Bax deficiency reduces infarct size and improves long-term function after myocardial infarction.

We have previously found that, following myocardial ischemia/reperfusion injury, isolated hearts from bax gene knockout mice [Bax(-/-)] exhibited higher cardioprotection than the wild-type. We here explore the effect of Bax(-/-), following myocardial infarction (MI) in vivo. Homozygotic Bax(-/-) and matched wild-type were studied. Mice underwent surgical ligation of the left anterior descending coronary artery (LAD). The progressive increase in left-ventricular end diastolic diameter, end systolic diameter, in Bax(-/-) was significantly smaller than in Bax(+/+) at 28 d following MI (p < 0.03) as seen by echocardiography. Concomitantly, fractional shortening was higher (35 +/- 4.1% and 27 +/- 2.5%, p < 0.001) and infarct size was smaller in Bax(-/-) compared to the wild-type at 28 days following MI (24 +/- 3.7 % and 37 +/- 3.3%, p < 0.001). Creatine kinase and lactate dehydrogenase release in serum were lower in Bax(-/-) than in Bax(+/+) 24 h following MI. Caspase 3 activity was elevated at 2 h after MI only in the wild-type, but reduced to baseline values at 1 and 28 d post-MI. Bax knockout mice hearts demonstrated reduced infarct size and improved myocardial function following permanent coronary artery occlusion. The Bax gene appears to play a significant role in the post-MI response that should be further investigated.

[Report of 12 years experience in the surgical treatment of 286 paraesophageal hernias]. / Erfahrungen aus 12 Jahren chirurgischer Versorgung von 286 paraösophagealen Hernien.

BACKGROUND: In contrast to axial hiatus hernias, paraesophageal hernias are rare but can lead to chronic iron deficiency anemia and severe acute complications. Treatment is manifold and consistent standards are lacking. OBJECTIVES: The aim of this study was to describe our experiences of 286 patients with paraesophageal hernias, who underwent surgery from 2003 to 2014 at a tertiary referral center. The study was particularly concerned with morbidity, mortality, quality of life and recurrence rates. MATERIAL AND METHODS: In 12 years a total of 286 paraesophageal hernias were surgically treated, 255 with a minimally invasive procedure and 31 with an open approach. In 138 patients (48 %) the suture-based hiatoplasty was reinforced by means of a lightweight mesh, which was fixed with fibrin glue in 90 cases. Abdominal fixation of the stomach consisted of a gastropexy and anterior (n = 244) or posterior (n = 42) fundoplication. RESULTS: Complications arose in 8.4 % of the patients. The mean hospital stay was 5.3 (± 2.8) days for elective surgery and 24.7 (± 17.8) days for emergency operations. The gastrointestinal quality of life index according to Eypasch significantly increased from mean preoperative values of 92.8 (± 22.5) to 109.6 (± 20.2) in the postoperative course (p < 0.001). Of the patients 20 (7 %) suffered a recurrence requiring surgery, including 7 early and 13 late recurrences. During the immediate postoperative period radiographically detected recurrences were promptly revised. The strategy of late recurrences in the long-term course was based on patient symptoms and asymptomatic hernias were treated conservatively while symptomatic hernias were surgically treated. Symptomatic late recurrences developed in 4.6 % of the patients, including 7.4 % (11 out of 148) without and 1.4 % (2 out of 138) with primary mesh repair. CONCLUSION: The repair of paraesophageal hernias in 286 patients provided excellent patient satisfaction and symptom improvement with low perioperative morbidity and mortality. Mesh reinforcement reduced the recurrence rate. The quality of life index is a suitable clinical course parameter for evaluation of paraesophageal hernias.

Comparing Effective Doses During Image-Guided Core Needle Biopsies with Computed Tomography Versus C-Arm Cone Beam CT Using Adult and Pediatric Phantoms.

