Rabin Gerrah - Academia.edu (original) (raw)

Papers by Rabin Gerrah

Circulation, Nov 23, 2010

Background: Optimizing biventricular pacing (BiVP) with RV-first pacing increases cardiac output ... more Background: Optimizing biventricular pacing (BiVP) with RV-first pacing increases cardiac output in acute RV pressure overload (RVPO). We tested the hypothesis that regional LV strain measurements ...

The complex three-dimensional (3D) anatomy of the cardiovascular system presents a steep learning... more The complex three-dimensional (3D) anatomy of the cardiovascular system presents a steep learning obstacle to patients in understanding cardiovascular diseases and surgical procedures. Although 3D printed models have become very popular in surgical education, 2D cross-sections remain standard in clinical practice due to costs and availability. In this report, we demonstrate how the free 3D modeling software Meshmixer can be used to add a fourth dimension to patient education by exploiting interactive 3D modeling. This report serves as proof of concept for the feasibility and potential utility of interactive 3D modeling as an inexpensive tool for cardiovascular surgery patient education.

Studies in health technology and informatics, 2013

Clot formation is a common complication in extracorporeal circuits. In this paper we describe a n... more Clot formation is a common complication in extracorporeal circuits. In this paper we describe a novel method for clot formation analysis using image processing. We assembled a closed extracorporeal circuit and circulated blood at varying speeds. Blood filters were placed in downstream of the flow, and clotting agents were added to the circuit. Digital images of the filter were subsequently taken, and image analysis was applied to calculate the density of the clot. Our results show a significant correlation between the cumulative size of the clots, the density measure of the clot based on image analysis, and flow duration in the system.

AIMS Biophysics, 2020

A modified Blalock-Taussig shunt (MBTS) is an aortopulmonary shunt to establish or augment pulmon... more A modified Blalock-Taussig shunt (MBTS) is an aortopulmonary shunt to establish or augment pulmonary perfusion in congenital cardiac defects with limited pulmonary blood flow. Proper function of this shunt is of utmost importance. In clinical practice, prediction of flow in an MBTS relies on previous experience. In the research field, computational modeling techniques have been developed to simulate flow in an MBTS and predict its performance. These techniques are promising but also time consuming and prone to uncertainties; therefore not yet suitable for clinical practice. Here we present a simplified, patient-based computational model to predict mean circulatory flow characteristics after MBTS insertion. Simulations performed over a range of pulmonary vascular resistances, were compared to data from: i) previous modeling studies; ii) data from the specific patient modeled, and iii) a cohort of patients with MBTS. Model predictions were within one standard deviation from cohort data; and within 1% from results of previous (more complex) computational models. In comparison to previous studies, our model is computationally stable with significantly shorter computational time to perform simulations. We envision that our approach could be used in the future to perform virtual surgeries, quickly testing different surgical scenarios using the patient own geometrical and physiological characteristics, to aid surgeons in decision making.

World Journal for Pediatric and Congenital Heart Surgery, 2019

Anomalous connection of the superior vena cava to the morphologic left atrium is a rare congenita... more Anomalous connection of the superior vena cava to the morphologic left atrium is a rare congenital systemic venous abnormality. As opposed to pulmonary venous anomalies, the significant right-to-left shunt in these patients warrants a correction early in life. Optimal repair technique for combined pulmonary and systemic venous anomalies is not defined yet. Herein, we describe a neonate with such a diagnosis treated with cavoatrial anastomosis, known as Warden procedure with excellent results.

The Annals of thoracic surgery, Jan 27, 2017

All biological processes are governed by principles of physics that dictate the pathophysiology a... more All biological processes are governed by principles of physics that dictate the pathophysiology and even the treatment of congenital heart diseases. In this review, basic concepts such as flow, pressure, resistance, and velocity are introduced, followed by more complex laws that describe the relationship between these variables and the disease processes. Finally, physical phenomena such as turbulence, steal and runoff phenomenon, and energy loss are discussed. By application of these principles, one can accurately quantify modifications undertaken to treat diseases, for example, the size of a patch that augments a vessel and the angle of an anastomosis to allow a certain flow.

