Whole-heart cine MRI using real-time respiratory self-gating.

Two-dimensional (2D) breath-hold cine MRI is used to assess cardiac anatomy and function. However, this technique requires cooperation from the patient, and in some cases the scan planning is complicated. Isotropic nonangulated three-dimensional (3D) cardiac MR can overcome some of these problems because it requires minimal planning and can be reformatted in any plane. However, current methods, even those that use undersampling techniques, involve breath-holding for periods that are too long for many patients. Free-breathing respiratory gating sequences represent a possible solution for realizing 3D cine imaging. A real-time respiratory self-gating technique for whole-heart cine MRI is presented. The technique enables assessment of cardiac anatomy and function with minimum planning or patient cooperation. Nonangulated isotropic 3D data were acquired from five healthy volunteers and then reformatted into 2D clinical views. The respiratory self-gating technique is shown to improve image quality in free-breathing scanning. In addition, ventricular volumetric data obtained using the 3D approach were comparable to those acquired with the conventional multislice 2D approach.     

Thoracic surgery in United Arab Emirates

The United Arab Emirates (UAE) has undergone a significant change in its population and economy in the last decades and in parallel its healthcare system has evolved rapidly to provide advanced, innovative and world-leading care. At the forefront of this revolution in healthcare is the development of a multidisciplinary multimodality thoracic service provision, offered at quaternary referral hospitals amalgamating academics, training, research and innovation. Previously, thoracic service care was limited to single providers at various public and private hospitals, usually performing lower complexity cases. Most complex thoracic cases were repatriated outside the UAE. This practice was replaced with the opening of Cleveland Clinic Abu Dhabi (CCAD), in 2015, which created a multidisciplinary thoracic program. This included the start of a mini-invasive surgical and lung transplantation program. Since that time other public and private hospitals have emerged providing care in a similar model. The impact of these programs has been a decreased transfer of patients abroad for treatment. Under the umbrella of the Emirates Thoracic Society (ETS) a platform for greater collaboration aimed at improving patient care, potential research and physician education has been created. Direct links have been established with world-leading Thoracic surgery and Respiratory Medicine Centers facilitating this development and offering support and guidance. This article charts these changes in thoracic care in the recent past, present, and delineates plans for the future in the UAE.     

Recurrent pleural effusion complicating liver cirrhosis

BACKGROUND: Pleural effusion (PE) is a rare complication of advanced liver cirrhosis, which may lead to an operation when uncontrolled. The purpose of this study was to evaluate the modality of the occurrence of pleural effusion and to describe its surgical management. METHODS: We studied 21 patients who were referred to the department of thoracic surgery because of massive and recurrent PE caused by liver cirrhosis. The PE was a transudate in 16 patients and an exudate in 5. Talc pleurodesis was attempted in all patients. The patients were divided into two groups. Video assisted thoracoscopy was performed in 13 patients in whom the clinical condition permitted general anesthesia; the pleural cavity was entirely explored before pleurodesis (group 1). Chest tube drainage alone was performed in 8 patients who were unable to undergo general anesthesia; talc pleurodesis was performed through the chest tube in these patients (group 2). RESULTS: In group 1 the PE was right-sided in 8 patients, left-sided in 3, and bilateral in 2. Diaphragmatic defects were observed in 2 patients, and a fluid leak oozing from the diaphragm was observed in 1 patient. Ten patients were considered cured and were without recurrence. Two patients underwent late recurrence before dying from their liver cirrhosis. Only 1 patient had an early recurrence that was cured by complementary talc slurry. In group 2 all patients presented with a right PE; of these, 3 patients died from septic shock caused by pleural infection. Three patients underwent early recurrence but were cured after repeat talc slurry. One patient had a midterm recurrence. One patient had an early recurrence treated by intrahepatic porto-systemic shunt with partial improvement. CONCLUSIONS: Passage of ascites through diaphragmatic defects appears to be the main cause of PE complicating cirrhosis. Patients may benefit from talc pleurodesis. Video assisted thoracoscopy pleurodesis is the technique of choice with consistent results. Repeated talc injection through the drain may prove useful for patients in poor clinical status.     

Superior hemodynamics in left heart bypass without systemic heparinization

Open-chest left heart bypass was performed in 10 canine experiments (30 +/- 9 kg) by a servo controlled roller pump for 6 h at a pump flow of 50 ml/min per kg bodyweight. The surfaces of the tubing sets were either standard (with systemic heparinization) or with end-point attached heparin (no systemic heparin). Besides continuous monitoring of hemodynamics, a standard battery of blood samples was taken before bypass, after 10 min and every hour thereafter. There is no evidence of increased fibrin production in the group with end-point attached heparin surfaces perfused without systemic heparinization. Superior hemodynamics in left heart bypass performed without systemic heparinization appear to be due to improved hemostasis, reduced blood loss and therefore reduced transfusion requirements. Left heart bypass with heparin-coated equipment has been successfully used for resection of a thoracoabdominal aneurysm in six patients.     

