PERICARDIAL PUNCTURE: WHEN AND HOW?

Pericardial effusion is a very common condition, due to the accumulation of fluid in the pericardial cavity (the impact depends on the volume, rate of accumulation and elasticity of the pericardium), it results in a: 1. Increased intrapericardial pressure. 2. Increase in intracardiac pressure 3. Decrease in ventricular filling 4. Decrease in ejection volume 5. Decrease in cardiac output The etiologies of effusions are diverse. Tamponade requires emergency decompression of the pericardium to achieve hemodynamic stabilization. Two techniques are possible, either percutaneous puncture with or without ultrasound guidance, or surgical drainage. The choice of drainage method depends on the medical-surgical teams, their experience with each method and the etiology.

Bioimpedance Vector Analysis for Heart Failure: Should We Put It on the Agenda?

Heart failure is a clinical syndrome, resulting in increased intracardiac pressure and/or decreased cardiac output under rest or stress. In acute decompensated heart failure, volume assessment is essential for clinical diagnosis and management. More and more evidence shows the advantages of bioimpedance vector analysis in this issue. Here, we critically present a brief review of bioimpedance vector analysis in the prediction and management of heart failure to give a reference to clinical physicians and guideline makers.

EFFECT OF STEERING WHEEL HEIGHT AND INCLINATION ANGLE ON BLUNT CARDIAC INJURY DURING THE THORAX-TO-STEERING WHEEL IMPACT

Blunt cardiac injury (BCI) in the traffic accidents usually causes serious consequences like heart failure or even death, and the impact of steering wheel to the thorax is one of the main causes of blunt heart injury. Therefore, more realistic heart models are needed to predict the biomechanical response and related injury of the heart during a thorax-to-steering wheel impact. This study developed three-dimensional finite element (FE) models of lungs, aorta and heart, and validated the models through published cadaver tests by comparing the contact force and intracardiac pressures in four heart chambers. Then, various simulations of thorax-to-steering wheel impact were carried out at different impact heights (lower, middle and higher) and different inclination angles of steering wheel (15°, 30°, 45° and 60°) to investigate the effects of impact height and inclination angle on heart injury. The result showed that (1) the biomechanical response of the heart model was agree with the test data; (2) the contact force, myocardial stress and intracardiac pressure were decreased when the inclination angle was increased; (3) when the impact height was middle and the inclination angle of steering wheel was 15°, the myocardial stress and intracardiac pressure were both maximum which indicated that the blunt heart injury was more likely to occur in this condition.

Mineralocorticoid Receptor in Smooth Muscle Contributes to Pressure Overload–Induced Heart Failure

Background: Mineralocorticoid receptor (MR) antagonists decrease heart failure (HF) hospitalization and mortality, but the mechanisms are unknown. Preclinical studies reveal that the benefits on cardiac remodeling and dysfunction are not completely explained by inhibition of MR in cardiomyocytes, fibroblasts, or endothelial cells. The role of MR in smooth muscle cells (SMCs) in HF has never been explored. Methods: Male mice with inducible deletion of MR from SMCs (SMC-MR-knockout) and their MR-intact littermates were exposed to HF induced by 27-gauge transverse aortic constriction versus sham surgery. HF phenotypes and mechanisms were measured 4 weeks later using cardiac ultrasound, intracardiac pressure measurements, exercise testing, histology, cardiac gene expression, and leukocyte flow cytometry. Results: Deletion of MR from SMC attenuated transverse aortic constriction-induced HF with statistically significant improvements in ejection fraction, cardiac stiffness, chamber dimensions, intracardiac pressure, pulmonary edema, and exercise capacity. Mechanistically, SMC-MR-knockout protected from adverse cardiac remodeling as evidenced by decreased cardiomyocyte hypertrophy and fetal gene expression, interstitial and perivascular fibrosis, and inflammatory and fibrotic gene expression. Exposure to pressure overload resulted in a statistically significant decline in cardiac capillary density and coronary flow reserve in MR-intact mice. These vascular parameters were improved in SMC-MR-knockout mice compared with MR-intact littermates exposed to transverse aortic constriction. Conclusions: These results provide a novel paradigm by which MR inhibition may be beneficial in HF by blocking MR in SMC, thereby improving cardiac blood supply in the setting of pressure overload–induced hypertrophy, which in turn mitigates the adverse cardiac remodeling that contributes to HF progression and symptoms.

Abstract 15938: B-type Natriuretic Peptide Levels Do Not Predict the Need for Mechanical Ventilation in Hospitalized Patients With COVID-19

Introduction: B-type natriuretic peptide (BNP) is widely used as a biomarker of heart failure and typically rises in response to increased intracardiac pressure. BNP levels have been measured in patients with coronavirus disease 2019 (COVID-19) to assess the cardiovascular contribution to respiratory failure and guide diuresis. Whether BNP levels do predict the need for mechanical ventilation (MV) is however unknown. Methods: The Michigan Medicine Covid-19 Cohort (M 2 C 2 ) is an ongoing prospective observational study in which detailed clinical, laboratory and outcomes data were collected from chart review of consecutive adult patients hospitalized for COVID-19. Patients who were positive for SARS-CoV-2 infection but without symptoms of COVID-19 were not included in this cohort. We identified 495 patients admitted between March 1 st and May 1 st for COVID-19, of whom 290 (58.6%) had BNP levels measured during their hospitalization. We examined the association between BNP and the need for MV during their hospitalization. Results: Among the 290 patients evaluated, the mean age was 62 (SD 15), 169 (58.3%) were male, 135 (46.6%) were blacks, and 61 (21.0%) had pre-existing heart failure. The median BNP level was 50 pg/ml, and 104 (35.9%) of patients had a BNP level > 100 pg/ml. A total of 130 (44.8%) required MV during their hospitalization. The median BNP level in patients who required MV was 63 pg/ml (IQR 25-171), compared to 46 pg /ml (IQR 17-187) in patients who did not, P=0.23. In multivariable analysis adjusting for age, gender, race, pre-existing heart failure, and serum creatinine on admission, BNP>100 pg/ml was not associated with the need for MV. Conclusions: In patients hospitalized for COVID-19, BNP levels were not associated with the need for MV, suggesting that the cardiovascular contribution to respiratory failure in these patients is likely minor compared to the inflammatory response or direct impact of the virus.