Low Systemic Vascular Resistance Research Articles

Short-Chain Fatty Acid Butyrate Is an Inotropic Agent With Vasorelaxant and Cardioprotective Properties.

The heart can metabolize the microbiota-derived short-chain fatty acid butyrate. Butyrate may have beneficial effects in heart failure, but the underlying mechanisms are unknown. We tested the hypothesis that butyrate elevates cardiac output by mechanisms involving direct stimulation of cardiac contractility and vasorelaxation in rats. We examined the effects of butyrate on (1) invivo hemodynamics using parallel echocardiographic and invasive blood pressure measurements, (2) isolated perfused hearts in Langendorff systems under physiological conditions and after ischemia and reperfusion, and (3) isolated coronary arteries mounted in isometric wire myographs. We tested Na-butyrate added to injection solutions or physiological buffers and compared its effects with equimolar doses of NaCl. Butyrate at plasma concentrations of 0.56 mM increased cardiac output by 48.8±14.9%, stroke volume by 38.5±12.1%, and left ventricular ejection fraction by 39.6±6.2%, and lowered systemic vascular resistance by 33.5±6.4% without affecting blood pressure or heart rate invivo. In the range between 0.1 and 5 mM, butyrate increased left ventricular systolic pressure by up to 23.7±3.4% in isolated perfused hearts and by 9.4±2.9% following ischemia and reperfusion, while reducing myocardial infarct size by 81.7±16.9%. Butyrate relaxed isolated coronary septal arteries concentration dependently with an EC50=0.57 mM (95% CI, 0.23-1.44). We conclude that butyrate elevates cardiac output through mechanisms involving increased cardiac contractility and vasorelaxation. This effect of butyrate was not associated with adverse myocardial injury in damaged hearts exposed to ischemia and reperfusion.

Digital thermography complements Laser Speckle Contrast Imaging for the diagnosis of quantified severe mesenteric traction syndrome — A prospective cohort study

IntroductionThe diagnosis of severe mesenteric traction syndrome (MTS) is based on assessing the developed degree of facial flushing. Only one validated objective diagnostic method, Laser Speckle Contrast Imaging (LSCI), exists. However, this method is sensitive to distance, motion, and angulation. Digital thermography is known to correlate well with LSCI without the same limitations, but has never been tested in relation to MTS. This study aimed to examine the thermographic changes during the development of severe MTS and to calculate a cut-off value for identifying severe MTS. MethodsA prospective cohort study was performed on patients planned for open esophagectomy and pancreatic surgery from March 2021 to April 2022. All patients underwent continuous measurement on their forehead using LSCI and digital thermography during the first hour of surgery. The validated LSCI cut-off value was used to grade the severity of MTS. Blood samples and hemodynamics were collected at predefined time points. ResultsFifty-seven patients were included. Patients developing severe MTS had increased facial skin temperature 15 min (p = 0.002) and 30 min into surgery (p < 0.001). A cut-off value for identifying severe MTS using thermography was identified (35.55 °C, p < 0.001). Patients identified as developing severe MTS using this cut-off value had a higher level of prostacyclin (p = 0.001) and lower systemic vascular resistance (p < 0.001) 15 min into surgery, as compared with patients not developing severe MTS. ConclusionThis study shows that digital thermography may complement LSCI in the objective identification of severe MTS.

The “Preeclampsia and Hypertension Target Treatment” study: a multicenter prospective study to evaluate the effectiveness of the antihypertensive therapy based on maternal hemodynamic findings

