Cardiac Work Research Articles

Impact of concomitant vasoactive treatment and mechanical left ventricular unloading in a porcine model of profound cardiogenic shock

BackgroundConcomitant vasoactive drugs are often required to maintain adequate perfusion pressure in patients with acute myocardial infarction (AMI) and cardiogenic shock (CS) receiving hemodynamic support with an axial flow pump (Impella CP).ObjectiveTo compare the effect of equipotent dosages of epinephrine, dopamine, norepinephrine, and phenylephrine on cardiac work and end-organ perfusion in a porcine model of profound ischemic CS supported with an Impella CP.MethodsCS was induced in 10 pigs by stepwise intracoronary injection of polyvinyl microspheres. Hemodynamic support with Impella CP was initiated followed by blinded crossover to vasoactive treatment with norepinephrine (0.10 μg/kg/min), epinephrine (0.10 μg/kg/min), or dopamine (10 μg/kg/min) for 30 min each. At the end of the study, phenylephrine (10 μg/kg/min) was administered for 20 min. The primary outcome was cardiac workload, a product of pressure-volume area (PVA) and heart rate (HR), measured using the conductance catheter technique. End-organ perfusion was assessed by measuring venous oxygen saturation from the pulmonary artery (SvO2), jugular bulb, and renal vein. Treatment effects were evaluated using multilevel mixed-effects linear regression.ResultsAll catecholamines significantly increased LV stroke work and cardiac work, dopamine to the greatest extend by 341.8 × 103 (mmHg × mL)/min [95% CI (174.1, 509.5), p < 0.0001], and SvO2 significantly improved during all catecholamines. Phenylephrine, a vasoconstrictor, caused a significant increase in cardiac work by 437.8 × 103 (mmHg × mL)/min [95% CI (297.9, 577.6), p < 0.0001] due to increase in potential energy (p = 0.001), but no significant change in LV stroke work. Also, phenylephrine tended to decrease SvO2 (p = 0.063) and increased arterial lactate levels (p = 0.002).ConclusionCatecholamines increased end-organ perfusion at the expense of increased cardiac work, most by dopamine. However, phenylephrine increased cardiac work with no increase in end-organ perfusion.

Adding Coronary Calcium Score to Exercise Treadmill Test: An Alternative to Refine Coronary Artery Disease Risk Stratification in Patients with Intermediate Risk Chest Pain

Introduction:Chest pain is a common symptom for cardiology referrals. The ACC-AHA guidelines recommend exercise stress electrocardiography (TMX) as the initial diagnostic test. However, the TMX only has moderate sensitivity and non-diagnostic cases may require further stress imaging studies. In this study we aimed to look at the feasibility of combining coronary artery calcium (CAC) score with TMX to refine risk stratification. This may be an alternative to stress imaging in cases of non low-risk TMX, with the added advantage of short time turnaround time and low radiation dose.Methods:A total of 145 patients who presented consecutively to the National Heart Centre Singapore with chest pain were included in this study. These were intermediate risk patients with an average Duke Clinical Score of 38.8%. All patients underwent both TMX and computed tomography scan of the coronary arteries (CTCA) which also includes CAC. The primary outcome was defined as obstructive coronary artery disease i.e. >50% left main artery stenosis and/or >70% stenosis in other epicardial arteries.Results:The combination of TMX and CAC was comparable to stress imaging in detecting obstructive coronary artery disease. When added to TMX, CAC has an integrated discriminative improvement of 74.1%, achieved an area under the curve of 0.974 and adjusted R2 of 0.670 in detecting the primary outcome.Conclusion:The strategy of combining TMX and CAC is feasible in clinical practice to refine risk stratification in outpatients with intermediate risk chest pain. The calcium score readout also further guides therapy for primary prevention.Highlights:Treadmill exercise is one of the first line tests for cardiac chest pain work up.Non diagnostic test treadmill results requires further adjunctive tests.Downstream stress imaging causes delay in time to diagnosis.Coronary artery calcium scoring needs minimal preparation with fast turnaround time.Addition of coronary artery calcium to treadmill performs comparably to stress imaging.This is a feasible alternative to risk stratify non diagnostic treadmill tests and guide therapy for primary prevention.

Effects of myocardial function and systemic circulation on regional coronary perfusion.

