Ventricular septal defect (VSD) is the most common congenital heart disease in children, contributing significantly to pediatric morbidity and mortality globally. In resource-limited settings like Pakistan, delayed diagnosis and limited access to pediatric cardiology services can exacerbate disease outcomes. Objectives: To evaluate the clinical presentation and echocardiographic profile of pediatric patients diagnosed with VSD at a tertiary care center in Pakistan. Methods: This retrospective, cross-sectional descriptive study was conducted at the Department of Pediatric Cardiology of the Peshawar Institute of Cardiology from July 1, 2025, to September 31, 2025. A total of 200 children under 18 years of age with echocardiographically confirmed VSD were included. Data on demographics, clinical symptoms, and physical examination findings were collected. Echocardiographic assessment was used to determine the size, type, and location of VSD, along with associated cardiac anomalies. Results: The median age at diagnosis was 9.4 months, with 78% diagnosed within the first year of life. The most common presenting feature was cardiac murmur (60%), followed by recurrent respiratory infections (49%), feeding problems (42.5%), and failure to thrive (38%). Perimembranous VSD was the most prevalent type (62%), followed by muscular (19%), inlet (10%), and outlet (9%) defects. Associated cardiac lesions included patent ductus arteriosus (18%), atrial septal defect (14%), aortic valve prolapse (11%), and pulmonary hypertension (24%). Conclusions: Early recognition and echocardiographic screening, especially in high-risk groups like children with Down syndrome, are essential to improving outcomes. These findings support the need for enhanced screening and resource allocation in pediatric cardiology services in Pakistan.

Atrial Septal Defect (ASD) is a common congenital heart defect, often requiring precise diagnostic evaluation for optimal treatment. The presence of left atrial anomalous band, an anatomical variation, can complicate diagnosis and intervention and may be misinterpreted on 2D imaging. This case highlights the critical role of three-dimensional transesophageal echocardiography (3D-TEE) both for pre-procedural anatomical clarification and for intra-procedural guidance, in accurately characterizing ASD morphology, particularly when anomalous band are present, ensuring appropriate device selection and procedural planning. A 25-year-old woman with a history of a cardiac murmur identified during pregnancy presented with occasional palpitations and mild foot swelling. Preoperative two-dimensional echocardiography suggested multiple ASDs, but 3D-TEE revealed a single defect with a mobile anomalous band, with the ASD measuring approximately 24*18mm in diameter and having a circular shape with smooth, well-defined edges, which altered the procedural approach. A single occluder was successfully deployed, leading to complete closure of the defect without complications. This case emphasizes the superiority of 3D-TEE over conventional imaging in assessing ASD morphology, particularly in the presence of anatomical variations like anomalous band. We emphasize its value not only for accurate device selection and procedural planning but also as a critical teaching tool for operators learning procedural 3D echocardiography guidance. Accurate visualization of the ASD and surrounding structures facilitates optimal device selection and improves clinical outcomes.

Aim: To evaluate the diagnostic value of potentially diagnostic clues in distinguishing infectious from non-infectious causes of fever of unknown origin (FUO). Material and methods: We conducted a retrospective–prospective, single-center study involving patients older than 14 years who met the criteria for classical FUO. Medical history, physical examination findings, and a standardized laboratory panel were collected for all participants. After the final diagnosis, patients were divided into infectious and non-infectious groups. Demographic characteristics, clinical features, and laboratory results were compared between groups. Results: A total of 79 patients were included, with a mean age of 50.6±17.1 years (range 15–77). Males represented 61.1% of cases and were more common in the infectious FUO group (p=0.016), with this group showing higher febrile peak (p<0.001). Infectious diseases accounted for 51.9% of cases. In this group, notable clinical findings included fatigue (sensitivity 63.4%), fever (sensitivity 75.6%), heart murmur (positive likelihood ratio [+LR] 4.8), and splenomegaly (+LR 2.23). Key features of the non-infectious group were arthralgia (+LR 3.96), neck pain (+LR 3.49), joint swelling (+LR 6.44), and rash (+LR 3.49). Elevated procalcitonin (p=0.006), ALT (p=0.04), AST (p=0.02), and globulin levels (p=0.016) was noted in infectious FUO, while ferritin (p=0.047) and LDH (p=0.03) were higher in the non-infectious group. Conclusions: The identified differences in diagnostic variables between infectious and noninfectious causes of classical FUO may assist initial etiologic differentiation and improve utilization of the diagnostic process.