Despite major advances in the pharmacological treatment of hypertension in the non-pregnant population, treatments for hypertension in pregnancy have remained largely unchanged over the years. There is recent evidence that a more adequate control of maternal blood pressure is achieved when the first given antihypertensive drug is able to correct the underlying hemodynamic disorder of the mother beside normalizing the blood pressure values. to compare the blood pressure control in women receiving an appropriate or inappropriate antihypertensive therapy in accordance with the baseline hemodynamic findings STUDY DESIGN: prospective multicenter study including a population of women with de novo diagnosis of HDP. A noninvasive assessment of the following maternal parameters was done upon the hospital admission by means of USCOM (Ultrasound Cardiac Output Monitor) before any antihypertensive therapy was given: Cardiac Output (CO), Heart Rate (HR), Systemic Vascular Resistance (SVR), Stroke Volume (SV). The clinician who prescribed the antihypertensive therapy was blinded to the hemodynamic evaluation and based on his preferences or on the local protocols used as 1st line a vasodilator (nifedipine or alpha methyldopa) or a beta-blocker (labetalol). The 1st line pharmacological treatment was retrospectively considered hemodynamically appropriate in either of the following circumstances: 1) Women with a hypodynamic profile (defined as low cardiac output [CO≤5L/min] and/or high systemic vascular resistance [SVR≥1300 dynes*s*cm]) who were administered oral nifedipine or alpha methyldopa. 2) Women with a hyperdynamic profile (defined as normal or high cardiac output [CO >5 L/min] and/or low systemic vascular resistances [SVR<1300 dynes*s*cm-]) who were administered oral labetalol. The primary outcome of the study was to compare the occurrence of severe hypertension between the women who were found to be treated with a hemodynamically appropriate or inappropriate therapy. A total of 152 women with HDP were included in the final analysis. Of these the majority displayed a hypodynamic profile (114 or 75.0%) and received a hemodynamically appropriate treatment (116 or 76.3%). The occurrence of severe hypertension prior to delivery was significantly lower in the group receiving an appropriate therapy compared with those inappropriately treated (6.0% vs. 19.4%; p= 0.02). Moreover, the number of women who achieved target values of BP within 48-72h from the treatment start was higher in the group who received an appropriate treatment (70.7% vs. 50.0%; p=0.02). In pregnant individuals with de novo HDP, a lower occurrence of severe hypertension is observed when the first line antihypertensive agent is tailored to the correct maternal hemodynamic profile.

Treatment of refractory shock with vitamin B12 : A narrative review.

High-dose vitamin B12 is a potential treatment for patients with vasodilatory shock that is refractory to other therapies. Vasodilatory shock is characterized by low blood pressure and low systemic vascular resistance. Nitric oxide and hydrogen sulfide, two potential targets of high-dose vitamin B12 given as hydroxocobalamin, facilitate this syndrome. This review explores the relationship between high-dose vitamin B12 and hemodynamic outcomes in adults with vasodilatory shock and provides an update on the literature since a 2019 review on this topic. A literature search of studies published in the past 5 years was conducted in the CINAHL, PubMed, Cochrane, and EMBASE databases in May 2023. After assessing for eligibility, eight studies met this review's inclusion criteria. Seven of the eight studies reported decreased vasopressor requirements for part or all of the study samples after receiving a hydroxocobalamin infusion. However, not all patients responded to hydroxocobalamin. These findings are limited by patient selection and differences in the timing of vasopressor requirement and blood pressure outcome assessments. The current evidence is promising as to whether vitamin B12 , given as a hydroxocobalamin infusion, may improve hemodynamic outcomes in vasodilatory shock, but the evidence is of low quality. The use of hydroxocobalamin to treat refractory, vasodilatory shock remains investigative. Larger randomized controlled trials are required to elucidate the role of vitamin B12 in treating refractory, vasodilatory shock, including in conjunction with other alternative therapies such as methylene blue and corticosteroids.

Extracorporeal Membrane Oxygenation for Septic Shock in Adults and Children: A Narrative Review.

