Mounir Obeid - Academia.edu (original) (raw)

Papers by Mounir Obeid

Research paper thumbnail of Absence of GJA1 gene mutations in four patients with anomalous left coronary artery from the pulmonary artery (ALCAPA)

Le Journal médical libanais. The Lebanese medical journal

Anomalous left coronary artery from the pulmonary artery (ALCAPA) is a rare form of congenital he... more Anomalous left coronary artery from the pulmonary artery (ALCAPA) is a rare form of congenital heart disease with no known genetic cause. It is usually diagnosed within the first year of life; it results in myocardial cell death, congestive heart failure and lethality if left untreated. Connexin 43alpha1 is a member of the gap junction family of proteins demonstrated by animal studies to have a role in coronary artery patterning during development. No previous studies have investigated the role of this gene in patients with ALCAPA. We forth herein describe the clinical presentation of four patients who presented to the Children's Heart Center at AUBMC and had the final diagnosis of ALCAPA. Screening the GJA1 gene coding for connexin 43alpha1 was undertaken. No mutations were found in the patients or their parents, except for one polymorphism in one of the parents in the 3' untranslated region. All four patients underwent surgical repair with excellent outcome. This paper rai...

Research paper thumbnail of Cox-maze procedure for treatment of atrial flutter associated with an atrial septal defect

Clinical Cardiology, 2000

A 52-year-old man presented with atrial flutter and was found to have an atrial septal defect (AS... more A 52-year-old man presented with atrial flutter and was found to have an atrial septal defect (ASD). The paper describes an effective surgical approach for the treatment of this atrial arrhythmia utilizing a right sided Cox-maze III procedure concomitant with ASD closure. Review of the literature and clinical implications are discussed.

Research paper thumbnail of The status of pediatric cardiology at a tertiary center in Lebanon

Le Journal medical libanais. The Lebanese medical journal, 2011

PROBLEM Cardiac disease, both congenital and acquired, contributes significantly to morbidity and... more PROBLEM Cardiac disease, both congenital and acquired, contributes significantly to morbidity and mortality in children. METHODS This article describes the status of pediatric cardiology at the Children's Heart Center in the American University of Beirut Medical Center. It addresses the available clinical services as well as the research and educational activities that are present at a tertiary center in Lebanon, a developing country with a population of 4 million. RESULTS Lebanon has witnessed major developments in the field of pediatric cardiology over the past few years. About 650 babies are born with heart disease every year, with more than 425 needing treatment. Nearly all types of interventional catheterization procedures are currently being performed. About 300 open and closed pediatric cardiac surgeries are performed per year in Lebanon. In 2008, the in-hospital surgical mortality rate at our center was 2.6%, reflecting the good level of care in the treatment of children...

Research paper thumbnail of Large congenital left atrial wall aneurysm: An updated and comprehensive review of the literature

Echocardiography

Congenital left atrial wall aneurysms are rare abnormalities that arise from a developmental weak... more Congenital left atrial wall aneurysms are rare abnormalities that arise from a developmental weakness in the muscular wall. It may be misdiagnosed or go undetected and the delay in diagnosis can lead to catastrophic consequences.

Research paper thumbnail of Effect of Continuous Positive Airway Pressure on the Rapid Shallow Breathing Index in Patients Following Cardiac Surgery

Chest Journal, Feb 1, 2002

Research paper thumbnail of Cardiac growth patterns in response to chronic hypoxia in a neonatal rat model mimicking cyanotic heart disease

Experimental and clinical cardiology, 2003

Myocardial growth during fetal life is accomplished by the proliferation of myocytes. Shortly aft... more Myocardial growth during fetal life is accomplished by the proliferation of myocytes. Shortly after birth, normal myocytes largely lose their capability to replicate. The present study aims to assess the effect of persistent postnatal hypoxia on myocardial growth patterns in an animal model mimicking cyanotic heart disease. Sprague-Dawley rats were placed in a normobaric hypoxic environment at birth and oxygen levels were maintained at 10% (group H). Controls (group C) remained in room air. The animals were sacrificed and the hearts were harvested at one, four and eight weeks. Significant polycythemia developed in the hypoxic rats. There was a significant increase in indexed right ventricle (RV) and left ventricle (LV) masses compared with controls. Myocardial DNA concentrations were significantly increased in both ventricles of the hypoxic rats. For the RV, the increase in DNA content for group H was 135%, 132% and 112% that of group C values at one, four and eight weeks, respectiv...

