systolic and diastolic dysfunction (RV s': r = -0.43, P < .0001; RV e'/a': r = 0.16, P = .0040; right atrial volume index: r = 0.20, P = .015). RV strain predicted long-term adverse events (hazard ratio, 1.30; 95% confidence interval, 1.02-1.70; P = .037). Furthermore, RV strain ≥ -14.8% predicted adverse events after adjustment for age, LVEF, RV s', E/e' septal, and right atrial volume index.

CONCLUSION

In patients with chronic systolic heart failure, worse RV strain provides prognostic value incremental to LV function.

Right ventricular diastolic performance in children with pulmonary arterial hypertension associated with congenital heart disease: correlation of echocardiographic parameters with invasive reference standards by high-fidelity micromanometer catheter

BACKGROUND

Right ventricular diastolic dysfunction influences outcomes in pulmonary arterial hypertension (PAH), but echocardiographic parameters have not been investigated in relation to invasive reference standards in pediatric PAH. We investigated echocardiographic parameters of right ventricular diastolic function in children with PAH in relation to simultaneously measured invasive reference measures.

METHODS AND RESULTS

We prospectively recruited children undergoing a clinically indicated cardiac catheterization for evaluation of PAH and pulmonary vasoreactivity testing. Echocardiography was performed simultaneously with invasive reference measurements by high-fidelity micromanometer catheter. For analysis, patients were divided into shunt and nonshunt groups. Sixteen children were studied. In the group as a whole, significant correlations were found among τ and tricuspid deceleration time, E', E/E', TimeE-E', A wave velocity, and global early and late diastolic strain rate. dp/dt minimum correlated significantly with late diastolic tricuspid annular velocity (A'), tissue Doppler imaging-derived systolic:diastolic duration ratio, and global late diastolic strain rate. End-diastolic pressure correlated significantly with tissue Doppler imaging-derived systolic:diastolic duration ratio. On multivariate analysis, tricuspid deceleration time, TimeE-E', and global early diastolic strain rate were independent predictors of τ, whereas tissue Doppler imaging-derived systolic:diastolic duration ratio was an independent predictor of dp/dt minimum. In general, correlations between echocardiographic and invasive parameters were better in the shunt group than in the nonshunt group.

CONCLUSIONS

Echocardiography correlates with invasive reference measures of right ventricular diastolic function in children with PAH, although it does not differentiate between early versus late diastolic abnormalities. Newer echocardiographic techniques may have added value to assess right ventricular diastolic dysfunction in this population.

Effect of imatinib as add-on therapy on echocardiographic measures of right ventricular function in patients with significant pulmonary arterial hypertension

AIMS

Imatinib mesylate, as add-on therapy in patients with pulmonary arterial hypertension (PAH) who remain inadequately treated despite receiving at least two PAH-specific drugs, improves exercise capacity and haemodynamics. We evaluated whether 24 weeks of add-on therapy with imatinib compared with placebo also improves right ventricular (RV) function assessed by echocardiography.

METHODS AND RESULTS

Echocardiograms were obtained at baseline, 12 weeks, and 24 weeks in 74 patients randomized to imatinib or placebo in the Imatinib in Pulmonary arterial hypertension, a Randomized Efficacy Study (IMPRES) trial. Right ventricular function was assessed by tissue Doppler tricuspid annular peak systolic velocity (TA S'), tricuspid annular plane systolic excursion (TAPSE), RV Tei index, and RV fractional area change. Between-treatment-group differences in the changes from baseline to week-24 were assessed using an ANCOVA with the last observation carried forward. At week-24 patients randomized to imatinib demonstrated greater improvements in TA S' (1.6 ± 2.3 imatinib vs. 0.5 ± 2.4 cm/s placebo, P = 0.007) and RV Tei index (-0.11 ± 0.18 imatinib vs. 0.05 ± 0.18 placebo, P = 0.005) compared with placebo, but not in TAPSE (0.07 ± 0.44 imatinib vs. 0.03 ± 0.32 cm placebo, P = 0.08). Imatinib therapy was also associated with significant reduction in peak tricuspid regurgitation velocity, increase in LV size, and improvement in LV early diastolic relaxation velocity.

CONCLUSIONS

Among patients with advanced PAH who remain symptomatic on at least two PAH-specific drugs, treatment with imatinib compared with placebo is associated with significant improvements in echocardiographic measures of RV function, in addition to LV size and LV early diastolic relaxation.