Refractory septic shock is associated with a high risk of death. Circulatory support in the form of veno-arterial extracorporeal membrane oxygenation (VA ECMO) may function as a bridge to recovery, allowing for the treatment of the source of the sepsis. Whilst VA ECMO has been accepted as the means of hemodynamic support for children, in adults, single center observational studies show survival rates of only 70-90% for hypodynamic septic shock. The use of VA ECMO for circulatory support in hyperdynamic septic shock with preserved cardiac output or when applied late during cardio-pulmonary resuscitation is not recommended. With unresolving septic shock and a loss of ventriculo-arterial coupling, stress cardiomyopathy often develops. If the cardiac index (CI) approaches subnormal levels (CI < 2.5 L/min m-2) that do not match low systemic vascular resistance with a resulting loss of vital systemic perfusion pressure, VA ECMO support should be considered. A further decrease to the level of cardiogenic shock (CI < 1.8 L/min m-2) should be regarded as an indication for VA ECMO insertion. For patients who maintain a normal-to-high CI as part of their refractory vasoparalysis, VA ECMO support is justified in children and possibly in patients with a low body mass index. Extracorporeal support for septic shock should be limited to high-volume ECMO centers.

Temporary Mechanical Circulatory Support in Sepsis-Associated Cardiogenic Shock With and Without Acute Myocardial Infarction

To describe the current use and outcomes of temporary mechanical circulatory support (MCS) in patients with sepsis-associated cardiogenic shocks with and without acute myocardial infarction (AMI) in the United States. Retrospective cohort study. The National Inpatient Sample database from 2017 to 2019. Adult patients with sepsis-associated cardiogenic shock with and without AMI. Temporary MCSs, including intra-aortic balloon pump (IABP), percutaneous left ventricular assist device (pLVAD), and extracorporeal membrane oxygenation (ECMO). Multivariate logistic regression analyses adjusting for patient characteristics, organ failures, and socioeconomic status. Although the uses of IABP and pLVAD were associated with significantly lower odds of in-hospital mortality in patients with sepsis-associated cardiogenic shock (IABP: adjusted odds ratio [aOR] 0.57, 95% CI 0.44-0.73, p < .001; pLVAD: aOR 0.66, 95% CI 0.45-0.98, p=.037), ECMO was not (aOR 1.51, 95% CI 0.93-2.45, p=0.096). In the subgroup with AMI, temporary MCSs were not associated with significantly lower or higher odds of in-hospital mortality. In the subgroup without AMI, IABP was associated with significantly lower odds of in-hospital mortality (aOR 0.43, 95% CI 0.28-0.65, p < 0.001). Although temporary MCS is deemed to be a feasible option in sepsis-associated cardiogenic shock, the selection of the right patients whose shock is driven mainly by cardiogenic shock rather than septic shock, as represented by low cardiac output and high systemic vascular resistance, plays a critical role in the feasibility of this approach in the absence of clinical trials.

SPECT for risk stratification in patients with advanced liver disease

BackgroundPatients with advanced liver disease (ALD) have unique hemodynamics including high resting cardiac output and low systemic vascular resistance which may reduce the sensitivity of pharmacological myocardial perfusion imaging (MPI). MPI is frequently ordered for patients with ALD if liver transplantation is being considered. Because of the limited data on effectiveness of MPI in the ALD population, we conducted this cohort study focused on cardiac outcomes after pharmacological MPI. MethodsWe conducted a cohort study comparing normal versus abnormal MPI among 454 patients with ALD between 1/1/2011 and 06/01/2021 at a single tertiarycare academic medical center. Abnormal MPI was defined as summed stress score > 2 on LVEF < 40 %. The primary outcome was to compare the frequency of major adverse cardiovascular events (MACEs) among ALD patients with and without abnormal MPI. Secondary outcome included individual components of MACE analyzed by chi square. Kaplan-Meier survival curves and a logistic-regression model of associations with MACE were also performed. ResultsIn this cohort, 58 patients were observed to have an abnormal MPI. Baseline characteristics between the groups were similar, except prior coronary disease, which was more common among the abnormal MPI group (risk ratio 2.07, 95 % confidence interval 1.30–3.30, P = 0.003). MACE was more common in the group with abnormal MPI (n = 24, 41.4 % versus normal MPI n = 104, 26.3 %, P < .001). No difference in MACE was observed when stratified by liver disease type. In the logistic regression model, diabetes mellitus, stage 3 chronic kidney disease, and summed stress score >2 were retained as being associated with MACE. ConclusionsOur data suggest that MPI remains an effective test for identifying ALD patients at higher risk of mortality and cardiac events. Further study is needed to understand whether a strategy of routine MPI for liver transplant candidates effectively improves long term survival.

