Mounir Obeid

Vocal cord paralysis after open-heart surgery

Vocal cord paralysis is a known entity often described as a complication of neck surgery. A less frequent site of injury to the recurrent laryngeal nerve is the chest. The left side is usually more affected than the right side in view of its long intrathoracic segment. Only few cases of right vocal cord paralysis following open-heart surgery are reported in the literature. The purpose of this article is to review the common possible mechanisms of injury to the right recurrent laryngeal nerve following open-heart surgery in order to draw the attention of the caring physician to the clinical significance of such a complication. In fact, transient hoarseness following open-heart surgery may be an ominous sign of recurrent laryngeal nerve injury. It should not be assumed to be secondary to intralaryngeal edema. Several mechanisms of injury to the recurrent laryngeal nerve have been suggested: (1) through central venous catheterization; (2) by traction on the esophagus; (3) by direct vocal cord damage or palsy from a traumatic endotracheal intubation; (4) trauma by compression of the recurrent laryngeal nerve or its anterior branch at the tracheoesophageal groove by an inappropriately sized endotracheal tube cuff; (5) by a faulty insertion of a nasogastric tube; (6) median sternotomy and/or sternal traction pulling laterally on both subclavian arteries; (7) direct manipulation and retraction of the heart during open-heart procedures; (8) hypothermic injury with ice/slush. If vocal cord paralysis was overlooked as a possible complication of open-heart surgery, the patient may suffer from dysphonia in addition to problems of paramount importance such as inefficient cough and aspiration. Although it is true that the incidence of vocal cord paralysis remains very low, yet its presence is alarming and necessitates close follow up on the patient for the possible need of surgical intervention if recovery fails.

Ocular pathology in congenital heart disease.

AbstractPurposeTo describe the ocular findings in subjects with congenital heart disease (CHD).Methods In a prospective study, the same observer examined 240 consecutive patients with CHD admitted to the medical centre. Two independent geneticists performed identification of syndromes.ResultsThe commonest anatomic cardiac anomalies were ventricular or atrial septal defects (62), tetralogy of Fallot (39), pulmonary stenosis (25), and transposition of the great arteries (24). The heart lesions were divided physiologically into volume overload (90), cyanotic (87), and obstructive (63). In all, 105 syndromic subjects included the velocardiofacial syndrome (18), Downs syndrome (17), CHARGE association (6), DiGeorge syndrome (5), Williams syndrome (3), Edwards syndrome (3), Noonan syndrome (3), VACTERL association (2), and Patau syndrome (trisomy 13) (2). The paediatric team recognized 51 patients as syndromic. Two independent geneticists recognized additional 54 patients as syndromic. Positive eye findings were present in 55% (132) and included retinal vascular tortuosity (46), optic disc hypoplasia (30), trichomegaly (15), congenital ptosis (12), strabismus (11), retinal haemorrhages (8), prominent eyes (7), and congenital cataract (6). There was a strong correlation between the retinal vascular tortuosity and both a low haematocrit (P=0.000) and a low arterial oxygen saturation (P=0.002).ConclusionsPatients with CHD are at a high risk for ocular pathology and need screening for various ocular abnormalities.

Traumatic pseudoaneurysm of the left sinus of Valsalva: a case report.

Deceleration injuries of the aorta result in tears that often lead to exsanguinating hemorrhage. The site is most often at the aortic isthmus, with injuries of the aortic root being rare. A minority of patients survive long enough to reach the hospital where prompt diagnosis and treatment are essential for survival. We hereby report on a patient who had a pseudoaneurysm of the left sinus of Valsalva 13 years after a deceleration accident, presumably caused by a contained rupture of the aortic root. Transesophageal echocardiography was of great value in studying the features of the pseudoaneurysm and its relation to the left main coronary artery and left upper pulmonary vein.