The Israel Medical Association journal : IMAJ, 2003

About 40% of patients with infective endocarditis will require surgical treatment. The guidelines... more About 40% of patients with infective endocarditis will require surgical treatment. The guidelines for such treatment were formulated by the American College of Cardiology and American Heart Association in 1998. To examine our experience with surgical treatment of infective endocarditis in light of these guidelines. Surgery was performed in 59 patients with infective endocarditis between 1990 and 1999. The patients' mean age was 48 years (range 13-80). The indications for surgery were hemodynamic instability, uncontrolled infection, and peripheral embolic events. The surgical treatment was based on elimination of infection foci and correction of the hemodynamic derangement. These objectives were met with valve replacement in the majority of patients. Whenever conservative surgery was possible, resection of vegetation and subsequent valve repair were performed and the native valve was preserved. Six patients (10%) died perioperatively from overwhelming sepsis (n = 3), low cardiac ...

Pediatric cardiology, Jan 3, 2015

We reviewed our experience of surgical repair of Tetralogy of Fallot (TOF) in children weighing l... more We reviewed our experience of surgical repair of Tetralogy of Fallot (TOF) in children weighing less than or equal to 4 kg to compare outcome of early palliation versus complete repair as the initial surgical approach. Seventy-six patients, weighing ≤4 kg, with TOF surgery between January 2005 and September 2013 were included in this single-center retrospective study. Twenty-five patients who underwent initial shunt procedure followed by later full repair were compared to 51 patients who had primary full repair for differences in baseline characteristics and outcomes. Shunt group patients had lower body weight, 2.76 ± 0.69 versus 3.11 ± 0.65 (kg), p = 0.03, and lower preoperative oxygen saturations, 82 ± 7 versus 90 ± 6 (%), p = 0.0001, than full repair group. A higher number of surgical procedures per patient was recorded in shunt patients, 2.29 ± 0.59 versus 1.27 ± 0.49, p = 0.00002. Thirteen of 51 patients in the full repair group required a repeat surgery. Catheterization proced...

Innovations (Philadelphia, Pa.), 2007

Objectives: During cardiac surgery, platelets undergo substantial changes. The purpose of this st... more Objectives: During cardiac surgery, platelets undergo substantial changes. The purpose of this study was to assess platelet function and compare these changes between different cardiac operations using an innovative technology. Methods: Perioperative platelet function was evaluated by the Impact test [cone and plate(let) analyzer (CPA)]. The Impact test yields 2 parameters for platelet function: average size (AS, the mean size of the platelet aggregates) and surface coverage (SC, the percentage of the surface covered by the platelet aggregates), which correspond to platelet aggregation and adhesion. The study groups were compared for platelet function results in various surgery stages and correlation with bleeding. Results: A significant decrease in surface coverage was detected on establishment of cardiopulmonary bypass, with an increase up to preoperative values at the end of the surgery in all groups. In contrast to operations performed on bypass, in patients operated without cardiopulmonary bypass, the postoperative AS and SC were higher than the preoperative values, 30.4 Ϯ 8.1 mol 2 versus 23.3 Ϯ 6.9 mol 2 , P ϭ 0.02 in AS, and 7.6 Ϯ 3.6% versus 5.2 Ϯ 1.8%, P ϭ 0.04 in SC. Preoperative AS and SC were the only parameters significantly (P ϭ 0.01) and linearly (r ϭ 0.6) related to postoperative bleeding. Conclusions: Preoperative platelet function, as evaluated by the CPA, is an independent risk factor determining postoperative bleeding. The off-pump patients presented an increased platelet function at the end of surgery, a finding that can imply a higher risk of thrombosis. The impact test appears to be a useful tool to determine perioperative platelet function and help in prediction of postoperative bleeding.