Ketone body 3-hydroxybutyrate elevates cardiac output through peripheral vasorelaxation and enhanced cardiac contractility

The ketone body 3-hydroxybutyrate (3-OHB) increases cardiac output and myocardial perfusion without affecting blood pressure in humans, but the cardiovascular sites of action remain obscure. Here, we test the hypothesis in rats that 3-OHB acts directly on the heart to increase cardiac contractility and directly on blood vessels to lower systemic vascular resistance. We investigate effects of 3-OHB on (a) in vivo hemodynamics using echocardiography and invasive blood pressure measurements, (b) isolated perfused hearts in Langendorff systems, and (c) isolated arteries and veins in isometric myographs. We compare Na-3-OHB to equimolar NaCl added to physiological buffers or injection solutions. At plasma concentrations of 2–4 mM in vivo, 3-OHB increases cardiac output (by 28.3±7.8%), stroke volume (by 22.4±6.0%), left ventricular ejection fraction (by 13.3±4.6%), and arterial dP/dtmax (by 31.9±11.2%) and lowers systemic vascular resistance (by 30.6±11.2%) without substantially affecting heart rate or blood pressure. Applied to isolated perfused hearts at 3–10 mM, 3-OHB increases left ventricular developed pressure by up to 26.3±7.4 mmHg and coronary perfusion by up to 20.2±9.5%. Beginning at 1–3 mM, 3-OHB relaxes isolated coronary (EC50=12.4 mM), cerebral, femoral, mesenteric, and renal arteries as well as brachial, femoral, and mesenteric veins by up to 60% of pre-contraction within the pathophysiological concentration range. Of the two enantiomers that constitute racemic 3-OHB, D-3-OHB dominates endogenously; but tested separately, the enantiomers induce similar vasorelaxation. We conclude that increased cardiac contractility and generalized systemic vasorelaxation can explain the elevated cardiac output during 3-OHB administration. These actions strengthen the therapeutic rationale for 3-OHB in heart failure management.

Incidence of Intraoperative Vasoplegic Syndrome in Lung Transplantation

Severe hypotension and low systemic vascular resistance in the setting of adequate cardiac output, known as "vasoplegic syndrome" (VS), is a physiologic disturbance reported in 9% to 44% of cardiac surgery patients. Although this phenomenon is well-documented in cardiac surgery, there are few studies on its occurrence in lung transplantation. The goal of this study was to characterize the incidence of VS in lung transplantation, as well as identify associated risk factors and outcomes. Retrospective study of single and bilateral lung transplants from April 2013 to September 2021. The study was conducted at an academic hospital. Patients ≥18 years of age who underwent lung transplantation. None. The authors defined VS as mean arterial pressure <65 mmHg, cardiac index ≥2.2 L/min/m2, and ≥30 minutes of vasopressor administration after organ reperfusion. The association between VS and risk factors or outcomes was assessed using t tests, Mann-Whitney U, and chi-square tests. The authors ran multivariate logistic regression models to determine factors independently associated with VS. The incidence of VS was 13.9% (CI 10.4%-18.4%). In the multivariate model, male sex (odds ratio 2.85, CI 1.07-7.58, p=0.04) and cystic fibrosis (odds ratio 5.76, CI 1.43-23.09, p=0.01) were associated with VS. The incidence of VS in lung transplantation is comparable to that of cardiac surgery. Interestingly, male sex and cystic fibrosis are strong risk factors. Identifying lung transplant recipients at increased risk of VS may be crucial to anticipating intraoperative complications.