This nursing care analysis explores the management of a 6-month-old male Weimaraner presenting with acute vomiting, inappetence, lethargy and a newly identified systolic heart murmur. The primary disease process was identified as a jejunal foreign body causing obstruction and subsequent dehydration, while the secondary disease process involved a heart murmur probably related to turbulent blood flow or a congenital defect. Clinical assessment included detailed physical examination, comprehensive blood gas analysis and vigilant monitoring of vital parameters, which revealed significant dehydration, electrolyte imbalances and elevated renal markers. Patient management involved intravenous fluid therapy with potassium supplementation, regular monitoring of hydration and urine output, and prophylactic antibiotics to prevent infection. Careful anaesthesia planning was implemented due to the increased risks posed by the patient's age, metabolic demands and systemic compromise. Postoperative care included controlled analgesia and continued support to restore fluid and electrolyte balance. The case highlights the importance of thorough assessment, individualised perioperative care and multidisciplinary teamwork in managing complex emergencies in veterinary practice. The analysis highlights the need for evidence-based protocols and diligent nursing observation to optimise patient outcomes in cases involving combined gastrointestinal and cardiovascular problems.

Low utility of pre-operative cardiology referrals in adolescent idiopathic scoliosis using a cutoff of Cobb > 70 degrees.

Echocardiographic description of shunt volume in dogs with patent ductus arteriosus.

A hybrid neural network with multistage feature fusion for detecting heart failure and murmurs from time–frequency representations of phonocardiograms

This study uses transfer learning architectures to detect cardiac murmurs in phonocardiogram signals by denoising the signal, extracting relevant features for spectrograms generation. The Short-Time Fourier Transform, Mel-Frequency Cepstral Coefficients, and Continuous Wavelet Transform techniques were applied on Physionet’s CirCor Digiscope PCG dataset. VGG16, VGG19, ResNet50, and InceptionV3 models, were trained on these spectrograms for binary classification. Fourth-order Butterworth bandpass filter, used with Savitzky-Golay filtering, gave the best results. The CWT Spectrogram and VGG19 combination yielded best accuracy of 89.44%. Different combinations of spectrograms and transfer learning architectures performed better on performance metrics of precision, recall, F1-score, and ROC-AUC.

Case: A 4-month-old female infant presented with cough and fever. A cardiac murmur was noted at the pulmonary valve area. Lab tests revealed mildly elevated WBC and CRP. CXR was unremarkable. TTE showed a markedly dilated RCA ostium (6.8 mm) and a saccular aneurysm arising from the proximal RCA communicating with the RA. Contrast-enhanced CCTA with 3D reconstruction confirmed an RCA ostial diameter of 5.5 mm, a 7 mm SNA aneurysm draining into the RA through two fistulas (2.0 mm and 2.5 mm). There were no clinical or laboratory findings suggestive of Kawasaki disease (KD). Surgical repair was performed with a right axillary thoracotomy approach. Proximal ligation of the sinoatrial nodal aneurysm (SNA) was performed, guided by an occlusion test. Postoperatively, P waves were absent on ECG on day 1 but reappeared by day 2. The postoperative course was uneventful. Discussion: This case presents the youngest reported patient with the rare triad of a RCA aneurysm, SNA aneurysm, and dual coronary artery fistulas (CAF) draining into the RA. Previous reports are limited and exclusively involve adults. CAF is rare, with a prevalence of 0.002% in the population. Multiple fistulas are 10.7% to 16% of these cases. This case does not align with KD, the most common cause of coronary artery aneurysms (CAA) in children. Given the localization of lesions to the RCA and SNA instead of diffused coronary dilation, a congenital abnormality is the most plausible etiology. Chronic shunting, even through a small CAF, can cause progressive dilation and aneurysm of the upstream level. In this infant, two giant aneurysms resulting from dual fistulas warranted surgical correction, even in the absence of heart failure or chamber dilation. This highlights the importance of considering aneurysm formation as a potential factor when evaluating the necessity for early intervention in infants. This is also the first report of a right axillary thoracotomy for repairing complex coronary anomaly in infants. This approach, adopted at our center for congenital heart disease, offers excellent access to right-sided cardiac structures with benefits in recovery and cosmetic outcomes. Unlike reports of immediate P wave loss during temporary SNA occlusion, our patient retained P waves intraoperatively, suggesting age- or anatomy-related variation in sinus node perfusion.

