Surgical aortic valve replacement etiologies, hemodynamics, and outcomes in 1346 patients from the Malaysian heart centre.

BACKGROUND: This study examined the characteristics and outcomes of surgical aortic valve replacement (SAVR) both isolated and in combination with other cardiac surgery in Malaysia from 2015 to 2021. METHODS: This was a retrospective study of 1346 patients analyzed on the basis of medical records, echocardiograms and surgical reports. The overall sample was both considered as a whole and divided into aortic stenosis (AS)/aortic regurgitation (AR)-predominant and similar-severity subgroups. RESULTS: The most common diagnosis was severe AS (34.6%), with the 3 most common etiologies being bicuspid valve degeneration (45.3%), trileaflet valve degeneration (36.3%) and rheumatic valve disease (12.2%). The second most common diagnosis was severe AR (25.5%), with the most common etiologies being root dilatation (21.0%), infective endocarditis (IE) (16.6%) and fused prolapse (12.2%). Rheumatic valve disease was the most common mixed disease. A total of 54.5% had AS-predominant pathology (3 most common etiologies: bicuspid valve degeneration valve, degenerative trileaflet valve and rheumatic valve disease), 36.9% had AR-predominant pathology (top etiologies: root dilatation, rheumatic valve disease and IE), and 8.6% had similar severity of AS and AR. Overall, 62.9% of patients had trileaflet valve morphology, 33.3% bicuspid, 0.6% unicuspid and 0.3% quadricuspid. For AS, the majority were high-gradient severe AS (49.9%), followed by normal-flow low-gradient (LG) severe AS (10.0%), paradoxical low-flow (LF)-LG severe AS (6.4%) and classical LF-LG severe AS (6.1%). The overall in-hospital and total 1-year mortality rates were 6.4% and 14.8%, respectively. Pure severe AS had the highest mortality. For AS-predominant pathology, the etiology with the highest mortality was trileaflet valve degeneration; for AR-predominant pathology, it was dissection. The overall survival probability at 5 years was 79.5% in all patients, 75.7% in the AS-predominant subgroup, 83.3% in the AR-predominant subgroup, and 87.3% in the similar-severity subgroup. CONCLUSIONS: The 3 most common causes of AS- predominant patients undergoing SAVR is bicuspid valve degeneration, degenerative trileaflet valve and rheumatic and for AR-predominant is root dilatation, rheumatic and IE. Rheumatic valve disease is an important etiology in our SAVR patients especially in mixed aortic valve disease. Study registration IJNREC/562/2022.

Recent Advances in Anode Electrocatalysts for Direct Formic Acid Fuel Cells - Part I - Fundamentals and Pd Based Catalysts.

Direct formic acid fuel cells (DFAFCs) have gained immense importance as a source of clean energy for portable electronic devices. It outperforms other fuel cells in several key operational and safety parameters. However, slow kinetics of the formic acid oxidation at the anode remains the main obstacle in achieving a high power output in DFAFCs. Noble metal-based electrocatalysts are effective, but are expensive and prone to CO poisoning. Recently, a substantial volume of research work have been dedicated to develop inexpensive, high activity and long lasting electrocatalysts. Herein, recent advances in the development of anode electrocatalysts for DFAFCs are presented focusing on understanding the relationship between activity and structure. This review covers the literature related to the electrocatalysts based on noble metals, non-noble metals, metal-oxides, synthesis route, support material, and fuel cell performance. The future prospects and bottlenecks in the field are also discussed at the end.

Incidence and demographical characteristics of patients with post-traumatic stress disorder due to motor vehicle accidents.

INTRODUCTION: Motor vehicle accidents (MVAs) are daily occurrences in Malaysia but the extent to which victims are psychologically affected is not well known. The objective of this study is to determine the incidence and demographic characteristics of patients with post-traumatic stress disorder (PTSD) due to MVAs at a university hospital in Malaysia. METHODS: Patients presenting to the emergency department from August to October 2014 due to MVA-related injuries were recruited. After a period of at least one month, they were followed-up and screened using the validated Malay Post Traumatic Stress Disorder Checklist Civilian version. A score of 30 was chosen as the cut-off point for PTSD. RESULTS: In total, 112 patients presented to the emergency department following MVAs during the study period. Of these, 60.7% agreed for the follow-up. Among the respondents, the mean age was 26 years, 91.2% were males, 66.2% were married, 85.3% were Malays and 88.3% were Muslims. The calculated incidence of PTSD was 7.4%. There was no significant difference noted between the PTSD and non-PTSD groups. CONCLUSION: A considerable number of MVA victims in Malaysia may develop PTSD after the accident. Further research is needed to explore the factors that contribute or protect to develop the condition.