Vasoplegic Syndrome and Anaesthesia: A Narrative Review.

Vasoplegic syndrome (VS) is defined as low systemic vascular resistance, normal or high cardiac output, and resistant hypotension unresponsive to vasopressor agents and intravenous volume. VS is a frequently encountered complication in cardiovascular and transplantation surgery, burns, trauma, pancreatitis, and sepsis. The basis of the pathophysiology is associated with an imbalance of vasodilator and vasoconstrictive structure in vascular smooth muscle cells and is highly complex. The pathogenesis of VS has several mechanisms, including overproduction of iNO, stimulation of ATP-dependent K+ channels and NF-κB, and vasopressin receptor 1A (V1A-receptor) down-regulation. Available treatments involve volume and inotropes administration, vasopressin, methylene blue, hydroxocobalamin, Ca++, vitamin C, and thiamine, and should also restore vascular tone and improve vasoplegia. Other treatments could include angiotensin II, corticosteroids, NF-κB inhibitor, ATP-dependent K+ channel blocker, indigo carmine, and hyperbaric oxygen therapy. Despite modern advances in treatment, the mortality rate is still 30-50%. It is challenging for an anaesthesiologist to consider this syndrome's diagnosis and manage its treatment. Our review aims to review the diagnosis, predisposing factors, pathophysiology, treatment, and anaesthesia approach of VS during anaesthesia and to suggest a treatment algorithm.

Causes and prognosis analysis of hyperdynamic left ventricular ejection fraction in intensive care unit patients with sepsis

To analyze the causes of hyperdynamic left ventricular ejection fraction (LVEF) in sepsis patients in the intensive care unit (ICU) and its impact on prognosis. A retrospective cohort study was conducted. The clinical data of 273 sepsis patients admitted to the department of critical care medicine of the Affiliated People's Hospital of Jiangsu University from January 2018 to October 2021 were collected including gender, age, severity score, comorbidities, source of infection, vital signs, transthoracic echocardiographic (TTE) parameters, fluid intake and output, vasoactive drug dose, therapeutic measures and prognostic indicators. The patients were divided into normal LVEF group (LVEF 0.55-0.70), low LVEF group (LVEF < 0.55) and hyperdynamic LVEF group (LVEF > 0.70) according to the TTE examination results within 7 days of ICU admission. The clinical indicators among the three groups were compared and analyzed, and multivariate Logistic regression analysis was used to screen risk factors for the development of hyperdynamic LVEF in patients with sepsis. Spearman correlation analysis was used to determine the correlation between the mortality of different types of LVEF and clinical variables. Among 273 patients, 20 patients with severe valvular or cardiomyopathy at admission and those who did not completed cardiac ultrasound within 7 days of ICU admission were excluded. A total of 253 patients were finally enrolled, including 169 patients in the normal LVEF group, 40 patients in the low LVEF group, and 44 patients in the hyperdynamic LVEF group. There were statistically significant differences in age, sequential organ failure assessment (SOFA) score, central venous pressure (CVP), heart rate (HR), oxygenation index (PaO2/FiO2), blood lactate (Lac), urine output, vasoactive drug dose, ratio of hypertension, ischemic heart disease, chronic liver disease, cancer, invasive mechanical ventilation and renal replacement therapy (RRT), and incidence of septic shock among the different types of LVEF groups. TTE results analysis showed that the hyperdynamic LVEF group had higher stroke volume (SV) and cardiac index (CI) than those in the normal LVEF and low LVEF groups, lower systemic vascular resistance (SVR) than that in the normal LVEF and low LVEF groups, and an increased E/A ratio. The 90-day mortality in the hyperdynamic LVEF group was significantly higher than that in the normal LVEF and low LVEF groups [59.1% (26/44) vs. 24.9% (42/169), 32.5% (13/40), both P < 0.05]. Multivariate Logistic regression analysis showed that chronic liver disease [odds ratio (OR) = 1.712, 95% confidence interval (95%CI) was 0.912-3.234, P < 0.001], cancer (OR = 2.784, 95%CI was 1.296-6.151, P < 0.001), HR (OR = 1.026, 95%CI was 1.014-1.038, P < 0.001), vasoactive drug dose (OR = 1.133, 95%CI was 1.009-1.291, P < 0.001), and invasive mechanical ventilation (OR = 2.141, 95%CI was 1.285-3.651, P < 0.001) were independent factors for hyperdynamic LVEF in ICU sepsis patients. Correlation analysis showed that the mortality of hyperdynamic LVEF, normal LVEF and low LVEF patients was positively correlated with vasoactive drug dose (r value was 0.251, 0.361, 0.289, respectively, all P < 0.001). The mortality of the hyperdynamic LVEF patients was negatively correlated with SVR (r = -0.545, P < 0.001). Chronic liver disease, cancer, HR, vasoactive drugs dose, and invasive mechanical ventilation are independent risk factors for hyperdynamic LVEF in patients with sepsis. Hyperdynamic LVEF is positively associated with mortality in sepsis patients, which may be due to the the decrease of SVR caused by septic vascular paralysis.