Cardiac-coronary interaction and the effects of its pathophysiological variations on spatial heterogeneity of coronary perfusion and myocardial work are still poorly understood. This hypothesis-generating study predicts spatial heterogeneities in both regional cardiac work and perfusion that offer a new paradigm on the vulnerability of the subendocardium to ischemia, particularly at the apex. We propose a mathematical and computational modeling framework to simulate the interaction of left ventricular mechanics, systemic circulation, and coronary microcirculation. The computational simulations revealed that the relaxation rate of the myocardium has a significant effect whereas the contractility has a marginal effect on both the magnitude and transmural distribution of coronary perfusion. The ratio of subendocardial to subepicardial perfusion density (Qendo/Qepi) changed by -12 to +6% from a baseline value of 1.16 when myocardial contractility was varied by +25 and -10%, respectively; Qendo/Qepi changed by 37% when sarcomere relaxation rate, b, was faster and increased by 10% from the baseline value. The model predicts axial differences in regional myocardial work and perfusion density across the wall thickness. Regional myofiber work done at the apex is 30-50% lower than at the center region, whereas perfusion density in the apex is lower by only 18% compared with the center. There are large axial differences in coronary flow and myocardial work at the subendocardial locations, with the highest differences located at the apex region. A mismatch exists between perfusion density and regional work done at the subendocardium. This mismatch is speculated to be compensated by coronary autoregulation.NEW & NOTEWORTHY We present a model of left ventricle perfusion based on an anatomically realistic coronary tree structure that includes its interaction with the systemic circulation. Left ventricular relaxation rate has a significant effect on the regional distribution of coronary flow and myocardial work.

NADPH Oxidase 2 Mediates Myocardial Oxygen Wasting in Obesity.

Obesity and diabetes are independent risk factors for cardiovascular diseases, and they are associated with the development of a specific cardiomyopathy with elevated myocardial oxygen consumption (MVO2) and impaired cardiac efficiency. Although the pathophysiology of this cardiomyopathy is multifactorial and complex, reactive oxygen species (ROS) may play an important role. One of the major ROS-generating enzymes in the cardiomyocytes is nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 2 (NOX2), and many potential systemic activators of NOX2 are elevated in obesity and diabetes. We hypothesized that NOX2 activity would influence cardiac energetics and/or the progression of ventricular dysfunction following obesity. Myocardial ROS content and mechanoenergetics were measured in the hearts from diet-induced-obese wild type (DIOWT) and global NOK2 knock-out mice (DIOKO) and in diet-induced obese C57BL/6J mice given normal water (DIO) or water supplemented with the NOX2-inhibitor apocynin (DIOAPO). Mitochondrial function and ROS production were also assessed in DIO and DIOAPO mice. This study demonstrated that ablation and pharmacological inhibition of NOX2 both improved mechanical efficiency and reduced MVO2 for non-mechanical cardiac work. Mitochondrial ROS production was also reduced following NOX2 inhibition, while cardiac mitochondrial function was not markedly altered by apocynin-treatment. Therefore, these results indicate a link between obesity-induced myocardial oxygen wasting, NOX2 activation, and mitochondrial ROS.

Change of Tolerance of Physical Load and Quality of Life using Physical Therapy in Patients after Myocardial Infarction in the Early Period of Rehabilitation

Each second a person dies from cardiovascular diseases in Lithuania. Mortality from cardiovascular diseases in 2020 will account for 37% of all deaths in the world. Movement is very important for blood circulation and cardiac work, but due to reduced blood supply to the heart physical capacity is disrupted. Physical therapy improves tolerance of physical load, reduces fatigue, dyspnoea, frequency of hospitalization and improves the quality of life. The maximum efficiency is achieved when physical therapy starts in the first week after myocardial infarction. Starting physical therapy each week later, rehabilitation period becomes a month longer. The purpose of this study was to evaluate the effects of physiotherapy on the tolerance of physical load and the quality of life changes in patients after myocardial infarction in the early period of rehabilitation. The study involved 14 people (58.1 ± 7,6) after a myocardial infarction (9 men and 5 women). In study there were two groups: 1 – control group (n = 7) with physical therapy 1 time per day, 5 days per week (n = 5), 2 – experimental group (n = 7) with physical therapy 3 times per day, 5 days per week (n = 15). Tolerance of physical load was determine using a 6 min walk test, before and after the 6 min walk test we evaluated subjective complaints using Borg scale. The quality of life was evaluated using SF – 36 questionnaire. Both groups were evaluating before physical therapy and after 5 days of physical therapy. After physical therapy the tolerance of physical load increased in control and experimental groups, it improved during the 6-minute walk distance (p &lt; 0.05), fatigue decreased (p &lt; 0.05) (there was no differences between groups (p &gt; 0.05)). The leg pain in both groups did not change (p &gt; 0.05), dyspnoea did not decrease (p &gt; 0.05). Physical therapy frequency did not influence the quality of life. Conclusion: physical therapy 3 times per day improved the tolerance of physical load – it increased in 6-minute walk distance, but the quality of life did not change significantly.Keywords: myocardial infarction, functional capacity, quality of life, physical therapy.

