Supraventricular arrhythmias in intensive care unit patients: short and long-term consequences

Atrial Fibrillation in Critically Ill Patients: Incidence and Outcomes

BACKGROUND

Atrial fibrillation (AF), either chronic or new onset, is common in critically ill patients. Its epidemiology and relationship with clinical outcomes are poorly known.

OBJECTIVE

To understand the burden of AF in patients admitted to the ICU and its impact on patients' outcomes.

METHODS

This is a single-center, retrospective cohort study evaluating all patients with AF admitted to a non-cardiac intensive care unit over the course of 54 months. Clinical outcomes were evaluated in the short (hospital discharge) and long term (two-year follow-up). The hazard ratio (HR) with 95% CI was computed for the whole population as well as for propensity score-matched patients, with or without AF.

RESULTS

A total of 1357 patients were screened (59.1% male), with a mean age of 75 ± 15.2 years, length of intensive care unit stay of 4.7 ± 5.1 days, and hospital mortality of 26%. A diagnosis of AF was found in 215 patients (15.8%), 142 of whom had chronic AF. The hospital all-cause mortality was similar in patients with chronic or new-onset AF (31% vs. 28.8%, p = 0.779). Patients with AF had higher in-hospital, one-year, and two-year crude mortality (30.2% vs. 22.9%, p = 0.024; 47.9% vs. 35.3%, p = 0.001; 52.6% vs. 38.4%, p < 0.001). However, after propensity score matching (N = 213), this difference was no longer significant for in-hospital mortality (OR: 1.17; 95% CI: 0.77-1.79), one-year mortality (OR: 1.38; 95% CI: 0.94-2.03), or two-year mortality (OR: 1.30; 95% CI: 0.89-1.90).

CONCLUSIONS

In ICU patients, the prevalence of AF, either chronic or new-onset, was 15.8%, and these patients had higher crude mortality. However, after adjustment for age and severity on admission, no significant differences were found in the short- and long-term mortality.

Sepsis as an independent risk factor in atrial fibrillation and cardioembolic stroke

BACKGROUND

Electrolyte balance is an important factor to sustain the homeostasis of human body environment and in sepsis pathogenesis. Many current cohort-based studies have already revealed that electrolyte disorder may intensify sepsis and induce stroke. However, the corresponding randomized controlled trials did not show that electrolyte disorder in sepsis has a harmful effect on stroke.

OBJECTIVES

The aim of this study was to examine the association of genetically sepsis-derived electrolyte disorder with stroke risk using meta-analysis and Mendelian randomization.

RESULTS

In four studies (182,980 patients), electrolyte disorders were compared with stroke incidence in patients with sepsis. The pooled odds ratio (OR) of stroke is 1.79 [95% confidence interval (CI): 1.23-3.06; p < 0.05], which shows a significant association between electrolyte disorder and stroke in sepsis patients. Furthermore, in order to evaluate the causal association between stroke risk and sepsis-derived electrolyte disorder, a two-sample Mendelian randomization (MR) study was conducted. The genetic variants extracted from a genome-wide association study (GWAS) of exposure data that are strongly associated with frequently used sepsis were used as instrumental variables (IVs). Based on the IVs' corresponding effect estimates, we estimated overall stroke risk, cardioembolic stroke risk, and stroke induced by large/small vessels from a GWAS meta-analysis with 10,307 cases and 19,326 controls. As a final step to verify the preliminary MR results, we performed sensitivity analysis using multiple types of Mendelian randomization analysis.

CONCLUSION

Our study revealed the association between electrolyte disorder and stroke in sepsis patients, and the correlation between genetic susceptibility to sepsis and increased risk of cardioembolic stroke, hinting that cardiogenic diseases and accompanying electrolyte disorder interference in due course could help sepsis patients get more benefits in stroke prevention.

Increased long-term mortality following new-onset atrial fibrillation in the intensive care unit: A systematic review and meta-analysis

PURPOSE

We performed a systematic review and meta-analysis to investigate the long-term outcomes of patients who develop new-onset atrial fibrillation (NOAF) during an intensive care unit (ICU) admission.

METHODS

We searched the MEDLINE and EMBASE databases from 2000 to 2022. We included studies of adults based in general ICUs that evaluated long-term outcomes (at least 30 days after hospital discharge) of NOAF. We excluded studies involving patients with a history of atrial fibrillation (AF). We performed risk of bias assessment of the included studies based on a modified Newcastle Ottawa score (NOS). We extracted summary data for long-term outcomes. Where the outcome was reported in three or more studies we pooled effect sizes.