Vasoplegia: A Review.

Vasoplegia is a condition characterized by persistent low systemic vascular resistance despite a normal or high cardiac index, resulting in profound and uncontrolled vasodilation. Vasoplegia may occur due to various conditions, including cardiac failure, sepsis, and post-cardiac surgery. In the cardiac cohort, multiple risk factors for vasoplegia have been identified. Several factors contribute to the pathophysiology of this condition, and various mechanisms have been proposed, including nitric oxide, adenosine, prostanoids, endothelins, the renin-angiotensin-aldosterone system, and hydrogen sulfide. Early identification and prompt management of vasoplegia is crucial to prevent development of shock. This review expands upon the different vasopressors used in management of vasoplegia, including catecholamines such as norepinephrine, dopamine, epinephrine, phenylephrine, and other agents including vasopressin, methylene blue, angiotensin II, hydroxocobalamin, vitamin C, thiamine, and corticosteroids (ie, hydrocortisone). It also emphasizes the importance of conducting further research and making advancements in treatment regimens for vasoplegia.

Low length-for-age Z-score within 1 month after birth predicts hyperdynamic circulation at the age of 21 years in rural Malawi

Low birth weight predisposes to the development of hypertension in middle- and high-income countries. We examined the relation of early life length-for-age score (Z-score) on cardiovascular function in young adults in Malawi, a low-income country. Capture of supine, seated, and standing brachial pulse waveforms (Mobil-O-Graph) were performed in 223 females and 152 males (mean age 21 years), and analyzed according to the length-for-age Z-score tertiles during the first month of life. Plasma LDL cholesterol in young adulthood was slightly lower in the lowest versus highest tertile. Otherwise, blood hemoglobin and plasma chemistry were similar in all tertiles. Irrespective of posture, blood pressure, forward and backward wave amplitudes, and pulse wave velocity were corresponding in all tertiles. In the three postures, the lowest tertile presented with 4.5% lower systemic vascular resistance than the highest tertile (p = 0.005), and 4.4% and 5.5% higher cardiac output than the middle and highest tertiles, respectively (p < 0.01). Left cardiac work was 6.8% and 6.9% higher in the lowest tertile than in the middle and highest tertiles, respectively (p < 0.01). To conclude, in a low-income environment, low length-for-age Z-score after birth predicted hyperdynamic circulation at 21 years of age without changes in blood pressure and metabolic variables.

The Outcome of Electrical Cardioversion in Hyperthyroid Induced Atrial Fibrillation.

