Usefulness of regional myocardial performance index to diagnose pulmonary embolism in patients with echocardiographic signs of pulmonary hypertension

The role of cardiovascular ultrasound in diagnosis and management of pulmonary embolism

The diagnosis of acute pulmonary embolism (PE) is one of the most important problems in medical emergencies. Commonly accepted criterion for diagnosis of deep venous thrombosis is the lack of vein compressibility assessed by Compression UltraSonography. Echocardiography represents an easily available and reliable imaging technique in the clinical setting of hemodynamic instability and in the direct visualization of thromboembolic masses in the right heart chambers. Moreover, echocardiography is useful for prognostic stratification after acute PE as right ventricular dysfunction is the most important predictor of mortality in this context. This review aims to highlight usefulness, potentialities and perspectives of standard and advanced echocardiography in evaluating patients affected by PE.

The significance of mitral and tricuspid valve systolic lateral annular velocities in the diagnosis of acute pulmonary embolism in patients with chronic heart failure

INTRODUCTION

The diagnosis of acute pulmonary embolism (APE) in patients with chronic heart failure (CHF) remains a difficult task, despite the refinement of imaging techniques. The goal of this study was to assess the value of measuring tricuspid and mitral valve systolic annular velocities in CHF patients with suspected PE by tissue Doppler imaging (TDI).

MATERIAL AND METHODS

The study included 75 patients with previously diagnosed CHF, admitted due to resting dyspnea, with a maximum tricuspid regurgitation pressure gradient (TRPG) of ≥ 35 mm Hg and positive D-dimer assay. Spiral computed tomography (sCT) was performed on all subjects to confirm APE. Acute pulmonary embolism was diagnosed in 35 patients (PE+), and excluded in 40 others (PE-). Tissue Doppler imaging was performed to measure maximum systolic lateral annular velocities in the mitral (SmLV) and tricuspid (SmRV) valves, as well as the SmRV/SmLV ratio.

RESULTS

PE+ subjects were found to have higher SmLV than PE- subjects (6.0 cm/s (2.0-13.8 cm/s) vs. 4.2 cm/s (1.3-9.1 cm/s), p = 0.003). SmRV/SmLV ratios were 1.05 (0.50-2.50) and 1.56 (0.62-4.30), respectively (p < 0.0001). Areas under ROC curves for diagnosis of APE were 0.700 for SmLV and 0.789 for SmRV/SmLV. In multivariate logistic regression analysis, only SmRV/SmLV was statistically significant, with an odds ratio for APE of 6.26 (95% CI: 1.53-25.59; p = 0.009).

CONCLUSIONS

Tissue Doppler imaging of the lateral tricuspid and mitral annuli is a useful clinical tool that can help identify PE in CHF patients. Those patients who fulfill these criteria should be considered for further diagnostic studies to confirm PE.

Cardiac findings and long-term thromboembolic outcomes following pulmonary embolism in children: a combined retrospective-prospective inception cohort study

In paediatric pulmonary embolism, cardiac findings and thromboembolic outcomes are poorly defined. We conducted a mixed retrospective-prospective cohort study of paediatric pulmonary embolism at the Children's Hospital Colorado between March, 2006 and January, 2011. A total of 58 consecutive children - age less than or equal to 21 years - with acute pulmonary embolism were enrolled. Data collection included clinical and laboratory characteristics, treatments, serial echocardiographic and electrocardiographic findings, and outcomes of pulmonary embolism non-resolution and recurrence. The median age was 16.5 years ranging from 0 to 21 years. The most prevalent clinical risk factors were oral contraceptive pill use (52% of female patients), presence of a non-infectious inflammatory condition (21%), and trauma (21%). Thrombophilias included heterozygous factor V Leiden in 21%; antiphospholipid antibody syndrome was established in 31% overall. Proximal pulmonary artery involvement was present in 34%. At presentation, nearly half of the patients had hypoxaemia and 37% had tachycardia. The classic electrocardiographic finding of S1Q3T3 was present in 12% acutely; tricuspid regurgitation greater than 3 metres per second, septal flattening, and right ventricular dilation were each present on acute echocardiogram in 25%. Nearly all patients received therapeutic anticoagulation, with initial systemic tissue plasminogen activator administered in 16% for occlusive iliofemoral deep venous thrombosis and/or massive pulmonary embolism. Pulmonary embolism resolution was observed in 82% by 6 months. Recurrent pulmonary embolism occurred in 9%. There were no pulmonary embolism-related deaths. Right ventricular dysfunction was rare in follow-up. These data indicate that acute heart strain is common, but chronic cardiac dysfunction is rare, following aggressive management of acute pulmonary embolism in children.

Twinned single-lung transplantation: a privileged model for the study of recipient-dependent factors of outcome

OBJECTIVES

Lung transplantation is the only life-saving treatment for end-stage respiratory disease. The outcome will depend on the graft quality, surgical conditions and recipient factors. Twinned single-lung transplantation defines as two different recipients treated with lung grafts from the same donor. Recipient-dependent factors of the outcome can be studied more accurately as the graft quality is supposed equal for both recipients.

METHODS

We reviewed all single-lung transplantations performed in France between 1998 and 2008 in the French registry run by the 'Agence de Biomédecine'. Criteria for donor lung quality and twinned recipient data were recorded in a database. The whole medical history and the transplantation outcome were reviewed for each patient and compared with its twin recipient. We compared twins on the basis of their opposed characteristics and on the basis of the opposed endpoint outcome. Endpoints were primary graft dysfunction (PGD) grade III, and mortality at 1, 3 and 12 months.

