Myocardial Dysfunction and Shock after Cardiac Arrest

The Relationship Between Heart Rate and Left Ventricular Isovolumic Relaxation During Normoxia and Hypoxia-Asphyxia in Newborn Piglets

Background: Many asphyxiated neonates have cardiac complications including arrhythmia and contractile dysfunction. Little is known about the relationship between heart rate (HR) and diastolic function in asphyxiated neonates. We aimed to study the relationship between HR and left ventricular (LV) isovolumic relaxation (IVR) in neonates with asphyxia using a swine model.

Methods: Term newborn piglets were anesthetized and acutely instrumented with the placement of Millar^® catheter in the left ventricle. Hemodynamic parameters including HR, cardiac output, stroke volume, dP/dt_max and dP/dt_min, and IVR time constant (Tau) were continuously measured and recorded. Sixteen piglets were exposed to 50-minute normocapnic hypoxia followed by asphyxia (mean of 3.2 min) by clamping of the endotracheal tube. Sham-operated piglets (n = 11) had no hypoxia nor asphyxia. The relationship between HR and other hemodynamic parameters were analyzed using Pearson Product Moment correlation test.

Results: Asphyxiated piglets had cardiogenic shock and metabolic acidosis (vs. sham-operated piglets). There were significant correlations between HR and diastolic function as shown by Tau at baseline (sham-operated: r = -0.68, p = 0.02; asphyxia: r = -0.55, p = 0.03) and during normoxia (53 min) of sham-operated piglets (r = -0.69, p = 0.02). HR and Tau was not correlated during hypoxia-asphyxia (HA) (r = -0.01, p = 0.97). Cardiac output was tightly correlated with stroke volume (p < 0.001) but not HR throughout the experimental period in both groups. There was no significant correlation between HR and other hemodynamic parameters during the experimental period in both groups.

Conclusion: We observed an uncoupling between HR and IVR Tau of the neonatal heart during HA, which deserves further studies of the relationship between HR and LV diastolic function.

The roles of oxidative stress and Beclin-1 in the autophagosome clearance impairment triggered by cardiac arrest

During cardiac arrest and return of spontaneous circulation (CA-ROSC), autophagosome clearance in the cortex is progressively impaired, but the role of reactive oxygen species (ROS) in this process and the mechanism underlying the autophagy impairment remain unknown. In this study, we investigated the impacts of ROS on the autophagy-lysosome pathway after CA-ROSC in rats. Cortices from CA-ROSC rats revealed accumulation of LC3, p62 and ubiquitin, indicating impaired autophagic flux. Furthermore, impairment of autophagic flux was related to lysosomal lesion, as indicated by decreased cathepsin D and lysosomal-associated membrane protein 2 (LAMP2) levels after CA-ROSC. In vitro, the resulting ROS generation blocked autophagosome processing and caused accumulation of LC3-II, ubiquitin, and p62, leading to mitochondrial dysfunction and cell death; this outcome was alleviated by cyclosporine A (CsA) pretreatment. Interestingly, ischemia/reperfusion injury was connected with ROS-mediated Beclin-1 upregulation and a reduction in LAMP2, which is a pivotal protein in the autophagy-lysosome pathway. Recovery of the LAMP2 levels and partial Beclin-1 silencing restored the autophagic flux and reduced cell death after CA-ROSC. Taken together, our data indicate that CA-ROSC injury impairs autophagosome clearance partially through a ROS-induced decline in LAMP2 and increase in Beclin-1, leading to increased neuronal cell death.

Paracrine Mechanisms Involved in Mesenchymal Stem Cell Differentiation into Cardiomyocytes

Cardiovascular Disease (CVD) is one of the world-wide healthcare problem that involves the heart or blood vessels. CVD includes myocardial infarction and coronary artery diseases (CAD). Dysfunctional myocardial cells are leading causes of low cardiac output or ventricular dysfunction after cardiac arrest and may contribute to the progression of CVD which could not generate new cardiomyocytes in human adult heart. The mesenchymal stem cells (MSCs) which are present in adult marrow can self-renew and have the capacity of differentiation into multiple types of cells including cardiomyocytes. Recent biochemical analyses greatly revealed that several regulators of MSCs, such as HGF, PDGF, Wnt, and Notch-1 signaling pathways have been shown to be involved in the proliferation and differentiation into cardiomyocytes. Preclinical studies are paving the way for further applications of MSCs in the repair of myocardial infarction. In this study, we discuss and summarize the paracrine mechanisms involved in MSCs differentiation into cardiomyocytes.