Adrenal gland-released vasostatin-I is a myocardial depressant factor.

Pheochromocytoma crisis is an exceptional consequence of the release of storage vesicles of the adrenal medulla. It is complicated by fulminant adrenergic myocarditis. It offers a unique opportunity to detect inotropic negative factors from neuroendocrine origin. Our objectives were (a) to describe a pheochromocytoma crisis, (b) to investigate in vivo myocardial depressant activities for the N-terminal 1-76 Chromogranin A-derived peptide, vasostatin-I (VS-I). A patient with a pheochromocytoma crisis was treated, including extracorporeal membrane oxygenation, until mass resection. Plasma concentrations of VS-I were time-dependently assessed with a specific immunoassay; correlations with invasive cardiovascular parameters were investigated. Increased VS-I concentrations were observed over 7 days until tumour resection. VS-I concentrations correlated positively with Chromogranin A levels, negatively with cardiac output and left ventricular stroke work index, but not with heart rate. This case illustrates the pharmacokinetics of VS-I in a pheochromocytoma crisis. It highlights myocardial depressant activity for this peptide at high concentrations.

A rare case of ischaemic stroke following cervical spine manipulation in an adolescent girl

Stroke in children is associated with a multitude of risk factors compared to risk factors of adult stroke such as hypertension, diabetes or atherosclerosis. A 15-year adolescent girl presented with acute onset weakness involving right upper and lower limb. She complained of neck pain and fever 2 days before the onset of hemiparesis for which her parents took her to traditional healer who performed neck manipulation after which she developed vomiting, tingling numbness and weakness of right upper and lower limb. There was no history of preceding headache, ear discharge or any other contributory history. Clinical examination revealed Glasgow Come Scale 12/15, power of grade 2/5 in right upper limb and 3/5 in right lower limb, exaggerated deep reflexes, extensor plantar reflex, right sided ptosis and right sided upper motor neuron facial palsy. CT scan brain showed right cerebellar and occipital infarct with posterior inferior cerebellar artery territory involvement. MRI Brain and MR Angiogram showed wedge shaped infarct involving right posterior inferior cerebellum, inferior vermis, ventral aspect of superior medulla, paracentral pons, right cerebral peduncle, tectum of both halves of midbrain with no internal hemorrhage and no vessel abnormality and right vertebral artery was not visualized. Her coagulation profile and cardiac work up were normal. She was treated with antiplatelet drugs, anticoagulants and physiotherapy following which the child gradually improved over a period of one month. In this case, with a positive history of neck manipulation authors can conclude that the etiology of young stroke wasinduced byneck manipulation. This case has been reported to increase awareness about the ill effects of neck manipulation and counsel parents against performing such procedures for children. Early recognition of pediatric stroke is critical for immediate diagnosis, imaging and treatment with better outcomes.

Head Injuries, a general approach

When a person with a head injury arrives at the hospital, doctors and nurses first check life signs: cardiac work, blood pressure and breathing. For those who do not breathe satisfactorily, a extractor fan may be required. Doctors immediately assess the patient's state of mind and memory. They also test the brain's basic functions by checking the size of the pupils and their response to light, assessing reactions to sensations such as heat and stab of the needle, and testing the ability to move their arms or legs. Computed tomography or magnetic resonance imaging is required to evaluate possible brain injury. Traumatic brain injury occurs when an external mechanical force causes brain dysfunction. Brain trauma is usually the result of a violent hit to the head. An object that pierces the skull, such as a bullet, can also cause brain trauma. Mild trauma can be caused by temporary brain cell dysfunction. More serious brain trauma can lead to bruising, torn tissue, bleeding and other physical injuries to the brain, which can result in long-term complications or even death. Head injuries are the cause of disability and death of people under the age of 50, more than any other type of neurological impairment. Nearly half of people with severe head injuries die. The brain can be damaged even when the skull is not pierced.

