Case Report: A Case of Post-Transplant Chagas Reactivation after Negative Trypanosoma cruzi Testing.

Patients with Chagas cardiomyopathy carry a significant risk of reactivation after heart transplantation. Reactivation of Chagas disease can lead to graft failure or systemic complications such as fulminant central nervous system disease and sepsis. As such, careful screening for Chagas seropositivity prior to transplant is crucial to preventing negative outcomes in the post-transplant setting. One challenge in screening these patients is the variety of laboratory tests available and their differing sensitivities and specificities. In this case report, we present a patient who tested positive by a commercial Trypanosoma cruzi antibody assay and later tested negative by CDC confirmatory serological analysis. After the patient underwent orthotopic heart transplant, he underwent protocol-based polymerase chain reaction surveillance for reactivation as a result of persistent concerns for T. cruzi infection. It was discovered shortly thereafter that the patient had reactivation of Chagas disease, confirming that he did have Chagas cardiomyopathy prior to transplantation, despite negative confirmatory testing. This case illustrates the complexities of serological diagnosis of Chagas disease and the importance of additional testing for T. cruzi when the post-test probability remains high even with a commercial, negative serologic test.

Pulse oximetry: why oxygen saturation is still not a part of standard pediatric guidelines in low-and-middle-income countries (LMICs).

BACKGROUND: With the high frequency of acute respiratory infections in children worldwide, particularly so in low-resource countries, the development of effective diagnostic support is crucial. While pulse oximetry has been found to be an acceptable method of hypoxemia detection, improving clinical decision making and efficient referral, many healthcare set ups in low- and middle-income countries have not been able to implement pulse oximetry into their practice. MAIN BODY: A review of past pulse oximetry implementation attempts in low- and middle-income countries proposes the barriers and potential solutions for complete integration in the healthcare systems. The addition of pulse oximetry into WHO health guidelines would prove to improve detection of respiratory distress and ensuing therapeutic measures. Incorporation is limited by the cost and unavailability of pulse oximeters, and subsequent oxygen accessibility. This restriction is compounded by the lack of trained personnel, and healthcare provider misconceptions. These hurdles can be combated by focus on low-cost devices, and cooperation at national levels for development in healthcare infrastructure, resource transport, and oxygen delivery systems. CONCLUSION: The implementation of pulse oximetry shows promise to improve child morbidity and mortality from pneumonia in low- and middle-income countries. Steady measures taken to improve access to pulse oximeters and oxygen supplies, along with enhanced medical provider training are encouraging steps to thorough pulse oximetry integration.

When coronary imaging and physiology are discordant, how best to manage coronary lesions? An appraisal of the clinical evidence.

BACKGROUND: Discordant physiology and anatomy may occur when nonsevere angiographic stenosis has positive physiology as well as the opposite situation. AIM: To underline the reasons behind the discrepancy in physiology and anatomy and to summarize the information that coronary imaging may add to physiology. METHODS: A review of the published literature on physiology and intravascular imaging assessment of intermediate lesions was carried out. RESULTS: The limitations of angiography, the possibility of an underlying diffuse disease, the presence of a "grey zone" in both techniques, the amount of myocardial mass that subtends the stenosis, and plaque vulnerability may play a role in such discrepancy. Intracoronary imaging has a poor diagnostic accuracy compared to physiology. However, it may add information about plaque vulnerability that might be useful in deciding whether to treat or not a certain lesion. CONCLUSIONS: Coronary revascularization is recommended for patients with ischemia based on physiology. Intracoronary imaging adds information on plaque vulnerability and can help on the decision whether to revascularize or not a lesion.

Ventricular Fibrillation Cardiopulmonary Arrest Following Micra™ Leadless Pacemaker Implantation.

Leadless cardiac pacemakers such as the Micra™ transcatheter leadless pacing system (Medtronic, Minneapolis, MN, USA) are an alternative to traditional transvenous pacemakers. Implantation of leadless pacemakers, albeit safe, may be associated with complications, including cardiac tamponade; high capture thresholds; and, rarely, ventricular arrhythmias. We report a case of ventricular fibrillation arrest following the implantation of a Micra™ leadless pacemaker.

