Low Output State Research Articles

Ultrasound guided stellate ganglion block for ventricular tachycardia storm

Ultrasound guided stellate ganglion block for ventricular tachycardia storm - IJCA- Print ISSN No: - 2394-4781 Online ISSN No:- 2394-4994 Article DOI No:- 10.18231/j.ijca.2019.120, Indian Journal of Clinical Anaesthesia-Indian J Clin Anaesth

Haemodynamic Balance in Acute and Advanced Heart Failure: An Expert Perspective on the Role of Levosimendan.

Acute and advanced heart failure are associated with substantial adverse short- and longer-term prognosis. Both conditions necessitate complex treatment choices to restore haemodynamic stability and organ perfusion, relieve congestion, improve symptoms and allow the patient to leave the hospital and achieve an adequate quality of life. Among the available intravenous vasoactive therapies, inotropes constitute an option when an increase in cardiac contractility is needed to reverse a low output state. Within the inotrope category, levosimendan is well suited to the needs of both sets of patients since, in contrast to conventional adrenergic inotropes, it has not been linked in clinical trials or wider clinical usage with increased mortality risk and retains its efficacy in the presence of beta-adrenergic receptor blockade; it is further believed to possess beneficial renal effects. The overall haemodynamic profile and clinical tolerability of levosimendan, combined with its extended duration of action, have encouraged its intermittent use in patients with advanced heart failure. This paper summarises the key messages derived from a series of 12 tutorials held at the Heart Failure 2019 congress organised in Athens, Greece, by the Heart Failure Association of the European Society of Cardiology.

Confidence Collapse in a Multi-Household, Self-Reflexive DSGE Model

We investigate a multi-household DSGE model in which past aggregate consumption impacts the confidence, and therefore consumption propensity, of individual households. We find that such a minimal setup is extremely rich, and leads to a variety of realistic output dynamics: high output with no crises; high output with increased volatility and deep, short lived recessions; alternation of high and low output states where relatively mild drop in economic conditions can lead to a temporary confidence collapse and steep decline in economic activity. The crisis probability depends exponentially on the parameters of the model, which means that markets cannot efficiently price the associated risk premium. We conclude by stressing that within our framework, narratives become an important monetary policy tool, that can help steering the economy back on track.

Cardiac adaptation in asphyxiated infants treated with therapeutic hypothermia.

Hypoxic ischemic encephalopathy (HIE) affects one to two newborns per 1,000 live births and oftentimes involves multi-organ insult. The objectives were to assess the evolution of cardiac function in infants with HIE treated with therapeutic hypothermia using echocardiography (ECHO). Archived data during the period 2010-2016 was assessed. Amongst the infants with baseline ECHO assessments, a sub-cohort which had assessments in all the three phases (baseline/pre-active cooling [T1], cooling [T2] and rewarming [T3]) was analyzed separately. Thirty three infants formed part of the overall cohort, the gestation and birthweight were 39.6 ± 1.6 weeks and 3306 ± 583 g, respectively. Baseline (T1) information noted impaired cardiac performance (right ventricle stroke volume 1.08 ± 0.04 ml/kg, fractional area change [FAC] 24 ± 0.5% and tricuspid annular peak systolic excursion [TAPSE] 7.46 ± 0.11mm). Serial information was available for 24 of 33 infants. Cardiac function improved significantly between the cooling and the re-warming kphases. This included changes in right ventricular output (127 ± 34 vs 164 ± 47 ml/kg/min, p <0.01) and FAC (20 ± 3 vs 28 ± 2%, p<0.01). Pairwise comparisons for fractional shortening did not show significant changes. From the cooling to the rewarming phase, maximum change was noted in FAC (26.3 ± 9.8%) while minimum change was noted in fractional shortening (median, interquartile range) of 4.6% (1.4, 9.1). Significant correlation between TAPSE and time to peak velocity as a proportion of right ventricular ejection time was noted (r2 = 0.68, p <0.001). In infants with moderate to severe HIE, cardiac function evolves during various phases of therapeutic hypothermia. Low output state during cooling may be due to a combination of the disease state (HIE) and cooling therapy.

