Pulse wave signal-driven machine learning for identifying left ventricular enlargement in heart failure patients.

BACKGROUND: Left ventricular enlargement (LVE) is a common manifestation of cardiac remodeling that is closely associated with cardiac dysfunction, heart failure (HF), and arrhythmias. This study aimed to propose a machine learning (ML)-based strategy to identify LVE in HF patients by means of pulse wave signals. METHOD: We constructed two high-quality pulse wave datasets comprising a non-LVE group and an LVE group based on the 264 HF patients. Fourier series calculations were employed to determine if significant frequency differences existed between the two datasets, thereby ensuring their validity. Then, the ML-based identification was undertaken by means of classification and regression models: a weighted random forest model was employed for binary classification of the datasets, and a densely connected convolutional network was utilized to directly estimate the left ventricular diastolic diameter index (LVDdI) through regression. Finally, the accuracy of the two models was validated by comparing their results with clinical measurements, using accuracy and the area under the receiver operating characteristic curve (AUC-ROC) to assess their capability for identifying LVE patients. RESULTS: The classification model exhibited superior performance with an accuracy of 0.91 and an AUC-ROC of 0.93. The regression model achieved an accuracy of 0.88 and an AUC-ROC of 0.89, indicating that both models can quickly and accurately identify LVE in HF patients. CONCLUSION: The proposed ML methods are verified to achieve effective classification and regression with good performance for identifying LVE in HF patients based on pulse wave signals. This study thus demonstrates the feasibility and potential of the ML-based strategy for clinical practice while offering an effective and robust tool for diagnosing and intervening ventricular remodeling.

Intratracheal instillation of polyacrylic acid induced pulmonary fibrosis with elevated transforming growth factor-ß1 and connective tissue growth factor.

We investigated the intratracheal instillation of Polyacrylic acid (PAA) in rats to determine if it would cause pulmonary disorders, and to see what factors would be associated with the pathological changes. Male F344 rats were intratracheally instilled with low (0.2 mg/rat) and high (1.0 mg/rat) doses of PAA. They were sacrificed at 3 days, 1 week, 1 month, 3 months, and 6 months after PAA exposure to examine inflammatory and fibrotic changes in the lungs. There was a persistent increase in the neutrophil count, lactate dehydrogenase (LDH) levels, cytokine-induced neutrophil chemoattractant (CINC) values in bronchoalveolar lavage fluid (BALF), and heme oxygenase-1 (HO-1) in lung tissue. Transforming growth factor-beta 1 (TGF-ß1), a fibrotic factor, showed a sustained increase in the BALF until 6 months after intratracheal instillation, and connective tissue growth factor (CTGF) in lung tissue was elevated at 3 days after exposure. Histopathological findings in the lung tissue showed persistent (more than one month) inflammation, fibrotic changes, and epithelial-mesenchymal transition (EMT) changes. There was also a strong correlation between TGF-ß1 in the BALF and, especially, in the fibrosis score of histopathological specimens. Intratracheal instillation of PAA induced persistent neutrophilic inflammation, fibrosis, and EMT in the rats' lungs, and TGF-ß1 and CTGF appeared to be associated with the persistent fibrosis.

Infective endocarditis caused by Lactococcus garvieae: A case report and review of the literature.

Lactococcus garvieae is a Gram-positive coccus that can be easily misidentified as Enterococcus spp. or streptococci. Infection with L. garvieae is associated with the consumption of raw fish and unpasteurized dairy products. Although rare, it can cause infective endocarditis (IE). Herein, we report a case in which aortic valve replacement (AVR) was required for IE caused by L. garvieae. A 79-year-old Japanese man with a history of hypertension, myocardial infarction, gastroesophageal reflux disease (GERD), and abdominal aortic aneurysm presented with loss of appetite, myalgia, and difficulty in moving. Physical examination revealed a diastolic murmur, an Osler's node on the right first toe, dental caries, and a palpable spleen, suggesting IE. Transthoracic echocardiography revealed a large, mobile vegetation on the aortic valve, which was associated with severe aortic regurgitation. Blood cultures revealed L. garvieae. The patient received antibiotic therapy, underwent AVR, and recovered without major complications. To date, 30 cases of L. garvieae-associated IE have been reported. We reviewed and summarized all cases of L. garvieae-associated IE including our case.

SARS-CoV-2 infection-induced immune thrombocytopenia: a systematic review of current reports.