P1263 Acute cerebrovascular infarct in a young adult with double septal defect and double outlet ventricle

Abstract Introduction Double outlet right ventricle is a rare cause of acute cerebrovascular disease among young adults. Case. We report a case of a 21 year old male who presented with aphasia and left sided weakness. This was associated with cyanosis, easy fatigablity, recurrent epistaxis and loss of consciousness since childhood. On admission, patient’s vital sign was stable at 100/60, 90 bpm regular, 20 cycles per minute afebrile 80% oxygen saturation on room air. Patient is conscious, aphasic but follows simple commands. He had central cyanosis, clubbing of the upper and lower extremities, adynamic precordium, single s2, right ventricular heave, grade 3/6 systolic ejection murmur at the 2nd left intercoastal space parasternal line, 4/6 holosystolic murmur at the 4th intercoastal space parasternal line, and clear breath sounds. Neurologic examination revealed a 0/5 motor response on both left upper and lower extremity. Cranial MRI showed acute ischemic infarcts at the right frontal centrum semiovale and left cerebral hemisphere. During his admission, cardiac work up was done to investigate cardioembolic cause of the acute cerebrovascular disease. Transesophageal echocardiogram revealed congenital heart disease situs solitus with atrioventricular discordance; double outlet right ventricle, pulmonic valve stenosis, interatrial septal aneurysm with atrial septal defect and persistent left superior vena cava syndrome. During his hospital course, patient was started on aspirin, citicholine and atorvastatin for his cerebrovascular disease which was noted to improve after 2 days. Patient was also referred to the thoracovascular surgery team for comanagement who did modified Blalock Tausig shunting. Patient was referred to cardiac rehabilitation post procedure. His vital signs remained to be stable, his oxygen saturation increased to 90% at room air, and his functional capacity improved. Patient was discharged stable. Discussion Double outlet right ventricle is a rare complex congenital heart disease characterized by a conotruncal malseptation from which more than or equal to 50% of each great artery arises from the morphologic right ventricle. Associated defects like atrial septal defect and persistent left superior vena cava were reported in some literature. Cerebrovascular infarcts in complex cyanotic congenital heart disease might be secondary to polycythemia and/or paradoxical emboli bypassing the interatrial defect. Prompt prophylaxis such as periodic phlebotomy and/or anticoagulation in patients high risk for deep vein thrombosis must be evaluated for each patient.

The effect of physical effort on the two variables of cardiac work and the maximum oxygen consumption base on different speeds and a specific distance for football players

The effect of physical effort on the two variables of cardiac work and the maximum oxygen consumption base on different speeds and a specific distance for football players

Efficacy of preoperative oral gabapentin for patients undergoing intracranial surgery: Effect on laryngoscopic stress response

ABSTRACT Background A reflex sympathoadrenal response could be elicited by laryngoscopy and intubation in the form of tachycardia and hypertension. These responses could be attenuated to decrease cardiac work and oxygen demands. This study was conducted to assess the role of oral gabapentin in decreasing the stress response associated with intubation. Objective This study was conducted to assess the role of oral gabapentin in decreasing the stress response associated with intubation. Patients and methods A total of 70 cases who underwent intracranial surgery in Mansoura University Hospitals were included. They were divided into two groups; group C who received placebo, and group G who received gabapentin 1000 mg orally. Heart rate, blood pressure, and catecholamine levels were measured prior to intubation, then after 1, 5, 10, and 15 minutes. Results there is no correction When given 1 hr prior to surgery, gabapentin effectively attenuated blood pressure, heart rate, and catecholamine levels compared to the placebo after intubation, although no statistical differences were detected statistically before intubation. Conclusion Pre-treatment with 1000 mg oral gabapentin before induction of anesthesia is both safe and effective in reducing the stress response to laryngoscopy and intubation.

