Ahmed Kharabish

Validation of Noninvasive Measurement of Cardiac Output Using Inert Gas Rebreathing in a Cohort of Patients With Heart Failure and Reduced Ejection FractionCLINICAL PERSPECTIVE

Background— Cardiac output (CO) is a key indicator of cardiac function in patients with heart failure. No completely accurate method is available for measuring CO in all patients. The objective of this study was to validate CO measurement using the inert gas rebreathing (IGR) method against other noninvasive and invasive methods of CO quantification in a cohort of patients with heart failure and reduced ejection fraction. Methods and Results— The study included 97 patients with heart failure and reduced ejection fraction (age 42±15.5 years; 64 patients (65.9%) had idiopathic dilated cardiomyopathy and 21 patients (21.6%) had ischemic heart disease). Median left ventricle ejection fraction was 24% (10%–36%). Patients with atrial fibrillation were excluded. CO was measured using 4 methods (IGR, cardiac magnetic resonance imaging, cardiac catheterization, and echocardiography) and indexed to body surface area (cardiac index [CI]). All studies were performed within 48 hours. Median CI measured by IGR was 1.75, by cardiac magnetic resonance imaging was 1.82, by cardiac catheterization was 1.65, and by echo was 1.7 L·min−1·m−2. There were significant modest linear correlations between IGR-derived CI and cardiac magnetic resonance imaging–derived CI (r=0.7; P<0.001), as well as cardiac catheterization–derived CI (r=0.6; P<0.001). Using Bland–Altman analysis, the agreement between the IGR method and the other methods was as good as the agreement between any 2 other methods with each other. Conclusions— The IGR method is a simple, accurate, and reproducible noninvasive method for quantification of CO in patients with advanced heart failure. The prognostic value of this simple measurement needs to be studied prospectively.

Cardiac MRI Findings of Endomyocardial Fibrosis (Loeffler's Endocarditis) in a Patient with Rheumatoid arthritis

Loeffler’s endocarditis and cardiac manifestations of the hypereosinophilic syndrome (HES) are rare and difficult to diagnose. We report a case of in a 36 year-old female with a history of rheumatoid arthritis with disabling dyspnea. The transthoracic echocardiogram demonstrated normal systolic cardiac functions and a left ventricular apical thrombus. However, using cardiovascular magnetic resonance (CMR) with inversion-recovery (IR) delayed enhancement, and cine steady-state free precession (SSFP) sequences, we were able to clearly demonstrate endocardial fibrosis, tissue inflammation, apical ventricular hypertrophy, and LV thrombus that correlate with clinical findings. We believe cardiac MRI is more useful than transthoracic echocardiography in the diagnosis and management of HES and ultimately it obviated the need for biopsy to confirm the diagnosis.

Prediction of Pulmonary Regurge and Right Ventricular Function in Asymptomatic Repaired Tetralogy of Fallot Patients in Developing Countries: A Comparison to Cardiac Magnetic Resonance Imaging

Objective: To assess the value of conventional echocardiographic measurements for quantification of pulmonary regurge and right ventricular function in comparison to Cardiac Magnetic Resonance Imaging (CMR) after surgical repair of Tetralogy Of Fallot (TOF). Methods: Twenty five asymptomatic children after TOF repair (9.2 ± 4 years) were compared to twenty five age matched healthy children. Echocardiographic quantification of pulmonary regurge was assessed by (1) pulmonary regurge jet width/pulmonary artery diameter, (2) pulmonary pressure half time, (3) pulmonary regurge index; pulmonary regurge duration to diastole duration, (4) no flow time; diastole duration - pulmonary regurge duration and (5) diastole/systole velocity time integral ratio. Measurements derived from conventional echocardiography were compared to pulmonary regurgitant fraction, right ventricular volumes and ejection fraction by CMR. Results: On CMR, the pulmonary regurgitant fraction was 28.64 ± 10.2%. By conventional echocardiography, pulmonary regurge index and no flow time were found to offer the best prediction for severity of pulmonary regurge. Pulmonary regurge index of 64 msec has sensitivity of 81% and specificity of 100% (AUC=0.894) in identifying significant pulmonary regurge. Compared to controls, patients after TOF repair showed significantly lower right ventricle myocardial velocities, higher E/ E‘ ratio and prolonged MPI. Among the TOF patients, right ventricular MPI showed significant negative correlation (r=-0.402; P=0.008) with tricuspid valve annulus peak systolic velocity (S‘) and significant positive correlation (r= 0. 413; P=0.04) with right ventricle stroke volume by CMR. Conclusion: Conventional echocardiography can offer a simple, readily available and accurate tool for quantification of pulmonary regurge and right ventricular function during mid- term follow up after surgical repair of tetralogy of Fallot.