Research paper thumbnail of The cleft sternum: a possible role for pliable prosthetic reconstruction

Le Journal médical libanais. The Lebanese medical journal

Faced with our intraoperative inability to primarily close a very wide isolated cleft sternum of ... more Faced with our intraoperative inability to primarily close a very wide isolated cleft sternum of a pediatric patient without causing cardiovascular decompensation, we describe our use of a synthetic material for partial approximation allowing muscular coverage. We report an infant who was born with an isolated large complete sternal cleft where a trial of primary surgical repair had to be abandoned because of cardiovascular compromise. A similar difficulty was encountered in approximating the origins of both pectoralis major muscle flaps at the midline. Thus, a pliable synthetic patch was helpful in partially obliterating the widened sternal defect allowing successful muscular coverage. Closure of a wide congenital sternal cleft using a synthetic material that partially obliterated an otherwise widely separated cleft sternum which was neither amenable for primary repair, nor by bilateral pectoralis major advancement alone, was possible. Strong prosthetic pliable material may offer a...

Research paper thumbnail of Equipoise between radial artery and right internal thoracic artery as the second arterial conduit in left internal thoracic artery-based coronary artery bypass graft surgery: a multi-institutional study†

European journal of cardio-thoracic surgery : official journal of the European Association for Cardio-thoracic Surgery, Jan 11, 2015

Multiple arterial coronary artery grafting (MABG) improves long-term survival compared with singl... more Multiple arterial coronary artery grafting (MABG) improves long-term survival compared with single arterial CABG (SABG), yet the best second arterial conduit to be used with the left internal thoracic artery (LITA) remains undefined. Outcomes in patients grafted with radial artery (RA-MABG) versus right internal thoracic artery (RITA-MABG) as the second arterial graft were compared with SABG. Multi-institutional, retrospective analysis of non-emergent isolated LITA to left anterior descending coronary artery CABG patients was performed using institutional Society of Thoracic Surgeon National Adult Cardiac Surgery Databases. 4484 (54.5%) SABG [LITA ± saphenous vein grafts (SVG)], 3095 (37.6%) RA-MABG (RA ± SVG) and 641 (7.9%) RITA-MABG (RITA ± SVG) patients were included. The RITA was used as a free (68%) or in situ (32%) graft. RA grafts were principally anastomosed to the ascending aorta. Long-term survival was ascertained from US Social Security Death Index and institutional follo...

Research paper thumbnail of Absence of GJA1 gene mutations in four patients with anomalous left coronary artery from the pulmonary artery (ALCAPA)

Le Journal médical libanais. The Lebanese medical journal

Anomalous left coronary artery from the pulmonary artery (ALCAPA) is a rare form of congenital he... more Anomalous left coronary artery from the pulmonary artery (ALCAPA) is a rare form of congenital heart disease with no known genetic cause. It is usually diagnosed within the first year of life; it results in myocardial cell death, congestive heart failure and lethality if left untreated. Connexin 43alpha1 is a member of the gap junction family of proteins demonstrated by animal studies to have a role in coronary artery patterning during development. No previous studies have investigated the role of this gene in patients with ALCAPA. We forth herein describe the clinical presentation of four patients who presented to the Children's Heart Center at AUBMC and had the final diagnosis of ALCAPA. Screening the GJA1 gene coding for connexin 43alpha1 was undertaken. No mutations were found in the patients or their parents, except for one polymorphism in one of the parents in the 3' untranslated region. All four patients underwent surgical repair with excellent outcome. This paper rai...

Research paper thumbnail of Bilateral percutaneous stent implantation in the pulmonary vasculature: a modality now available in Lebanon

Le Journal médical libanais. The Lebanese medical journal

We report a child with Truncus Arteriosus who developed bilateral proximal branch pulmonary steno... more We report a child with Truncus Arteriosus who developed bilateral proximal branch pulmonary stenosis, following total surgical repair of her condition with construction of the right ventricular outflow tract utilizing a Contegra conduit (Medtronic Inc., Minneapolis, Minn.). The obstruction was relieved completely utilizing bilateral percutaneous stent implantation. To the best of our knowledge, this is the first reported case of bilateral stent implantation to relieve branch pulmonary artery stenosis in Lebanon. This technique could be applied to similar cases of obstruction in the pulmonary tree.

Research paper thumbnail of Congenital heart disease at a tertiary care center in Lebanon

Middle East journal of anaesthesiology, 1999

To study the epidemiology of congenital heart disease (CHD) at the American University of Beirut-... more To study the epidemiology of congenital heart disease (CHD) at the American University of Beirut-Medical Center, we reviewed the medical records of all cardiac patients seen at our outpatient cardiology clinic (OPD) between 1980 and 1995. The charts of all patients with CHD seen as inpatients and/or outpatients at our center during the year 1995 were also reviewed. A cardiologist evaluated all patients and the diagnosis was confirmed at least by echocardiography. The frequency of CHD was reported among three groups: 1980-1995 OPD groups (Group A); the group with CHD seen during the year 1995 (Group B); and (Group C), a subgroup of group B, included all newborns with CHD born at our hospital during the year 1995. Stillbirth and premature infants with the diagnosis of patent ductus arteriosus were excluded from the study. Group A included 883 patients. 344 patients were evaluated in Group B, with a mean age of 3.8 years. The incidence of CHD was 11.5/1,000 live births at our center. T...