Survival and function of MiHA epitope-specific host CD8 TM cells following ablative conditioning and HCT.

Memory T cell (TM) populations specific for transplantation Ags may arise from sensitization due to blood transfusions, tissue transplants, or in multiparous females. In each of these scenarios, TM cells are likely generated, and have been shown to persist in such individuals for extended time periods. Heightened resistance to allogeneic marrow engraftment in certain individuals is therefore consistent with the presence of antidonor TM. CD8 TM were generated against a single minor H Ag (MiHA) epitope to determine if such cells could inhibit allogeneic marrow engraftment. The present results demonstrate that B6 mice sensitized to a single immunodominant (H60) epitope efficiently reject donor marrow allografts expressing this MiHA alone or together with multiple minor transplantation antigens, even following ablative TBI conditioning. To further address the survival and function of these CD8 TM, sensitized mice were ablatively conditioned and administered a syngeneic HCT. CD8(+)H60(TCR+) TM were clearly detected up to 2 weeks later in such recipients. Additionally, the memory cells present were capable of mediating effector responses as evidenced by their ability to resist a second, allogeneic HCT. In summary, these observations highlight the increased risk of resistance in the presence of antidonor antigen-specific CD8 TM due to their ability to survive and function even following rigorous conditioning and HCT.

Coarctation of aorta repair at the National Heart Institute (1983-1994).

This retrospective study illustrates our approach to this problem over the years, from performing subclavian flap aortoplasty initially to the more accepted procedure now, which is resection and end-to-end anastomosis. Coarctation of aorta in our population is seen in a varying age groups and are also associated with other cardiac anomalies including both acyanotic and cyanotic congenital cardiac defects. Therefore a wide variety of surgical procedures were performed including resection of the coarcted segment and end-to-end anastomosis, subclavian flap aortoplasty, patch aortoplasty and synthetic tube graft interposition. Subclavian flap aortoplasty is not widely practised anymore in favour of resection with end-to-end anastomosis. Fifty four point four percent of patients had isolated coarctation, 10.5% had associated valvular defects, 28.1% had other simple congenital defects and 7.0% had associated complex cyanotic congenital defects. Perioperative mortality was 5.26% and is correlated with the younger age of patients at time of surgery and severity of cardiac failure at time of presentation. We did not see any difference in mortality for patients with complex congenital disease or between the different surgical procedures. However, we did find that in the early period when resection with end-to-end anastomosis was performed, there was a significantly higher incidence of morbidities.

Engraftment of splenic tissue as a method to investigate repopulation by hematopoietic cells from host and donor marrow.

The lymphohematopoietic function of the spleen in mice varies dependent on age and hematopoietic requirements. A method was developed to study splenic repopulation of mature and progenitor cell populations by grafting neonatal or adult spleen tissue under the renal capsule of splenectomized mice. Two weeks following implant of irradiated syngeneic neonatal spleens into B6-Ly 5.1 or B6-gfp recipients, host lymphoid (B220(+), CD4/8(+)) and myeloid cells (CD11b(+)) had repopulated the splenic grafts and constituted the majority of cells contained in these heterotopic implants. Notably, the percentage of lymphoid and myeloid cells approximated adult levels in contrast to preimplant neonatal spleen levels. This observation indicated relatively rapid repopulation of the grafted tissue by adult host cells and suggests that the repopulation patterns were regulated by the host. Three months post-implantation, the cell composition in the graft remained comparable to adult levels. Microscopic examination demonstrated normal splenic architecture including follicles and red pulp. Lymphocytes within the graft were functional as indicated by their proliferation in response to lipopolysaccharide (LPS) and concanavalin A (ConA) stimulation. Progenitor cell activity determined by colony-forming unit interleukin-3 (CFU-IL-3) levels was also present in these grafts. Splenic implants were then assessed in transplant models following lethal irradiation and syngeneic or allogeneic bone marrow transplantation (BMT). Two weeks post-BMT, adult splenic tissue implants contained donor-derived B cells, T cells, and myeloid cell populations. As typically detected in the host spleen post-BMT, the grafted tissue also contained elevated levels of donor progenitor cells. By 3 months post-BMT, CFU-IL3 levels in the graft reflected the decreased levels characteristic of adult levels. The functional integrity of post-transplant splenocytes in the implants was also demonstrated by mitogenic responsiveness. In summary, this method should provide a useful model for the transfer of the splenic microenvironment to study the biology of the spleen in non-transplant and BMT settings.