A randomised, double-blind, placebo-controlled trial of metformin on myocardial efficiency in insulin-resistant chronic heart failure patients without diabetes.

The present study tested the hypothesis that metformin treatment may increase myocardial efficiency (stroke work/myocardial oxygen consumption) in insulin-resistant patients with heart failure and reduced ejection fraction (HFrEF) without diabetes. Thirty-six HFrEF patients (ejection fraction 37 ± 8%; median age 66 years) were randomised to metformin (n = 19) or placebo (n = 17) for 3 months in addition to standard heart failure therapy. The primary endpoint was change in myocardial efficiency expressed as the work metabolic index (WMI), assessed by 11 C-acetate positron emission tomography and transthoracic echocardiography. Compared with placebo, metformin treatment (1450 ± 550 mg/day) increased WMI [absolute mean difference, 1.0 mmHg·mL·m-2 ·106 ; 95% confidence interval (CI) 0.1 to 1.8; P = 0.03], equivalent to a 20% relative efficiency increase. Patients with above-median plasma metformin levels displayed greater WMI increase (25% vs. -4%; P = 0.02). Metformin reduced myocardial oxygen consumption (-1.6 mL O2 ·100 g-1 ·min-1 ; P = 0.014). Cardiac stroke work was preserved (-2 J; 95% CI -11 to 7; P = 0.69). Metformin reduced body weight (-2.2 kg; 95% CI -3.6 to -0.8; P = 0.003) and glycated haemoglobin levels (-0.2%; 95% CI -0.3 to 0.0; P = 0.02). Changes in resting and exercise ejection fraction, global longitudinal strain, and exercise capacity did not differ between groups. Metformin treatment in non-diabetic HFrEF patients improved myocardial efficiency by reducing myocardial oxygen consumption. Measurement of circulating metformin levels differentiated responders from non-responders. These energy-sparing effects of metformin encourage further large-scale investigations in heart failure patients without diabetes.

Cardiovascular Responses and Cardiac Work of Selected Daily Activities in Young Healthy Indian Participants

Background: Studies suggest that habitual daily activities may result in significant cardiovascular responses that might have implications for individuals with coronary artery disease. This study determined the cardiac work for various activities of daily living among healthy young participants. Methods: We evaluated cardiovascular responses in 42 young adults (21 male, 21 female) to graded activities. Subjects were divided into three groups. In each group, one light, one moderate, and one heavy activity were performed based on published METS. Cardiovascular responses were evaluated using impedance cardiography (BOMED Instruments, USA) and automated blood pressure monitor (Welch Allyn, USA). Cardiac work was computed as the double product (heart rate × systolic blood pressure) and triple product (systolic blood pressure × cardiac output [stroke volume × heart rate]). Perceived exertion was evaluated using Borg’s scale. Results: There was high inter-individual variability in cardiovascular responses for each activity. There were, by and large, no gender differences across the activities. Cardiac work was significantly higher with heavy activities than light activities using both indices; however, the triple product showed greater discriminatory ability in evaluating differences in cardiac work across all categories of activities. Conclusion: The data suggest a need to develop a compendium of cardiac work related to habitual activities to guide doctors and patients.

Changes in hemodynamics associated with metabolic syndrome are more pronounced in women than in men

The increase in cardiovascular risk associated with metabolic syndrome (MS) seems higher in women than in men. We examined hemodynamics during head-up tilt in 252 men and 250 women without atherosclerosis, diabetes, or antihypertensive medication, mean age 48 years, using whole-body impedance cardiography and radial pulse wave analysis. MS was defined according to Alberti et al. 2009. Men and women with MS presented with corresponding elevations of systolic and diastolic blood pressure (10-14%, p ≤ 0.001) versus controls. Supine pulse wave velocity (16–17%, p < 0.001) and systemic vascular resistance (7–9%, p ≤ 0.026), and upright cardiac output (6–11%, p ≤ 0.008) were higher in both MS groups than controls. Elevation of supine aortic characteristic impedance was higher in women than in men with MS (16% vs. 8%, p = 0.026), and in contrast to men, no upright impedance reduction was observed in women. When upright, women but not men with MS showed faster return of reflected pressure wave (p = 0.036), and smaller decrease in left cardiac work (p = 0.035) versus controls. The faster upright return of reflected pressure, lower upright decrease in left cardiac work, and higher elevation of aortic characteristic impedance may contribute to the greater increase in MS-related cardiovascular risk in women than in men.