Research paper thumbnail of Total parenteral nutrition

Middle East journal of anaesthesiology, 1988

Research paper thumbnail of Complete cleft sternum and congenital heart disease: Review of the literature

Pediatrics International, 2002

Research paper thumbnail of An unusual case of hyperkalaemia-induced cardiac arrest in a paediatric patient during transfusion of a 'fresh' 6-day-old blood unit

Transfusion Medicine, 2002

A well-recognized complication of the transfusion of red blood cells (RBCs) is hyperkalaemia. Thi... more A well-recognized complication of the transfusion of red blood cells (RBCs) is hyperkalaemia. This occurs in paediatric or adult patients receiving massive transfusion and can lead to cardiac arrest. Hyperkalaemia may follow the transfusion of 'stored' RBCs and/or haemolysed units, and depends on the quantity and rate of transfusion. We report on an unusual case of hyperkalaemia-induced cardiac arrest during transfusion of a 'fresh' blood unit. A 62-day-old baby girl was scheduled for a construction of a Blalock-Taussig shunt, after the completion of anastomosis, and upon release of vascular control, there was bleeding at the anastomotic site that was controlled with a suture placement. To compensate for the blood loss, a stat order was given for a push of 120 mL of RBCs over 10 min through the inferior vena cava central line. The blood unit was 6 days old and had been gamma-irradiated 48 h earlier. Shortly after the transfusion, the patient's electrocardiogram showed changes typical of hyperkalaemia; she then went into cardiac asystole. The blood unit potassium concentration was 55.3 mmol L-1, which flushed the atrioventricular node during transfusion. This is the first report of a high potassium level found in a 'fresh', less than 7 days old, nonhaemolysed RBC blood unit. The high concentration of potassium in this unit seems to be due to accelerated alterations of the RBC sodium/potassium adenosine triphosphatase pump (Na+/K+ pump), resulting in the release of intracellular potassium. This early and severe alteration of the pump and the unusually high potassium level may be due to as yet unexplained causes, warranting awareness, future investigation and routine saline washing of 'fresh' RBCs for paediatric patients who are candidates for central line transfusion.

Research paper thumbnail of Tissue-specific ceramide response in the chronically hypoxic rat model mimicking cyanotic heart disease

Prostaglandins & Other Lipid Mediators, 2003

Acute hypoxia is associated with apoptosis and increase in ceramide levels in various organs. To ... more Acute hypoxia is associated with apoptosis and increase in ceramide levels in various organs. To assess the effect of chronic hypoxia on ceramide accumulation in the lungs and kidneys, we utilized an animal model mimicking cyanotic heart disease. Rats were placed in a hypoxic environment at birth and oxygen levels were maintained at 10% in an air-tight Plexiglas chamber. Controls remained in room air. Animals were sacrificed and the lung and kidneys were harvested and weighed at 1 and 4 weeks, respectively. Ceramide levels were measured using a modified diacylglycerol kinase assay. Significant polycythemia developed in the hypoxic rats at 1 and 4 weeks. Indexed lung and kidney masses were significantly increased in the hypoxic animals as compared to controls at 1 and 4 weeks, respectively. The ceramide levels in the hypoxic lungs and kidneys were not significantly different from control groups at 1 and 4 weeks. [Ceramide/phosphate ratio in the kidneys was 1.28 +/- 0.17 (C) versus 1.18 +/- 0.12 (H) at 1 week; P = 0.39, and 1.46 +/- 0.08 (C) versus 1.33 +/- 0.15 (H) at 4 weeks (P = 0.44)] and [ceramide/phosphate ratio (pmol/nmol) in the lungs was 2.29 +/- 0.14 (C) versus 1.98 +/- 0.12 (H) at 1 week (P = 0.17), and 2.42 +/- 0.16 (C) versus 2.30 +/- 0.05 (H) at 4 weeks, P = 0.34]. The response of lungs and kidneys to chronic hypoxia includes increase in indexed mass and lack of ceramide accumulation. This is similar to the response previously reported in the chronically hypoxic brain and heart. Thus, various organs appear to have similar ceramide response pattern to chronic hypoxia.

Research paper thumbnail of Acute respiratory distress associated with external jugular vein catheterization in the newborn

Pediatric Pulmonology, 2003

We report on the acute onset of respiratory distress secondary to fluid accumulation in the chest... more We report on the acute onset of respiratory distress secondary to fluid accumulation in the chest within hours of placement of an external jugular venous line in a newborn. External jugular venous catheterization in the newborn is a procedure with potentially serious complications, and should be avoided unless the patient is monitored closely.