PURPOSE: To compare the effective doses of needle biopsies based on dose measurements and simulations using adult and pediatric phantoms, between cone beam c-arm CT (CBCT) and CT. METHOD: Effective doses were calculated and compared based on measurements and Monte Carlo simulations of CT- and CBCT-guided biopsy procedures of the lungs, liver, and kidney using pediatric and adult phantoms. RESULTS: The effective doses for pediatric and adult phantoms, using our standard protocols for upper, middle and lower lungs, liver, and kidney biopsies, were significantly lower under CBCT guidance than CT. The average effective dose for a 5-year old for these five biopsies was 0.36 ± 0.05 mSv with the standard CBCT exposure protocols and 2.13 ± 0.26 mSv with CT. The adult average effective dose for the five biopsies was 1.63 ± 0.22 mSv with the standard CBCT protocols and 8.22 ± 1.02 mSv using CT. The CT effective dose was higher than CBCT protocols for child and adult phantoms by 803 and 590% for upper lung, 639 and 525% for mid-lung, and 461 and 251% for lower lung, respectively. Similarly, the effective dose was higher by 691 and 762% for liver and 513 and 608% for kidney biopsies. CONCLUSIONS: Based on measurements and simulations with pediatric and adult phantoms, radiation effective doses during image-guided needle biopsies of the lung, liver, and kidney are significantly lower with CBCT than with CT.

Determination of pulmonary to systemic blood flow ratio in children by a simplified Doppler echocardiographic method.

Doppler echocardiographic determination of the pulmonary to systemic blood flow (Qp/Qs) ratio requires calculation of pulmonary artery and aortic luminal areas and integrals of the Doppler systolic velocity curves. To simplify the Doppler calculation of the Qp/Qs ratio, the square of the ratio of pulmonary to aortic luminal diameters, substituted for the ratio of vessel areas, was multiplied by the ratio of pulmonary to aortic peak flow velocities, substituted for the ratio of velocity time integrals. The Qp/Qs ratios were calculated by both the conventional and the simplified Doppler method in 42 children, 1 month to 16 years of age. Fifteen children had no evidence of shunt and 27 had an intracardiac left to right shunt at the atrial or ventricular level, or both. In children with a shunt, the Qp/Qs ratio obtained at cardiac catheterization by oximetry ranged from 1.4:1 to 4.3:1. Both the conventional and the simplified Doppler Qp/Qs ratios correlated well with the oximetric Qp/Qs ratios (r = 0.94 and 0.93, respectively). Since the pulmonary to aortic luminal area ratio and velocity time integral ratio varied in each patient, neither measurement alone correlated well with the oximetric Qp/Qs ratio and, therefore, neither alone could be used as an estimate of the Qp/Qs ratio. The simplified Doppler calculation of the Qp/Qs ratio, which requires less time and no computer facilities, provides an excellent estimate of the Qp/Qs ratio in children.

Echocardiographic evaluation of dilated cardiomyopathy in the human fetus.

The diagnosis of dilated cardiomyopathy was established and subsequently confirmed in 6 of 625 fetuses studied by echocardiography. All 6 had structurally normal hearts. Abnormal findings included reduced fractional shortening index in 5, atrioventricular valve regurgitation in 3, abnormal chamber dimensions in 3 and nonimmune hydrops in 4. In 2 fetuses referred because of a family history of dilated cardiomyopathy in previous siblings, echocardiographic abnormalities were absent on a first examination performed at 20 weeks of gestation. This suggested that a normal fetal echocardiogram in a midtrimester fetus does not always rule out the subsequent development of dilated cardiomyopathy. However, all fetuses followed serially developed some abnormality later in pregnancy. Only 2 neonates survived, 1 of whom required a heart transplant during infancy. Death from cardiac failure occurred in 1 fetus and 3 neonates. This study demonstrates that dilated cardiomyopathy may develop during fetal life and might be diagnosed by echocardiography if serial studies are performed. Dilated cardiomyopathy presenting prenatally appears to have a poor prognosis.

A one-way, valved, atrial septal patch in the management of postoperative right heart failure. An animal study.

Patients who undergo surgical repair of congenital heart defects that are characterized by hypoplastic right ventricle or pulmonary hypertension are at high risk for the development of postoperative right heart failure. To minimize this risk, a new one-way, valved, atrial septal patch was developed that serves as an artificial one-way foramen ovale. The feasibility of this device was tested in five dogs in which reversible right heart failure had been induced. Use of the one-way valved patch significantly improved right ventricular performance and reduced right ventricular hydrostatic pressures. The interatrial pressure gradient was reduced from 10 +/- 3.5 mm Hg during right heart failure to 4.4 +/- 1.4 mm Hg. When the device was opened, cardiac output increased significantly. This hemodynamic improvement was achieved at the expense of systemic arterial desaturation, which was, however, well tolerated. When the state of right heart failure was reversed, the one-way valved patch spontaneously closed, allowing no interarterial shunting. The results of this experimental trial suggest that this device can play a useful role in selected patients in whom postoperative right heart failure can be anticipated after surgical repair of certain congenital heart defects.