Change in myocardial function after resuscitated sudden cardiac arrest and its impact on long-term mortality and defibrillator implantation

Background

The impact of left ventricular ejection fraction (LVEF) changes after sudden cardiac arrest (SCA) on implantable defibrillator (ICD) utilization and long-term survival is not known. We therefore evaluated the influence of LVEF on these parameters in SCA survivors.

Methods

Data were collected on consecutive SCA survivors who had ≥1 echocardiogram after SCA and who survived to hospital discharge (n = 655). The median time from baseline to first follow-up echocardiogram was 162 days. LVEF ≥50% was defined as normal. Patients were classified into 4 groups according to baseline (LVEFb) and follow-up (LVEFf) myocardial function: normal LVEFb and LVEFf (group1, n = 261); reduced LVEFb and normal LVEFf (group 2, n = 104); normal LVEFb but reduced LVEFf (group 3, n = 41); and reduced LVEFb and LVEFf (group 4, n = 249). All-cause mortality and time to ICD implantation were examined in all groups.

Results

Over a median follow up of 4.3 years, death occurred in 279 (42%) of patients. Compared with patients in group 1, patients with any reduced LVEF at any time (groups 2–4) had significantly higher mortality, even after adjusting for unbalanced covariates (HR = 1.44, 95.0% CI 1.05–1.95, p = 0.022). ICDs were most commonly implanted in patients with persistently reduced LVEF (group 4: HR = 1.72, 95% CI = 1.26–2.35, p = 0.001).

Conclusion

We demonstrate that, in survivors of SCA, a reduced LVEF at or after the index event is associated with higher mortality but that patients with persistently reduced LVEF were most likely to receive ICD therapy. These findings have implications on the management of SCA survivors.

Repetitive anodal transcranial direct current stimulation improves neurological outcome and survival in a ventricular fibrillation cardiac arrest rat model

BACKGROUND

Transcranial direct current stimulation (tDCS) modulates neuronal activity and is a potential therapeutic tool for many neurological diseases. However, its beneficial effects on post cardiac arrest syndrome remains uncertain.

OBJECTIVE/HYPOTHESIS

We investigated the effects of repetitive anodal tDCS on neurological outcome and survival in a ventricular fibrillation (VF) cardiac arrest rat model.

METHODS

Cardiopulmonary resuscitation was initiated after 6 min of VF in 36 Sprague-Dawley rats. The animals were randomized into three groups immediately after resuscitation (n = 12 each): no-treatment control (NTC) group, targeted temperature management (TTM) group, and tDCS group. For tDCS, 1 mA anodal tDCS was applied on the dorsal scalp for 0.5 h. The stimulation was repeated for four sessions with 1-h resting interval under normothermia. Post-resuscitation hemodynamic, cerebral, and myocardial injuries, 96-h neurological outcome, and survival were evaluated.

RESULTS

Compared with the NTC group, post-resuscitation serum astroglial protein S100 beta and cardiac troponin T levels and 96-h neuronal and myocardial damage scores were markedly reduced in the tDCS and TTM groups. Myocardial ejection fraction, neurological deficit score, and 96-h survival rate were also significantly better for the tDCS and TTM groups. The period of post-resuscitation arrhythmia with hemodynamic instability was considerably shorter in the tDCS group, but no differences were observed in neurological outcome and survival between the tDCS and TTM groups.

CONCLUSIONS

In this cardiac arrest rat model, repeated anodal tDCS commenced after resuscitation improves 96-h neurological outcome and survival to an extent comparable to TTM by attenuating post-resuscitation cerebral and cardiac injuries.

Prevalence of Torsades de Pointes inducing drugs usage among elderly outpatients in North Jordan Hospitals

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Demonstrating the urgent need for increasing awareness of TdP's risk induced by chronically used medications.

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The importance of establishing an extensive pharmaceutical care for geriatric population with the aim of improving health outcomes and quality of life in elderly patients.

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To identify the major risk factors associated with increasing the incidence of TdP’s among geriatric patients in Jordan.