Research paper thumbnail of Rheumatic Fever in Children: A 15-Year Experience in a Developing Country

Pediatric Cardiology, 2000

Clinical data from 91 patients with rheumatic fever (RF), who were hospitalized at a tertiary hos... more Clinical data from 91 patients with rheumatic fever (RF), who were hospitalized at a tertiary hospital in Lebanon between 1980 and 1995, were reviewed retrospectively. Age on hospitalization was 11.1 ± 2.9 years (mean ± SD, range 3-17 years). Nineteen patients were <6 years of age. Manifestations included carditis (93%), arthritis (39%), Sydenham's chorea (2%), erythema marginatum (4%), subcutaneous nodules (1%), fever (62%), arthralgia (55%), and acute congestive heart failure (CHF) on initial presentation (44%). Pericardial effusion occurred in 11%. There was positive family history of RF in 14%. Mitral insufficiency and aortic insufficiency occurred in 67 and 35%, respectively. Both mitral and aortic valves were involved in 30% of cases. Tricuspid insufficiency developed in 3% and pulmonary insufficiency in 1%. Mitral stenosis developed in 19%. Twentyeight patients underwent surgical intervention: mitral valve repair and commissurotomy in 9/91 (10%), mitral valve replacement in 18/91 (20%), and aortic valve replacement in 9/91 (10%). Overall mortality was 12%: 5 following surgical intervention (3 after mitral valve surgery and 2 after mitral and aortic valve surgery). All patients that died had CHF on initial presentation (p ‫ס‬ 0.006). This study includes hospitalized patients with predominant rheumatic heart disease. Initial presentation with CHF is a risk factor for surgical intervention and mortality. A significant high surgical intervention rate is noted that is probably related to the nature of the selected group studied. This study emphasizes the significant morbidity and death in patients with RF and carditis.

Research paper thumbnail of Research in Congenital Heart Disease: A Comparative Bibliometric Analysis Between Developing and Developed Countries

Pediatric Cardiology, 2013

Congenital heart disease (CHD) is the most common congenital anomaly, affecting 1 % of live birth... more Congenital heart disease (CHD) is the most common congenital anomaly, affecting 1 % of live births. The field of pediatric cardiology has witnessed major advances over the past 25 years triggered by research initiatives focusing on CHD. However, large disparities exist in research capabilities between Arab developing nations and the developed nations. This study used bibliometric analysis to assess the contribution of the Arab countries to CHD research. To identify articles on CHD published in the Arab countries, the United States, and Europe, a systematic search was run on MEDLINE, PubMed, and Scopus. The Arab countries, with an estimated population of 362 million, published 530 research articles addressing CHD in the last 25 years (average, 1.5 articles/10(6) population). This compares with 12,936 research articles published in the United States (average, 41 articles/10(6) population) and 12,260 published in Europe (average, 24.3 articles/10(6) population). Basic research relating to genetics and animal models of CHD is emerging sparsely in the Arab world, with few articles published in high-impact-factor journals. The Arab world research output in the field of CHD per capita is substantially low, estimated to be 29 times less than in developed countries. Despite the minimal increase in published research articles in global periodicals, most of the research relating to CHD continues to be far from innovative. Regional collaborations with international linkage are starting to evolve. The research facilities in the Arab countries need to increase substantially in research and infrastructure funding to keep up with the pace of research in developing countries.

Research paper thumbnail of Intrapericardial teratoma in an adult: A rare presentation

Medical and Pediatric Oncology, 1998

Intrapericardial teratomas are rare and usually present early in infancy or childhood. We describ... more Intrapericardial teratomas are rare and usually present early in infancy or childhood. We describe herein a rare case of an adult patient with an intrapericardial teratoma who presented with fever, cardiac arrhythmias, and oppressive substernal chest pain. Preoperative diagnosis was suggested by echocardiography and computerized tomography of the chest. The tumor weighed 530 g and its histologic features were those of a mature cystic teratoma. It was excised totally and 10 years&amp;amp;#39; follow-up revealed no evidence of residual disease. Our patient is one of the very few adult patients with intrapericardial teratomas who was treated successfully with surgery. Both echocardiography and tomography of the chest suggested the diagnosis and delineated the relationship of the tumor to the great vessels. The diagnosis of Intrapericardial teratomas is suspected by echocardiography and/or tomography of the chest and confirmed by specific histologic features. These tumors should be excised whenever detected.