A one-way valved atrial septal patch: a new surgical technique and its clinical application.

Patients who undergo surgical repair of congenital heart defects, characterized by a hypoplastic right ventricle or high pulmonary vascular resistance, are at high risk for the development of postoperative right heart failure. This risk may discourage the surgical team from carrying out a biventricular or complete repair in such patients. To reduce the risk for right heart failure, we developed a one-way, valved, atrial septal patch to serve as an artificial one-way foramen ovale and tested it in an animal model. By permitting right-to-left shunt, this device decompresses the failing right ventricle and maintains systemic cardiac output. The device has been used in 15 patients divided into three different groups: group 1 (n = 8), patients with a hypoplastic right ventricle and pulmonic stenosis or atresia, seven of whom underwent a biventricular repair; group 2 (n = 5), patients with evidence of pulmonary disease after longstanding left-to-right shunt caused by a correctable atrial or ventricular septal defect, all of whom had a complete repair; group 3, two patients with acute right heart failure in whom the device was used as a last option of treatment to wean them from cardiopulmonary bypass. This article presents our data in regard to the use of the one-way, valved, atrial septal patch and the indications for its clinical use.

Autologous monocusp pulmonary valve: preliminary results.

BACKGROUND: There is growing recognition that postoperative pulmonary regurgitation may result in early or late progressive right heart failure. METHOD: A technique for fashioning an autologous monocusp pulmonary valve from the wall of the pulmonary artery was developed. The monocusp valve was fashioned from the anterior wall of the main pulmonary artery, and the remaining defect was filled with autologous pericardium. The procedure was performed in 8 dogs and 5 children. RESULTS: Early follow-up and serial echocardiographic assessment in both dogs and children proved the functionality of this monocusp pulmonary valve. All valves were pliable and demonstrated mild to moderate pulmonary stenosis and insufficiency. CONCLUSIONS: Construction of the autologous monocusp pulmonary valve is a feasible technique, and the valve performs efficiently. The acute performance in the canine model was excellent, and preliminary midterm results in the clinical study are reasonable. It is logical to assume that the monocusp, being an integral part of the arterial wall, will retain its viability and share in the subsequent growth of the pulmonary artery. Should follow-up studies demonstrate its long-term competence, this autologous valve may provide a good solution for various forms of pulmonary regurgitation and be useful in pulmonary autograft replacement of the aortic valve.

Nosocomial infections after cardiac surgery in infants and children: incidence and risk factors.

This prospective study was undertaken to determine the spectrum, sites and main risk factors for hospital-acquired infections (HAI) in our paediatric cardiothoracic intensive care unit (PCICU), and to determine the main organisms causing bloodstream infection in this setting. All patients admitted between January and December 1999 were prospectively followed for the development of HAI. To define risk factors, patients were grouped by age, complexity score, length of stay in PCICU, and whether the patient's chest was open or closed postoperatively. Three hundred and thirty-five patients underwent cardiac surgery. Fifty-five patients acquired 69 HAIs (HAI patient rate 16.4%). The most common HAI were bloodstream and surgical wound infection in 10 and 8%, respectively. The main causative organisms were Klebsiella spp.,Enterobacter spp. and Pseudomonas spp. in 22, 17 and 16% of episodes, respectively. Staphylococcus spp. accounted for 16% of episodes. The main risk factors for developing HAI were: neonatal age [P < 0.05, odds ratio (OR): 5.89, 95% confidence interval (CI): 2.96-11.58] prolonged PCICU stay (P < 0.05, OR: 6.82, 95% CI: 3.37-14.48), open chest postoperatively (P < 0.05, OR: 3.44, 95% CI: 1.31-8.52) and high complexity score (P < 0.05, OR: 4.03 95% CI: 1.87-8.43). The main causative organisms of bloodstream infections in children hospitalized in the PCICU differ from those in adult and pediatric general intensive care units (ICUs) and include mainly Gram-negative bacilli. High complexity score, neonatal age, prolonged ICU stay, and open chest postoperatively are risk factors of HAI in this patient population.

Surgical management of ventricular septal defect with aortic valve prolapse: clinical considerations and results.