Emergency Repair of a Perforated Mycotic Aneurysm with a Self-made Pericardial Tube-graft

A 63-year-old female with a history of kidney transplantation was admitted for emergency repair of a perforated mycotic aneurysm of the right subclavian artery (RSA) in combination with a paravertebral and posterior mediastinal abscess. After resection of the aneurysm and after radical local debridement, orthotopic repair was performed with a self-made pericardial tube graft from the brachiocephalic bifurcation to the thoracic outlet. The paravertebral and posterior mediastinal abscess was drained. The postoperative course was uneventful. Using a self-made readily available pericardial neo-tube enlarges the armamentarium of handling complex infective surgical scenarios and presents a smart alternative to alloplastic vascular reconstruction.

Can myocardial remodeling be a useful surrogate predictor of myocardial iron load? A 3D echocardiographic multicentric study

The relationship between myocardial iron load and eccentric myocardial remodeling remains an under‐investigated area; it was thought that remodeling is rather linked to fibrosis. This study aims to determine whether or not measures of remodeling can be used as predictors of myocardial iron. For this purpose, 60 patients with thalassemia were studied with 3D echocardiography and myocardial relaxometry (T2*) by Cardiac MRI. 3D derived sphericity index was significantly higher in patients with myocardial iron load. It was correlated with T2* with a 100% sensitivity and specificity (cut‐off value of 0.34) to discriminate between patients with and without myocardial iron overload.

Congenital biscuspid aortic valve in pediatric and early adulthood: Is there a relationship between the valvular leaflet fusion pattern and other functional parameters

Methods One hundered patients between 3 months to 26 years were included in the study. They were 78 males and 22 females. BSA for the patients ranged from 0.45-2.27. All patients were subjected to clinical examination, transthoracic echocardiography and CMR on a 1.5T machine. We recorded the leaflet fusion pattern, presence of AS, AR, pressure gradient, EF, LVEDV, aortic diameter at the annulus, sinus, arch and ascending aorta levels. Associated findings were all recorded.

An interatrial tunnel: a rare form of atrial septal defects

Atrial septal defects (ASDs) account for approximately 6%–10% of congenital heart defects. The well‐known types of atrial septal communications are the ostium secundum, ostium primum, sinus venosus types, and coronary sinus defects. A 50‐year‐old female was referred for TEE for better assessment of MR severity and mechanism. 2D/3D‐TEE showed a rare combination of different abnormalities; bi‐leaflet mitral valve prolapse, cleft P2, cor triatriatum sinister, and a tunnel‐shaped IAS communication. To the best of our knowledge, this is a very rare case with a rare form of atrial septal defect that was not described before. We named this defect an interatrial tunnel.

Intraindividual validation of 4D flow measurement against 2D flow measurements in aortas with bicuspid or tricuspid valves by cardiovascular magnetic resonance (CMR)

Background Theoretically, blood flow in the ascending aorta of patients with helical flow patterns, as in patients with bicuspid aortic valves (BAV), are underestimated by routine two dimensional (2D) phase contrast velocity encoding (PC-VENC). Four dimensional (4D) PC-VENC is theoretically not influenced by flow patterns. Hence, both, 2D PC-VENC and 4D PC VENC should result in similar blood flow measurements in the ascending aorta of subjects without helical flow patterns, as in subjects with tricuspid aortic valves (TAV).