INTRODUCTION: Congenitally corrected transposition of the great arteries(CCTGA) is a rare congenital heart defect characterized by L-looping of the heart tube,resulting in atrioventricular(AV) and ventriculoarterial(VA) discordance.Despite physiologically normal circulation, complications like complete heart block(CHB),VSD,pulmonary stenosis,tricuspid valve regurgitation,and right heart failure are common.Pregnant women with CCTGA may have successful outcomes but face increased maternal and fetal risks,especially with cyanosis or CHB.We report a rare case of a primigravida with CCTGA and CHB who suffered postpartum cardiac arrest from bradycardia-induced polymorphic ventricular tachycardia(PMVT). CASE DESCRIPTION: A 24-year-old primigravida at 35 weeks’ gestation with history of CCTGA presented with fatigue,bradycardia,and reduced fetal movements.Examination revealed bradycardia,cannon waves in the JVP,regular pulse,and varying first heart sound intensity without murmur.EKG showed CHB.Echocardiography revealed situs solitus with levocardia,AV and VA discordance,Ebstein-like systemic AV valve,moderate regurgitation,and reduced systemic ventricular EF.A temporary pacemaker was placed preoperatively,and an emergency cesarean was performed.On postoperative day 11,she had a cardiac arrest with seizure and was resuscitated.ECG showed CHB,narrow QRS escape rhythm,bradycardia-induced PMVT,deep Q waves in lead III,and absent Q waves in lateral leads(Fig.1).She was intubated,admitted to the cardiac ICU,and managed with temporary pacing.After stabilization,she underwent dual-chamber(DDD) permanent pacemaker implantation(Fig.2) and was discharged on medical therapy with dietary advice,pacemaker checks,and regular follow-up. DISCUSSION: CCTGA is rare,occurring in ~0.02 per 1000 live births and comprising <1% of congenital heart disease.It involves AV and VA discordance.Presentation depends on associated lesions,with many patients exhibiting bradycardia from complete heart block,murmur,cyanosis,or heart failure and pregnancy imposes additional hemodynamic stress, making management challenging.Our case underscores this complexity, which was further compounded by bradycardia-induced polymorphic ventricular tachycardia, a rare arrhythmia in this setting.It highlights the importance of continuous cardiac monitoring not only antepartum, but also postpartum, and emphasizes close multidisciplinary monitoring and timely intervention to optimize both maternal and fetal outcomes.