The Israel Medical Association journal : IMAJ, 2003

Cardiac surgery is being performed with increasing frequency in patients aged 80 years and older.... more Cardiac surgery is being performed with increasing frequency in patients aged 80 years and older. To examine the long and short-term results of surgery in this age group. We retrospectively investigated 202 consecutive patients aged 80 years or older who underwent cardiac surgery between 1991 and 1999, Ninety-six operations (48%) were urgent. The study group comprised 140 men (69%) and 62 women (31%) with a mean age of 82.1 years (range 80-89). Preoperatively, 120 patients (59%) had unstable angina, 37 (18%) had left main coronary artery disease, 22 (11%) had renal failure, 17 (8.5%) had a history of stroke and 13 (6.5%) had previous cardiac surgery. Hospital mortality for the whole group was 7.4%. Postoperative complications included: re-exploration for bleeding in 15 (7.4%), stroke in 8 (4%), sternal wound infection in 3 (1.5%), low cardiac output in 17 (8.4%), new Q wave myocardial infarction in 5 (2.5%), renal failure in 17 (8.5%), and atrial fibrillation in 71 (35%). The actuar...

The Annals of Thoracic Surgery, 2015

Seminars in Thoracic and Cardiovascular Surgery: Pediatric Cardiac Surgery Annual, 2013

Neonatal patients with hypoplasia of the aortic arch constitute a heterogeneous group with a wide... more Neonatal patients with hypoplasia of the aortic arch constitute a heterogeneous group with a wide spectrum of severity. The milder end of the spectrum comprises patients with aortic coarctation and isthmus hypoplasia. At the other end of the spectrum are patients with severe transverse arch hypoplasia or hypoplastic left heart syndrome. The aim of this paper is to discuss the various strategies and surgical approaches available for this group of patients, focusing on the surgical decisions that influence individual patient management. Many of the things discussed are applicable to any neonatal arch problem. We also describe and discuss in detail our surgical technique for patients who undergo neonatal repair of a hypoplastic aortic arch via median sternotomy.

The Heart Surgery Forum, 2005

The Heart Surgery Forum, 2004

Background: Off-pump coronary artery bypass (OPCAB) is believed to reduce cardiopulmonary bypass ... more Background: Off-pump coronary artery bypass (OPCAB) is believed to reduce cardiopulmonary bypass (CPB)-related complications, including platelet damage. A hypercoagulable state instead of coagulopathy has been reported following OPCAB surgeries due to CPB. Whether platelet function is changed when the injurious effect of CPB is eliminated was investigated. Methods: Platelet function was determined with the cone and plate(let) analyzer (CPA) method. The 2 parameters, average size (AS) and surface coverage (SC) of platelet aggregates, were measured with the CPA method to assess platelet aggregation and adhesion. These parameters were evaluated, and their values were compared at several stages of OPCAB surgery. The correlations of postoperative bleeding with platelet function at different stages of the surgery and with other factors, such as platelet count, hematocrit, and transfusions, were studied. Results: Both AS and SC increased during several stages of the operation, and postoperative values (mean ± SD) were significantly higher than preoperative values (30.4 ± 8.1 µm 2 versus 23.3 ± 6.9 µm 2 for AS [P = .02] and 7.6% ± 3.6% versus 5.2% ± 1.8% for SC [P = .04]). The mean total bleeding volume was 875 ± 415 mL. Preoperative AS and SC were the only parameters significantly (P = .01) and linearly (r = 0.7) related to postoperative bleeding. Conclusions: An increased platelet function, as determined by the CPA method, is found following OPCAB surgery. This phenomenon is probably at least partially responsible for the thrombogenic state after OPCAB surgery. Lack of platelet injury attributed to CPB may divert the system toward a more thrombogenic state. Preoperative platelet function, as evaluated by the CPA method, is an independent risk factor determining postoperative bleeding.

