Cory Noel

State of the art review: Chemotherapy-induced cardiotoxicity in children

Chemotherapy-induced cardiotoxicity in adults and children is a topic with a growing interest in the cardiology literature. The ability to detect cardiac dysfunction in a timely manner is essential in order to begin adequate treatment and prevent further deterioration. This article aims to provide a review on the myocardial injury process, chemotherapeutic agents that lead to cardiotoxicity, the definition of cardiotoxicity, and the methods of timely detection and treatment.

Imaging of the pulmonary valve in the adults

Purpose of review Pulmonary valve is the least imaged of the cardiac valves in adults. This review will address the strengths and the limitations of various imaging modalities that are commonly used for evaluation of pulmonary valve diseases in the adults. Recent findings Valvular pulmonary stenosis is mostly congenital and pulmonary regurgitation is usually an acquired pulmonary valve disease. Combined pulmonary stenosis and pulmonary regurgitation as sequel to previous surgeries for congenital heart diseases is the most common form of pulmonary valve disease in the adults. Transthoracic echocardiography (TTE) is the first-line imaging for the pulmonary valve, however, TTE pose considerable technical limitations in adults secondary to the body habitus, previous surgeries, and imaging artifacts by the interposed foreign tissue. Transesophageal echocardiography is infrequently used because of farther location of the imaging probe from the pulmonary valve precluding optimal imaging. Cardiac computerized tomography (CT) and cardiac MRI are fast emerging as the most preferred imaging modalities for pulmonary valve diseases in the adults. CT is used to obtain precise anatomic information about the pulmonary valve and the contiguous anatomy such as the right ventricular outflow tract, the distal pulmonary arteries including the coronary arteries. MRI by virtue of its high temporal resolution has the unique advantage of obtaining hemodynamic information related to the pulmonary valve; such as quantification of the pulmonary regurgitation, the right ventricle volumes, mass, and the systolic function. Combined imaging with CT and MRI provide anatomic and hemodynamic information in a variety of pulmonary valve diseases; is useful for understanding of the right ventricle adaptive mechanism and remodeling process, for preprocedure planning during percutaneous pulmonary valve implantation and for surveillance of different pulmonary valve diseases. Summary Multimodality imaging involving a combination of TTE, CT, and (or) MRI are useful to delineate the anatomic and hemodynamic abnormalities associated with different pulmonary valve diseases in the adults.

Cardiac stress MRI evaluation of anomalous aortic origin of a coronary artery

Myocardial ischemia is an insult that is primarily thought of in an adult population. However, there are several congenital and acquired cardiac lesions that may lead to myocardial ischemia in a pediatric population. One of the prominent congenital lesions is anomalous aortic origin of a coronary artery (AAOCA). Anomalous aortic origin of a coronary artery is one of the leading causes sudden cardiac death in pediatric and young adult patients, and thus the assessment of myocardial perfusion is of the utmost importance. Over the past decade, pharmacologic stress MRI has proven to be a highly sensitive and accurate diagnostic examination for qualifying myocardial perfusion in adults with coronary artery disease. This noninvasive imaging modality may be a useful tool in assessing the function impact of AAOCA on myocardial perfusion.

Prospective comparison of circumferential and longitudinal strain in asymptomatic children with single left ventricle, single right ventricle and normal hearts

Background Ventricular dysfunction in patients with a single right ventricle (SRV) or as ingle left ventricle (SLV) is a known risk factor for morbidity and mortality. However, the differences in SRV and SLV function remain poorly understood, with only a few studies performed1-3. In this study, we measure the strain using cardiac MRI and perform comprehensive comparison of the global and regional strain in both the circumferential (ecc) and longitudinal (eL) dimension. Purpose: In normal subjects and asymptomatic patients with SLV and SRV after total cavopulmonary connection (TCPC), compare: 1) Global ecc and eL strain, 2) Regional circumferential and longitudinal strains at free wall (ecc-free, eL-free) and septum (ecc-sept, eL-sept), 3) ecc and eL across the ventricle from apex to base. Methods We performed a prospective analysis of 18 subjects (7 normal age: 11.8 +/- 3; 6 SRV age: 11.4 +/- 2.3; 5 SLV age: 12.7 +/- 4.2). Acquisition Protocol: Strain information was acquired at three short axis slices at basal, mid-cavity, and apical locations in all 18 subjects in a 1.5T MRI scanner (Philips Acheiva) using: a) Complementary Spatial Modulation of Magnetization (CSPAMM)4 images: Used for generating ecc; and b) Fast-Strain Encoded (fSENC)5 images: Used for generating eL. Data Analysis: ecc and eL across all cardiac phases and slices were calculated from SAX slices using DiagnosoftTM. The ventricular regions at each slice were assigned based upon the AHA 16 segment model. ecc-sept, eL-sept, ecc-free, and eL-free were also calculated for each slice and compared. Results