Research paper thumbnail of Letter to the editor: Disappearance of patent ductus arteriosus in a child with leukemia receiving chemotherapy

Medical and Pediatric Oncology, 1998

Research paper thumbnail of Absence of GJA1 gene mutations in four patients with anomalous left coronary artery from the pulmonary artery (ALCAPA)

Le Journal médical libanais. The Lebanese medical journal

Anomalous left coronary artery from the pulmonary artery (ALCAPA) is a rare form of congenital he... more Anomalous left coronary artery from the pulmonary artery (ALCAPA) is a rare form of congenital heart disease with no known genetic cause. It is usually diagnosed within the first year of life; it results in myocardial cell death, congestive heart failure and lethality if left untreated. Connexin 43alpha1 is a member of the gap junction family of proteins demonstrated by animal studies to have a role in coronary artery patterning during development. No previous studies have investigated the role of this gene in patients with ALCAPA. We forth herein describe the clinical presentation of four patients who presented to the Children's Heart Center at AUBMC and had the final diagnosis of ALCAPA. Screening the GJA1 gene coding for connexin 43alpha1 was undertaken. No mutations were found in the patients or their parents, except for one polymorphism in one of the parents in the 3' untranslated region. All four patients underwent surgical repair with excellent outcome. This paper rai...

Research paper thumbnail of Cox-maze procedure for treatment of atrial flutter associated with an atrial septal defect

Clinical Cardiology, 2000

A 52-year-old man presented with atrial flutter and was found to have an atrial septal defect (AS... more A 52-year-old man presented with atrial flutter and was found to have an atrial septal defect (ASD). The paper describes an effective surgical approach for the treatment of this atrial arrhythmia utilizing a right sided Cox-maze III procedure concomitant with ASD closure. Review of the literature and clinical implications are discussed.

Research paper thumbnail of The status of pediatric cardiology at a tertiary center in Lebanon

Le Journal medical libanais. The Lebanese medical journal, 2011

PROBLEM Cardiac disease, both congenital and acquired, contributes significantly to morbidity and... more PROBLEM Cardiac disease, both congenital and acquired, contributes significantly to morbidity and mortality in children. METHODS This article describes the status of pediatric cardiology at the Children's Heart Center in the American University of Beirut Medical Center. It addresses the available clinical services as well as the research and educational activities that are present at a tertiary center in Lebanon, a developing country with a population of 4 million. RESULTS Lebanon has witnessed major developments in the field of pediatric cardiology over the past few years. About 650 babies are born with heart disease every year, with more than 425 needing treatment. Nearly all types of interventional catheterization procedures are currently being performed. About 300 open and closed pediatric cardiac surgeries are performed per year in Lebanon. In 2008, the in-hospital surgical mortality rate at our center was 2.6%, reflecting the good level of care in the treatment of children...

Research paper thumbnail of Large congenital left atrial wall aneurysm: An updated and comprehensive review of the literature

Echocardiography

Congenital left atrial wall aneurysms are rare abnormalities that arise from a developmental weak... more Congenital left atrial wall aneurysms are rare abnormalities that arise from a developmental weakness in the muscular wall. It may be misdiagnosed or go undetected and the delay in diagnosis can lead to catastrophic consequences.

Research paper thumbnail of Effect of Continuous Positive Airway Pressure on the Rapid Shallow Breathing Index in Patients Following Cardiac Surgery

Chest Journal, Feb 1, 2002

Research paper thumbnail of Cardiac growth patterns in response to chronic hypoxia in a neonatal rat model mimicking cyanotic heart disease

Experimental and clinical cardiology, 2003

Myocardial growth during fetal life is accomplished by the proliferation of myocytes. Shortly aft... more Myocardial growth during fetal life is accomplished by the proliferation of myocytes. Shortly after birth, normal myocytes largely lose their capability to replicate. The present study aims to assess the effect of persistent postnatal hypoxia on myocardial growth patterns in an animal model mimicking cyanotic heart disease. Sprague-Dawley rats were placed in a normobaric hypoxic environment at birth and oxygen levels were maintained at 10% (group H). Controls (group C) remained in room air. The animals were sacrificed and the hearts were harvested at one, four and eight weeks. Significant polycythemia developed in the hypoxic rats. There was a significant increase in indexed right ventricle (RV) and left ventricle (LV) masses compared with controls. Myocardial DNA concentrations were significantly increased in both ventricles of the hypoxic rats. For the RV, the increase in DNA content for group H was 135%, 132% and 112% that of group C values at one, four and eight weeks, respectiv...