Left ventricular remodelling among Turner syndrome patients: insights from non-invasive 3D echocardiography-derived pressure-volume loop analysis.

Turner syndrome (TS) is a X-chromosomal disease affecting one in 2500-3000 female newborns. TS individuals are at high cardiovascular risk and more likely to be overweight or obese. The aim of this study was to assess left ventricular performance in TS patients through three-dimensional speckle tracking echocardiography (3DSTE) and non-invasive left ventricular pressure-volume loop (PVL) analysis. Moreover, this study focused on the impact of excess weight on the left ventricular efficiency in TS patients. Thirty-six TS patients and 19 healthy age-matched controls were included in this study. 3DSTE and non-invasive left ventricular PVL analysis were performed and left ventricular efficiency parameters were calculated. TS patients had significantly lower values than controls in longitudinal strain (- 16.67 ± 3.23% vs. - 18.47 ± 1.87%; p = 0.029), but significantly higher values for arterial elastance (BSA) (3.31, 1.87-5.88mmHg/mL vs. 2.99, 2.31-4.61mmHg/mL; p = 0.011) and cardiac work (BSA) (292,070 ± 71,348mmHg*mL*HR vs. 248,595 ± 70,510mmHg*mL*HR; p = 0.036). Compared with normal weight patients, overweight and obese TS subjects demonstrated worse left ventricular efficiency (175.08 ± 17.73mmHg vs. 157.24 ± 26.75mmHg; p = 0.037). Even after excluding TS patients with cardiovascular morbidity, arterial elastance (BSA) was compared to healthy peers, significantly increased in TS patients. 3DSTE and non-invasive left ventricular PVL analysis might be useful tools to detect early cardiac changes in TS. Arterial elastance seems to be significantly increased in TS patients, independent of cardiovascular morbidity. Compared with normal weight TS patients, overweight/obese TS patients displayed lower left ventricular efficiency.

Beta-blockers in sepsis

Catecholamines are an integral component of the host stress response and usually increase appropriately at times of need. Unfortunately, in severe and prolonged critical illness, they can contribute to significant harm with unwanted biological effects on cardiac function, inflammatory, immune, metabolic, and coagulation pathways1. A good example is Takotsubo (‘stress’) cardiomyopathy where heart failure ensues after an emotional stress resulting in extremely high levels of circulating catecholamines, considerably above that seen in a significant myocardial infarction2.Unwittingly, we are likely contributing to catecholamine toxicity in our management of the critically ill septic patient through use of exogenous catecholamine therapies which carry the same detrimental effects as endogenous catecholamines1,3. Catecholamines are currently recommended first-line agents for septic shock, and are used in an attempt to overcome the vascular hyporeactivity and myocardial depression associated with sepsis. Use of higher doses of catecholamines is however associated with worse outcomes4. This is usually ascribed to the patient's underlying illness severity and an iatrogenic contribution is not considered – but perhaps should be.Beta-blockers have multiple actions, on cardiac function and beyond. They reduce cardiac work through negative inotropic and chronotropic effects. Importantly, through slowing an excessive heart rate, both systolic and diastolic ventricular function are improved. They also act on adrenergic receptor responsiveness, enhancing the activity of catecholamines and allowing reductions in dose to achieve the same haemodynamic effect. Outside the heart, they improve vascular tone, enhance metabolic efficiency, and have anti-inflammatory effects and anti-thrombotic activity.The first use of beta-blockade in sepsis goes back nearly 50 years with successful use in some patients in refractory shock. In the last decade an increasing number of observational studies and a few single-centre randomised controlled trials have shown both safety and improved outcomes5. These reflect findings in animal models of sepsis where various mechanisms were demonstrated including protective effects on the heart, anti-inflammatory actions and preservation of the gut barrier5.Clearly, the patient needs to be adequately fluid-resuscitated and stabilised before commencing beta-blockers. Ideally, the use of a short-acting agent such as esmolol or landiolol allows easy titration, or cessation, of the infusion should hypotension or excess bradycardia occur with the unwanted effects wearing off within minutes. The largest study to date by Morelli et al., randomised 154 septic shock patients to receive either placebo or esmolol to reduce heart rate to 80-95 bpm. This was successfully achieved with no increase in complication rates compared to placebo. Importantly, there were also benefits in terms of earlier recovery of renal function, cessation of norepinephrine infusion, lower troponin levels (indicative of less cardiac damage), and improved survival rates. These encouraging findings need to be repeated in multicentre settings and two studies (one UK-based “STRESS-L”, one in 4 European countries) are currently ongoing.