Ventricular coupling in single ventricle patients: a MRI study of cardiac biomechanics

Background Ventricular dysfunction in patients with a single right ventricle (SRV) or a single left ventricle (SLV) is a known risk factor for morbidity and mortality. In normal hearts, LV and RV augment each other, while this is not possible in single ventricle (SV) patients. Ventricular-ventricular relationship in SV patients remain poorly understood, with only a few studies performed [1-3]. Our earlier results show a decreased peak circumferential (εcc) and longitudinal (εL) strain in SV patients when compared to a normal population [4]. However, an increase in longitudinal strain is noted in regions of decreased circumferential strain. The purpose of this study is to understand the ventricular-ventricular interactions in systemic ventricles coupled and uncoupled to a dysfunctional ventricle.

Myocardial T1 mapping as a diagnostic tool in pediatric patients with a concern for cardiac disease

Background Myocardial tissue characterization with both native T1 mapping and T1 mapping following gadolinium based contrast agents (T1 enhanced) has emerged as an important asset of CMR imaging [1]. However, there is only minimal experience in pediatrics [2]. Native T1 has shown to be a marker of myocardial edema, and may play a role in pathologic states such as myocarditis [3]. T1 enhanced mapping has shown to be a useful biomarker for disease sates with diffuse fibrosis, such as hypertrophic cardiomyopathy (HCM), and is comparable to myocardial biopsy [4]. Purpose: To examine the effectiveness of CMR myocardial characterization by native T1 and T1 enhanced mapping in a heterogenous group of pediatric patients with signs concerning for cardiomyopathy or myocarditis.

Prospective evaluation of circumferential and longitudinal strain in asymptomatic children with dual ventricles who underwent single ventricle repair: comparison to single LV, single RV and normal hearts.

Background Rarely, patients with normally sized RV and LV will undergo total cavopulmonary connection (TCPC) due to the complexity of their intracardiac anatomy giving them a dual ventricle (DV) for a single cardiac output. The ventricular function in this unique physiology compared to SRV, SLV and normal hearts remains poorly understood, with few studies performed. In this study, we perform a comprehensive comparison of global and regional strain in both the circumferential (ecc) and longitudinal (eL) dimensions to conventional SV hearts and normal hearts.

Regadenoson as a pharmacologic stressor in cardiac magnetic resonance imaging in congenital and acquired pediatric heart disease: initial experience

Background Adenosine has traditionally been utilized for coronary hyperemia during myocardial perfusion assessment in adults, however regadenoson has recently become more popular [1]. With improved survival of congenital heart disease (CHD), and increased diagnosis of acquired heart disease (AHD), there’s an increasing need for assessment of myocardial perfusion in pediatrics [2]. Only dipyridamole and adenosine have reportedly been utilized as hyperemia stressors in CHD patients. As a selective A2A agonist, regadenoson has a more favorable side-effect profile and less stimulation of receptors associated with bronchospasm, and decreased chronotropy [1]. It is administered as an intravenous (IV) bolus and thus only a single IV is required. Peak onset is at 60-90 seconds, with hyperemia lasting up to 6 minutes allowing additional wall motion assessment [3].

Comparison of myocardial rotation and torsion in asymptomatic children with single RV, single LV and normal hearts

Background Abnormal myocardial rotation and torsion have been investigated earlier as markers of ventricular failure1-2. However, there are no previous studies on global or regional torsion in functional single ventricle (SV) or the contribution of torsion to biomechanical differences between single RV (SRV) and single LV (SLV) hearts. Additionally, regional variations in rotation between the ventricular free wall and the septal wall which borders the hypoplastic chamber in SV have not been studied. Purpose: In normal subjects and in asymptomatic patients with SLV and SRV after total cavopulmonary connection (TCPC), to compare: 1) Global rotation (ROTglo). 2) Regional rotation in systole at free wall (ROTfree) and septal wall (ROT sept) for each slice location. 3) Torsion across the ventricle from apex to base.