Aortic valve prolapse is found in over 5% of children with ventricular septal defect (VSD). Although this association occurs mostly with doubly committed subarterial VSDs, in this study the predominant type of VSD was perimembranous. In order to determine the need and timing for surgery and whether the anatomical features of septal defect may influence clinical management and outcome in this lesion, we reviewed our experience with 28 consecutive patients, operated on for VSD with prolapsed aortic valve cusp, with or without aortic regurgitation. Twenty-two patients had a perimembranous VSD and six had doubly committed VSD. Aortic regurgitation was trivial or absent in nine patients, mild in ten and moderate to severe in nine. Associated cardiac anomalies were present in 18 patients, all having perimembranous VSD, and included right ventricular outflow tract (RVOT) obstruction (n = 6), discrete subaortic membrane (n = 4) or both (n = 8). None of these patients had more than moderate aortic regurgitation. The patients underwent surgical closure of the septal defect between the ages of 1.5 and 34 years of age (median = 7). Sixteen patients having mild or trivial aortic regurgitation underwent closure of the VSD only, and 12 patients underwent VSD closure with aortic valvuloplasty. Valvuloplasty was required more often in doubly committed VSDs (66%) and in the perimembranous type without associated anomalies (100%), and significantly less often in the presence of RVOT obstruction, subaortic membrane or both (22%). At follow-up (up to 5 years, mean 18 months), the grade of aortic regurgitation was unchanged in 11 and decreased in 5 patients undergoing closure of the VSD only.(ABSTRACT TRUNCATED AT 250 WORDS)

Superior vena cava syndrome following neonatal cardiac surgery.

OBJECTIVE: To review the incidence, diagnosis, and management of superior vena cava syndrome (SVCS) after surgery for congenital heart disease. DESIGN: Retrospective clinical review. All patients were computer registered. Our database includes daily follow-up. SETTING: Pediatric cardiac surgery intensive care unit in a university hospital. PATIENTS: A total of 1853 consecutive pediatric cardiac operations performed in 285 neonates and 1568 older children from 1993 to 1999 are reviewed. MEASUREMENTS AND MAIN RESULTS: The diagnosis of SVCS was suspected clinically: Color changes and swelling of the upper part of the body, confirmed by echo-Doppler, showed no or minimal flow in the superior vena cava at the beginning and collateral flow later on. Nine patients developed SVCS (0.5%). All the study patients were neonates. The prevalence of SVCS in our neonatal patients was 3.15% (nine of 285), with no SVCS in older children. Accompanying complications included chylothorax (five), hydrocephalous (four)-three of whom required ventriculoperitoneal shunt during follow-up. Thrombolytic therapy was used in five patients, and thrombectomy was used in one patient. The ventilation period ranged from 4 to 46 days (mean 20.1 days), and the length of hospital stay ranged from 37 to 120 days (mean 61.3 days). No mortality was observed during follow-up. CONCLUSIONS: SVCS is an uncommon, severe complication following neonatal cardiac surgery. It may cause chylothorax, hydrocephalus, and severe respiratory complications leading to high morbidity. Early diagnosis and thrombolytic therapy may prevent the progression of this syndrome to its subsequent sequels.

Interruption of right sided aortic arch. Case report and review of the literature.

Interrupted right sided aortic arch is a very rare anomaly, and to our knowledge only one such case in which the patient underwent complete repair has been recorded in the literature. Twelve additional cases were found on autopsy or underwent palliative surgery. We present the case of a 25-day-old infant with an interrupted right sided aortic arch. The anomaly was repaired by a one-stage surgical approach, and the patient discharged from the hospital. Surgical technique considerations are discussed.

Total cavopulmonary connection (TCPC) for complicated congenital heart malformations.

We reviewed our experience with 40 patients who had undergone total cavopulmonary connection (TCPC) during the past three years. Thirty-one patients had functional single ventricle; only 8 of these with tricuspid atresia, five patients had complex forms of double outlet right ventricle (DORV), and four complex A-V canal. Previous palliative procedures, mostly systemic-pulmonic shunts, were performed in 34 patients. Concomitant procedures were required in 18 patients, mainly reconstruction of distorted pulmonary arteries. A subgroup of 14 high risk patients, that did not fulfil the classical Fontan criteria, underwent 4 mm fenestration of the intra-atrial baffle. There were three (7.5%) early postoperative deaths which occurred in the higher risk group (fenestrated group). However, the remaining patients were all in functional class I or II. Total cavopulmonary connection provides reasonably good definitive palliation for patients with single ventricle physiology. Fenestration of the intra-atrial baffle increases the number of candidates suitable for the Fontan procedure, although the exact inclusion criteria for these patients has yet to be defined.

Transcatheter closure of secundum atrial septal defects with the amplatzer septal occluder: early experience.