Research paper thumbnail of The cleft sternum: a possible role for pliable prosthetic reconstruction

Le Journal médical libanais. The Lebanese medical journal

Faced with our intraoperative inability to primarily close a very wide isolated cleft sternum of ... more Faced with our intraoperative inability to primarily close a very wide isolated cleft sternum of a pediatric patient without causing cardiovascular decompensation, we describe our use of a synthetic material for partial approximation allowing muscular coverage. We report an infant who was born with an isolated large complete sternal cleft where a trial of primary surgical repair had to be abandoned because of cardiovascular compromise. A similar difficulty was encountered in approximating the origins of both pectoralis major muscle flaps at the midline. Thus, a pliable synthetic patch was helpful in partially obliterating the widened sternal defect allowing successful muscular coverage. Closure of a wide congenital sternal cleft using a synthetic material that partially obliterated an otherwise widely separated cleft sternum which was neither amenable for primary repair, nor by bilateral pectoralis major advancement alone, was possible. Strong prosthetic pliable material may offer a...

Research paper thumbnail of Equipoise between radial artery and right internal thoracic artery as the second arterial conduit in left internal thoracic artery-based coronary artery bypass graft surgery: a multi-institutional study†

European journal of cardio-thoracic surgery : official journal of the European Association for Cardio-thoracic Surgery, Jan 11, 2015

Multiple arterial coronary artery grafting (MABG) improves long-term survival compared with singl... more Multiple arterial coronary artery grafting (MABG) improves long-term survival compared with single arterial CABG (SABG), yet the best second arterial conduit to be used with the left internal thoracic artery (LITA) remains undefined. Outcomes in patients grafted with radial artery (RA-MABG) versus right internal thoracic artery (RITA-MABG) as the second arterial graft were compared with SABG. Multi-institutional, retrospective analysis of non-emergent isolated LITA to left anterior descending coronary artery CABG patients was performed using institutional Society of Thoracic Surgeon National Adult Cardiac Surgery Databases. 4484 (54.5%) SABG [LITA ± saphenous vein grafts (SVG)], 3095 (37.6%) RA-MABG (RA ± SVG) and 641 (7.9%) RITA-MABG (RITA ± SVG) patients were included. The RITA was used as a free (68%) or in situ (32%) graft. RA grafts were principally anastomosed to the ascending aorta. Long-term survival was ascertained from US Social Security Death Index and institutional follo...

Research paper thumbnail of Absence of GJA1 gene mutations in four patients with anomalous left coronary artery from the pulmonary artery (ALCAPA)

Le Journal médical libanais. The Lebanese medical journal

Anomalous left coronary artery from the pulmonary artery (ALCAPA) is a rare form of congenital he... more Anomalous left coronary artery from the pulmonary artery (ALCAPA) is a rare form of congenital heart disease with no known genetic cause. It is usually diagnosed within the first year of life; it results in myocardial cell death, congestive heart failure and lethality if left untreated. Connexin 43alpha1 is a member of the gap junction family of proteins demonstrated by animal studies to have a role in coronary artery patterning during development. No previous studies have investigated the role of this gene in patients with ALCAPA. We forth herein describe the clinical presentation of four patients who presented to the Children's Heart Center at AUBMC and had the final diagnosis of ALCAPA. Screening the GJA1 gene coding for connexin 43alpha1 was undertaken. No mutations were found in the patients or their parents, except for one polymorphism in one of the parents in the 3' untranslated region. All four patients underwent surgical repair with excellent outcome. This paper rai...

Research paper thumbnail of Bilateral percutaneous stent implantation in the pulmonary vasculature: a modality now available in Lebanon

Le Journal médical libanais. The Lebanese medical journal

We report a child with Truncus Arteriosus who developed bilateral proximal branch pulmonary steno... more We report a child with Truncus Arteriosus who developed bilateral proximal branch pulmonary stenosis, following total surgical repair of her condition with construction of the right ventricular outflow tract utilizing a Contegra conduit (Medtronic Inc., Minneapolis, Minn.). The obstruction was relieved completely utilizing bilateral percutaneous stent implantation. To the best of our knowledge, this is the first reported case of bilateral stent implantation to relieve branch pulmonary artery stenosis in Lebanon. This technique could be applied to similar cases of obstruction in the pulmonary tree.

Research paper thumbnail of Congenital heart disease at a tertiary care center in Lebanon

Middle East journal of anaesthesiology, 1999

To study the epidemiology of congenital heart disease (CHD) at the American University of Beirut-... more To study the epidemiology of congenital heart disease (CHD) at the American University of Beirut-Medical Center, we reviewed the medical records of all cardiac patients seen at our outpatient cardiology clinic (OPD) between 1980 and 1995. The charts of all patients with CHD seen as inpatients and/or outpatients at our center during the year 1995 were also reviewed. A cardiologist evaluated all patients and the diagnosis was confirmed at least by echocardiography. The frequency of CHD was reported among three groups: 1980-1995 OPD groups (Group A); the group with CHD seen during the year 1995 (Group B); and (Group C), a subgroup of group B, included all newborns with CHD born at our hospital during the year 1995. Stillbirth and premature infants with the diagnosis of patent ductus arteriosus were excluded from the study. Group A included 883 patients. 344 patients were evaluated in Group B, with a mean age of 3.8 years. The incidence of CHD was 11.5/1,000 live births at our center. T...