RESULTS

We screened 2206 studies and included 15 studies reporting data from 561,797 patients. Pooled analysis of 4 studies using a random effects model revealed an association between NOAF acquired in an ICU and 90-day mortality (including ICU and hospital mortality) (RR 1.53, 95% CI 1.12-2.08). We also found an association between NOAF and 1-year mortality from 7 studies (RR 1.79, 95% CI 1.65-1.96), which remained when analysing 1-year mortality in hospital survivors (RR 1.72 (95% CI 1.49-1.98).

CONCLUSIONS

In patients who develop NOAF in an ICU, both 90-day and 1-year mortality are increased in comparison to those who do not develop NOAF. Current evidence suggests an increased risk of thromboembolic events after hospital discharge in patients who develop NOAF in an ICU.

Risk factors for new-onset atrial fibrillation during critical illness: A Delphi study

Background

New-onset atrial fibrillation (NOAF) is common during critical illness and is associated with poor outcomes. Many risk factors for NOAF during critical illness have been identified, overlapping with risk factors for atrial fibrillation in patients in community settings. To develop interventions to prevent NOAF during critical illness, modifiable risk factors must be identified. These have not been studied in detail and it is not clear which variables warrant further study.

Methods

We undertook an international three-round Delphi process using an expert panel to identify important predictors of NOAF risk during critical illness.

Results

Of 22 experts invited, 12 agreed to participate. Participants were located in Europe, North America and South America and shared 110 publications on the subject of atrial fibrillation. All 12 completed the three Delphi rounds. Potentially modifiable risk factors identified include 15 intervention-related variables.

Conclusions

We present the results of the first Delphi process to identify important predictors of NOAF risk during critical illness. These results support further research into modifiable risk factors including optimal plasma electrolyte concentrations, rates of change of these electrolytes, fluid balance, choice of vasoactive medications and the use of preventative medications in high-risk patients. We also hope our findings will aid the development of predictive models for NOAF.

Meta-Analysis of New-Onset Atrial Fibrillation Versus No History of Atrial Fibrillation in Patients With Noncardiac Critical Care Illness

The incidence of new-onset secondary atrial fibrillation (NOSAF) is as high as 44% in noncardiac critical illness. A systematic review and meta-analysis were performed to evaluate the impact of NOSAF, compared with history of prior atrial fibrillation (AF) and no history of AF in noncardiac critically ill patients. Patients undergoing cardiothoracic surgery were excluded. NOSAF incidence, intensive care unit (ICU)/hospital length of stay (LOS), and mortality outcomes were analyzed. Of 2,360 studies reviewed, 19 studies met inclusion criteria (n = 306,805 patients). NOSAF compared with no history of AF was associated with increased in-hospital mortality (risk ratio [RR] 2.06, 95% confidence interval [CI] 1.76 to 2.41, p <0.001), longer ICU LOS (standardized difference in means [SMD] 0.66, 95% CI 0.41 to 0.91, p <0.001), longer hospital LOS (SMD 0.31, 95% CI 0.07 to 0.56, p = 0.001) and increased risk of long-term (>1 year) mortality (RR 1.76, 95% CI 1.29 to 2.40, p <0.001). NOSAF compared with previous AF was also associated with higher in-hospital mortality (RR 1.29, 95% CI 1.12 to 1.49, p <0.001), longer ICU LOS (SMD 0.37, 95% CI 0.03 to 0.70, p = 0.03) but no difference in-hospital LOS (SMD -0.18, 95% CI -0.66 to 0.31, p = 0.47). In conclusion, NOSAF, in the setting of noncardiac critical illness is associated with increased in-hospital mortality compared with no history of AF and previous AF. NOSAF (vs no history of AF) is also associated with increased long-term mortality.

Association Between Perioperative Atrial Fibrillation and Long-term Risks of Stroke and Death in Noncardiac Surgery: Systematic Review and Meta-analysis

BACKGROUND

Atrial fibrillation (AF) is frequently reported as a complication of noncardiac surgery. It is unknown whether new-onset perioperative AF is associated with an increased risk of stroke and death beyond the perioperative period. We performed a systematic review and meta-analysis to assess the long-term risks of stroke and mortality associated with new-onset perioperative AF after noncardiac surgery.

METHODS

MEDLINE and EMBASE were searched from inception to March 2020 for studies reporting on the association between perioperative AF and the risk of stroke and death occurring beyond 30 days after noncardiac surgery. Reference screening, study selection, data extraction, and quality assessment were performed in duplicate. Data were pooled using inverse variance-weighted random-effects models and presented as risk ratios (RRs).