Engineering Relaxation Pathways in Building Blocks of Artificial Spin Ice for Computation

Nanomagnetic logic, which makes use of arrays of dipolar-coupled single domain nanomagnets for computation, holds promise as a low power alternative to traditional computation with CMOS. Beyond the use of nanomagnets for Boolean logic, nanomagnets can also be exploited for non-deterministic computational schemes such as edge detection in images and for solving the traveling salesman problem. Here, we demonstrate the potential of arrangements of thermally-active nanomagnets based on artificial spin ice for both deterministic and probabilistic computation. This is achieved by engineering structures that follow particular thermal relaxation pathway consisting of a sequence of reorientations of magnet moments from an initial field-set state to a final low energy output state. Additionally, we demonstrate that it is possible to tune the probability of attaining a particular final low-energy state, and therefore the likelihood of a given output, by modifying the intermagnet distance. Finally, we experimentally demonstrate a scheme to connect several computational building blocks for complex computation.

Safety and Efficacy of Home Inotropes as Bridge to LVAD and Transplant

Purpose Advanced heart failure (HF) patients in low output state (cardiogenic shock) not planned for LVAD or transplant prior to discharge are often transitioned home on inotropes. This study exams safety and efficacy of ambulatory inotropes as bridge to LVAD or transplant or pending evaluation for these therapies. Methods We performed retrospective data collection on 66 patients discharged from the hospital with inotropes between January 2013 and June 2018. Results Sixty-six patients receiving home inotrope therapy were identified and 14 patients receiving inotropes as palliation were eliminated. Baseline clinical characteristics of 52 patients on home inotropes as a bridge therapy are listed in Table 1. At the end of the study, 5 patients (9.6 %) were determined to not be candidates for LVAD/transplant, 2 patients died (4 %), 32 received LVADs (62 %), 5 were transplanted (9.6 %), 5 remained on inotropes (9.6 %) and 3 were weaned off inotropes (6 %). Inotrope use was associated with a lower proBNP level, improved diastolic BP and cardiac output (Table 2). Hospital admissions for decompensated HF in the 6 months prior to initiation of inotropes were 1.98 ± 1.5 versus 1.46 ± 1.02 in the 6 months post-inotropes (p 0.04). Eleven patients had PICC line infections and 10 patients had VT or VF (8 had prior VT/VFib) needing ICD discharge but none significant enough to stop inotrope therapy. The median post-LVAD length of stay was 17 compared to national median of 18 days. Conclusion Advanced HF patients in cardiogenic shock can be safely managed on ambulatory inotrope therapy and it can be a successful bridge to LVAD/transplant.

RANCANG BANGUN PERANGKAT PEMBANGKIT PWM BIPOLAR

Electrical power settings, both AC and DC can be done by linear or switching. Controlled loads may be motors, heating elements or incandescent lamps. Generally the efficiency of load power control by way of switching is better than linear way so the way switching is widely used today. Switching also allows for automatic, remote and wireless control In load power management system with microcontroller, PWM generator circuit output is used for control of power switch. The output pulse can be TTL standard or with lower amplitude and on the control of the H bridge circuit required bipolar PWM with additional dead band on each side of the pulse ride. The bipolar PWM generator designed in this study has an output with TTL standard with a dead band circuit and a short circuit protection for VCC = 5 volts and a ground path, Testing with no load and short circuit in low and high output states is as follows. VOL(min) = 0.4 volts, VOH(max) = 4.2 volts. The short circuit of output to high GND is 100 mA and short circuit current to VCC path at low output is 90 mA, The output frequency of bipolar pulses is, 50, 100, 1k, 10k and 20k Hz with 10μs dead band

Cardiac Output Monitoring in Preterm Infants.

Maintaining optimal circulatory status is a key component of preterm neonatal care. Low-cardiac output (CO) in the preterm neonate leads to inadequate perfusion of vital organs and has been linked to a variety of adverse outcomes with heightened acute morbidity and mortality and adverse neurodevelopmental outcomes. Having technology available to monitor CO allows us to detect low-output states and potentially intervene to mitigate the unwanted effects of reduced organ perfusion. There are many technologies available for the monitoring of CO in the preterm neonatal population and while many act as useful adjuncts to aid clinical decision-making no technique is perfect. In this review, we discuss the relative merits and limitations of various common methodologies available for monitoring CO in the preterm neonatal population. We will discuss the ongoing challenges in monitoring CO in the preterm neonate along with current gaps in our knowledge. We conclude by discussing emerging technologies and areas that warrant further study.