Hyperthyroidism is a prevalent cause of atrial fibrillation (AF). High cardiac output with low systemic vascular resistance, driven by hyperthyroidism, is associated with a rapid heartbeat, enhanced left ventricular systolic and diastolic function, and a higher incidence of supraventricular tachyarrhythmias. After returning to euthyroid status, hyperthyroidism-induced AF generally spontaneously reverts to sinus rhythm (SR), and a significant number of patients remain in chronic AF and require electrical cardioversion (ECV). After effective cardioversion, the long-term outcome of hyperthyroidism-induced persistent AF is unknown. Early ECV before the antithyroid medication should be explored for hyperthyroidism-induced AF to reduce the risk of thromboembolic consequences. The recurrence rate of AF between Hyperthyroid and Euthyroid Patients after ECV did not significantly differ. This review article compares the recurrence rate of AF as an outcome of ECV in Hyperthyroid induced atrial fibrillation.

Are There Distinct Cardiovascular Subclasses in Acute Respiratory Distress Syndrome? Maybe.

Are There Distinct Cardiovascular Subclasses in Acute Respiratory Distress Syndrome? Maybe.

Using omics to breathe new life into our understanding of the ductus arteriosus oxygen response

The ductus arteriosus (DA) connects the aorta to the pulmonary artery (PA), directing placentally oxygenated blood away from the developing lungs. High pulmonary vascular resistance and low systemic vascular resistance facilitate shunting of blood in utero from the pulmonary to the systemic circulation through the widely patent DA, thereby optimizing fetal oxygen (O2) delivery. With the transition from fetal (hypoxia) to neonatal (normoxia) oxygen conditions, the DA constricts while the PA dilates. This process often fails in prematurity, promoting congenital heart disease. Impaired O2-responsivness in the DA promotes persistent ductus arteriosus (PDA), the most common form of congenital heart disease. Knowledge of DA oxygen sensing has greatly advanced in the past few decades, however we still lack a complete understanding of the sensing mechanism. The genomic revolution of the past two decades has facilitated unprecedented discovery in every biological system. This review will demonstrate how multiomic integration of data generated from the DA can breathe new life into our understanding of the DA's oxygen response.

Diurnal cardio-respiratory changes in ambulatory individuals deciphered using a multi-parameter wearable device.

Recent technological developments enable big data-driven insights on diurnal changes. This study aimed to describe the trajectory of multiple and advanced parameters using a medical-grade wearable remote patient monitor. Parameters were monitored for 24 h in 256 ambulatory participants who kept living their normal life. Parameters included heart rate, blood pressure, stroke volume, cardiac index, systemic vascular resistance, blood oxygen saturation, and respiratory rate. Diurnal variations were evaluated, and analyses were stratified based on sex, age, and body mass index. All parameters showed diurnal changes (p < 0.001). Females demonstrated higher heart rate and cardiac index with lower systemic vascular resistance. Obese participants had a higher blood pressure, and lower stroke volume and cardiac index. Systemic vascular resistance was higher among the elderly. Diurnal changes corresponded with awake-sleep hours and differed between sex, age, and body mass index groups. Wearable monitoring platforms could decipher hemodynamic changes in subgroups of individuals, and might help with efforts to provide personalized medicine, pre-symptomatic diagnosis and prevention, and drug development.

Vasoplegic syndrome after cardiopulmonary bypass for paravalvular leak of mitral bioprosthesis

Vasoplegic syndrome (VS) is characterized by low systemic vascular resistance paired with relatively preserved cardiac output that may result in increased morbidity and mortality rate after open-heart surgery utilizing cardiopulmonary bypass. We report a case of a 61-year-old male who underwent redo open-heart surgery due to a paravalvular leak of the previous implanted mitral bioprosthesis and severe tricuspid regurgitation. The patient experienced the VS in the intensive care unit after the operation. He was resuscitated by vasopressors and recovered uneventfully.