Immune thrombocytopenia (ITP) is an autoimmune disorder characterized by a low platelet count with increased risk of bleeding, and viral infection may trigger ITP. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection-induced ITP has been increasingly reported. We systemically reviewed the previously reported cases of SARS-CoV-2 infection-induced ITP and identified a total of 105 patients from 68 studies. The median age was 61 years, and 14 patients (12%) were < 18 years old (pediatric cases). In adult cases, a total of 53% patients were classified as moderate to severe SARS-CoV-2 infection. The median platelet count at diagnosis and nadir were 6,000/µL and 4,000/µL, respectively. When comparing platelet levels between non-severe SARS-CoV-2 infection and moderate to severe SARS-CoV-2 infection, the median values of platelet levels at diagnosis were not significantly different between the groups (4,000/µL in non-severe SARS-CoV-2 infection and 9,000/µL in moderate to severe SARS-CoV-2 infection, p-value = 0.22). Median nadir platelet levels were also not significantly different between groups (4,000/µL in non-severe SARS-CoV-2 infection and 8,000/µL in moderate to severe SARS-CoV-2 infection, p-value = 0.27). More than half of the cases (53 patients) were treated with combination therapy including steroid, intravenous immunoglobulin, and eltrombopag. Major bleeding and intracranial hemorrhage occurred in ten (11%) and six (6.6%) cases, respectively. The overall mortality rate was 7%. In pediatric cases, none of the patients experienced major bleeding and lethal outcomes.

The Effects of Endoplasmic Reticulum Stress via Intratracheal Instillation of Water-Soluble Acrylic Acid Polymer on the Lungs of Rats.

Polyacrylic acid (PAA), an organic chemical, has been used as an intermediate in the manufacture of pharmaceuticals and cosmetics. It has been suggested recently that PAA has a high pulmonary inflammatory and fibrotic potential. Although endoplasmic reticulum stress is induced by various external and intracellular stimuli, there have been no reports examining the relationship between PAA-induced lung injury and endoplasmic reticulum stress. F344 rats were intratracheally instilled with dispersed PAA (molecular weight: 269,000) at low (0.5 mg/mL) and high (2.5 mg/mL) doses, and they were sacrificed at 3 days, 1 week, 1 month, 3 months and 6 months after exposure. PAA caused extensive inflammation and fibrotic changes in the lungs' histopathology over a month following instillation. Compared to the control group, the mRNA levels of endoplasmic reticulum stress markers Bip and Chop in BALF were significantly increased in the exposure group. In fluorescent immunostaining, both Bip and Chop exhibited co-localization with macrophages. Intratracheal instillation of PAA induced neutrophil inflammation and fibrosis in the rat lung, suggesting that PAA with molecular weight 269,000 may lead to pulmonary disorder. Furthermore, the presence of endoplasmic reticulum stress in macrophages was suggested to be involved in PAA-induced lung injury.

Fulminant Myocarditis with SARS-CoV-2 Infection: A Narrative Review from the Case Studies.

One of the severe complications of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is myocarditis. However, the characteristics of fulminant myocarditis with SARS-CoV-2 infection are still unclear. We systematically reviewed the previously reported cases of fulminant myocarditis associated with SARS-CoV-2 infection from January 2020 to December 2022, identifying 108 cases. Of those, 67 were male and 41 female. The average age was 34.8 years; 30 patients (27.8%) were ≤20 years old, whereas 10 (9.3%) were ≥60. Major comorbidities included hypertension, obesity, diabetes mellitus, asthma, heart disease, gynecologic disease, hyperlipidemia, and connective tissue disorders. Regarding left ventricular ejection fraction (LVEF) at admission, 93% of the patients with fulminant myocarditis were classified as having heart failure with reduced ejection fraction (LVEF ≤ 40%). Most of the cases were administered catecholamines (97.8%), and mechanical circulatory support (MCS) was required in 67 cases (62.0%). The type of MCS was extracorporeal membrane oxygenation (n = 56, 83.6%), percutaneous ventricular assist device (Impella®) (n = 19, 28.4%), intra-aortic balloon pumping (n = 12, 12.9%), or right ventricular assist device (n = 2, 3.0%); combination of these devices occurred in 20 cases (29.9%). The average duration of MCS was 7.7 ± 3.8 days. Of the 76 surviving patients whose cardiac function was available for follow-up, 65 (85.5%) recovered normally. The overall mortality rate was 22.4%, and the recovery rate was 77.6% (alive: 83 patients, dead: 24 patients; outcome not described: 1 patient).

Staphylococcus aureus Bacteremia With Disseminated Multiple Foci and Pyomyositis in an Immunocompetent Patient: A Case Report.

Pyomyositis is an uncommon primary infection of skeletal muscle resulting in muscle inflammation followed by pus formation. Pyomyositis is typically caused by Staphylococcus aureus (S. aureus), and most cases are associated with skin penetration and/or immunosuppressive conditions in tropical or even temperate climates. We report a previously healthy, immunocompetent 44-year-old man who presented with fever and right lower back pain. He had received an analgesic injection for his back pain 12 days prior to this visit. His clinical course was further complicated by the coexistence of multiple muscular abscesses, renal infarction, and septic arthritis of the right shoulder. He underwent computed tomography-guided drainage of the abscess. The abscess and blood cultures were positive for methicillin-susceptible S. aureus. The patient responded well to prolonged treatment with cefazolin and cephalexin and was discharged 12 weeks after initial admission.