Introduction: Cardiac auscultation often provides the first indication of underlying cardiac conditions through identification of heart murmurs. Auscultation is conducted during routine physical exams and is traditionally performed via stethoscope. However, conventional auscultation has limited sensitivity and accuracy due to high inter-rater discrepancy. Given its importance in the diagnostic process, an enhanced protocol is necessary. Artificial intelligence (AI) has been implemented in various medical settings. However, AI is limited by its need for vast quantities of high-quality training data. Data augmentation (DA) can be used to generate new samples from existing data by applying various transformations, which increases algorithm robustness and generalizability. Hypothesis: We hypothesized that implementing the Minimally Random Convolutional Kernel Transform (MiniROCKET) AI model with DA techniques improves the accuracy and speed of murmur detection in phonocardiogram (PCG) data. Methods: We used data from the 2022 George Moody PhysioNet Heart Sound Classification Challenge, containing PCG recordings of individuals under 21 years of age in Northeast Brazil. Patients without recordings from all four heart valves were excluded. Each patient’s audio files were synchronized at the first heartbeat. The file group then underwent 10 random time-series DA techniques, yielding four files from each original. Then, a Mel spectrogram was generated from each file, and one random DA technique was applied to each to make three spectrograms (Figure 1). Through DA, our sample size was increased from 928 spectrograms to 14,848. After pre-processing, MiniROCKET classified each patient as: “murmur present,” “murmur absent,” or “further assessment required” - if sufficient certainty is not achieved. Results: We assessed the effect of varying levels of DA, the overall accuracy of our MiniROCKET methodology, and the speed of our model by comparing with existing models (Tables 1&2). Overall, our method yielded improved quality assessment metrics and enhanced speed compared to existing models and was further improved through DA techniques. Conclusion: With DA (p=8.600e-05), our method boasts rapid and precise detection of murmurs in PCG data, with a weighted accuracy of 96.4% and an evaluation time of 0.02 seconds per patient, outperforming existing methods. Implementing this method may streamline diagnosis, promote scalability and adaptability, and allow for early-stage treatment.

Clinical Course: A 72-year-old male with a history of hypertrophic obstructive cardiomyopathy (HOCM), chronic atrial fibrillation, septal myomectomy, and mitral regurgitation presented with dyspnea on exertion, unintentional 80-pound weight loss for one year and two weeks of progressive dysphagia with difficulty tolerating liquids. On presentation, he was hemodynamically stable. Physical examination revealed temporal wasting, III/VI holosystolic cardiac murmur, and bilateral pitting edema. Right heart catheterization revealed an elevated pulmonary capillary wedge pressure (36 mmHg) and low cardiac index (Fick 1.1 L/min/m2). The patient was started on a milrinone infusion and treated with intravenous bumetanide. A nasogastric feeding tube was inserted for tube feeds. The patient was a former smoker, former alcohol consumer, and had no prior colonoscopies. Barium esophagram revealed concave deformities consistent with left atrial (LA) enlargement. CT chest, abdomen and pelvis with contrast revealed severe cardiomegaly, significant LA enlargement and no visible malignancy. Trans-thoracic echocardiogram (TTE) revealed left ventricular ejection fraction 55-60%, abnormal diastolic function, massively dilated LA with a volume index of 298 ml/m2 and severe mitral regurgitation with a diminutive posterior leaflet. Later gastrointestinal endoscopy and colonoscopy showed no evidence of malignancy. Due to the absence of malignancy, the patient’s failure to thrive was thought to be secondary to end stage heart failure and dysphagia due to severely dilated LA causing esophageal compression. The patient underwent percutaneous endoscopic gastrotomy tube placement for nutritional supplementation and was discharged to a rehabilitation facility. Discussion: Cardiac cachexia is often discussed in the context of advanced heart failure due to multi-organ interactions. However, in HOCM, external compression must be considered in patients with dysphagia to reduce morbidity and maintain nutritional status. In addition to TTE, barium esophagram and CT imaging are crucial for excluding malignancy. The patient’s history of HOCM, chronic atrial fibrillation and chronic mitral regurgitation likely contributed to his severe LA dilation. As the patient also suffers chronic heart failure, cardiac cachexia was likely a significant contributor to the patient’s weight loss. Early recognition and intervention are crucial to improving quality of life and survival.