The effect of the spleen on compartmental levels and distribution of donor progenitor cells after syngeneic and allogeneic bone marrow transplants.

These studies investigate the involvement of the spleen in progenitor (PC) cell numbers and "cross-talk" with the marrow compartment following syngeneic or allogeneic bone marrow transplantation (BMT) in sham or fully splenectomized mice. Intact recipient B6 mice were lethally irradiated prior to transplant with T cell-depleted bone marrow (BM-TCD). The kinetics of PC reconstitution following i.v. transplant consistently revealed a dramatic increase in splenic colony-forming unit interleukin-3 (CFU IL-3) and CFU (high proliferative potential-(HPP) levels between days 5 and 12 post-BMT. Direct injection of TCD-BM into the recipient marrow cavity did not alter this pattern of reconstitution in the splenic compartment. In contrast to spleens from normal adult B6 mice containing 0.9% and 0.6% of the total combined splenic and marrow committed (CFU IL-3) and primitive (CFU-HPP) progenitors, respectively, spleens of syngeneic BMT recipients at day 12 contained a 10-fold increase (p < 0.001) over the progenitor levels in normal spleens. These splenic numbers decreased to normal, homeostatic levels by day 28 post-BMT. In contrast, the level of marrow CFU IL-3 progenitors continued to increase post-transplant, reaching near homeostatic levels by day 28 post-BMT. Interestingly, early seeding of 5- (and -6)carboxyfluorescein diacetate succinimidyl ester (CFSE)-labeled or green fluorescent protein (GFP) donor bone marrow cells (BMC) to the marrow compartment was not different in sham splenectomies or recipients splenectomized 14 days earlier. However, recipient splenectomy consistently resulted in significantly higher numbers of CFU IL-3 in the bone marrow during the first 2 weeks post-transplant compared to sham controls. These elevated levels exceeded the combined progenitor numbers of the splenic and marrow compartments of intact recipients. Notably, this increase in marrow progenitor activity in splenectomized recipients was observed after syngeneic as well as allogeneic BMT. Allogeneic transplants across major, or those limited to minor, histocompatibility antigen differences exhibited this increased marrow progenitor activity. Splenectomy performed 2 h post-transplant to assure "normal" marrow seeding also resulted in higher marrow progenitor activity. Thus, this "marrow response" to splenectomy is not induced by early "shunting" of infused BM cells to the marrow compartment. These results suggest that communication between the splenic and marrow compartments following syngeneic and allogeneic BMT exists during early hematopoietic reconstitution, one effect of which is to impact the compartmental distribution of donor progenitor cells. The role of the spleen on engraftment, chimerism, and tolerance in allogeneic BMT models are now under investigation.

The value of transesophageal echocardiography in transcatheter closure of atrial septal defects in the oval fossa using the Amplatzer septal occluder.

BACKGROUND: From January, 1997, as part of an international multicentric trial, we have been closing small-to-moderate atrial septal defects within the oval fossa using the Amplatzer Septal Occluder (ASO, AGA Medical). METHODS: All patients with defects within the oval fossa deemed potentially suitable for transcatheter closure were investigated by transesophageal echocardiography with the aim of gaining extra information that might alter the decision to use the device to close the defect. Views were obtained in transverse and longitudinal planes, permitting measurements of the diameter of the defect, and its distance from the atrioventricular valves, coronary sinus, and pulmonary veins. Additionally, we sought to identify multiple defects, and to exclude sinus venosus defects. RESULTS: Of 56 patients with left-to-right shunts, 41 (73.2%) were deemed suitable for closure with the Amplatzer Septal Occluder. All underwent the procedure successfully, with no complications. This includes 5 patients with multiple small defects that were sufficiently close to the main defect to be closed with a single device. Only two of these had been detected on the transthoracic study. In the remaining 15 of 56 patients, transcatheter closure was deemed unsuitable. In 9 patients, this was due to the limitation of the size of the device available during the period of study, this representing a relative contraindication. In the remaining 6 (10.7%), transcatheter closure was not performed because multiple defects were too far apart to be closed with a single device in 3 patients, two patients were noted to have a sinus venosus defect, and another was noted to have anomalous connection of the right upper pulmonary vein to the right atrium. Excluding patients contraindicated due to the size of the defect alone, transesophageal echocardiography provided extra information in one-tenth of our patients, which altered the decision regarding management. CONCLUSION: Transesophageal echocardiography is indispensable in the evaluation of patients undergoing transcatheter closure of atrial septal defect.