BACKGROUND: Secundum atrial septal defect is a common congenital heart defect that causes right heart volume overload and produces symptoms usually after the third decade of life. Treatment until the last few years has been open heart surgery. OBJECTIVES: To review our early experience with transcatheter closure of ASD2 using the Amplatzer septal occluder. METHODS: Between November 1999 and February 2000, 20 children and young adults with a median age of 9.1 years (4.2-35.1 years) were referred for transcatheter closure of ASD2. Diagnosis was established by transthoracic echocardiography. Implantation was performed under general anesthesia through the femoral vein with the guidance of transesophageal echocardiography and fluoroscopy. Femoral arterial puncture was performed for blood pressure monitoring during the procedure. The device size chosen was similar to the balloon-stretched diameter of the ASD2. RESULTS: Implantation was completed successfully in 18 patients. Two patients were referred for elective surgery: one had an unsuitable anatomy for transcatheter closure by TEE in the catheterization laboratory and the device could not be implanted properly, the other patient had a large multiperforated septal aneurysm that was retrieved. Mean ASD2 diameter by TTE and TEE was similar (13.9 +/- 3 mm, 13.4 +/- 3.5 mm) and mean stretched diameter was 18.3 +/- 4.3 mm. Mean Qp:Qs (pulmonary flow:systemic flow) was 2.2 +/- 0.6. Mean fluoroscopy time for the procedure was 14.8 +/- 4.8 minutes. The patients were discharged the day after the procedure. Four patients had a tiny leak immediately post-procedure, and none had a leak at one month follow-up. The only complication was a small pseudoaneurysm of the femoral artery in one patient, that resolved spontaneously. CONCLUSIONS: Transcatheter closure of ASD2 with the Amplatzer septal occluder is a safe and effective alternative to surgical closure. Long-term outcome has to be evaluated.

Anomalous origin of the left coronary artery from the pulmonary artery: diagnosis and postoperative follow up.

BACKGROUND: Anomalous origin of the left coronary artery from the pulmonary artery is a rare congenital malformation that presents a diagnostic challenge to the pediatrician and pediatric cardiologist. Although surgical repair is always indicated, the optimal technique has yet to be determined. OBJECTIVES: To review our experience with the diagnosis of children with ALCAPA and to assess short to midterm surgical results. METHODS: Between 1992 and 1998, 13 infants and children (2 months to 15 years) were treated for ALCAPA at our medical center. Eight were diagnosed during the first year of life; all were symptomatic and had severe dysfunction of the left ventricle. The five patients diagnosed at an older age had normal myocardial function. Diagnosis was established by echocardiography alone in seven patients; six required catheterization (one infant and all older patients). Surgery was performed in 12 patients to establish dual coronary artery system: 7 underwent the Takeuchi procedure and 5 had re-implantation of the anomalous left coronary artery. RESULTS: One infant died shortly after diagnosis before surgical repair was attempted, and one died postoperatively. Four patients required additional surgery: three for late complications of the Takeuchi procedure and one valve replacement for mitral insufficiency. Recent evaluation revealed good global left ventricle function in all patients except for one, who is still within the recovery phase and shows gradual improvement. However, most patients who presented with severe myocardial dysfunction upon diagnosis still display abnormal features such as echo-dense papillary muscles or evidence of small akinetic segments. In this group, early repair was associated with faster myocardial recovery. CONCLUSIONS: The diagnosis of ALCAPA remains a clinical challenge to the pediatrician and cardiologist. Diagnosis can be established echocardiographically, and early diagnosis and treatment may lead to faster myocardial recovery. The preferred surgical method appears to be re-implantation of the ALCA. The chance for good recovery of global ventricular function is high even in the sickest patients, nonetheless abnormal myocardial features can be identified even years after surgery.

The Ross operation: initial Israeli experience.

BACKGROUND: The need for aortic valve replacement in children and young adults poses a special problem to cardiologists and surgeons. Replacing the sick aortic valve with the patient's pulmonary valve as described by Ross has proven to be a good option in this special age group. OBJECTIVE: To review our initial experience in order to assess the short-term results. METHODS: From January 1996 to June 1999, 40 patients (age 8 months to 41 years) underwent aortic valve replacement with pulmonary autograft. Indications for surgery were congenital aortic valve disease in 30 patients, bacterial endocarditis in 5, rheumatic fever in 3, and complex left ventricular outflow tract obstruction in 3. Trans-esophageal echocardiography was performed preoperatively and post-bypass in all patients, and transthoracic echocardiography was done prior to discharge and on follow-up. RESULTS: There was no preoperative or late mortality. All patients remain in functional class I (New York Heart Association) and are free of complications and medication. None showed progression of autograft insufficiency or LVOT obstruction. Homograft insufficiency in the pulmonary position has progressed from mild to moderate in one patient, and three developed mild homograft stenosis. CONCLUSIONS: The Ross procedure can be performed with good results in the young population and is considered an elegant surgical alternative to prosthetic values and homografts.