Assessing Pancreas Transplant Candidate Cardiac Disease: Preoperative Protocol Development at a Rapidly Growing Transplant Program.

Pancreas transplant rates, despite improving outcomes, have decreased over the past two decades. This is due, in part, to ageing, increasingly co-morbid pancreas transplant candidates. There is a paucity of published data regarding coronary artery disease (CAD) in this population. To inform peri-operative management strategies, we sought to understand the frequency of CAD among recipients of pancreas transplants at our center. Informed by these data, we sought to develop a standard protocol for evaluation. A retrospective review of pancreas transplants (solitary pancreas and simultaneous pancreas-kidney) was undertaken at the University of Maryland. Transplant outcomes and frequency of cardiac disease were analyzed. Current data were compared with historic controls. Over the study period, 59 patients underwent pancreas transplantation. Coronary architecture was assessed in 38 patients (64.4%). Discrete evidence of CAD was present in 28 of 39 patients (71.7%). All pancreas candidates (n = 21) who underwent left heart catheterization (LHC) demonstrated CAD (100%). No patients experienced myocardial infarction (MI) and no deaths resulted from cardiac disease in the early post-transplant period. Pancreas transplant candidates are at high risk for CAD. At a center in which pancreas transplant rates are increasing, a rigorous cardiac work up revealed that 71.7% of assessed recipients had CAD. Although asymptomatic, 6.8% required coronary artery bypass graft (CABG). Despite increasing age and co-morbid status, pancreas transplant recipients can enjoy excellent results if protocolized preoperative testing is used.

Cardiac power output accurately reflects external cardiac work over a wide range of inotropic states in pigs

BackgroundCardiac power output (CPO), derived from the product of cardiac output and mean aortic pressure, is an important yet underexploited parameter for hemodynamic monitoring of critically ill patients in the intensive-care unit (ICU). The conductance catheter-derived pressure-volume loop area reflects left ventricular stroke work (LV SW). Dividing LV SW by time, a measure of LV SW min− 1 is obtained sharing the same unit as CPO (W). We aimed to validate CPO as a marker of LV SW min− 1 under various inotropic states.MethodsWe retrospectively analysed data obtained from experimental studies of the hemodynamic impact of mild hypothermia and hyperthermia on acute heart failure. Fifty-nine anaesthetized and mechanically ventilated closed-chest Landrace pigs (68 ± 1 kg) were instrumented with Swan-Ganz and LV pressure-volume catheters. Data were obtained at body temperatures of 33.0 °C, 38.0 °C and 40.5 °C; before and after: resuscitation, myocardial infarction, endotoxemia, sevoflurane-induced myocardial depression and beta-adrenergic stimulation. We plotted LVSW min− 1 against CPO by linear regression analysis, as well as against the following classical indices of LV function and work: LV ejection fraction (LV EF), rate-pressure product (RPP), triple product (TP), LV maximum pressure (LVPmax) and maximal rate of rise of LVP (LV dP/dtmax).ResultsCPO showed the best correlation with LV SW min− 1 (r2 = 0.89; p < 0.05) while LV EF did not correlate at all (r2 = 0.01; p = 0.259). Further parameters correlated moderately with LV SW min− 1 (LVPmaxr2 = 0.47, RPP r2 = 0.67; and TP r2 = 0.54). LV dP/dtmax correlated worst with LV SW min− 1 (r2 = 0.28).ConclusionCPO reflects external cardiac work over a wide range of inotropic states. These data further support the use of CPO to monitor inotropic interventions in the ICU.