Identifying Risk and Management of Acute Haemodynamic Decompensation During Catheter Ablation of Ventricular Tachycardia

Radiofrequency catheter ablation (CA) has an established role in the management of patients with structural heart disease presenting with recurrent ventricular tachycardia (VT). Due to the complex underlying substrate, high burden of comorbidities and concomitant heart failure (HF) status, these patients may be at higher risk of periprocedural complications. The prolonged low-output state related to VT induction and mapping, as well as the fluid overload due to irrigated CA and the use of general anaesthesia, may decompensate the HF status, leading to multiple-organ failure and increase in early post-procedural mortality. Proper identification of patients at high risk of periprocedural acute haemodynamic decompensation (AHD) has important implications in terms of procedural planning (i.e. prophylactic use of mechanical assistance devices) and pre-procedural management in order to optimise the HF status. In the present manuscript we focus on the clinical predictors of AHD and the strategies to improve pre-procedural risk stratification, as well as the evidence supporting the use of haemodynamic support during CA procedures.

Management of Complex Ventricular Arrhythmias in Heterotopic Heart Transplant Patients

A 55-year-old woman was admitted with palpitations on a background of heterotopic heart transplantation 13 years earlier. Prior to transplant, a dual-chamber permanent pacemaker was implanted in her native heart for a severe ischaemic cardiomyopathy with a left ventricular ejection fraction of 5%. Post-transplant, our patient's donor heart had been affected by both allograft vasculopathy requiring percutaneous coronary intervention and one episode of cellular rejection. Her current donor left ventricular ejection fraction was 40%. Our patient's palpitations were identified as recurrent episodes of native heart ventricular tachycardia lasting up to 21 hours at rates of 180 beats per minute. Direct cardioversion to the native heart was performed twice, unsuccessfully. Amiodarone infusion also failed to control the burden of ventricular tachycardia. Lignocaine was then added, but at this point the patient developed bradycardia in the donor heart. In the setting of competing native tachycardia and donor bradycardia, our patient developed cardiogenic shock due to her doubly low-output state. Further cardioversion to the native heart was considered too high risk given the new donor bradycardia. A dual-chamber permanent pacemaker was implanted into the donor heart. Anti-tachycardic therapy was optimised to bisoprolol, oral amiodarone, and mexiletine. With aggressive anti–arrhythmic therapy, ventricular arrhythmias in the native heart ceased while the donor heart was supported with pacing. This is the first report of double dual-chamber pacemakers being implanted in a heterotopic heart transplant recipient to treat complex competing arrhythmias. This case emphasises the difficult balance of controlling two connected cardiomyopathic hearts developing conflicting arrhythmias.

Safety and Feasibility of the Transcatheter Approach to Create a Reverse Potts Shunt in Children With Idiopathic Pulmonary Arterial Hypertension

BackgroundThe reversed Potts shunt improves right ventricular (RV) function in patients with suprasystemic pulmonary arterial hypertension (PAH). The proximity of the left pulmonary artery (LPA) to the descending aorta (DAo) permits the creation of a transcatheter connection. We sought to assess the safety, feasibility, and hemodynamic efficacy of the transcatheter Potts shunt (TPS) in children. MethodsThe TPS procedure was performed using radiofrequency energy for vessel perforation and deployment of a covered stent to connect the DAo and LPA. Procedural details and clinical follow-up data were collected prospectively. ResultsA TPS was successfully created in 6 children (mean age, 11.0 ± 4.2 years) with drug-refractory suprasystemic PAH and deteriorating RV function. All patients exhibited nearly complete equalization of aortic and pulmonary pressures and improvement in RV contractility within days after TPS placement. Two patients with pre-existing severe biventricular dysfunction and pericardial effusion experienced acute low-output states immediately after shunt creation because of sudden reductions in left ventricular (LV) preload, resulting in cardiac arrest, irreversible brain damage, and death. Stent dislodgement and embolization into the iliac artery occurred in 1 patient. The stent was successfully secured and followed by placement of a second stent at the target location. The procedure was uncomplicated in 4 patients, who remain alive after a mean follow-up of 10 ± 2.6 months. Intravenous vasodilator therapy was weaned uneventfully after TPS in 3 patients. ConclusionsTPS creation in children is feasible and results in hemodynamic improvement. Further insights into high-risk markers, such as reduced preprocedural LV function and preload reserves, are important for guiding patient selection.