[First year's experience of the Post-Operative Cardiac Care Unit, Schneider Children's Medical Center].

In the past 10 years there has been a growing preference for early, complete correction of congenital heart disease. The first year of operation of this cardiac unit is described. 216 operations were performed: 15% in the neonatal age group and 35% in the newborn to 1-year-old groups; 2% were palliative procedures. Mortality was 4.9%. Average stay in the ICU was 3.2 days, with a median of 2.25. Average length of ventilation was 35 hours, with a median of 17.5. Complications were: diaphragm paralysis in 13 (6%), 2/3 of which were recurrent operations; in 2 patients (0.9%) we had to plicate the diaphragm. There was severe neurological damage in 2 which deteriorated to brain death in 1. There was peripheral, reversible neurological damage in 4 (1.8%), and acute renal failure in 3%, with half of them requiring dialysis. 75% of these children died and there was superficial infection in 4.1%, deep wound infection in 1.3%, bacteremia in 4.1%, superior vena cava syndrome in 3 (1.3%) and chylothorax in 2 of them (0.9%). 1 patient (0.45%) required a ventricle-peritoneal shunt after acute viral meningitis. We are encouraged by our results to offer early complete correction to all children with congenital heart disease.

[Transcatheter closure of atrial septal defects: initial clinical applications].

The incidence of congenital heart defects is 0.8% of liveborn infants. Of these 13% are ostium secundum atrial septal defects (ASD) which can be successfully repaired by open heart surgery with less than 1% mortality. However, morbidity associated with cardiac surgery is universal. Transcatheter closure of ASDs was introduced 2 decades ago to decrease surgical complications, hospital stay and cost. Few devices have undergone clinical trials but all of them have been associated with instances of failure and complications. The most important mechanism for acute failure was selection of cases with too large a defect or selection of a defective device. In the past decade great progress has been made with the aid of transesophageal echocardiography (TEE) and modifications of the device. We present our experience in our first 5 patients. They ranged in age from 4 to 27 years; the ASD diameter was 11-15 mm and the device diameter was 17-33 mm. All transcatheter closures were performed on the same day without any complications, and all patients were discharged home after 2 days of hospitalization. We conclude that transcatheter occlusion of ASDs up to 15 mm is feasible, relatively safe and effective. This transcatheter method appears to be a viable alternative to surgery for some patients with secundum atrial septal defects.

UTP reduces infarct size and improves mice heart function after myocardial infarct via P2Y2 receptor.

Pyrimidine nucleotides are signaling molecules, which activate G protein-coupled membrane receptors of the P2Y family. P2Y(2) and P2Y(4) receptors are part of the P2Y family, which is composed of 8 subtypes that have been cloned and functionally defined. We have previously found that uridine-5'-triphosphate (UTP) reduces infarct size and improves cardiac function following myocardial infarct (MI). The aim of the present study was to determine the role of P2Y(2) receptor in cardiac protection following MI using knockout (KO) mice, in vivo and wild type (WT) for controls. In both experimental groups used (WT and P2Y(2)(-/-) receptor KO mice) there were 3 subgroups: sham, MI, and MI+UTP. 24h post MI we performed echocardiography and measured infarct size using triphenyl tetrazolium chloride (TTC) staining on all mice. Fractional shortening (FS) was higher in WT UTP-treated mice than the MI group (44.7±4.08% vs. 33.5±2.7% respectively, p<0.001). However, the FS of P2Y(2)(-/-) receptor KO mice were not affected by UTP treatment (34.7±5.3% vs. 35.9±2.9%). Similar results were obtained with TTC and hematoxylin and eosin stainings. Moreover, troponin T measurements demonstrated reduced myocardial damage in WT mice pretreated with UTP vs. untreated mice (8.8±4.6 vs. 12±3.1 p<0.05). In contrast, P2Y(2)(-/-) receptor KO mice pretreated with UTP did not demonstrate reduced myocardial damage. These results indicate that the P2Y(2) receptor mediates UTP cardioprotection, in vivo.