Research paper thumbnail of Total parenteral nutrition

Middle East journal of anaesthesiology, 1988

Research paper thumbnail of Complete cleft sternum and congenital heart disease: Review of the literature

Pediatrics International, 2002

Research paper thumbnail of An unusual case of hyperkalaemia-induced cardiac arrest in a paediatric patient during transfusion of a 'fresh' 6-day-old blood unit

Transfusion Medicine, 2002

A well-recognized complication of the transfusion of red blood cells (RBCs) is hyperkalaemia. Thi... more A well-recognized complication of the transfusion of red blood cells (RBCs) is hyperkalaemia. This occurs in paediatric or adult patients receiving massive transfusion and can lead to cardiac arrest. Hyperkalaemia may follow the transfusion of &#39;stored&#39; RBCs and/or haemolysed units, and depends on the quantity and rate of transfusion. We report on an unusual case of hyperkalaemia-induced cardiac arrest during transfusion of a &#39;fresh&#39; blood unit. A 62-day-old baby girl was scheduled for a construction of a Blalock-Taussig shunt, after the completion of anastomosis, and upon release of vascular control, there was bleeding at the anastomotic site that was controlled with a suture placement. To compensate for the blood loss, a stat order was given for a push of 120 mL of RBCs over 10 min through the inferior vena cava central line. The blood unit was 6 days old and had been gamma-irradiated 48 h earlier. Shortly after the transfusion, the patient&#39;s electrocardiogram showed changes typical of hyperkalaemia; she then went into cardiac asystole. The blood unit potassium concentration was 55.3 mmol L-1, which flushed the atrioventricular node during transfusion. This is the first report of a high potassium level found in a &#39;fresh&#39;, less than 7 days old, nonhaemolysed RBC blood unit. The high concentration of potassium in this unit seems to be due to accelerated alterations of the RBC sodium/potassium adenosine triphosphatase pump (Na+/K+ pump), resulting in the release of intracellular potassium. This early and severe alteration of the pump and the unusually high potassium level may be due to as yet unexplained causes, warranting awareness, future investigation and routine saline washing of &#39;fresh&#39; RBCs for paediatric patients who are candidates for central line transfusion.

Research paper thumbnail of Tissue-specific ceramide response in the chronically hypoxic rat model mimicking cyanotic heart disease

Prostaglandins & Other Lipid Mediators, 2003

Acute hypoxia is associated with apoptosis and increase in ceramide levels in various organs. To ... more Acute hypoxia is associated with apoptosis and increase in ceramide levels in various organs. To assess the effect of chronic hypoxia on ceramide accumulation in the lungs and kidneys, we utilized an animal model mimicking cyanotic heart disease. Rats were placed in a hypoxic environment at birth and oxygen levels were maintained at 10% in an air-tight Plexiglas chamber. Controls remained in room air. Animals were sacrificed and the lung and kidneys were harvested and weighed at 1 and 4 weeks, respectively. Ceramide levels were measured using a modified diacylglycerol kinase assay. Significant polycythemia developed in the hypoxic rats at 1 and 4 weeks. Indexed lung and kidney masses were significantly increased in the hypoxic animals as compared to controls at 1 and 4 weeks, respectively. The ceramide levels in the hypoxic lungs and kidneys were not significantly different from control groups at 1 and 4 weeks. [Ceramide/phosphate ratio in the kidneys was 1.28 +/- 0.17 (C) versus 1.18 +/- 0.12 (H) at 1 week; P = 0.39, and 1.46 +/- 0.08 (C) versus 1.33 +/- 0.15 (H) at 4 weeks (P = 0.44)] and [ceramide/phosphate ratio (pmol/nmol) in the lungs was 2.29 +/- 0.14 (C) versus 1.98 +/- 0.12 (H) at 1 week (P = 0.17), and 2.42 +/- 0.16 (C) versus 2.30 +/- 0.05 (H) at 4 weeks, P = 0.34]. The response of lungs and kidneys to chronic hypoxia includes increase in indexed mass and lack of ceramide accumulation. This is similar to the response previously reported in the chronically hypoxic brain and heart. Thus, various organs appear to have similar ceramide response pattern to chronic hypoxia.

Research paper thumbnail of Acute respiratory distress associated with external jugular vein catheterization in the newborn

Pediatric Pulmonology, 2003

We report on the acute onset of respiratory distress secondary to fluid accumulation in the chest... more We report on the acute onset of respiratory distress secondary to fluid accumulation in the chest within hours of placement of an external jugular venous line in a newborn. External jugular venous catheterization in the newborn is a procedure with potentially serious complications, and should be avoided unless the patient is monitored closely.