Peripartum cardiomyopathy in patients with psychiatric disorders successfully treated with bromocriptine: Two case reports.

Peripartum cardiomyopathy (PPCM) is a rare disorder in which left ventricular systolic dysfunction and heart failure symptoms occur during the peripartum period. Inhibition of prolactin secretion by bromocriptine mediates beneficial effects on cardiac function in PPCM. Mental disorders are also associated with the onset of PPCM. Psychiatric medications for mental disorders would affect serotonin production and tryptophan and dopamine metabolism, and they are associated with PPCM. Conversely, bromocriptine affects psychiatric symptoms; therefore, the treatment of PPCM complicated by mental disorders using bromocriptine may be difficult. Herein, we report cases of two patients with PPCM and mental disorders successfully treated with bromocriptine therapy. The first case involved a 33-year-old woman with a history of atypical depression and anxiety disorder, who developed PPCM with a left ventricular ejection fraction (LVEF) of 19 %. The second case was that of a 42-year-old woman with a history of bipolar and panic disorders who developed PPCM with an LVEF of 18 %. Both patients were administered bromocriptine; however, psychiatric symptoms did not worsen and cardiac function improved. We also review the literature on the relationship between PPCM and mental disorders. Learning objective: Mental disorders and psychiatric medications may be associated with the onset of peripartum cardiomyopathy (PPCM). Although bromocriptine has beneficial effects on PPCM, it has also been reported to increase the risk of worsening psychiatric symptoms; therefore, the efficacy and safety of bromocriptine in PPCM patients with mental disorders is controversial. Our cases showed that bromocriptine can be used safely without worsening psychiatric symptoms in PPCM with mental disorders.

Pulse wave-based evaluation of the blood-supply capability of patients with heart failure via machine learning.

Pulse wave, as a message carrier in the cardiovascular system (CVS), enables inferring CVS conditions while diagnosing cardiovascular diseases (CVDs). Heart failure (HF) is a major CVD, typically requiring expensive and time-consuming treatments for health monitoring and disease deterioration; it would be an effective and patient-friendly tool to facilitate rapid and precise non-invasive evaluation of the heart's blood-supply capability by means of powerful feature-abstraction capability of machine learning (ML) based on pulse wave, which remains untouched yet. Here we present an ML-based methodology, which is verified to accurately evaluate the blood-supply capability of patients with HF based on clinical data of 237 patients, enabling fast prediction of five representative cardiovascular function parameters comprising left ventricular ejection fraction (LVEF), left ventricular end-diastolic diameter (LVDd), left ventricular end-systolic diameter (LVDs), left atrial dimension (LAD), and peripheral oxygen saturation (SpO2). Two ML networks were employed and optimized based on high-quality pulse wave datasets, and they were validated consistently through statistical analysis based on the summary independent-samples t-test (p > 0.05), the Bland-Altman analysis with clinical measurements, and the error-function analysis. It is proven that evaluation of the SpO2, LAD, and LVDd performance can be achieved with the maximum error < 15%. While our findings thus demonstrate the potential of pulse wave-based, non-invasive evaluation of the blood-supply capability of patients with HF, they also set the stage for further refinements in health monitoring and deterioration prevention applications.

Giant cell myocarditis with prolonged cardiac standstill after drug-induced hypersensitivity syndrome: a case report.

Giant cell myocarditis (GCM) is a rare but fatal disease that can lead to cardiac failure. Survival with a cardiac standstill requires mechanical circulatory support or a biventricular assist device (BiVAD) and prolonged survival is extremely rare. Drug-induced hypersensitivity syndrome (DIHS) is a severe cutaneous adverse reaction. Some cases of DIHS are reportedly associated with the onset of GCM. We present a case of a 28-year-old woman who developed GCM during steroid tapering after DIHS. She went into continuous cardiac standstill but survived for 74 days under BiVAD support. Our case is noteworthy because the histopathologic specimens obtained on three occasions contributed to the diagnosis of this particular condition over time. We also reviewed previous literature on concomitant cases of GCM and DIHS. We found that two are potentially associated and most cases of GCM occur within 3 months of DIHS during steroid tapering.

Hemodynamic parameters at rest predicting exercise capacity in patients supported with left ventricular assist device.