Background

Torsade de Pointes (TdP) is an abnormal cardiac rhythm associated with a prolongation of QT interval. Although in most cases it spontaneously returns to the normal rhythm, TdP can lead to sudden cardiac death. Medications are the main cause of QT-prolongation and subsequent TdP flare, even though the exact mechanism of why some people evoke TdP but others do not is still unknown. It is evident that elderly patients are more susceptible to experience drug's side effects especially with chronically used medications.

Objectives

To describe the pattern of prescribing drugs with risk of Torsade’s de Pointes among elderly patients who were visiting different outpatient clinics in North Jordan Hospitals.

Methods

All patients who were aged ≥65 years old and were visiting outpatient clinics in King Abdullah University Hospital (KAUH) and Princess Basma Hospital (PBH) through December 2016 were included in the study. A total of 5319 patients’ dispending records were collected and analyzed for the prevalence of drug-induced TdP using both Microsoft Excel and the SPSS statistical software.

Results

A total of 5319 patients were included in the study, more than half (58.5%, n = 3114) of patients were consuming drugs with risk of TdP. Almost half (49.4%, n = 1539) of these patients were women. The majority of patients (62.3%, n = 1939) were using only one drug with TdP risk. However, other patients were found to take five or six different TdP-inducing drugs. Excluding age and gender, 94.3% (n = 2937) of patients who were using TdP-inducing drugs had at least one additional risk factor of inducing TdP.

Conclusion

High usage of TdP-inducing drugs among geriatric patients in North Jordan demonstrated the urgent need for increasing awareness of TdP’s risk induced by commonly prescribed medications.

Markers of cardiogenic shock predict persistent acute kidney injury after out of hospital cardiac arrest

OBJECTIVE

Ischemia and reperfusion injury (IRI) in cardiac arrest patients after return to spontaneous circulation causes dysfunctions in multiple organs. Kidney injury is generally transient but in some patients persists and contributes both to mortality and increased resource utilisation. Ongoing shock may compound renal injury from IRI, resulting in persistent dysfunction. We tested whether cardiac dysfunction was associated with the development of persistent acute kidney injury (PAKI) in the first 72 h after cardiac arrest.

METHODS

We performed an observational retrospective study from January 2013 to April 2017. We included consecutive patients treated after out-of-hospital cardiac arrest at a single academic medical center with renal function measured and immediately and for 48 h post arrest. We also recorded each patient's pre arrest baseline creatinine, demographic and clinical characteristics. Our primary outcome of interest was PAKI, defined as acute kidney injury (AKI) on at least 2 measurements 24 h apart. We compared demographics and outcomes between patients with PAKI and those without, and used logistic regression to identify independent predictors of PAKI.

RESULTS

Of 98 consecutive patients, we excluded 24 for missing data. AKI was present in 75% of subjects on arrival. PAKI developed in 35% of patients. PAKI patients had a longer hospital length of stay (median 21 vs 11 days) and lower hospital survival (47% vs 71%). Serum lactate levels, dosage of adrenaline during resuscitation and days of dobutamine infusion strongly predicted PAKI.

CONCLUSIONS

Among patient who survive cardiac arrest, acute AKI is common and PAKI occurs in more than one third. PAKI is associated both with survival and with length of stay at the hospital. High doses of adrenaline, high serial serum lactate levels, and dose of dobutamine predict PAKI. Evaluation of the trajectory of renal function over the first few days after resuscitation can provide prognostic information about patient recovery.

Extracorporeal organ support (ECOS) in critical illness and acute kidney injury: from native to artificial organ crosstalk

The complex nature of single organ failure potentially leading to multiple organ dysfunction syndrome (MODS) in critically ill patients necessitates integrated supportive therapy. Rather than a primary disease, acute kidney injury (AKI) is considered a window to a potentially serious underlying systemic disease, which may partially explain the high morbidity and mortality rates associated with the condition. Renal replacement therapy (RRT) has been routinely used for more than a decade in various intensive care settings and there has also been an increase in the use of extracorporeal membrane oxygenation and extracorporeal carbon dioxide removal. When these renal and cardiopulmonary modalities are used together, a multidisciplinary approach is necessary to minimize negative interactions and unwanted adverse effects. In this review, we describe the patterns of organ crosstalk between the native and artificial organs, the incidence of AKI and need for RRT and associated mortality after extracorporeal organ support (ECOS) therapy, including the potential short- and long-term advantages and disadvantages of organ support in terms of renal function. We also review potential indications of RRT outside its conventional indications in patients with MODS, as well as technical considerations when RRT is used alongside other organ support therapies. Overall, available literature has not definitely established the ideal timing of these interventions, and whether early implementation impacts organ recovery and optimizes resource utilization is still a matter of open debate: it is possible that future research will be devoted to identify patient groups that may benefit from short- and long-term multiple organ support.