The Amplatzer duct occluder: experience in 209 patients.

OBJECTIVES: The aim of the study was to assess the safety and efficacy of the Amplatzer ductal occluder (ADO) in transcatheter occlusion of patent ductus arteriosus (PDA). BACKGROUND: Transcatheter closure of small to moderate sized PDAs is an established procedure. The ADO is a self-expandable device with a number of salutary features, notably its retrievability, ease of delivery via small 5F to 7F catheters and a range of sizes suitable even for the larger PDAs. METHODS: Between November 1997 and August 1999, the ADO was successfully implanted in 205 of 209 patients with PDA. The inclusion criteria for this device occlusion method were patients with clinical and echocardiographic features of moderate to large PDA, weighing > or =3.5 kg as well as asymptomatic adolescents and adults with PDA measuring > or =5.0 mm on two-dimensional (2D) echocardiogram. Occlusion was achieved via the antegrade venous approach. Follow-up evaluations were performed with 2D echocardiogram, color-flow mapping and Doppler measurement of the descending aorta and left pulmonary artery velocity at 24 h and 1, 3, 6 and 12 months after implantation. RESULTS: Two hundred and five patients had successful PDA occlusion using this device. The patients were between two months and 50 years (median 1.9) and weighed between 3.4 kg and 63.2 (median 8.4). Infants made up 26% of the total patients. The PDA measured from 1.8 to 12.5 mm (mean 4.9) at the narrowest diameter. Forty-four percent of patients achieved immediate complete occlusion. On color Doppler the closure rates at 24 h and 1 month after implant were 66% and 97%, respectively. At 6 and 12 months all except one patient attained complete occlusion. Device embolization occurred in three patients; in two this was spontaneous, and in the other it was due to catheter manipulation during postimplant hemodynamic measurement. Mild aortic narrowing was seen in an infant. CONCLUSIONS: Patent ductus arteriosus occlusion using ADO is safe and efficacious. It is particularly useful in symptomatic infants and small children with relatively large PDA. Embolization can be minimized by selection of appropriate sized devices, and caution should be exercised in infants <5 kg.

Pulmonary atresia with intact ventricular septum percutaneous radiofrequency-assisted valvotomy and balloon dilation versus surgical valvotomy and Blalock Taussig shunt.

OBJECTIVE: We compared the result of radiofrequency (RF)-assisted valvotomy and balloon dilation with closed surgical valvotomy and Blalock Taussig (BT) shunt as primary treatment in selected patients with pulmonary atresia and intact ventricular septum (PA-IVS). BACKGROUND: Patients with PA-IVS who have mild to moderate hypoplasia of the right ventricle (RV) and patent infundibulum have the greatest potential for complete biventricular circulation. The use of RF or laser wires to perforate the atretic valve followed by balloon dilation provides an alternative to surgery. METHODS: Between May 1990 and March 1998, 33 selected patients underwent either percutaneous RF valvotomy and balloon dilation (group 1, n = 21; two crossed over to group 2) or surgical valvotomy with concomitant BT shunt (group 2, n = 14). Second RV decompression by balloon dilation or right ventricular outflow tract (RVOT) reconstruction were performed if necessary. Patients who remained cyanosed were subjected to transcatheter trial closure of the interatrial communication. Partial biventricular repair was offered to those with inadequate growth of the RV. RESULTS: The primary procedure was successful in 19 patients in group 1. There was one in-hospital death and two late deaths. Of the remaining 16 survivors, 12 achieved complete biventricular circulation, 7 of whom required no further interventions. Two patients required repeat balloon dilation, 1 RVOT reconstruction and 2 transcatheter closure of interatrial communication. Two patients underwent partial biventricular repair. In group 2, there were 3 in-hospital deaths after the primary procedure and 1 patient died four months later. All survivors (n = 10) required a second RV decompression, 8 by balloon dilation and 2 by RVOT reconstruction, after which, two patients died. Of the final 8 survivors, 7 achieved complete biventricular circulation, 5 after coil occlusion of the BT shunt and 2 after closure of interatrial communication. CONCLUSIONS: Radiofrequency valvotomy and balloon dilation is more efficacious and safe compared with closed pulmonary valvotomy and BT shunt in selected patients with PA-IVS.