Endocrine Changes in a Rat Model of Chronic Hypoxia Mimicking Cyanotic Heart Disease

Objective. The endocrine system plays an important role in the adaptation to hypoxia. The aim of this study is to assess the effect of chronic hypoxia on endocrine changes in a neonatal animal model mimicking cyanotic heart disease. Methods. Sprague–Dawley rats were placed in a normobaric hypoxic environment at birth and oxygen levels were maintained at 10% in an airtight Plexiglas chamber. Controls remained in room air. Animals were sacrificed at 4 and 8 weeks of life. Hematocrit, Free T4 (FT4), Thyrotropin (TSH), corticosterone, and Growth hormone (GH) were measured. Results. Significant polycythemia developed in the hypoxic rats. Free T4 levels were significantly lower in the hypoxic (H) group compared to the control (C) group at 4 and 8 weeks with FT4 of 2.44 ± 1.11 ng/dL (H) and 4.35 ± 1.62 (C) at 4 weeks with a p value <0.005 and FT4 of 2.01 ± 0.36 (H) and 3.25 ± 0.54 (C) ng/dL at 8 weeks with p < 0.01. At 8 weeks TSH levels were significantly lower in the hypoxic group (1.84 ± 0.9 ng/mL (H) vs. 3.11 ± 1.1 (C)) with p < 0.05. Corticosterone levels were higher in the hypoxic group with values of 126 ± 14.8 ng/mL (H) and 114.1 ± 12.6 (H) at 4 and 8 weeks respectively, when compared to the control group with values of 82.9 ± 18.1 (C) and 92.7 ± 10.3 (C) and 4 and 8 weeks with p < 0.0005 and <0.05 respectively. Growth hormone levels were significantly lower in the hypoxic group at 4 and 8 weeks with p < 0.05 and p < 0.001, respectively. Conclusion. Chronic hypoxia in our neonatal rat model was associated with a decrease in growth hormone levels and an increase in corticosterone levels. Furthermore, hypoxia resulted in thyroid hormone axis suppression. This effect seems to be centrally mediated.

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

OBJECTIVES 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. METHODS 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 follow-up. Triplet propensity matching and covariate-adjusted multivariate logistic regression were used to adjust for baseline differences between study cohorts. RESULTS Compared with the SABG cohort, the RITA-MABG cohort was younger (58.6 ± 10.2vs65.9 ± 10.4, P < 0.001), had a higher prevalence of males (87% vs 65%, P < 0.001) and was generally healthier (MI: 36.7% vs 56.7%, P < 0.001, smoking: 56.8% vs 61.1%, IDDM: 3.0% vs 14.4%, CVA: 2.6% vs 10.0%). The RA-MABG cohort was generally characterized by a risk profile intermediate to that of SABG and RlTA-MABG. Unadjusted 5-, 10- and 15-year survival rates were best in RITA-MABG (95.2%, 89% and 82%), intermediate in RA-MABG (89%, 74%, 57%) and worst in SABG (82%, 61% and 44%) cohorts (all P < 0.001). Propensity matching yielded 551 RA-MABG, RITA-MABG and SABG triplets, which showed similar 30-day mortality. Late survival (16 years) was equivalent in the RA-MABG and RITA-MABG cohorts [68.2% vs 66.7%, P = 0.127, hazard ratio (HR) = 1.28 (0.96-1.71)] and both significantly better than SABG (61.1%). The corresponding SABG versus RITA-MABG and SABG versus RA-MABG HRs (95% confidence interval) were 1.52 (1.18-1.96) and 1.31 (1.01-1.69) with P < 0.002 and P = 0.038, respectively. CONCLUSIONS RA-MABG or RITA-MABG equally improve long-term survival compared with SABG and thus should be embraced by the Heart Team as the therapy of choice in LITA-based coronary artery bypass surgery.

Complete cleft sternum and congenital heart disease: review of the literature.

Cleft sternum is a rare malformation due to failure of sternal fusion. It forms a distinct entity from the thoracic subtype of ectopia cordis where there is extra mediastinal displacement of the heart with various degrees of sternal clefting. The intrinsic cardiac anomalies contribute to a very high neonatal mortality rate.1 Isolated cleft of the sternum which is extremely rare has not been commonly associated with cardiac anomalies and usually has a very good prognosis. We reviewed a total of 35 cases of isolated complete cleft sternum (CCS) published since 1900, with their associated anomalies. We report, to the best of our knowledge, a newborn male with complete cleft sternum and a previously unreported association of cardiac malformation consisting of mesocardia, double outlet right ventricle (DORV), large subarterial ventricular septal defect (VSD) and pulmonary hypertension.