Background: Hypereosinophilic syndrome (HES) is a rare systemic condition characterized by persistent eosinophilia with potential cardiac involvement, manifesting as Loeffler endocarditis. Cardiac involvement in HES can closely resemble infective endocarditis both clinically and echocardiographically, complicating diagnosis and appropriate management. Case Presentation: A 33-year-old woman with sickle cell disease (HbSS) presented with vaso-occlusive crisis, persistent fever, and a new cardiac murmur suggestive of mitral regurgitation. Initial transthoracic echocardiography revealed a mobile, vegetation-like mass (0.9×1.5 cm) on the posterior mitral leaflet (Figure 1). Blood cultures transiently yielded Escherichia coli, prompting treatment with antibiotics for suspected infective endocarditis. Despite antibiotic treatment, the patient continued to have febrile episodes and labs were notable for significant eosinophilia (>1500/µL), raising suspicion for a non-infectious etiology such as Loeffler endocarditis. Methodology: Transesophageal echocardiography demonstrated an extensive lesion (1.4×1.3 cm) contiguous with the subvalvular myocardium, consistent with mural involvement and fibrotic changes atypical for bacterial endocarditis but highly suggestive of eosinophilic endocarditis (Figures 2-3). Comprehensive hematologic evaluation identified elevated serum IgE, tryptase levels, and confirmed the presence of the FIP1L1-PDGFRA fusion gene, supporting a diagnosis of myeloproliferative HES. Results: The patient's management subsequently shifted to targeted HES therapy with high-dose corticosteroids, alongside supportive treatments with hydroxyurea and exchange transfusions for sickle cell disease. Following this adjustment, the patient showed rapid clinical improvement, and follow-up imaging confirmed regression of the cardiac lesion. Discussion: This case highlights the essential role of multimodal echocardiography for differentiating Loeffler endocarditis—with significant myocardial infiltration and fibrosis—from infective endocarditis, especially in atypical cases involving rare pathogens like Gram-negative bacteria. Clinicians should maintain a high index of suspicion for underlying inflammatory causes when faced with persistent symptoms refractory to antibiotics. Early recognition of Loeffler endocarditis enables prompt targeted anti-inflammatory therapy with steroids--thereby improving patient outcomes and preventing progression to restrictive cardiomyopathy.

Right sinus of Valsalva aneurysm ruptured into the right atrium in a dog.

We report the case of a 17-year-old male who presented with progressive headache, fever, vomiting, and neck stiffness. On admission, he was febrile, tachycardic, tachypneic, hypoxic, and severely anemic, with conjunctival hemorrhages and new cardiac murmurs. Neurologically, he had reduced consciousness, left-sided weakness, hypertonia, and meningeal signs. Echocardiography revealed large vegetations on the aortic and mitral valves with moderate regurgitations and pulmonary hypertension, confirming native-valve infective endocarditis. Neuroimaging demonstrated a left parietal mass extending from the choroid plexus with multiple subarachnoid and scalp cystic lesions, consistent with racemose neurocysticercosis, complicated by severe vasogenic edema, obstructive hydrocephalus, subfalcine herniation, and intraparenchymal hemorrhages. The patient underwent burr-hole decompression (yielding mainly blood) and was treated with albendazole, praziquantel, corticosteroids, and antiepileptics for neurocysticercosis, alongside intravenous vancomycin and ceftriaxone for six weeks for infective endocarditis. This case highlights the rare coexistence of infective endocarditis and racemose neurocysticercosis with intracerebral hemorrhage, underscoring the importance of multidisciplinary care in managing overlapping infectious and neurological pathologies.