Pediatric Transplantation, 2012

Pediatric patients bridged to heart transplant with LVADs require chronic anticoagulation and are... more Pediatric patients bridged to heart transplant with LVADs require chronic anticoagulation and are at increased risk of hemorrhagic complications, including intracranial hemorrhage. In this population, intracranial hemorrhage is often fatal. We report a case of successful management of a five-yr-old-boy with DCM on an LVAD who developed a subdural hematoma. We initially chose medical management, weighing the patient's high risk of thromboembolism from anticoagulation reversal against the risk of his chronic subdural hematoma. When head CT showed expansion of the hemorrhage with increasing midline shift, we chose prompt surgical evacuation of the hematoma with partial reversal of anticoagulation, given the increased risk of acute deterioration. The patient ultimately received an orthotopic heart transplant and was discharged with no permanent neurological complications. This represents a case of a pediatric patient on an LVAD who survived a potentially fatal subdural hematoma and was successfully bridged to cardiac transplantation.

The Journal of Thoracic and Cardiovascular Surgery, 2011

Journal of Surgical Research, 2012

Background: We used speckle-tracking echocardiography to test the hypothesis that regional left v... more Background: We used speckle-tracking echocardiography to test the hypothesis that regional left ventricular (LV) strain would improve during optimized biventricular pacing (BiVP) in acute right ventricular (RV) pressure overload (PO). Materials and methods: Complete heart block and RVPO were induced in five open-chest fully anesthetized pigs. BiVP was optimized by adjusting atrioventricular and interventricular delays to maximize cardiac output derived from an aortic flow probe. LV short axis views were obtained during atrio-RV pacing (RVP), atrio-LV pacing (LVP), and BiVP. Intraventricular synchrony was assessed by comparing speckle-tracking echocardiography-derived time to peak (TTP) strain in the anterior septal (AS) and posterior wall segments. Segmental function was assessed using radial strain. Results: Cardiac output was higher with optimized (RV first) BiVP than with L VP (0.96 ± 0.26 L/min versus 0.89 ± 0.27 L/min; P = 0.05). AS TTP strain (502 ± 19 ms) during LVP was prolonged versus BiVP (392 ± 58 ms) and versus RVP (390 ± 53 ms) (P = 0.0018). AS TTP strain during LVP was prolonged versus posterior (502 ± 19 ms versus 396 ± 72 ms, P = 0.0011). No significant difference in TTP strain in these segments was seen with BiVP or RVP. Posterior strain (20% ± 5%) increased 66% versus AS strain (12% ± 6%) during BiVP (P = 0.0029). A similar increase occurred during RVP (posterior 20% ± 3% versus AS 12% ± 7%, P = 0.0002). Posterior strain did not increase during LVP. Conclusions: BiVP and RVP restore intraventricular LV synchrony and increase regional function versus LVP during RVPO. RV pre-excitation unloads the RV and reduces the duration of AS contraction, facilitating synchrony of all LV segments and increasing free wall LV contraction.

JACC: Cardiovascular Interventions, 2013

We prospectively included patients admitted to our department for acute HF or exacerbation of chr... more We prospectively included patients admitted to our department for acute HF or exacerbation of chronic HF between December 2010 and May 2011. We excluded patients over 80 years old, those with severe renal failure (GFR Ͻ 50ml/min/1.73 m2) or severe worsening of renal function during hospitalization and patients having dysthyroidism or under immunosuppressive therapy. A dosage of plasmatic cystatin C concentration was done using particule-enhanced turbidimetric immunoassay method. The main endpoint was death at a 120 days follow up. Results: Sixty four patients were enrolled, aged 62.2 Ϯ 11.4 years, with a sex ratio of 1.56. Patients were at NYHA class III or IV at admission in 87% of cases, with an ischemic etiology in 55% of cases. LVEF was 51.7 Ϯ 13.8% and GFR was 76 Ϯ 19.8 ml/min. Mean cystatin C was 1.42 Ϯ 0.37 mg/l. During follow-up, 10 (15.6%) patients died. Higher levels of Cystatin C (third tertile) were associated with a significant increase in mortality rate with an RR of 8 when moving from the first to the third tertile and a RR of 3 when moving from the second to the third (pϭ0.033). Prognostic value is uncertain for milder elevations between the first and second tertiles (pϭ0.45). Conclusion: A high level of Cystatin C at admission is a strong predictor of 120-days mortality among patients with HF. Discriminative value falls for milder elevations.