Research paper thumbnail of Rheumatic Fever in Children: A 15-Year Experience in a Developing Country

Pediatric Cardiology, 2000

Clinical data from 91 patients with rheumatic fever (RF), who were hospitalized at a tertiary hos... more Clinical data from 91 patients with rheumatic fever (RF), who were hospitalized at a tertiary hospital in Lebanon between 1980 and 1995, were reviewed retrospectively. Age on hospitalization was 11.1 ± 2.9 years (mean ± SD, range 3-17 years). Nineteen patients were <6 years of age. Manifestations included carditis (93%), arthritis (39%), Sydenham's chorea (2%), erythema marginatum (4%), subcutaneous nodules (1%), fever (62%), arthralgia (55%), and acute congestive heart failure (CHF) on initial presentation (44%). Pericardial effusion occurred in 11%. There was positive family history of RF in 14%. Mitral insufficiency and aortic insufficiency occurred in 67 and 35%, respectively. Both mitral and aortic valves were involved in 30% of cases. Tricuspid insufficiency developed in 3% and pulmonary insufficiency in 1%. Mitral stenosis developed in 19%. Twentyeight patients underwent surgical intervention: mitral valve repair and commissurotomy in 9/91 (10%), mitral valve replacement in 18/91 (20%), and aortic valve replacement in 9/91 (10%). Overall mortality was 12%: 5 following surgical intervention (3 after mitral valve surgery and 2 after mitral and aortic valve surgery). All patients that died had CHF on initial presentation (p ‫ס‬ 0.006). This study includes hospitalized patients with predominant rheumatic heart disease. Initial presentation with CHF is a risk factor for surgical intervention and mortality. A significant high surgical intervention rate is noted that is probably related to the nature of the selected group studied. This study emphasizes the significant morbidity and death in patients with RF and carditis.

Research paper thumbnail of Research in Congenital Heart Disease: A Comparative Bibliometric Analysis Between Developing and Developed Countries

Pediatric Cardiology, 2013

Congenital heart disease (CHD) is the most common congenital anomaly, affecting 1 % of live birth... more Congenital heart disease (CHD) is the most common congenital anomaly, affecting 1 % of live births. The field of pediatric cardiology has witnessed major advances over the past 25 years triggered by research initiatives focusing on CHD. However, large disparities exist in research capabilities between Arab developing nations and the developed nations. This study used bibliometric analysis to assess the contribution of the Arab countries to CHD research. To identify articles on CHD published in the Arab countries, the United States, and Europe, a systematic search was run on MEDLINE, PubMed, and Scopus. The Arab countries, with an estimated population of 362 million, published 530 research articles addressing CHD in the last 25 years (average, 1.5 articles/10(6) population). This compares with 12,936 research articles published in the United States (average, 41 articles/10(6) population) and 12,260 published in Europe (average, 24.3 articles/10(6) population). Basic research relating to genetics and animal models of CHD is emerging sparsely in the Arab world, with few articles published in high-impact-factor journals. The Arab world research output in the field of CHD per capita is substantially low, estimated to be 29 times less than in developed countries. Despite the minimal increase in published research articles in global periodicals, most of the research relating to CHD continues to be far from innovative. Regional collaborations with international linkage are starting to evolve. The research facilities in the Arab countries need to increase substantially in research and infrastructure funding to keep up with the pace of research in developing countries.

Research paper thumbnail of Intrapericardial teratoma in an adult: A rare presentation

Medical and Pediatric Oncology, 1998

Intrapericardial teratomas are rare and usually present early in infancy or childhood. We describ... more Intrapericardial teratomas are rare and usually present early in infancy or childhood. We describe herein a rare case of an adult patient with an intrapericardial teratoma who presented with fever, cardiac arrhythmias, and oppressive substernal chest pain. Preoperative diagnosis was suggested by echocardiography and computerized tomography of the chest. The tumor weighed 530 g and its histologic features were those of a mature cystic teratoma. It was excised totally and 10 years&amp;amp;#39; follow-up revealed no evidence of residual disease. Our patient is one of the very few adult patients with intrapericardial teratomas who was treated successfully with surgery. Both echocardiography and tomography of the chest suggested the diagnosis and delineated the relationship of the tumor to the great vessels. The diagnosis of Intrapericardial teratomas is suspected by echocardiography and/or tomography of the chest and confirmed by specific histologic features. These tumors should be excised whenever detected.

Research paper thumbnail of Letter to the editor: Disappearance of patent ductus arteriosus in a child with leukemia receiving chemotherapy

Medical and Pediatric Oncology, 1998