Cryoballoon Ablation for Persistent Atrial Fibrillation in a Patient with a Left Pneumonectomy.

Pulmonary vein (PV) isolation (PVI) is the most important component of catheter ablation of atrial fibrillation (AF) and can be achieved by radiofrequency or cryoballoon ablation (CBA). The CBA system has shown excellent efficacy and safety in a number of clinical trials and is independent of the PV anatomy. However, pneumonectomy can significantly alter the anatomy posing a challenge to CBA. Few cases of PVI accomplished by CBA have been described in patients with lobectomy, but none in the pneumonectomy population. We describe a case of successful CBA for paroxysmal AF in a patient with a left total pneumonectomy.

Detection of subclinical rheumatic heart disease in children using a deep learning algorithm on digital stethoscope: a study protocol.

INTRODUCTION: Rheumatic heart diseases (RHDs) contribute significant morbidity and mortality globally. To reduce the burden of RHD, timely initiation of secondary prophylaxis is important. The objectives of this study are to determine the frequency of subclinical RHD and to train a deep learning (DL) algorithm using waveform data from the digital auscultatory stethoscope (DAS) in predicting subclinical RHD. METHODS AND ANALYSIS: We aim to recruit 1700 children from a group of schools serving the underprivileged over a 12-month period in Karachi (Pakistan). All consenting students within the age of 5-15 years with no underlying congenital heart disease will be eligible for the study. We will gather information regarding sociodemographics, anthropometric data, history of symptoms or diagnosis of rheumatic fever, phonocardiogram (PCG) and electrocardiography (ECG) data obtained from DAS. Handheld echocardiogram will be performed on each study participant to assess the presence of a mitral regurgitation (MR) jet (>1.5 cm), or the presence of aortic regurgitation (AR) in any view. If any of these findings are present, a confirmatory standard echocardiogram using the World Heart Federation (WHF) will be performed to confirm the diagnosis of subclinical RHD. The auscultatory data from digital stethoscope will be used to train the deep neural network for the automatic identification of patients with subclinical RHD. The proposed neural network will be trained in a supervised manner using labels from standard echocardiogram of the participants. Once trained, the neural network will be able to automatically classify the DAS data in one of the three major categories-patient with definite RHD, patient with borderline RHD and normal subject. The significance of the results will be confirmed by standard statistical methods for hypothesis testing. ETHICS AND DISSEMINATION: Ethics approval has been taken from the Aga Khan University, Pakistan. Findings will be disseminated through scientific publications and to collaborators. ARTICLE FOCUS: This study focuses on determining the frequency of subclinical RHD in school-going children in Karachi, Pakistan and developing a DL algorithm to screen for this condition using a digital stethoscope.

Comparative analysis of connective tissue disease-associated interstitial lung disease and idiopathic pulmonary fibrosis from a tertiary care centre in Pakistan.

OBJECTIVE: To compare the characteristics of connective tissue disease-associated interstitial lung disease with idiopathic pulmonary fibrosis at a tertiary care hospital. METHODS: The retrospective study was conducted at the Aga Khan University Hospital, Karachi, and comprised demographical, clinical and radiological data of patients with interstitial lung disease between October 2016 and October 2017 accessed through the outpatient data registry. Data was compared in terms of characteristics and key features of patients with connective tissue disease-associated interstitial lung disease with those of idiopathic pulmonary fibrosis. Statistical analysis was done using STATA 12. RESULTS: Of the 184 patients, 52(29.3%) had connective tissue disease-associated interstitial lung disease and 62(35%) had idiopathic pulmonary fibrosis. The most prevalent conditions among connective tissue disease-associated interstitial lung disease patients were rheumatoid arthritis 22(42.3%) and scleroderma 13(25%). Compared to patients with idiopathic pulmonary fibrosis, those with connective tissue disease-associated interstitial lung disease were predominantly younger (p<0.001) and female (p<0.001). History of gastroesophageal reflux disease was also significantly lower in connective tissue disease-associated interstitial lung disease (p=0.05). CONCLUSIONS: Connective tissue disease-associated interstitial lung disease patients were found to be younger and predominantly female compared to patients of idiopathic pulmonary fibrosis.

Mediastinal tissue friability-An unreported complication from Mycobacterium chimaera infection post-cardiac surgery.