Circulation, Nov 23, 2010

Background: Optimizing biventricular pacing (BiVP) with RV-first pacing increases cardiac output ... more Background: Optimizing biventricular pacing (BiVP) with RV-first pacing increases cardiac output in acute RV pressure overload (RVPO). We tested the hypothesis that regional LV strain measurements ...

The complex three-dimensional (3D) anatomy of the cardiovascular system presents a steep learning... more The complex three-dimensional (3D) anatomy of the cardiovascular system presents a steep learning obstacle to patients in understanding cardiovascular diseases and surgical procedures. Although 3D printed models have become very popular in surgical education, 2D cross-sections remain standard in clinical practice due to costs and availability. In this report, we demonstrate how the free 3D modeling software Meshmixer can be used to add a fourth dimension to patient education by exploiting interactive 3D modeling. This report serves as proof of concept for the feasibility and potential utility of interactive 3D modeling as an inexpensive tool for cardiovascular surgery patient education.

Studies in health technology and informatics, 2013

Clot formation is a common complication in extracorporeal circuits. In this paper we describe a n... more Clot formation is a common complication in extracorporeal circuits. In this paper we describe a novel method for clot formation analysis using image processing. We assembled a closed extracorporeal circuit and circulated blood at varying speeds. Blood filters were placed in downstream of the flow, and clotting agents were added to the circuit. Digital images of the filter were subsequently taken, and image analysis was applied to calculate the density of the clot. Our results show a significant correlation between the cumulative size of the clots, the density measure of the clot based on image analysis, and flow duration in the system.

AIMS Biophysics, 2020

A modified Blalock-Taussig shunt (MBTS) is an aortopulmonary shunt to establish or augment pulmon... more A modified Blalock-Taussig shunt (MBTS) is an aortopulmonary shunt to establish or augment pulmonary perfusion in congenital cardiac defects with limited pulmonary blood flow. Proper function of this shunt is of utmost importance. In clinical practice, prediction of flow in an MBTS relies on previous experience. In the research field, computational modeling techniques have been developed to simulate flow in an MBTS and predict its performance. These techniques are promising but also time consuming and prone to uncertainties; therefore not yet suitable for clinical practice. Here we present a simplified, patient-based computational model to predict mean circulatory flow characteristics after MBTS insertion. Simulations performed over a range of pulmonary vascular resistances, were compared to data from: i) previous modeling studies; ii) data from the specific patient modeled, and iii) a cohort of patients with MBTS. Model predictions were within one standard deviation from cohort data; and within 1% from results of previous (more complex) computational models. In comparison to previous studies, our model is computationally stable with significantly shorter computational time to perform simulations. We envision that our approach could be used in the future to perform virtual surgeries, quickly testing different surgical scenarios using the patient own geometrical and physiological characteristics, to aid surgeons in decision making.

World Journal for Pediatric and Congenital Heart Surgery, 2019

Anomalous connection of the superior vena cava to the morphologic left atrium is a rare congenita... more Anomalous connection of the superior vena cava to the morphologic left atrium is a rare congenital systemic venous abnormality. As opposed to pulmonary venous anomalies, the significant right-to-left shunt in these patients warrants a correction early in life. Optimal repair technique for combined pulmonary and systemic venous anomalies is not defined yet. Herein, we describe a neonate with such a diagnosis treated with cavoatrial anastomosis, known as Warden procedure with excellent results.

The Annals of thoracic surgery, Jan 27, 2017

All biological processes are governed by principles of physics that dictate the pathophysiology a... more All biological processes are governed by principles of physics that dictate the pathophysiology and even the treatment of congenital heart diseases. In this review, basic concepts such as flow, pressure, resistance, and velocity are introduced, followed by more complex laws that describe the relationship between these variables and the disease processes. Finally, physical phenomena such as turbulence, steal and runoff phenomenon, and energy loss are discussed. By application of these principles, one can accurately quantify modifications undertaken to treat diseases, for example, the size of a patch that augments a vessel and the angle of an anastomosis to allow a certain flow.