Anticipated difficulties in house-officership for graduating medical students of the school of medical sciences, universiti sains malaysia kubang kerian, kelantan, malaysia.

To aid future curriculum revision and planning, a batch of newly graduated medical students were surveyed using a questionnaire containing items representing possible areas of concern during house-officership. Students rated items representing communication issues as areas of concern. They did not agree that areas concerning responsibilities as a doctor, continuing medical education, theoretical and practical skills and potentially stressful working conditions were problem areas. Communication skills should remain among the priority areas for undergraduate training. Students should also be given more information about the house-officership period prior to graduation. Further study is needed to confirm perceived strengths of the USM curriculum suggested by the study, which are skills in finding resources for further learning and skills in leadership. A task-analysis of the house-officership period is also needed.

Transcatheter closure of multiple muscular ventricular septal defects using Gianturco coils.

A 10-month-old boy underwent operation to close a large secundum atrial septal defect and multiple muscular ventricular septal defects. Closure of the ventricular septal defects was unsuccessful and led to worsening cardiac failure and inability to wean the patient from mechanical ventilation. Transcatheter closure of the ventricular septal defects using Gianturco coils was undertaken. This technique is an effective alternative for closure of multiple muscular ventricular septal defects in infants and small children.

Balloon dilatation of congenital mitral stenosis in a critically ill infant.

We report a case of a 14-month-old-infant with severe congenital mitral stenosis who presented with pulmonary oedema, acute renal failure and haemodynamic instability. Balloon dilatation was successfully performed under fluoroscopic and transesophageal echocardiographic guidance. Cathet. Cardiovasc. Intervent. 48:191-193, 1999.

Transcatheter occlusion of native persistent ductus arteriosus using conventional Gianturco coils.

Two hundred eleven patients with small- to moderate-sized native patent ductus arteriosus underwent closure using Gianturco coils, employing the transvenous multiple catheter approach. Short-term results showed a high rate of complete occlusion and a potential long-term complication of mild left pulmonary artery stenosis in a small number of patients.

Use of interlocking detachable coils in embolization of coronary arteriovenous fistulas.

Thirteen patients underwent transcatheter closure of coronary artery fistulas using interlocking detachable coils alone or combined with fibered coils. Complete occlusion was achieved in 92% of patients; although inadvertent embolization of coils occurred in 23% of patients, all these coils were easily retrieved using snares.

Treatment with flecainide for symptomatic and refractory tachyarrhythmias in children.

Nine children, aged 2.5 months to 16 years, presenting with tachyarrhythmias were treated with intravenous (i.v.) flecainide, a type 1C antiarrhythmic drug. There were four boys and five girls; seven were supraventricular and two ventricular tachycardias and three had structural cardiac abnormalities. The i.v. dose required to terminate the arrhythmias ranged from 1.0 to 2.4 mg/kg (mean 1.55 mg/kg) although a mean of 1.94 mg/kg per dose was required to maintain sustained sinus rhythm after a single i.v. dose. Eight of the patients--six supraventricular and two ventricular tachyarrhythmias, required maintenance oral flecainide. Oral dosages of 6.7-9.5 mg/kg per day (mean of 7.97 mg/kg per day in three divided doses) were required to effectively prevent the tachyarrhythmias. Intravenous and oral flecainide are safe and effective in terminating supraventricular and ventricular tachyarrhythmias. No evidence of proarrhythmia was found in the patients during follow up of between 5 and 9 months. The present limitation of performing radiofrequency ablation on infants and small children justifies the important place of medical therapy for re-entrant supraventricular tachyarrhythmias.

A characteristic continuous wave Doppler signal in cor triatriatum?

Continuous wave Doppler recordings of the turbulent jet through the restrictive orifice of a left atrial partition in a patient with corrected transposition of the great arteries and cor triatriatum showed alternate bands of high intensity diastolic and low intensity systolic signals with preservation of the normal configuration of the diastolic E and A peaks. It is thought that Doppler studies in cor triatriatum will provide useful complementary haemodynamic information in the echocardiographic diagnosis of this anomaly.