Left ventricular assist devices improve prognosis and quality of life, but exercise capacity remains limited in most patients after device implantation. Left ventricular assist device optimization through right heart catheterization reduces device-related complications. However, hemodynamic parameters associated with exercise capacity under optimized conditions. The aim of this study was to elucidate the predictors of exercise capacity from hemodynamic parameters at rest after left ventricular assist device optimization. We retrospectively reviewed 24 patients who underwent a ramp test with right heart catheterization, echocardiography and cardiopulmonary exercise testing more than 6 months after left ventricular assist device implantation. Pump speed was optimized to a lower setting that achieved right atrial pressure < 12 mmHg, pulmonary capillary wedge pressure < 18 mmHg, and cardiac index > 2.2 L/min/m2, then exercise capacity was assessed by cardiopulmonary exercise testing. After left ventricular assist device optimization, the mean right atrial pressure, pulmonary capillary wedge pressure, cardiac index, and peak oxygen consumption were 7 ± 5 mmHg, 10 ± 7 mmHg, 2.7 ± 0.5 L/min/m2, and 13.2 ± 3.0 mL/min/kg, respectively. Pulse pressure, stroke volume, right atrial pressure, mean pulmonary artery pressure, and pulmonary capillary wedge pressure were significantly associated with peak oxygen consumption. Multivariate linear regression analysis of factors predicting peak oxygen consumption revealed that pulse pressure, right atrial pressure, and aortic insufficiency remained independent predictors (ß = 0.401, p = 0.007; ß = - 0.558, p < 0.001; ß = - 0.369, p = 0.010, respectively). Our findings suggests that cardiac reserve, volume status, right ventricular function, and aortic insufficiency predict exercise capacity in patients with a left ventricular assist device.

Modified Algorithm Using Total Count for Calculating Myocardial Washout Rate in Single-Photon Emission Computerized Tomography.

Background: The arithmetic mean of washout rate (WR) (namely, AMWR) of each segment is a commonly used algorithm for calculating WR from a polar map in single-photon emission computerized tomography (SPECT). However, in this algorithm, uneven radiotracer uptake among segments affects WR calculation. To solve this possible issue, we formulated a modified algorithm for calculating WR based on the total count (namely, TCWR). Methods: The WR of iodine-123-ß-methyl-p-iodophenylpentadecanoic acid (BMIPP) was calculated using TCWR and AMWR, and WR values using TCWR and AMWR were compared by disease. Participants included those without cardiovascular diseases (normal), those with CD36 deficiency, triglyceride deposit cardiomyovasculopathy (TGCV), TGCV with old myocardial infarction (OMI), and non-TGCV with OMI. Results: WR values using TCWR and AMWR did not differ significantly in the following groups: normal, 27.4±8.5 and 27.3±8.5% (p=0.97); CD36 deficiency, -3.2±6.5 and -4.1±7.4% (p=0.81); TGCV, 2.4±6.3 and 2.2±6.3% (p=0.93); and TGCV with OMI, -0.9±7.6 and -3.7±8.4% (p=0.32). However, AMWR showed a lower WR than TCWR in non-TGCV with OMI (4.8±8.7 and 18.9±6.7%, p=0.0008). Conclusions: TCWR is suitable for calculating WR using SPECT polar maps even in cases with heterogeneous radiotracer uptake, such as OMIs. TCWR may be applied to measuring the WR of radiopharmaceuticals other than BMIPP in investigating the pathophysiology of heart diseases.

Supra-Normal Left Ventricular Function.

Heart failure (HF) is often categorized by left ventricular (LV) ejection fraction (LVEF). A new category of HF characterized by supra-normal LVEF (>65%), named HF with supra-normal ejection fraction (HFsnEF), has been recently proposed. Some studies reported that patients with supra-normal LVEF might have an increased risk of long-term major adverse cardiovascular events and U-shaped mortality patterns. Currently, the prognosis of HFsnEF is not well established but seems to be associated with an increased risk of long-term major adverse cardiovascular events. It has been reported that HFsnEF is more prevalent in women and is associated with higher prevalence of nonischemic HF, higher blood urea nitrogen plasma levels, lower levels of natriuretic peptides, and to be less likely treated with ß blockers. The pathophysiology of HFsnEF would be associated with microvascular dysfunction because of microvascular inflammation or reduced coronary flow reserve, and low stroke volume index with smaller cardiac chamber dimensions and concentric LV geometry. In this study, we systematically reviewed published data on patients with s supra-normal LV function and reported its definition, proposed pathophysiology, phenotypes, diagnostic strategy, and prognosis.

May-Thurner syndrome due to abdominal aortic aneurysm compression.

May-Thurner syndrome (MTS) can be caused by abdominal aortic aneurysm (AAA) compressing the left common iliac vein against the lumbar vertebra. We reported a rare case of MTS due to AAA Compression successfully treated with anticoagulation.