Echocardiographic left ventricular diastolic dysfunction predicts hospital mortality after out-of-hospital cardiac arrest

PURPOSE

To determine whether systolic or diastolic dysfunction on transthoracic echocardiogram (TTE) predicts mortality after out-of-hospital cardiac arrest (OHCA).

METHODS

Retrospective cohort study of 173 OHCA subjects undergoing targeted temperature management who underwent TTE during hospitalization. Univariate analysis and multivariate logistic regression were used to determine associations between TTE measurements of systolic and diastolic function and systemic hemodynamics with all-cause mortality.

RESULTS

Mean age was 61.6 ± 12.4 years (72.7% male) and initial rhythm was shockable in 89%. Hospital mortality was 30.6%. Mean LVEF was 40% and was not different in hospital survivors (p = 0.81). TTE parameters reflecting systolic function and systemic hemodynamics did not predict hospital mortality. Medial mitral E/e' ratio was associated with hospital mortality, with an optimal cut-off > 13 (p = 0.002). After multivariate adjustment, medial mitral E/e' ratio remained predictive of hospital mortality (OR 1.11, 95% CI 1.03-1.20, p = 0.004). Subjects with a medial mitral E/e' ratio > 13 had higher mortality during long-term follow-up (p < 0.001 by log-rank).

CONCLUSIONS

Diastolic dysfunction (higher medial mitral E/e' ratio) on TTE independently predicted mortality after OHCA; systolic dysfunction and TTE hemodynamic parameters did not. This reflects a novel use of Doppler TTE to predict outcomes after OHCA.

Independent Predictors of 6-Month Mortality in Patients Successfully Resuscitated for Out-of-Hospital Cardiac Arrest: Observational Retrospective Single Center Study

Background

Mortality of admitted out-of-hospital cardiac arrest (OHCA) patients is decreasing. Our aim was to evaluate independent predictors of six-month mortality of successfully resuscitated OHCA patients.

Methods

We reviewed retrospectively the records of 119 OHCA patients, admitted in 2011 to 2013 (73.1% men, mean age 64 ± 13,5 years) and registered their clinical data, treatments, and predictors of 6-month mortality.

Results

Six-month mortality of admitted OHCA patients was 47.5% and was associated significantly with older age (67.7 ± 12.9 years versus 59.9 ± 13 years, p < 0.05), mechanical ventilation, longer time of resuscitation (24.6 ± 18.9 sec versus 8.9 ± 8.4 sec, p < 0.05), use of vasopressors (87.3% versus 62.5%, p < 0.05), and increased serum lactate (8.1 ± 3.9 mmol/l versus 4.5 ± 3.6 mmol/l, p < 0.05) but less likely with prior shockable rhythm (38% versus 73.2%, p < 0.05), percutaneous coronary intervention (27% versus 55.4%, p < 0.05), achieved target temperatures 32°-34°C of mild therapeutic hypothermia (47.6% versus 71.4%, p < 0.05), acute coronary syndromes (31.7% versus 51.8%, p < 0.05), and neurological recovery (4.8% versus 69.6%, p < 0.05) when compared to survivors. Neurological outcome was most significant early independent predictor of 6-month mortality (OR 50.47; 95% CI 6.74 to 377.68; p < 0.001).

Conclusions

Postcardiac arrest brain injury most significantly and independently predicted 6-month mortality in hospitalized OHCA patients.

Impact of Different Serum Potassium Levels on Postresuscitation Heart Function and Hemodynamics in Patients with Nontraumatic Out-of-Hospital Cardiac Arrest

Background

Sustained return of spontaneous circulation (ROSC) can be initially established in patients with out-of-hospital cardiac arrest (OHCA); however, the early postresuscitation hemodynamics can still be impaired by high levels of serum potassium (hyperkalemia). The impact of different potassium levels on early postresuscitation heart function has remained unclear. We aim to analyze the relationship between different levels of serum potassium and postresuscitation heart function during the early postresuscitation period (the first hour after achieving sustained ROSC).