Luminal NaCl delivery regulates basolateral PGE2 release from macula densa cells

Macula densa (MD) cells express COX-2 and COX-2-derived PGs appear to signal the release of renin from the renal juxtaglomerular apparatus, especially during volume depletion. However, the synthetic machinery and identity of the specific prostanoid released from intact MD cells remains uncertain. In the present studies, a novel biosensor tool was engineered to directly determine whether MD cells release PGE2 in response to low luminal NaCl concentration ([NaCl]L). HEK293 cells were transfected with the Ca2+-coupled E-prostanoid receptor EP1 (HEK/EP1) and loaded with fura-2. HEK/EP1 cells produced a significant elevation in intracellular [Ca2+] ([Ca2+]i) by 29.6 +/- 12.8 nM (n = 6) when positioned at the basolateral surface of isolated perfused MD cells and [NaCl]L was reduced from 150 mM to zero. HEK/EP1 [Ca2+]i responses were observed mainly in preparations from rabbits on a low-salt diet and were completely inhibited by either a selective COX-2 inhibitor or an EP1 antagonist, and also by 100 microM luminal furosemide. Also, 20-mM graduated reductions in [NaCl]L between 80 and 0 mM caused step-by-step increases in HEK/EP1 [Ca2+]i. Low-salt diet greatly increased the expression of both COX-2 and microsome-associated PGE synthase (mPGES) in the MD. These studies provide the first direct evidence that intact MD cells synthesize and release PGE2 during reduced luminal salt content and suggest that this response is important in the control of renin release and renal vascular resistance during salt deprivation.     

Extra corporal membrane oxygenation in general thoracic surgery: a new single veno-venous cannulation

Extracorporeal membrane oxygenation (ECMO) is used in severe respiratory failure to maintain adequate gas exchange. So far, this technique has not been commonly used in general thoracic surgery. We present a case using ECMO for peri-operative airway management for pulmonary resection, using a novel single-site, internal jugular, veno-venous ECMO cannula.     

Effect of atrial fibrillation ablation on myocardial function: insights from cardiac magnetic resonance feature tracking analysis

Restoration of sinus rhythm may result in an improvement of left heart function in patients with atrial fibrillation (AF). Cardiovascular magnetic resonance (CMR) feature tracking (FT) technique may help detect subtle wall-motion abnormalities. Consequently this study aimed to analyse existence and reversibility of subclinical cardiac dysfunction following atrial fibrillation ablation. 28 consecutive patients (mean age 61 years) with paroxysmal AF underwent pulmonary vein isolation. CMR imaging was done 3 (±3) days before and 3.4 (±1.1) months after ablation. Left heart function was determined by performing FT analysis. Statistical analysis included paired student’s t test, random effects metaanalysis to assess the cohort’s health status and Bland–Altman analysis. 17 patients (61 %) were free from AF at follow-up. Bland–Altman analysis showed good coefficients of variation. Of all 195 parameters, 27 changed (14 %):9 improved significantly (5 %), 12 worsened significantly (6 %), whereas 6 parameters worsened not significantly (3 %). 18 of 120 systolic parameters changed (15 %), 14 worsened (12 %), 4 improved (3 %). In 9 of 75 diastolic parameters, values changed (12 %): 5 improved (7 %) and 4 worsened (5 %). Meta-analysis revealed that our collective’s FT values at baseline didn’t differ significantly from healthy volunteers’ values [Q values of 0.01 (p value 0.921) and 1.499 (p value 0.221)]. AF patients undergoing ablation appear to have near normal cardiac wall motion, which does not improve following successful ablation. Feature tracking analysis is a reliable tool to determine treatment effects but is more likely to show positive findings if the population is unhealthy.     

Effect of physical activity on levels of homocysteine,folate, and vitamin B12 in the elderly

Objectives: Homocysteine (Hcy) has emerged as a risk factor for cardiovascular diseases (CVD). However the relationship of physical activity (PA) with Hcy levels in the elderly is controversial. Accordingly, the current study examined the effect of low and high participation in PA on serum Hcy in young (n = 77; 18–50 years) and old (n = 207; > 65 years) males (n = 141) and females (n = 142). Methods: Level of PA was obtained in a 1-to-1 interview and participants divided into low and high groups. Serum Hcy, folate, and vitamin B₁₂ were obtained after 12 hour fast drawn by venipuncture. Results: Levels of Hcy correlated with folate (r = ?0. 5; p = 0.000) and vitamin B₁₂ (r = ?0.3; p = 0.000). The ANOVA revealed a main effect of PA for Hcy (p = 0.04) but not for folate (p = 0.2) and vitamin B₁₂ (p = 0.2). Main effects were found also of age for Hcy (p = 0.000) and folate (p = 0.005) as well as of gender for Hcy (p = 0.000) and vitamin B₁₂ (p = 0.000). Subsequent ANCOVA showed lower levels of Hcy in the participants with greater versus lower PA even after controlling for B₁₂ vitamin. Conclusion: These results confirm the importance of the vitamins for regulating Hcy levels. Additionally, the data suggests that PA affects Hcy levels without affecting and independent of B vitamins in the elderly.