RESULTS

A total of 387 single-lung transplantations were performed in 10 French centres; 180 were twinned recipients from 90 donors. Statistical analysis revealed a significantly different outcome for PGD only. PGD was significantly higher (P < 0.05) in fibrosis recipients compared with emphysema twins. In 28 pairs (31%), the outcome was discordant for PGD, and fibrosis was significantly more often involved compared with emphysema (P = 0.04). Sixty-two pairs had a similar outcome: two pairs showed PGD in both recipients while 60 pairs were free of PGD.

CONCLUSIONS

We conclude that recipient's disease is a major determinant of the outcome. Fibrosis is associated with an increased risk for PGD.

Do we have two hearts? New insights in right ventricular function supported by myocardial imaging echocardiography

RV performance is difficult to evaluate, given its geometry, interrelationship with the left ventricle, and sensitivity to alterations in pulmonary pressure. This article focuses on some of the challenges related to the assessment of RV function in the setting of the RV's unique anatomic, physiologic, conventional and newer echocardiographic aspects, and therapeutic implications. The majority of proposed methods of echocardiographic assessment of RV function are based on volumetric approximations of the RV. Such approaches have inherent limitations, first as volume-related measures such as EF are load dependent, second because of the complex geometry of the RV. The issue of RV geometry is usually overcome using geometry-independent parameters such as tricuspid annular excursion and the Tei index. The recent introduction of real-time three-dimensional echocardiography and myocardial imaging echocardiography (tissue Doppler imaging, 1D-strain and 2D-strain echocardiography) implied a great progress in echocardiography. Tissue Doppler imaging allows the quantitative assessment of RV systolic and diastolic function by means of measurement of myocardial velocities. Strain measurements have been shown to correlate well with sonomicrometry segment length measurements both in the inflow and outflow tract of the RV and under different loading conditions. Other findings have been reported in chronic and acute clinical settings. Standard and novel echocardiographic methods of assessment of RV size and performance can help clinicians in the treatment of acute and chronic RV failure and contribute to a better understanding of the peculiar chamber-related functional mechanisms in the context of ventricular interdependent independency.

Critical appraisal on the utility of echocardiography in the management of acute pulmonary embolism

Echocardiography can be used for rapid and accurate risk stratification of patients with pulmonary embolism to appropriately direct the therapeutic strategies for those at high risk. Echocardiography is an ideal risk stratification tool in this regard because of its easy portability to the emergency room or to the bed side. It can be performed at a relatively low cost and at no risk to the patient. Furthermore, echocardiography allows repetitive noninvasive assessment of the cardiovascular and hemodynamic status of the patient and the response to the therapeutic interventions. Right ventricular hypokinesis, persistent pulmonary hypertension, a patent foramen ovale, and a free floating right heart thrombus are echocardiographic markers that identify patients at a higher risk for morbidity and mortality. Such patients warrant special consideration for thrombolysis or embolectomy.

Right ventricular heart failure from pulmonary embolism: key distinctions from chronic pulmonary hypertension

BACKGROUND

The right ventricle normally operates as a low pressure, high-flow pump connected to a high-capacitance pulmonary vascular circuit. Morbidity and mortality in humans with pulmonary hypertension (PH) from any cause is increased in the presence of right ventricular (RV) dysfunction, but the differences in pathology of RV dysfunction in chronic versus acute occlusive PH are not widely recognized.

METHODS AND RESULTS

Chronic PH that develops over weeks to months leads to RV concentric hypertrophy without inflammation that may progress slowly to RV failure. In contrast, pulmonary embolism (PE) results in an abrupt vascular occlusion leading to increased pulmonary artery pressure within minutes to hours that causes immediate deformation of the RV. RV injury is secondary to mechanical stretch, shear force, and ischemia that together provoke a cytokine and chemokine-mediated inflammatory phenotype that amplifies injury.

CONCLUSIONS

This review will briefly describe causes of pulmonary embolism and chronic PH, models of experimental study, and pulmonary vascular changes, and will focus on mechanisms of right ventricular dysfunction, contrasting mechanisms of RV adaptation and injury in these 2 settings.

Comparison of myocardial performance index obtained either by conventional echocardiography or tissue Doppler echocardiography in healthy subjects and patients with heart failure

This study was planned to investigate the normal reference values of myocardial performance index (MPI) obtained by tissue Doppler echocardiography (TDE) and the agreement between MPI measured by TDE and conventional MPI measured by pulsed-wave Doppler (PWD) in healthy subjects and patients with heart failure (HF). Two hundred and three patients with HF and 190 healthy subjects were enrolled in this study. Isovolumic contraction and relaxation time (ICT and IRT) and ejection time (ET) were measured from mitral inflow and left ventricular (LV) outflow. Tissue Doppler echocardiography recordings were obtained at the septal, lateral, inferior, and anterior of the mitral annulus and same time intervals were measured. Myocardial performance index was calculated. The functional capacity of the patients with HF was determined according to New York Heart Association classification. TDE-MPI values were higher than conventional PWD-MPI values in both groups (53%+/-8% vs 48%+/-11%, P<0.0001 in the healthy subjects; 84%+/-21% vs 72%+/-19%, P<0.0001 in the patients with HF). Moderate agreement was found between PWD-MPI and LV mean TDE-MPI in both groups. In identifying patients with moderately or severely decreased LV ejection fraction, TDE-MPI had higher cutoff values than conventional PWD-MPI, and TDE-MPI had higher specificity, sensitivity, negative predictive value, and diagnostic accuracy. In patients with HF, TDE-MPI had a stronger correlation with LV ejection fraction and functional capacity than did PWD-MPI. TDE-MPI is an alternative to conventional PWD-MPI in assessment of cardiac function. However, the higher MPI cutoff points should be considered when this method is used for the evaluation of cardiac function.