Methods

Information on 479 nontraumatic OHCA patients with sustained ROSC was retrospectively obtained. Measures of early postresuscitation heart function (rate, blood pressure, and rhythm), hemodynamics (urine output and blood pH), and the duration of survival were analyzed in the case of different serum potassium levels (low: <3.5; normal: 3.5–5; high: >5 mmol/L).

Results

Most patients (59.9%, n = 287) had previously presented with high levels of potassium. Bradycardia, nonsinus rhythm, urine output <1 ml/kg/hr, and acidosis (pH < 7.35) were more common in patients with high levels of potassium (all p < 0.05). Compared with hyperkalemia, a normal potassium level was more likely to be associated with a normal heart rate (OR: 2.97, 95% CI: 1.74–5.08) and sinus rhythm (OR: 2.28, 95% CI: 1.45–3.58). A low level of potassium was more likely to be associated with tachycardia (OR: 3.54, 95% CI: 1.32–9.51), urine output >1 ml/kg/hr (OR: 5.35, 95% CI: 2.58–11.10), and nonacidosis (blood pH >7.35, OR: 7.74, 95% CI: 3.78–15.58). The duration of survival was shorter in patients with hyperkalemia than that in patients whose potassium levels were low or normal (p < 0.05).

Conclusion

Early postresuscitation heart function and hemodynamics were associated with the serum potassium level. A high potassium level was more likely to be associated with bradycardia, nonsinus rhythm, urine output <1 ml/kg/hr, and acidosis. More importantly, a high potassium level decreased the duration of survival.

Erythropoietin alleviates post-resuscitation myocardial dysfunction in rats potentially through increasing the expression of angiotensin II receptor type 2 in myocardial tissues

Activation of renin-angiotensin system (RAS) is one of the pathological mechanisms associated with myocardial ischemia-reperfusion injury following resuscitation. The present study aimed to determine whether erythropoietin (EPO) improves post‑resuscitation myocardial dysfunction and how it affects the renin‑angiotensin system. Sprague‑Dawley rats were randomly divided into sham, vehicle, epinephrine (EP), EPO and EP + EPO groups. Excluding the sham group, all groups underwent cardiopulmonary resuscitation (CPR) 4 min after asphyxia‑induced cardiac arrest (CA). EP and/or EPO was administrated by intravenous injection when CPR began. The results demonstrated that the vehicle group exhibited lower mean arterial pressure, left ventricular systolic pressure, maximal ascending rate of left ventricular pressure during left ventricular isovolumic contraction and maximal descending rate of left ventricular pressure during left ventricular isovolumic relaxation (+LVdP/dt max and ‑LVdP/dt max, respectively), and higher left ventricular end‑diastolic pressure, compared with the sham group following return of spontaneous circulation (ROSC). Few significant differences were observed concerning the myocardial function between the vehicle and EP groups; however, compared with the vehicle group, EPO reversed myocardial function indices following ROSC, excluding‑LVdP/dt max. Serum renin and angiotensin (Ang) II levels were measured by ELISA. The serum levels of renin and Ang II were significantly increased in the vehicle group compared with the sham group, which was also observed for the myocardial expression of renin and Ang II receptor type 1 (AT1R), as determined by reverse transcription‑quantitative polymerase chain reaction and western blotting. EPO alone did not significantly reduce the high serum levels of renin and Ang II post-resuscitation, but changed the protein levels of renin and AT1R expression in myocardial tissues. However, EPO enhanced the myocardial expression of Ang II receptor type 2 (AT2R) following ROSC. In conclusion, the present study confirmed that CA resuscitation activated the renin‑Ang II‑AT1R signaling pathway, which may contribute to myocardial dysfunction in rats. The present study confirmed that EPO treatment is beneficial for protecting cardiac function post‑resuscitation, and the roles of EPO in alleviating post‑resuscitation myocardial dysfunction may potentially be associated with enhanced myocardial expression of AT2R.