The Israel Medical Association journal : IMAJ, 2003

About 40% of patients with infective endocarditis will require surgical treatment. The guidelines... more About 40% of patients with infective endocarditis will require surgical treatment. The guidelines for such treatment were formulated by the American College of Cardiology and American Heart Association in 1998. To examine our experience with surgical treatment of infective endocarditis in light of these guidelines. Surgery was performed in 59 patients with infective endocarditis between 1990 and 1999. The patients' mean age was 48 years (range 13-80). The indications for surgery were hemodynamic instability, uncontrolled infection, and peripheral embolic events. The surgical treatment was based on elimination of infection foci and correction of the hemodynamic derangement. These objectives were met with valve replacement in the majority of patients. Whenever conservative surgery was possible, resection of vegetation and subsequent valve repair were performed and the native valve was preserved. Six patients (10%) died perioperatively from overwhelming sepsis (n = 3), low cardiac ...

Pediatric cardiology, Jan 3, 2015

We reviewed our experience of surgical repair of Tetralogy of Fallot (TOF) in children weighing l... more We reviewed our experience of surgical repair of Tetralogy of Fallot (TOF) in children weighing less than or equal to 4 kg to compare outcome of early palliation versus complete repair as the initial surgical approach. Seventy-six patients, weighing ≤4 kg, with TOF surgery between January 2005 and September 2013 were included in this single-center retrospective study. Twenty-five patients who underwent initial shunt procedure followed by later full repair were compared to 51 patients who had primary full repair for differences in baseline characteristics and outcomes. Shunt group patients had lower body weight, 2.76 ± 0.69 versus 3.11 ± 0.65 (kg), p = 0.03, and lower preoperative oxygen saturations, 82 ± 7 versus 90 ± 6 (%), p = 0.0001, than full repair group. A higher number of surgical procedures per patient was recorded in shunt patients, 2.29 ± 0.59 versus 1.27 ± 0.49, p = 0.00002. Thirteen of 51 patients in the full repair group required a repeat surgery. Catheterization proced...

Innovations (Philadelphia, Pa.), 2007

Objectives: During cardiac surgery, platelets undergo substantial changes. The purpose of this st... more Objectives: During cardiac surgery, platelets undergo substantial changes. The purpose of this study was to assess platelet function and compare these changes between different cardiac operations using an innovative technology. Methods: Perioperative platelet function was evaluated by the Impact test [cone and plate(let) analyzer (CPA)]. The Impact test yields 2 parameters for platelet function: average size (AS, the mean size of the platelet aggregates) and surface coverage (SC, the percentage of the surface covered by the platelet aggregates), which correspond to platelet aggregation and adhesion. The study groups were compared for platelet function results in various surgery stages and correlation with bleeding. Results: A significant decrease in surface coverage was detected on establishment of cardiopulmonary bypass, with an increase up to preoperative values at the end of the surgery in all groups. In contrast to operations performed on bypass, in patients operated without cardiopulmonary bypass, the postoperative AS and SC were higher than the preoperative values, 30.4 Ϯ 8.1 mol 2 versus 23.3 Ϯ 6.9 mol 2 , P ϭ 0.02 in AS, and 7.6 Ϯ 3.6% versus 5.2 Ϯ 1.8%, P ϭ 0.04 in SC. Preoperative AS and SC were the only parameters significantly (P ϭ 0.01) and linearly (r ϭ 0.6) related to postoperative bleeding. Conclusions: Preoperative platelet function, as evaluated by the CPA, is an independent risk factor determining postoperative bleeding. The off-pump patients presented an increased platelet function at the end of surgery, a finding that can imply a higher risk of thrombosis. The impact test appears to be a useful tool to determine perioperative platelet function and help in prediction of postoperative bleeding.