CLINICAL TRIAL REGISTRATION

NCT00902174 (Clinicaltrials.gov).

Update on Perioperative Right Heart Assessment Using Transesophageal Echocardiography

Purpose of the review. This review aims to summarize recent findings relevant for perioperative 2- and 3-dimensional imaging of the right heart with transesophageal echocardiography. Special attention is given to developments that are likely to affect future approaches for prevention and therapy of perioperative right heart failure. Recent findings. Three-dimensional transesophageal echocardiography techniques are becoming more common for the evaluation of anatomy, volumes, and functional indices. Summary. Right heart failure continues to contribute to morbidity and mortality in the context of cardiothoracic surgery. The advent and widespread clinical use of innovative tools permitting more accurate echocardiographic assessment of the right heart will open the door to renewed interest in novel therapeutic strategies.

Prognostic value of emergency physician performed echocardiography in patients with acute pulmonary thromboembolism

INTRODUCTION

Pulmonary embolism (PE) is a life-threatening illness with high morbidity and mortality. Echocardiography (ECG) plays an important role in the early identification of right ventricular (RV) dysfunction, making it a helpful tool in identifying hemodynamically stable patients affected by PE with a higher mortality risk. The purpose of this study was to evaluate if one or more ECG indexes could predict a short-term evolution towards RV dysfunction.

METHODS

We selected all patients consecutively admitted to the Careggi Hospital Emergency Department with the clinical suspicion of PE, confirmed by computed tomography angiography prior to enrollment. Subsequently, properly trained emergency physicians acquired a complete ECG to measure RV morphological and functional indices. For each patient, we recorded if he or she received a fibrinolytic treatment, a surgical embolectomy or heparin therapy during the emergency department (ED) stay. Then, every patient was re-evaluated with ECG, by the same physician, after 1 week in our intensive observation unit and 1 month as outpatient in our ED regional referral center for PE.

RESULTS

From 2002 to 2007, 120 consecutive patients affected by PE were evaluated by echocardiography at the Careggi Hospital ED. Nine patients (8%) were treated with thrombolytic therapy. Six died within 1 week and 4 abandoned the study, while the remaining 110 survived and were re-evaluated by ECG after 1 week and 1 month. The majority of the echocardiographic RV indexes improve mostly in the first 7 days: Acceleration Time (AT) from 78±14 ms to 117±14 ms (p<0.001), Diameter of Inferior Vena Cava (DIVC) from 25±6 mm to 19±5 mm (p<0.001), Tricuspid Annular Plane Systolic Excursion (TAPSE) from 16±6 mm to 20±6 mm (p<0.001). Pulmonary Artery Systolic Pressure (PASP) showed a remarkable decrease from 59±26 mmHg to 37±9 mmHg, (p<0.001). The measurements of the transverse diameters of both ventricles and the respective ratio showed a progressive normalization with a reduction of RV diameter, an increase of Left Ventricular (LV) diameter and a decrease of RV/LV ratio over time. To evaluate the RV function, the study population was divided into 3 groups based on the TAPSE and PASP mean values at the admission: Group 1 (68 patients) (TAPSE+/ PASP-), Group 2 (12 patients) (TAPSE-/PASP-), and Group 3 (30 patients) (TAPSE-/PASP+). Greater values of AT, minor RV diameter, greater LV diameter and a lesser RV/LV ratio were associated with a short-term improvement of TAPSE in the Group 2. Instead, in Group 3 the only parameter associated with short-term improvement of TAPSE and PASP was the treatment with thrombolytic therapy (p<0.0001).

CONCLUSION

Greater values of AT, minor RV diameter, greater LV diameter and a lesser RV/LV ratio were associated with a short-term improvement of TAPSE-/PASP- values. Patients with evidence of RV dysfunction (TAPSE-/PASP+), may benefit from thrombolytic therapy to improve a short- term RV function. After 1 month, also a decreased DIVC predicted improved RV function.

Impact of net atrioventricular compliance on clinical outcome in mitral stenosis

BACKGROUND

Net atrioventricular compliance (Cn) has been reported to be an important determinant of pulmonary hypertension in mitral stenosis (MS). We hypothesized that it may be useful in assessing prognosis because Cn reflects hemodynamic consequences of MS. To date, limited data with an assumed Cn cutoff have indicated the need for larger prospective studies. This prospective study was designed to determine the impact of Cn on clinical outcome and its contribution to pulmonary pressure in MS. In addition, we aimed to identify a cutoff value of Cn for outcome prediction in this setting.