In vivo opening of the mitochondrial permeability transition pore in a rat model of ventricular fibrillation and closed-chest resuscitation

Opening of the mitochondrial permeability transition pore (mPTP) is considered central to reperfusion injury. Yet, most of our knowledge comes from observations in isolated mitochondria, cells, and organs. We used a rat model of ventricular fibrillation (VF) and closed-chest resuscitation to examine whether the mPTP opens in vivo and whether cyclosporine A (CsA) attenuates the associated myocardial injury. Two series of 26 and 18 rats each underwent 10 minutes of untreated VF before attempting resuscitation. In series-1, rats received 50 µCi of tritium-labeled 2-deoxyglucose ([³H]DOG) harvesting their hearts at baseline (n=5), during VF (n=5), during resuscitation (n=6), and at post-resuscitation 60 minutes (n=5) and 240 minutes (n=5). mPTP opening was estimated measuring the ratio of mitochondria to left ventricular intracellular [³H]. In series-2, rats received 10 mg/kg of CsA or vehicle before resuscitation, measuring mitochondrial NAD⁺ content to indirectly assess mPTP opening. In Series-1, the mPTP opening ratio vs baseline (10.4 ± 1.9) increased during VF (16.8 ± 2.4, NS), closed-chest resuscitation (20.8 ± 6.3, P<0.05), and at post-resuscitation 60 minutes (20.9 ± 4.7, P<0.05) and 240 minutes (25.7 ± 11.0, P<0.01). In series 2, CsA failed to attenuate reductions in mitochondrial NAD⁺ and did not affect plasma cytochrome c, plasma cardiac troponin I, myocardial function, and survival. We report for the first time in an intact rat model of VF that mPTP opens during closed-chest resuscitation consistent with previous observations in mitochondria, cells, and organs of mPTP opening upon reperfusion. CsA, at the dose of 10 mg/kg neither prevented mPTP opening nor attenuated post-resuscitation myocardial injury.

Neurologic Recovery After Cardiac Arrest: a Multifaceted Puzzle Requiring Comprehensive Coordinated Care

OPINION STATEMENT

Surviving cardiac arrest (CA) requires a longitudinal approach with multiple levels of responsibility, including fostering a culture of action by increasing public awareness and training, optimization of resuscitation measures including frequent updates of guidelines and their timely implementation into practice, and optimization of post-CA care. This clearly goes beyond resuscitation and targeted temperature management. Brain-directed physiologic goals should dictate the post-CA management, as accumulating evidence suggests that the degree of hypoxic brain injury is the main determinant of survival, regardless of the etiology of arrest. Early assessment of the need for further hemodynamic and electrophysiologic cardiac interventions, adjusting ventilator settings to avoid hyperoxia/hypoxia while targeting high-normal to mildly elevated PaCO₂, maintaining mean arterial blood pressures >65 mmHg, evaluating for and treating seizures, maintaining euglycemia, and aggressively pursuing normothermia are key steps in reducing the bioenergetic failure that underlies secondary brain injury. Accurate neuroprognostication requires a multimodal approach with standardized assessments accounting for confounders while recognizing the importance of a delayed prognostication when there is any uncertainty regarding outcome. The concept of a highly specialized post-CA team with expertise in the management of post-CA syndrome (mindful of the brain-directed physiologic goals during the early post-resuscitation phase), TTM, and neuroprognostication, guiding the comprehensive care to the CA survivor, is likely cost-effective and should be explored by institutions that frequently care for these patients. Finally, providing tailored rehabilitation care with systematic reassessment of the needs and overall goals is key for increasing independence and improving quality-of-life in survivors, thereby also alleviating the burden on families. Emerging evidence from multicenter collaborations advances the field of resuscitation at an incredible pace, challenging previously well-established paradigms. There is no more room for "conventional wisdom" in saving the survivors of cardiac arrest.

Recent developments in the management of patients resuscitated from cardiac arrest

Cardiac arrest is the leading cause of death in Europe and the United States. Many patients who are initially resuscitated die in the hospital, and hospital survivors often have substantial neurologic dysfunction. Most cardiac arrests are caused by coronary artery disease; patients with coronary artery disease likely benefit from early coronary angiography and intervention. After resuscitation, cardiac arrest patients remain critically ill and frequently suffer cardiogenic shock and multiorgan failure. Early cardiopulmonary stabilization is important to prevent worsening organ injury. To achieve best patient outcomes, comprehensive critical care management is needed, with primary goals of stabilizing hemodynamics and preventing progressive brain injury. Targeted temperature management is frequently recommended for comatose survivors of cardiac arrest to mitigate the neurologic injury that drives outcomes. Accurate neurologic assessment is central to managing care of cardiac arrest survivors and should combine physical examination with objective neurologic testing, with the caveat that delaying neurologic prognosis is essential to avoid premature withdrawal of supportive care. A combination of clinical findings and diagnostic results should be used to estimate the likelihood of functional recovery. This review focuses on recent advances in care and specific cardiac intensive care strategies that may improve morbidity and mortality for patients after cardiac arrest.