Cardiovascular diseases (CVDs) remain a leading global health challenge, necessitating diagnostic solutions that combine high accuracy with clinical interpretability and reproducibility. Traditional auscultation methods rely extensively on clinician expertise, resulting in variability and potential diagnostic delays, especially for subtle murmurs indicative of existing cardiac abnormalities. While automated methods have improved diagnostic accuracy, they frequently lack reproducibility and transparency, contributing to clinical mistrust. To address these challenges, we propose an Explainable Attention-Based Deep Learning framework specifically designed for classification and interpretation of heart murmurs using phonocardiogram (PCG) signals. Our approach employs a Transformer architecture tailored for robust time frequency feature extraction—such as spectrograms and Mel Frequency Cepstral Coefficients (MFCCs) applied to PCGs. Visual explanations generated through Gradient weighted Class Activation Mapping (Grad-CAM) explicitly highlight critical systolic and diastolic murmur segments driving the model’s diagnostic predictions. We rigorously validated our framework across multiple datasets, including the HeartWave dataset (over 1,300 recordings), and further corroborated our results using CirCor DigiScope, PhysioNet, and Shenzhen datasets. Our revised validation strategy, adopting robust A-Test methods, demonstrated enhanced reliability with an accuracy of 96.7%, macro-F1 score of 95.5%, and an AUC above 0.97. Compared to ten baseline models—including CNN-RNN hybrids, ResNet variants, and Time Growing Neural Networks (TGNNs) our framework showed a 3–5% improvement in accuracy and a 2–4% increase in macro F1 score, particularly excelling in identifying rare conditions such as valvular defects and congenital anomalies. Ablation studies underscored the crucial role of attention mechanisms for both accuracy enhancement and interpretability, showing strong alignment between model-generated explanations and expert annotations. Future work will further explore model scalability, robustness in diverse clinical environments, and integration with multimodal data, including electrocardiograms, aiming for comprehensive and clinically trusted diagnostic support.

Rationale:Overall, 5% to 10% of all atrial septal defects (ASDs) are of the sinus venosus type, a rare congenital disease. This defect must be identified and treated immediately since it might cause significant left atrial dilatation and dyspnea.Patient concerns:A 15-year-old male presented with previously undetected sinus venosus type ASD. The patient arrived with a high-grade heart murmur and a history of recurring respiratory illnesses.Diagnoses:A clinical examination identified a 3/6 systolic ejection murmur in the second left intercostal gap and a fixed split second heart sound. Electrocardiography revealed sinus rhythm with partial right bundle branch block, while echocardiography indicated considerable enlargement of the right atrium and right ventricle, accompanied by a D-shaped left ventricle. A sinus venosus type ASD with an inferior vena cava–right atrial shunt was verified.Interventions:The patient had surgical closure of the defect via midline sternotomy, thereafter gaining access to the right atrium and performing pericardial patch repair.Outcomes:Two months postoperatively, the patient’s right ventricular diameters and pulmonary artery pressures were significantly diminished (25–30 mm Hg), and his overall status was excellent.Lessons:Sinus venosus type ASD is an infrequent etiology of persistent respiratory problems in adolescents. Early detection by thorough clinical and echocardiographic assessment, followed by timely surgical intervention, may lead to superior functional recovery and improved long-term quality of life.

Background: Vein of Galen Malformation (VOGM) is a rare congenital arteriovenous malformation affecting the paediatric population, characterized by a fistula between the diencephalon and a dilated vein of Galen. Case Description: This report presents the case of a 6-month-old male infant referred for developmental delays and abnormal head circumference. Clinical examination revealed macrocephaly, dilated scalp veins, and neurological abnormalities. Neuroimaging, including CT, MRI and MRA, confirmed a large VOGM with associated hydrocephalus. Furthermore, an echocardiography revealed a high-flow cardiac murmur, confirming the hemodynamic impact of the VOGM. A multidisciplinary team devised a treatment plan involving a combined transvenous and trans-arterial endovascular embolization method using a “kissing microcatheter technique” and ventriculoperitoneal shunt placement. Postoperative recovery showed improvement in neurodevelopmental milestones and reduced head circumference. VOGM management requires a comprehensive approach, including early diagnosis, precise imaging, and timely intervention. Conclusion: This is a novel case because the interventional radiology speciality approach demonstrates the optimum diagnosticand preplanning investigations for cases of vascular origin. In addition, the kissing microcatheter endovascular embolisation technique highlights the importance of considering this innovative surgical option in complex vascular cases.