Coronary artery bypass grafting after pneumonectomy

The need to perform coronary artery bypass grafting in patients who have a single lung is not uncommon. To date, the safety of such procedures has not been well documented. In this article, we review the literature using the Medline 1966 to September 2000 database to identify patients with pneumonectomy who underwent coronary artery grafting and we provide a compilation of all reported cases. We also present an additional case in whom the use of nasal bilevel positive airway pressure was beneficial in preventing postoperative pulmonary complications.

Effect of aminophylline on complete atrioventricular block with ventricular asystole following blunt chest trauma

A 39-year-old man was the driver of a car involved in an accident, in which he was thrown forward against the steering wheel. On presentation to the emergency room of a local hospital, he was hypotensive and in respiratory distress. The electrocardiogram (ECG), as reported, showed sinus tachycardia. He was intubated, stabilized and transferred to our institution 5 h later. Upon arrival, his pulse was faint and slow. The ECG showed evidence of complete AV-block with ventricular asystole (Fig. 1A). He received 1 mg of atropine IV three times at 3 min intervals and 1 mg of epinephrine IV to no avail. Arrangements for internal cardiac pacing were made, however, following the administration of 500 mg of aminophylline IV, his heart rate increased to 75 (Fig. 1B) and then 150 beats/min (Fig. 1C), at 3 and 5 min, respectively. His ECG reverted to normal sinus rhythm (Fig. 2) with left anterior hemiblock (LAHB) and T-wave inversion in I and aVL 10 min later with a blood pressure of 120/80 mmHg. Echocardiography revealed flailing of the anterior leaflet of the tricuspid valve with severe tricuspid regurgitation. He was admitted to the intensive care unit with a smooth course. Two months later, he was asymptomatic but with persistent LAHB and grade II–III tricuspid regurgitation.

Rupture of sinus of Valsalva aneurysm with aorto-biventricular fistulas and right-ventricular outflow tract obstruction: a unique association.

Sinus of Valsalva aneurysms are a rare entity. Rupture of such aneurysms is a major cause of aortocardiac fistulas usually occurring between the right sinus of Valsalva and right cardiac chambers. We report an exceptional case of a ruptured congenital sinus of Valsalva aneurysm with fistulas involving both the right- and left-ventricular outflow tracts and causing RVOT obstruction. We also demonstrate the utility of computed tomography angiography and transesophageal echocardiography in diagnosing these fistulas.

Role of glucagon-like peptide-1 analogues on insulin receptor regulation in diabetic rat hearts

This study focused on the regulation and affinity modulation of the insulin receptor of coronary endothelium and cardiomyocytes in nondiabetic and STZ-induced type 1 diabetic rats. Male rats were divided into the following 9 groups: nondiabetic (N), nondiabetic treated with exendin-4 (NE), nondiabetic treated with dipeptidyl peptidase IV (DPP-IV) inhibitor (NDp), diabetic (D), diabetic treated with insulin (DI), diabetic treated with exendin-4 (DE), diabetic co-treated with insulin and exendin-4 (DIE), diabetic treated with DPP-IV inhibitor (DDp), and diabetic co-treated with insulin and DPP-IV inhibitor (DIDp). After the rats were treated for 1 month, a first-order Bessel function was employed to estimate the insulin binding affinity (with time constant tau = 1/k-n) to its receptors on the coronary endothelium and cardiomyocytes using CHAPS-untreated and CHAPS-treated heart perfusion, respectively. The results showed that diabetes (D) decreased the tau value on the coronary endothelium and increased it on cardiomyocytes compared with the nondiabetic group (N). Treatment with insulin and (or) exendin-4, a glucagon-like peptide-1 (GLP-1) analogue, increased tau on the coronary endothelium only. On the coronary endothelium, tau values of DI and DIDp were normalized. Western blots of the insulin receptor showed upregulation in D, downregulation in DI, and normalization in DE and DDp. Immunohistochemistry and RT-PCR findings indicated atrial natriuretic factor (ANF) in all diabetic ventricles, thus ascertaining hypertrophy. Therefore, negative myocardial effects related to the insulin receptor were diminished in diabetic rats treated with DPP-IV inhibitor and, more efficiently, by exendin-4.