Perioperative management of the patient with diabetes requiring emergency surgery

Perioperative management of the patient with diabetes requiring emergency surgery

Pharmacological approaches to cardio-renal syndrome: a role for the inodilator levosimendan.

Pathological interplay between the heart and kidneys—also known as cardio-renal syndrome (CRS)—is frequently encountered in heart failure and is linked to worse prognosis and quality of life. Drug therapies for this complex situation may include nitroprusside or the recombinant B-type natriuretic peptide nesiritide for patients with acute CRS with normal or high blood pressure, and inotropes or inodilators for patients with acute CRS with low blood pressure. Clinical data for a renal-protective action of levosimendan are suggestive, and meta-analysis data obtained in a range of low-output states are consistent with a levosimendan-induced benefit. Evidence of favourable organ-specific effects of levosimendan, including pre-glomerular vasodilation and increased renal artery diameter and renal blood flow, were collected both in preclinical and clinical studies. Larger randomized controlled trials are however needed to confirm the renal effects of levosimendan in various clinical settings.

Multisite Tissue Oxygenation Monitoring Indicates Organ-Specific Flow Distribution and Oxygen Delivery Related to Low Cardiac Output in Preterm Infants With Clinical Sepsis.

Cardiac output may be compromised in preterm infants with sepsis. Whether low cardiac output is associated with low tissue oxygen supply in these patients is unclear. The aim of the current study was to assess the association between cardiac output, assessed by echocardiography, and tissue oxygenation, measured with multisite near-infrared spectroscopy, in a cohort of preterm infants with clinical sepsis. Prospective observational cohort study. Level III neonatal ICU. Twenty-four preterm infants (gestational age < 32 wk) with clinical sepsis. None. Clinical and echocardiographic assessment of hemodynamics was performed within 48 hours of sepsis workup and repeated at least 24 hours later. We measured cerebral, renal, and intestinal tissue oxygen saturation using near-infrared spectroscopy during an hour of stable measurements directly preceding or following echocardiography and calculated fractional tissue oxygen extraction in each tissue. We determined Spearman correlation coefficients between fractional tissue oxygen extraction and right ventricular output corrected for patent foramen ovale flow, left ventricular output corrected for ductus arteriosus flow, and superior vena cava flow. Right ventricular output corrected for patent foramen ovale and left ventricular output corrected for ductus arteriosus flow both correlated significantly with intestinal fractional tissue oxygen extraction (ρ, -0.700; p = 0.036 and ρ, -0.604; p = 0.029, respectively). In contrast, no significant correlations were found between cardiac output measurements and cerebral and renal fractional tissue oxygen extraction, respectively. Changes in cardiac output measurements were not associated with observed changes in fractional tissue oxygen extraction values. Right ventricular output corrected for patent foramen ovale and left ventricular output corrected for ductus arteriosus flow, indicators of systemic blood flow in preterm infants with shunts, were negatively associated with intestinal fractional tissue oxygen extraction, but not with renal and cerebral fractional tissue oxygen extraction. These findings suggest that during low output states due to clinical sepsis intestinal perfusion is most at risk.

Primary Cardiac Tumors in Infants and Children: Surgical Strategy and Long-Term Outcome