ABSTRACTBackgroundAdministration of N‐butylscopolammonium bromide (NBB) with metamizol sodium (NBBM) causes tachycardia and hypertension, and has been associated with accentuated cardiac murmurs.ObjectivesTo evaluate the effect of a pharmacological challenge using NBBM on valvular regurgitation and cardiac murmurs in horses with aortic (AR) and mitral valve regurgitation (MR).AnimalsTwenty Warmblood horses with AR and 20 with MR.MethodsCardiac auscultation and two‐dimensional (2D), M‐mode, color flow, pulsed wave Doppler flow, and tissue Doppler echocardiography were performed with simultaneous ECG recording and non‐invasive blood pressure measurements during rest and pharmacological challenge using 0.2 mg/kg NBB and 25 mg/kg metamizol sodium. Cardiac dimensions and functional parameters were assessed. Regurgitant jet size was subjectively evaluated, and jet area was measured. Data at rest and during pharmacological challenge were compared using repeated measures analysis or related samples Wilcoxon signed rank test. p‐values were adjusted using the Benjamini‐Hochberg method.ResultsCompared with rest, pharmacological challenge resulted in decreased atrial and ventricular dimensions and increased aortic and pulmonary dimensions (PBHa ≤ 0.02). Left ventricular end‐diastolic diameter decreased in horses with AR (PBHa < 0.02) but not in horses with MR. Pharmacological challenge resulted in increased median cardiac murmur intensity (PBHa = 0.03 and PBHa < 0.02) and jet area (PBHa ≤ 0.02 and PBHa = 0.03) in horses with AR and MR, respectively.Conclusions and Clinical ImportancePharmacological challenge with NBBM affects cardiac chamber sizes, regurgitant jet, and cardiac murmur intensity in horses with AR and MR. Influences on heart rate and blood pressure should be considered during longitudinal follow‐up examinations.

Abstract Myxomatous mitral valve disease is the most commonly diagnosed cardiovascular disease in dogs and is usually identified by the presence of a heart murmur caused by valvular regurgitation. As the disease progresses, blood volume overload of the left side of the heart can lead to cardiac remodeling through abnormal hypertrophy and eventually congestive heart failure. Therefore, the objective of this retrospective study was to investigate the relationship between heart murmur severity and changes in mRNA abundance as a potential indicator of disease progression. Blood samples for mRNA analysis were collected from 24 dogs at end of life, when quality of life had declined. All study procedures were approved by the Hill’s Institutional Animal Care and Use Committee. Blood samples were from dogs without heart murmurs (n=9; control), with moderate heart murmurs and not diagnosed with congestive heart failure (n=7; grades III/VI (n=4) and IV/VI (n=3)), and with severe heart murmurs (n=8; grades IV/VI (n=2), V/VI (n=5), and V-VI/VI (n=1)). Six of the dogs in the severe group were diagnosed with congestive heart failure including the two dogs diagnosed with grades IV/VI murmurs. Gene expression was determined using the NanoString nCounter® platform and data analysis was performed using the nSolver software provided by NanoString. In all dogs with heart murmurs, there was an increased (P&amp;lt; 0.05) abundance of granzyme A (2.02-fold), granzyme B (1.92-fold), granzyme H (1.60-fold), and adenosine receptor A3 (1.98-fold) when compared to control dogs without heart murmurs. Additionally, there was a decreased (P&amp;lt; 0.05) abundance of C-X-C motif chemokine ligand 8 (-2.11-fold), fibronectin 1 (-1.76-fold), and thioredoxin interacting protein (-1.54-fold) in dogs with murmurs compared to control dogs without murmurs. In the severe murmur group, there was an increased (P&amp;lt; 0.05) abundance of C-X-C motif chemokine ligand 8 (2.48-fold) and cathepsin G (1.62-fold) when compared to the moderate murmur group. These genes have been associated with cardiac remodeling, fibrosis and potentially other processes related to disease progression. As such, these identified genes may have the potential to be used as indicators of myxomatous mitral valve disease severity and progression. Additional validation and research of these identified genes is necessary to determine how nutritional support may affect their expression in dogs living with various stages of myxomatous mitral valve disease.