Insights into diurnal variations of advanced hemodynamic parameters in ambulatory individuals enabled by a photoplethysmography-based wearable monitor

Abstract Background Recent technological developments enable non-invasive monitoring of advanced hemodynamic parameters, allowing big data-driven insights on diurnal changes for the first time. This study aimed to describe the trends of multiple advanced cardiovascular parameters among ambulatory individuals using a medical grade wearable monitor. Methods Common and advanced cardio-respiratory parameters were monitored for 24 hours in ambulatory volunteers using a photoplethysmography-based wearable monitor. The multi vital ambulatory monitoring (MVAM) included stroke volume (SV), cardiac index (CI), systemic vascular resistance (SVR), blood oxygen saturation (SpO2), respiratory rate (RR), systolic (SBP) and diastolic blood pressure (DBP), mean arterial pressure (MAP), pulse pressure (PP), and heart rate (HR). Diurnal variations were evaluated among all participants, and analyses were stratified based on sex, age, and body-mass index (BMI). Results A total of 256 participants were included in the analysis. All measured parameters showed significant (p&amp;lt;0.001) diurnal changes. Nighttime values were lower excluding RR and SVR, reaching the nadir at 5 am, and then increasing to a maximum at 10 am, plateauing, and then gradually declining from 7 to 8 pm. CI demonstrated a reduction of 0.6 L/min/m2 (20%), while SVR demonstrated the opposite trend and was higher during the night increasing by up to 212 dynes/sec/cm5 (16%). Females demonstrated higher HR and CI with lower SVR during daytime and nighttime. Obese participants (BMI &amp;gt;30 kg/m2) had a higher SBP and DBP, and lower SV and CI. SVR was higher among the elderly. Conclusions Diurnal changes using MVAM corresponding with awake-sleep hours were noticed in the monitored parameters and differed between sex, age, and BMI groups. This suggests that wearable monitoring platforms could shed more light on hemodynamic changes in subgroups, and might help with future efforts to provide tailored personalized medicine and pre-symptomatic diagnosis and prevention. Funding Acknowledgement Type of funding sources: None.

A Unique High-Output Cardiac Hypertrophy Phenotype Arising From Low Systemic Vascular Resistance in Cantu Syndrome.

Background Cardiomegaly caused by left ventricular hypertrophy is a risk factor for development of congestive heart failure, classically associated with decreased systolic and/or diastolic ventricular function. Less attention has been given to the phenotype of left ventricular hypertrophy with enhanced ventricular function and increased cardiac output, which is potentially associated with high-output heart failure. Lack of recognition may pose diagnostic ambiguity and management complexities. Methods and Results We sought to systematically characterize high-output cardiac hypertrophy in subjects with Cantu syndrome (CS), caused by gain-of-function variants in ABCC9, which encodes cardiovascular KATP (ATP-sensitive potassium) channel subunits. We studied the cardiovascular phenotype longitudinally in 31 subjects with CS with confirmed ABCC9 variants (median [interquartile range] age 8 years [3-32 years], body mass index 19.9 [16.5-22.9], 16 male subjects). Subjects with CS presented with significant left ventricular hypertrophy (left ventricular mass index 86.7 [57.7-103.0] g/m2 in CS, n=30; 26.6 [24.1-32.8] g/m2 in controls, n=17; P<0.0001) and low blood pressure (systolic 94.5 [90-103] mm Hg in CS, n=17; 109 [98-115] mm Hg in controls, n=17; P=0.0301; diastolic 60 [56-66] mm Hg in CS, n=17; 69 [65-72] mm Hg in control, n=17; P=0.0063). Most (21/31) subjects with CS exhibited eccentric hypertrophy with normal left ventricular wall thickness. Congestive heart failure symptoms were evident in 4 of the 5 subjects with CS aged >40 years on long-term follow-up. Conclusions The data define the natural history of high-output cardiac hypertrophy resulting from decreased systemic vascular resistance in subjects with CS, a defining population for long-term consequences of high-output hypertrophy caused by low systemic vascular resistance, and the potential for progression to high-output heart failure.