METHODS AND RESULTS

A total of 128 patients with rheumatic MS without other significant valve disease were prospectively enrolled. Comprehensive echocardiography was performed and Doppler-derived Cn estimated using a previously validated equation. The end point was either mitral valve intervention or death. Cn was an important predictor of pulmonary pressure, regardless of classic measures of MS severity. During a median follow-up of 22 months, the end point was reached in 45 patients (35%). Baseline Cn predicted outcome, adding prognostic information beyond that provided by mitral valve area and functional status. Cn ≤4 mL/mm Hg best predicted unfavorable outcome in derivation and validation sets. A subgroup analysis including only initially asymptomatic patients with moderate to severe MS without initial indication for intervention (40.6% of total) demonstrated that baseline Cn predicted subsequent adverse outcome even after adjustment for classic measures of hemodynamic MS severity (hazard ratio, 0.33; 95% confidence interval, 0.14-0.79; P=0.013).

CONCLUSIONS

Cn contributes to pulmonary hypertension beyond stenosis severity itself. In a wide spectrum of MS severity, Cn is a powerful predictor of adverse outcome, adding prognostic value to clinical data and mitral valve area. Importantly, baseline Cn predicts a progressive course with subsequent need for intervention in initially asymptomatic patients. Cn assessment therefore has potential value for clinical risk stratification and monitoring in MS patients.

A porcine model for acute ischaemic right ventricular dysfunction

OBJECTIVES

To establish an experimental model for acute ischaemic isolated right ventricular dysfunction and the subsequent haemodynamic changes.

METHODS

An open-chest porcine model with ischaemic dysfunction of the right ventricle induced by ligation of the three main branches supporting the right ventricular free wall. Invasive monitoring of mean arterial blood pressure (MAP), central venous pressure (CVP), left atrial pressure (LAP) and right ventricular pressure (RVP); ultrasonic measurement of cardiac output (CO) and calculation of haemodynamic parameters such as stroke volume (SV), systemic vascular resistance (SVR), pulmonary vascular resistance (PVR) and right ventricular stroke work (RVSW) using standard formulae.

RESULTS

The ischaemic challenge to the right ventricle resulted in a significant (≥30%) reduction in RVSW associated with an increase (6-25%) in CVP and reduction (8-18%) in pulmonary artery pressure (PAP) despite unchanged PVR, all reflecting the failing right ventricle. There was also a significant drop in CO (14-22%) despite unchanged LAP indicating lessened transpulmonary delivery of left ventricular preload due to the failing right ventricle causing the haemodynamic compromise rather than left ventricular failure. Supraventricular and ventricular arrhythmias occurred in three and two out of seven pigs, respectively-all of which except one were successfully resuscitated with cardioversion and/or defibrillation.

CONCLUSIONS

This novel open-chest porcine model of induced ischaemia of the right ventricular free wall resulted in significant haemodynamic compromise confirmed using standard haemodynamic measurements making it useful for further research on acute, ischaemic isolated right ventricular failure.

The optimal use of cardiac imaging in the quantification of carcinoid heart disease

Carcinoid heart disease is a rare cause of right-sided valvular dysfunction, primarily mediated by serotonin. It is an important complication in patients with carcinoid syndrome and occurs in 20-50% of such patients. Echocardiography is the main technique used for the assessment of carcinoid heart disease, but other imaging modalities are also important, particularly in the quantification of the severity of the disease. We sought to review the role of cardiac imaging in the assessment of carcinoid heart disease.

Right heart function prediction of outcome in heart failure patients after catheter ablation for recurrent ventricular tachycardia

OBJECTIVES

This study sought to determine the relevance of echocardiographic assessment focusing on right ventricular (RV) function to estimate prognosis in patients with heart failure (HF) and low left ventricular ejection fraction (LVEF) after ablation of ventricular tachycardia (VT).

BACKGROUND

Recurrent VT is a marker of increased mortality in HF. Decision making remains challenging as some patients have a poor outcome despite successful catheter ablation of VT due to progressive biventricular HF.

METHODS

Retrospective analysis was performed on data from 320 consecutive patients with HF and LVEF ≤40% who underwent ablation for recurrent VT between 1999 and 2008. Baseline clinical and echocardiographic data were analyzed in relation to survival.