The Israel Medical Association journal : IMAJ, 2003

Cardiac surgery is being performed with increasing frequency in patients aged 80 years and older.... more Cardiac surgery is being performed with increasing frequency in patients aged 80 years and older. To examine the long and short-term results of surgery in this age group. We retrospectively investigated 202 consecutive patients aged 80 years or older who underwent cardiac surgery between 1991 and 1999, Ninety-six operations (48%) were urgent. The study group comprised 140 men (69%) and 62 women (31%) with a mean age of 82.1 years (range 80-89). Preoperatively, 120 patients (59%) had unstable angina, 37 (18%) had left main coronary artery disease, 22 (11%) had renal failure, 17 (8.5%) had a history of stroke and 13 (6.5%) had previous cardiac surgery. Hospital mortality for the whole group was 7.4%. Postoperative complications included: re-exploration for bleeding in 15 (7.4%), stroke in 8 (4%), sternal wound infection in 3 (1.5%), low cardiac output in 17 (8.4%), new Q wave myocardial infarction in 5 (2.5%), renal failure in 17 (8.5%), and atrial fibrillation in 71 (35%). The actuar...

The Annals of Thoracic Surgery, 2015

Seminars in Thoracic and Cardiovascular Surgery: Pediatric Cardiac Surgery Annual, 2013

Neonatal patients with hypoplasia of the aortic arch constitute a heterogeneous group with a wide... more Neonatal patients with hypoplasia of the aortic arch constitute a heterogeneous group with a wide spectrum of severity. The milder end of the spectrum comprises patients with aortic coarctation and isthmus hypoplasia. At the other end of the spectrum are patients with severe transverse arch hypoplasia or hypoplastic left heart syndrome. The aim of this paper is to discuss the various strategies and surgical approaches available for this group of patients, focusing on the surgical decisions that influence individual patient management. Many of the things discussed are applicable to any neonatal arch problem. We also describe and discuss in detail our surgical technique for patients who undergo neonatal repair of a hypoplastic aortic arch via median sternotomy.

The Heart Surgery Forum, 2005

The Heart Surgery Forum, 2004

Background: Off-pump coronary artery bypass (OPCAB) is believed to reduce cardiopulmonary bypass ... more Background: Off-pump coronary artery bypass (OPCAB) is believed to reduce cardiopulmonary bypass (CPB)-related complications, including platelet damage. A hypercoagulable state instead of coagulopathy has been reported following OPCAB surgeries due to CPB. Whether platelet function is changed when the injurious effect of CPB is eliminated was investigated. Methods: Platelet function was determined with the cone and plate(let) analyzer (CPA) method. The 2 parameters, average size (AS) and surface coverage (SC) of platelet aggregates, were measured with the CPA method to assess platelet aggregation and adhesion. These parameters were evaluated, and their values were compared at several stages of OPCAB surgery. The correlations of postoperative bleeding with platelet function at different stages of the surgery and with other factors, such as platelet count, hematocrit, and transfusions, were studied. Results: Both AS and SC increased during several stages of the operation, and postoperative values (mean ± SD) were significantly higher than preoperative values (30.4 ± 8.1 µm 2 versus 23.3 ± 6.9 µm 2 for AS [P = .02] and 7.6% ± 3.6% versus 5.2% ± 1.8% for SC [P = .04]). The mean total bleeding volume was 875 ± 415 mL. Preoperative AS and SC were the only parameters significantly (P = .01) and linearly (r = 0.7) related to postoperative bleeding. Conclusions: An increased platelet function, as determined by the CPA method, is found following OPCAB surgery. This phenomenon is probably at least partially responsible for the thrombogenic state after OPCAB surgery. Lack of platelet injury attributed to CPB may divert the system toward a more thrombogenic state. Preoperative platelet function, as evaluated by the CPA method, is an independent risk factor determining postoperative bleeding.