Primary cardiac tumors in infants and children are extremely rare; hence, there is very little literature available, and most knowledge is based on collections of case reports. This report is a comprehensive review of our 26-year experience with primary cardiac tumors in children with emphasis on surgical indications, strategies, and long-term outcome. Between 1986 and 2012, 47 children (mean age 5.9 ± 2.4 months; range, 1 day to 17 years) underwent either subtotal or total resection of cardiac tumors (rhabdomyoma, 13; fibroma, 12; teratoma, 9; myxoma, 8; hemangioma, 2; rhabdomyosarcoma, 1; non-Hodgkin's lymphoma, 1; lymphangioma, 1). The majority were diagnosed by echocardiography (n= 33). Clinical patterns were varied: 40 had an atypical heart murmur and 6 were asymptomatic. Outflow tract obstruction of more than 30 mm Hg was present in 11 children. Three patients had abnormal coronary arteries secondary to pressure from tumor bulk. Indications of resection were hemodynamic/respiratory compromise, severe arrhythmia, and asignificant embolization risk. Strategy of resection varied according to location and hemodynamic status without damage to adjacent structures. Morbidity included bleeding in a patient and a transient low output state in another. A 5-month-old infant with left ventricular fibroma underwent left ventricular assist device implantation secondary to failure from weaning off cardiopulmonary bypass, and she eventually underwent heart transplantation 17 days later. Early mortality (n= 2, 4.2%) included a 5-month-old infant who underwent complete resection of rhabdomyoma located in the left ventricle, with concomitant pulmonary valve replacement; unfortunately, he underwent left ventricular assist device implantation for postoperative heart failure and died on the 13th postoperative day. An8-month-old child with 3 cm× 4 cm fibroma obstructing the right ventricular outflow tract compressing the right coronary artery died of severe right-side heart failure on the 13th postoperative day. One late death (2.1%) occurred; a 16-year-old with non-Hodgkin's lymphoma died 7 months after the surgery. Mean duration of follow-up is 11.6 ± 3.5 years. All survivors (93.4%) are well, free of tumor-related symptoms and tumor recurrence/progression, even when resection was incomplete. This study illustrates that although primary cardiac tumors in infants and children have a wide and unusual spectrum of clinical presentation, an individualized approach to tumor resection allows restoration of an adequate hemodynamic function and satisfactory long-term, tumor-free outcome.

Prolonged chest compressions during cardiopulmonary resuscitation for in-hospital cardiac arrest due to acute pulmonary embolism.

Patients with hemodynamic collapse due to acute pulmonary embolism have a dismal prognosis if not treated rapidly. Therapeutic options include systemic thrombolytic therapy, rheolytic thrombectomy, and surgical embolectomy. However, the efficacy of thrombolytic therapy is diminished because the low-output state hinders effective delivery of the lytic agent to the thrombus. In the absence of any form of mechanical circulatory support, such as extracorporeal membrane oxygenation or cardiac surgery on site, we think that prolonged vigorous manual compressions might be the only way to support the circulation during the initial critical state, when thrombolytic therapy has been administered. We report the results of prolonged manual chest compressions (exceeding 30 minutes) on 6 patients who received tenecteplase in treatment of acute pulmonary embolism that induced in-hospital cardiopulmonary arrest. Four of 6 patients survived and were discharged from the hospital. In an era of increasing technologic complexity for patients with hemodynamic instability, we emphasize the importance of prolonged chest compressions, which can improve systemic perfusion, counteract the prothrombotic state associated with cardiopulmonary arrest, and give the lytic agent time to act.

Pediatric cardiogenic shock: Current perspectives

Cardiogenic shock is a pathophysiologic state where an abnormality of cardiac function is responsible for the failure of the cardiovascular system to meet the metabolic needs of the body tissues.Though it is less common than hypovolemia as the primary etiology in paediatric shock, eventually myocardial function is affected because of reduced perfusion in all forms of shock. Myocardial malfunction, in other forms of shock, is secondary to ischemia, acidosis, drugs, toxins or inflammation. Cardiogenic shock is a low output state characterized by elevated filling pressures, neurohormonal activation with the evidence of end-organ hypoperfusion. The management is challenging and consists of a combination of conventional cardio-respiratory support, vasoactive medications with correction of the anatomic cardiac defects. Treatment options like Extracorporeal membrane oxygenation and Ventricular assist devices provide a bridge to recovery, surgery or transplant. As cardiogenic shock in children carries a high risk of morbidity and mortality, emphasis should be placed on expedient management to arrest the pathophysiological cascade and avoid hypotension.This article aims to review the aetio-pathophysiological basis of pediatric cardiogenic shock, diagnostic options, recent advances in management modalities and outcome.