RESULTS

Among the 320 patients included, the mean age was 63 years, and 86% were male. During follow-up (median: 36 months) 127 patients (40%) died. RV dysfunction (hazard ratio [HR]: 1.4) and tricuspid regurgitation (TR) (HR: 1.7), together with age, New York Heart Association (NYHA) class, and serum creatinine, were independent predictors of death in a Cox regression model. Mortality was more than 2-fold higher in patients with at least moderate RV dysfunction and TR (HR: 2.6; p < 0.001). In patients with at least moderate RV dysfunction, TR, and estimated pulmonary arterial pressure ≥45 mm Hg, mortality was 61% at 2 years, compared with 16% in patients with good RV function without pulmonary hypertension (p < 0.0001).

CONCLUSIONS

Despite low LVEF, patients with recurrent VT who had good RV function without elevated pulmonary pressures had a good prognosis after VT ablation. RV dysfunction, TR, and elevated pulmonary pressures identified a high-risk group of VT survivors in whom additional interventions may be necessary to improve survival.

Imaging techniques for cardiac strain and deformation: comparison of echocardiography, cardiac magnetic resonance and cardiac computed tomography

Myocardial function assessment is essential for determining the health of the myocardium. Global assessment of myocardial function is widely performed (by estimating the ejection fraction), but many common cardiac diseases initially affect the myocardium on a regional, rather than global basis. Regional myocardial wall motion can be quantified using myocardial strain analysis (a normalized measure of deformation). Myocardial strain can be measured in terms of three normal strains (longitudinal strain, radial strain and circumferential) and six shear strains. Cardiac MRI (cMRI) is usually considered the reference standard for measurement of myocardial strain. The most common cMRI method, termed tagged cMRI, allows full, 3D assessment of regional strain. However, due to its complexity and lengthy times for analysis, tagged cMRI is not usually used outside of academic centers. Tagged cMRI is also primarily used only in research studies. Echocardiography combined with tissue Doppler imaging or a speckle tracking technique is now widely available in the clinical setting. Myocardial strain measurement by echocardiography shows reasonable agreement with cMRI. Limited standardization and differences between vendors represent current limitations of the technique. Cardiac computed tomography (CCT) is the newest and most rapidly growing modality for noninvasive imaging of the heart. While CCT studies are most commonly applied to assess the coronary arteries, CCT is easily adapted to provide functional information for both the left and right ventricles. New methods for CCT assessment of regional myocardial function are being developed. This review outlines the current literature on imaging techniques related to cardiac strain analysis and discusses the strengths and weaknesses of various methods for myocardial strain analysis.

The impact of right ventricular stroke work on B-type natriuretic peptide levels in patients with mitral stenosis undergoing percutaneous mitral valvuloplasty

OBJECTIVES

We aimed to explore the relationship between brain natriuretic peptide (BNP) levels and right ventricular (RV) function in patients with mitral stenosis (MS), and to investigate the hemodynamic parameters that predict reduction of BNP levels after percutaneous mitral valvuloplasty (PMV).

BACKGROUND

Few studies have evaluated BNP in the context of MS, specifically the impact of the RV stroke work (RVSW) on serum BNP levels has not been defined.

METHODS

Thirty patients with symptomatic rheumatic MS in sinus rhythm who were referred for a PMV were enrolled. Right and left heart pressures were obtained before and after valvuloplasty. RVSW index (RVSWI) was calculated by cardiac catheterization.

RESULTS

Basal BNP levels were elevated in MS patients and correlated with several hemodynamic parameters including pulmonary pressure, pulmonary vascular resistance index, cardiac index (CI), and RVSWI. In multivariate analysis, CI and RVSWI were independent predictors of raised basal BNP levels. PMV resulted in a significant decrease in the RVSWI with a concurrent increase in CI (2.4 ± 0.43 to 2.9 ± 0.8 L/min/m(2), P = 0.010). Overall, plasma BNP levels significantly decreased from 124 (63/234) to 73 (48/148) pg/ml postvalvuloplasty. Multivariate analysis revealed that the reduction of left atrial (LA) pressure post-PMV was an independent predictor of change in BNP levels.

CONCLUSIONS

Elevated baseline BNP level in MS patients was independently associated with CI and RVSWI. Plasma BNP levels were reduced after successful PMV, which was associated with the reduction of the LA pressure.