3260Prognostic value of cardiac power reserve in patients with normal left ventricular ejection fraction undergoing exercise stress echocardiography

Abstract Background Cardiac power output-to-mass (CPOM) ratio is a measure of myocardial performance that incorporates both pressure and flow output, normalized to left ventricular (LV) mass generating that cardiac work. Prior small studies have shown that CPOM predicts outcomes in patients with ischemic cardiomyopathy and reduced LV ejection fraction (EF). We sought to evaluate the prognostic significance of peak exercise CPOM and power reserve (increase from rest to peak exercise) in patients with normal EF. Methods and results Retrospective study in 24,783 patients (age 59±13 years, 45% females) with EF≥50% and no significant valve disease or right ventricular (RV) dysfunction, undergoing exercise stress echocardiography between 2004–2018. CPOM was calculated as previously described (0.222 x cardiac output x mean blood pressure / LV mass) and expressed in Watts/100g myocardium. Power reserve was calculated as difference in CPOM between peak stress and rest. All-cause mortality was the primary endpoint. Patients were divided into quartiles of power reserve. Patients with higher power reserve were younger, had higher blood pressure and heart rate, lower LV mass, and lower prevalence of prior myocardial infarction. (Table). During follow-up (median (IQR) 3.9 (0.6–8.3) years), 931 (3.8%) patients died. Progressively lower power reserve was associated with increasing mortality (Figure A). Compared to patients with abnormal stress test, patients with the lowest power reserve but otherwise normal stress test had the same survival as those with infarction/cardiomyopathy or ischemia on stress test (Figure B). Resting CPOM had lower predictive value. After adjusting for age, sex, METs achieved, ischemia/infarction on stress test results, and diastolic function grade, both peak exercise CPOM and power reserve were independent predictors of mortality (p&lt;0.0001), incremental to conventional measures. Conclusion Cardiac power output and reserve measured during exercise stress echo provides independent prognostic information in patients with normal resting EF and no significant valve disease or RV dysfunction. The survival of patients with low power reserve but normal stress test was similar to patients with prior infarction/ cardiomyopathy or ischemia on stress test.

1366 Primary Antiphospholipid Syndrome, Acute Necrotizing Pancreatitis, and IgA Nephropathy in a Young Male: Single Pathogenesis or Rare Association?

INTRODUCTION: Primary Antiphospholipid syndrome (APS) is characterized by recurrent thrombosis, fetal loss and the presence of lupus anticoagulant (LA)/anticardiolipin antibodies. Primary APS is uncommon in males and poses diagnostic difficulties. Primary APS is considered as a rare cause of acute pancreatitis and IgA nephropathy (IgAN). We describe a patient of primary APS (probably the first reported case), who sequentially presented with cerebral venous thrombosis, later with recurrent episodes of acute necrotizing pancreatitis (ANP) followed by IgAN. Despite the initial diagnostic dilemmas, the patient was managed successfully. CASE DESCRIPTION/METHODS: A 30 year old male initially presented with sudden onset headache and generalized seizures. CECT brain revealed cerebral venous thrombosis. Cardiac and Pro thrombotic work up (including ANA and LA) was normal. He was treated with antiepileptics and warfarin. 3 months later, he presented with 3 episodes of acute pancreatitis. Each time the patient was managed conservatively with fluids and analgesics. However the last episode was very severe, CECT abdomen was suggestive of severe ANP with extensive splenic vein thrombosis (SVT). Anti-β2glycoprotein1 antibody test was strongly positive. APS was diagnosed according to revised Sapporo criteria. Low molecular heparin and steroids were started. After 5 months, although the patient recovered from ANP, he presented with hypoproteinemia and renal failure. Urine analysis showed RBC casts and proteinuria. Kidney biopsy showed mesangial IgAN with secondary segmental sclerosis. Patient recovered fully and is on follow up for two years. He is doing fine with low dose steroids, ACE inhibitors and warfarin with regular INR (target 2-3). DISCUSSION: This patient had multiple hospitalizations, all attributable to the rare manifestations of APS. It is perhaps the first case report where APS, ANP and IgAN are described in a single patient. Clinical suspicion can lead to early diagnosis, which makes it easy to manage such patients. Acute pancreatitis is considered as one of the rarest manifestation of APS, which is distinct from autoimmune pancreatitis. Renal biopsy was suggestive of IgAN, which is unusual and distinct from the APS nephropathy. Thrombosis of the pancreatic and renal microcirculation and vasculitis has been postulated as the underlying pathogenesis. To conclude, APS is a rare, yet treatable cause of acute pancreatitis. Urine examination is a must in cases of primary APS, with or without pancreas involvement.