Mycobacterium chimaera can cause disseminated infection following cardiac surgery with cardiopulmonary bypass and contaminated heater-cooler devices. We discuss a 41-year-old man with a disseminated M. chimaera infection following surgery for a type A aortic dissection. His presentation included cachexia and dorsalgia with a work-up revealing vertebral osteomyelitis with an epidural abscess, bone marrow, and pulmonary infiltration, and fluid collection around his aortic graft. He received 1 month of antibiotics before the explantation of infected foreign material, mediastinal debridement, and aortic reconstruction. Complications included septic shock, respiratory and renal failure, mediastinitis, and four distal aortic anastomotic dehiscences from friable tissue and persistent infection.

Quality Initiative to Reduce Cardiac CT Angiography Radiation Exposure in Patients with Congenital Heart Disease.

BACKGROUND: The use of cardiac computed tomography angiography (CCTA) as a complementary diagnostic modality to echocardiography in patients with congenital heart diseases (CHDs) is expanding in low- and middle-income countries. The adoption of As Low As Reasonably Achievable techniques is not widespread, resulting in significant unintended radiation exposure, especially in children. Simple quality improvement measures geared toward reducing radiation dose can have a impact on patient safety in resource-limited centers in low- and middle-income countries. OBJECTIVES: To determine how a quality improvement initiative can reduce radiation exposure during CCTA in patients with CHD. METHODS: We designed a key driver -based quality initiative to reduce radiation dose during CCTA for CHD using protocol optimization, communication, and training and implementation as the drivers for intervention. Preintervention variables (radiation exposure, scanning protocols, and image quality) were collected from September 2012 to July 2016 and compared with variables in the postimplementation phase (February 2017 to July 2017). We compared quantitative and categorical variables using the chi-square test. Linear regression analysis was used to evaluate the effect of various factors on radiation dose. RESULTS: We documented a reduction in the effective dose in the postintervention versus preintervention phase (mean, 2.0 versus 21 mSv, P < 0.0001, respectively). Linear regression showed that the optimal organizational levels are associated with the same reduction in radiation. This finding shows that the time factor translates a combination of organizational and technical factors that contributed to the reduction in radiations. CONCLUSIONS: Our project showed a reduction in CCTA-associated radiation exposure.

Clinical characteristics and factors associated with mortality in idiopathic pulmonary fibrosis: An experience from a tertiary care center in Pakistan.

INTRODUCTION: Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive interstitial lung disease (ILD) that predominantly affects older adults. IPF has the highest mortality burden of all ILDs. Data on mortality in patients with IPF is limited in developing countries. OBJECTIVES: To identify factors associated with mortality in patients with IPF at a tertiary care center in Pakistan. METHODS: A retrospective chart review was conducted at the Aga Khan University Hospital (AKUH) in Karachi, Pakistan from January 2005 to December 2015. Patients were assessed for smoking status, clinical onset of disease, pulmonary hypertension, disease severity based on spirometry and hypoxemia. RESULTS: A total of 239 cases were reviewed, of which 103 were non-survivors. A total of 45 (18%) were current smokers and 71 (29.7%) were ex-smokers. Smoking was more common in non-survivors (56.3% P ≤ .01). Pulmonary hypertension was present in 18.8% of patients. 95.4% of patients who had received pirfenidone treatment were alive at the time of study. On multivariate analysis, pirfenidone treatment (OR 0.03; 95% CI 0.01-0.08), current smoking (OR 2.60; 95% CI 1.04-6.58), age older than 60 years (OR 2.63; 95% CI 1.04-6.58) and hypoxemia (OR 3.29; 95% CI 1.58-6.84) were the factors associated with mortality. CONCLUSION: Smoking, age greater than 60 years and hypoxemia were identified as factors that increased the odds of mortality in IPF patients, whereas pirfenidone was found to lower the odds of mortality.

Spectrum of interstitial lung disease from a tertiary care hospital in Karachi.