Pediatric Transplantation, 2012

Pediatric patients bridged to heart transplant with LVADs require chronic anticoagulation and are... more Pediatric patients bridged to heart transplant with LVADs require chronic anticoagulation and are at increased risk of hemorrhagic complications, including intracranial hemorrhage. In this population, intracranial hemorrhage is often fatal. We report a case of successful management of a five-yr-old-boy with DCM on an LVAD who developed a subdural hematoma. We initially chose medical management, weighing the patient's high risk of thromboembolism from anticoagulation reversal against the risk of his chronic subdural hematoma. When head CT showed expansion of the hemorrhage with increasing midline shift, we chose prompt surgical evacuation of the hematoma with partial reversal of anticoagulation, given the increased risk of acute deterioration. The patient ultimately received an orthotopic heart transplant and was discharged with no permanent neurological complications. This represents a case of a pediatric patient on an LVAD who survived a potentially fatal subdural hematoma and was successfully bridged to cardiac transplantation.

The Journal of Thoracic and Cardiovascular Surgery, 2011

Journal of Surgical Research, 2012

Background: We used speckle-tracking echocardiography to test the hypothesis that regional left v... more Background: We used speckle-tracking echocardiography to test the hypothesis that regional left ventricular (LV) strain would improve during optimized biventricular pacing (BiVP) in acute right ventricular (RV) pressure overload (PO). Materials and methods: Complete heart block and RVPO were induced in five open-chest fully anesthetized pigs. BiVP was optimized by adjusting atrioventricular and interventricular delays to maximize cardiac output derived from an aortic flow probe. LV short axis views were obtained during atrio-RV pacing (RVP), atrio-LV pacing (LVP), and BiVP. Intraventricular synchrony was assessed by comparing speckle-tracking echocardiography-derived time to peak (TTP) strain in the anterior septal (AS) and posterior wall segments. Segmental function was assessed using radial strain. Results: Cardiac output was higher with optimized (RV first) BiVP than with L VP (0.96 ± 0.26 L/min versus 0.89 ± 0.27 L/min; P = 0.05). AS TTP strain (502 ± 19 ms) during LVP was prolonged versus BiVP (392 ± 58 ms) and versus RVP (390 ± 53 ms) (P = 0.0018). AS TTP strain during LVP was prolonged versus posterior (502 ± 19 ms versus 396 ± 72 ms, P = 0.0011). No significant difference in TTP strain in these segments was seen with BiVP or RVP. Posterior strain (20% ± 5%) increased 66% versus AS strain (12% ± 6%) during BiVP (P = 0.0029). A similar increase occurred during RVP (posterior 20% ± 3% versus AS 12% ± 7%, P = 0.0002). Posterior strain did not increase during LVP. Conclusions: BiVP and RVP restore intraventricular LV synchrony and increase regional function versus LVP during RVPO. RV pre-excitation unloads the RV and reduces the duration of AS contraction, facilitating synchrony of all LV segments and increasing free wall LV contraction.

JACC: Cardiovascular Interventions, 2013

We prospectively included patients admitted to our department for acute HF or exacerbation of chr... more We prospectively included patients admitted to our department for acute HF or exacerbation of chronic HF between December 2010 and May 2011. We excluded patients over 80 years old, those with severe renal failure (GFR Ͻ 50ml/min/1.73 m2) or severe worsening of renal function during hospitalization and patients having dysthyroidism or under immunosuppressive therapy. A dosage of plasmatic cystatin C concentration was done using particule-enhanced turbidimetric immunoassay method. The main endpoint was death at a 120 days follow up. Results: Sixty four patients were enrolled, aged 62.2 Ϯ 11.4 years, with a sex ratio of 1.56. Patients were at NYHA class III or IV at admission in 87% of cases, with an ischemic etiology in 55% of cases. LVEF was 51.7 Ϯ 13.8% and GFR was 76 Ϯ 19.8 ml/min. Mean cystatin C was 1.42 Ϯ 0.37 mg/l. During follow-up, 10 (15.6%) patients died. Higher levels of Cystatin C (third tertile) were associated with a significant increase in mortality rate with an RR of 8 when moving from the first to the third tertile and a RR of 3 when moving from the second to the third (pϭ0.033). Prognostic value is uncertain for milder elevations between the first and second tertiles (pϭ0.45). Conclusion: A high level of Cystatin C at admission is a strong predictor of 120-days mortality among patients with HF. Discriminative value falls for milder elevations.