Aortic Ballon Valvuloplasty Is Still A Valuable Option For High Risk Patients With Severe Aortic Stenosis Before Surgery For Hip Fracture

Aortic Ballon Valvuloplasty is still a Valuable Option for High Risk Patients with Severe Aortic Stenosis before Surgery for Hip Fracture Early treatment of hip fracture in the elderly has been reported to increase long-term survival and favor functional recovery. Comorbidities are common in this population and may negatively affect survival after surgery. Severe aortic stenosis has been reported in 5-10% of patients with hip fracture. Patients with low left ventricular ejection fraction and subject with other severe comorbidities are at particular high risk when they need to undergo major non cardiac surgery. In aortic stenosis hip surgery, a high bleeding risk condition, 9 a, may be associated with a severe lowoutput state. In patients who require urgent major non-cardiac surgery balloon aortic valvuloplasty may decrease pressure overload and perioperative risk? The procedure is suggested by the recent ESC guidelines (recommendation Class IIb), but not by AHA/ACC guidelines. The two cases of high risk severe aortic stenosis treated with aortic balloon valvuloplasty undergoing thereafter uneventful hip surgery suggest that aortic valve balloon valvuloplasty may still be useful in selected patients.

Acute heart failure: acute cardiorenal syndrome and role of aggressive decongestion.

Congestion and acute renal dysfunction are at the center of acute heart failure (HF) syndromes. Acute cardiorenal syndrome, which refers to worsening of renal function in a patient with acute HF syndrome, is partly related to venous congestion and high renal afterload. Aggressive decongestion improves renal and myocardial flow and ventricular loading conditions, potentially resulting in reduced HF progression, rehospitalization, and mortality. High-dose diuretic therapy remains the mainstay therapy. Ultrafiltration and inotropic therapy are useful in the subgroup of patients with a low-output state and diuretic resistance.

Expanding minimally invasive innovation to complex mitral reoperations.

The increasing familiarity with minimally invasive mitral surgical approaches have enabled the technical progression from sternotomy to mini-sternotomy, from direct vision mini-thoracotomy to video-assisted mini-thoracotomy, and now to a resurgence of robotic-assisted mitral surgery [1]. Maintaining quality outcomes through this step-wise progression is essential. Perfusion and cannula enhancements facilitating non-sternotomy mitral access can be applied safely using conventional cross-clamping and endoballoon aortic occlusion, even in reoperations [2]. Similarly, good outcomes to isolated mitral reoperations can be accomplished via right thoracotomy on the normothermic centrally cannulated beating heart. At our institution, this has become the favoured method to address these complex cases, with the majority of patients extubated immediately postoperatively without blood products. In this issue of the Multimedia Manual of Cardio-Thoracic Surgery, Botta et al. [3] from Milano bravely outline their approach to complex reoperations using a minimally invasive approach on the unclamped aorta. Their experience with 40 patients between 2008 and 2014 showcases their use of moderate hypothermic ventricular fibrillation including an elegantly performed video case example on a 75-year-old patient requiring a fourth time redo operation. Though the average ejection fraction was 50%, their patients were admittedly at high risk with one-quarter having more than one prior cardiac operation, one-third in renal failure and half having undergone prior surgical revascularization. The authors believe that fibrillatory arrest performed between 27 and 28° centigrade for an average time of 95 min with transient flow reductions enabled better valve exposure with minimal dis section while still achieving adequate myocardial protection. However, in this series of complex patients, 10% (4/40) had low output states requiring intra-aortic balloon pump assistance, 7.5% (3/40) had a cerebrovascular event, the majority were transfused and there was a 10% (4/40) in-hospital operative mortality. Whether centrally or peripherally cannulated, the use of fibrilla tory arrest under moderate hypothermia for redo mitral operations remains popular in selected experienced centres. As demon strated by the authors, this may indeed be a useful tool in certain cases where surgical courage is called upon to navigate otherwise very complex patients through a mitral reoperation. While fibrillatory arrest can be useful, history recounts that even with hypothermia, the ventricular subendocardium may be suboptimally protected when the perfusion pressure is reduced to the levels used in clinical cardiac surgery [4]. The reduced wall stress and myocardial demands from an empty beating heart or arrested heart may continue to have a role in these complex operations. Moreover, the use of CT angiographic mapping preoperatively, as done by the authors, is essential to avoid complications of femoral cannulation in mitral reoperations [1, 5]. Botta et al. have provided us with a progressive approach to add to the armamentarium of high-risk mitral reoperations. However, as programmes attempt these cases for the first time, the use of outcome-focused patient-specific alternate cannulation and perfusion strategies should still be considered. Attention to safety and quality should always be kept at the forefront as we expand the application of technical innovation to a broader array of patients.