The role of cardiac dysfunction in multiorgan dysfunction

PURPOSE OF REVIEW

The aim of this review was to examine the main determinants of cardiac dysfunction in critically ill patients, as well as how a reduction in cardiac performance influences other organ function.

RECENT FINDINGS

Cardiac dysfunction is a frequent complication in critically ill patients and contributes to organ hypoperfusion and poor outcome. Pathophysiological determinants may include a primary ischaemia/reperfusion injury of the heart, effects of systemic inflammatory and adrenergic responses of the body to a variety of acute insults, as well as cardiovascular effects of commonly applied intensive respiratory or haemodynamic treatments. A strict connection exists between cardiac and other organ function, mediated by haemodynamic, humoral, and immune mechanisms. Heart, lungs, kidneys, and other splanchnic organs such as gut and liver influence each other function in a bidirectional way: this organ crosstalk must be regarded as a key aspect in multiorgan dysfunction.

SUMMARY

The heart should never be regarded as an isolated organ. When dealing with cardiac dysfunction, clinicians must consider the underlying pathophysiology, potential myocardial depressant effects of intensive treatments, and the complex interaction with other organ function.

Improving Survival From Cardiac Arrest: A Review of Contemporary Practice and Challenges

Cardiac arrest is a common and lethal condition frequently encountered by emergency medicine providers. Resuscitation of persons after cardiac arrest remains challenging, and outcomes remain poor overall. Successful resuscitation hinges on timely, high-quality cardiopulmonary resuscitation. The optimal method of providing chest compressions and ventilator support during cardiac arrest remains uncertain. Prompt and effective defibrillation of ventricular arrhythmias is one of the few effective therapies available for treatment of cardiac arrest. Despite numerous studies during several decades, no specific drug delivered during cardiac arrest has been shown to improve neurologically intact survival after cardiac arrest. Extracorporeal circulation can rescue a minority of highly selected patients with refractory cardiac arrest. Current management of pulseless electrical activity is associated with poor outcomes, but it is hoped that a more targeted diagnostic approach based on electrocardiography and bedside cardiac ultrasonography may improve survival. The evolution of postresuscitation care appears to have improved cardiac arrest outcomes in patients who are successfully resuscitated. The initial approach to early stabilization includes standard measures, such as support of pulmonary function, hemodynamic stabilization, and rapid diagnostic assessment. Coronary angiography is often indicated because of the high frequency of unstable coronary artery disease in comatose survivors of cardiac arrest and should be performed early after resuscitation. Optimizing and standardizing our current approach to cardiac arrest resuscitation and postresuscitation care will be essential for developing strategies for improving survival after cardiac arrest.

Resveratrol and the mitochondria: From triggering the intrinsic apoptotic pathway to inducing mitochondrial biogenesis, a mechanistic view

BACKGROUND

Mitochondria, the power plants of the cell, are known as a cross-road of different cellular signaling pathways. These cytoplasmic double-membraned organelles play a pivotal role in energy metabolism and regulate calcium flux in the cells. It is well known that mitochondrial dysfunction is associated with different diseases such as neurodegeneration and cancer. A growing body of literature has shown that polyphenolic compounds exert direct effects on mitochondrial ultra-structure and function. Resveratrol is known as one of the most common bioactive constituents of red wine, which improves mitochondrial functions under in vitro and in vivo conditions.

SCOPE OF REVIEW

This paper aims to review the molecular pathways underlying the beneficial effects of resveratrol on mitochondrial structure and functions. In addition, we discuss the chemistry and main sources of resveratrol.

MAJOR CONCLUSIONS

Resveratrol represents the promising effects on mitochondria in different experimental models. However, there are several reports on the detrimental effects elicited by resveratrol on mitochondria.

GENERAL SIGNIFICANCE

An understanding of the chemistry and source of resveratrol, its bioavailability and the promising effects on mitochondria brings a new hope to therapy of mitochondrial dysfunction-related diseases.