OBJECTIVE: To determine the clinical features and patterns of interstitial lung disease. METHODS: This retrospective study was conducted at the Aga Khan University Hospital, Karachi, and comprised record of patients diagnosed with interstitial lung disease from January 2005 to December 2015. All patients aged 16 years and above diagnosed with interstitial lung disease on the basis of clinical features, radiological features on high-resolution computed tomography of the chest, and lung biopsies were included. SPSS 19 was used for data analysis. RESULTS: Of the 537 patients, 324(60.3%) of the participants were females. The overall mean age was 60.5±14.9 years. The most common co-morbid condition was diabetes mellitus in 72(13.4%) patients, followed by hypertension in 48(8.9%) and ischaemic heart disease in 21(3.9%). The most common interstitial lung disease was idiopathic pulmonary fibrosis in 217(40.4%) patients, followed by non-specific interstitial pneumonia in 106(19.7%), sarcoidosis in 82(15.3%) and connective tissue disease-related interstitial lung disease in 56(10.4%) patients. CONCLUSIONS: Idiopathic pulmonary fibrosis was found to be the most common interstitial lung disease subtype followed by non-specific interstitial pneumonia, sarcoidosis and connective tissue disease-related-interstitial lung disease.

Impact of International Quality Improvement Collaborative on Congenital Heart Surgery in Pakistan.

BACKGROUND: The International Quality Improvement Collaborative (IQIC) was formed to reduce mortality and morbidity from congenital heart disease (CHD) surgeries in low/middle-income countries. OBJECTIVES: We conducted this study to compare the postoperative outcomes of CHD surgeries at a centre in Pakistan before and after joining IQIC. METHODS: The IQIC provides guidelines targeting key drivers responsible for morbidity and mortality in postoperativepatients with CHD. We focused primarily on nurse empowerment and improving the infection control strategies at our centre. Patients with CHD who underwent surgery at this site during the period 2011-2012 (pre-IQIC) were comparedwith those getting surgery in 2013-2014 (post-IQIC). Morbidity (major infections), mortality and factors associated with them were assessed. RESULTS: There was a significant decrease in surgical site infections and bacterial sepsis in the post-IQIC versus pre-IQIC period (1% vs 30%, p=0.0001, respectively). A statistically insignificant decrease in the mortality rate was also noted in post-IQIC versus pre-IQIC period (6% vs 9%, p=0.17, respectively). Durations of ventilation and intensive care unit (ICU) and hospital stay were significantly reduced in the post-IQIC period. Age <1 year, malnutrition, low preoperative oxygen perfusion, Risk Adjustment for Congenital Heart Surgery score >3, major chromosomal anomalies, perfusion-related event, longer ventilation and ICU/hospital stay durations were associated with greater odds of morbidity and mortality. CONCLUSION: Enrolling in the IQIC programme was associated with an improvement in the postsurgical outcomes of the CHD surgeries at our centre.

Effects of Pinealectomy and Short Day Lengths on Reproduction and Neuronal RFRP-3, Kisspeptin, and GnRH in Female Turkish Hamsters.

Long days (LDs) stimulate and short days (SDs) inhibit reproduction in photoperiodic rodents by modifying nocturnal pineal melatonin secretion. In LD Turkish hamsters, unlike other rodents, pinealectomy induces reproductive quiescence comparable to that produced by SDs. We assessed whether SDs and pinealectomy induce similar or different patterns of kisspeptin and gonadotropin-inhibitory hormone (also known as RFamide-related peptide-3 [RFRP-3] in mammals) expression, important mediators of seasonal reproductive changes in other species. Brains were harvested from sham-operated female Turkish hamsters maintained in LDs and SDs and LD-pinealectomized (pinx) females, all housed in their respective photoperiods for 12 weeks. Uterine weights were substantially higher in LD-sham than in LD-pinx and SD-sham females. RFRP-3-immunoreactive(-ir) cells in the dorsomedial hypothalamic nucleus were greater in number and size in the reproductively competent LD-sham hamsters than in both reproductively suppressed SD-sham and LD-pinx hamsters. LD-sham hamsters had more kisspeptin-ir cells in the anteroventral periventricular nucleus than did LD-pinx hamsters. Reproductive quiescence, whether induced by short-day lengths or pinealectomy, was generally accompanied by comparable changes in RFRP-3 and kisspeptin, suggesting that long-duration melatonin signaling and withdrawal of melatonin by pinealectomy may act through the same neural substrates to induce gonadal quiescence.