RESULTS

From 7344 citations, we included 31 studies (3,529,493 patients). The weighted mean incidence of perioperative AF was 0.7%. During a mean follow-up of 28.1 ± 9.4 months, perioperative AF was associated with an increased risk of stroke (1.5 vs 0.9 strokes per 100 patient-years; RR: 2.9, 95% confidence interval [CI]: 2.1-3.9, I2 = 78%). Perioperative AF was also associated with a significantly higher risk of all-cause mortality (21.0 vs 7.6 deaths per 100 patient-years; RR: 1.8, 95% CI: 1.5-2.2, I2 = 94%). The pooled adjusted hazard ratios for stroke and all-cause mortality were 1.9 (95% CI: 1.6-2.2, I2 = 31%) and 1.5 (95% CI: 1.3-1.7, I2 = 20%), respectively.

CONCLUSIONS

Patients who had perioperative AF after noncardiac surgery had a higher long-term risk of stroke and mortality compared with patients who did not. Whether this risk is modifiable with oral anticoagulation therapy should be investigated.

Rhythm-control therapy for new-onset atrial fibrillation in critically ill patients: A post hoc analysis from the prospective multicenter observational AFTER-ICU study

BACKGROUND

Sustained new-onset atrial fibrillation (AF) in the intensive care unit has been reported to be associated with poor outcomes. However, in critical illness, whether rhythm-control therapy can achieve sinus rhythm (SR) restoration is unknown. This study aimed to assess the impact of rhythm-control therapy on SR restoration for new-onset AF in critically ill patients.

METHODS

This post-hoc analysis of a prospective multicenter observational study involving 32 Japan intensive care units compared patients with and without rhythm-control therapy for new-onset atrial fibrillation (AF) and conducted a multivariable analysis using Cox proportional hazards regression analysis including rhythm-control therapy as a time-varying covariate for SR restoration.

RESULTS

Of 423 new-onset AF patients, 178 patients (42%) underwent rhythm-control therapy. Among those patients, 131 (31%) underwent rhythm-control therapy within 6 h after AF onset. Magnesium sulphate was the most frequently used rhythm-control drug. The Cox proportional hazards model for SR restoration showed that rhythm-control therapy had a significant positive association with SR restoration (adjusted hazard ratio: 1.46; 95% confidence interval: 1.16-1.85). However, the rhythm-control group had numerically higher hospital mortality than the non-rhythm-control group (31% vs. 23%, p = 0.09).

CONCLUSIONS

Rhythm-control therapy for new-onset AF in critically ill patients was associated with SR restoration. However, patients with rhythm-control therapy had poorer prognosis, possibly due to selection bias. These findings may provide important insight for the design and feasibility of interventional studies assessing rhythm-control therapy in new-onset AF.

Outcomes of new-onset atrial fibrillation in patients with sepsis: A systematic review and meta-analysis of 225,841 patients

BACKGROUND

The outcomes of new-onset atrial fibrillation (AF) during sepsis are inconsistent and inconclusive. This meta-analysis aims to provide a comprehensive description of the impact of new-onset AF on the prognosis of sepsis.

METHODS

Three electronic databases (PubMed, Embase, and the Cochrane Library) were searched for relevant studies. Meta-analysis was performed using odds ratios (OR) and 95% confidence intervals (CI) as effect measures.

RESULTS

A total of 225,841 patients from 13 individual studies were incorporated to the meta-analysis. The summary results revealed that new-onset AF during sepsis was associated with increased odds of in-hospital mortality (pooled OR: 2.09; 95% CI: 1.53-2.86; p < 001), post-discharge mortality (pooled OR: 2.44; 95% CI: 1.81-3.29; p < .001), and stroke (pooled OR:1.88; 95% CI: 1.13-3.14; p < .05). Results also indicated that the incidence of new-onset AF varied from 1.9% for mild sepsis to 46.0% for septic shock. Furthermore, compared to those without AF, people with new-onset AF had longer ICU and hospital stays, as well as a higher recurrence of AF.

CONCLUSIONS

New-onset AF is frequently associated with adverse outcomes in patients with sepsis. This is a clinical issue that warrants more attention and should be managed appropriately to prevent poor prognosis.

Prevalence, Outcomes, and Risk Factors of New-Onset Atrial Fibrillation in Critically Ill Patients

The purpose of this article is to systematically evaluate the prevalence, outcomes, and risk factors of new-onset atrial fibrillation (AF) in critically ill patients.Medline, Embase, Science Citation Index, Wanfang, CNKI, and Wiley Online Library were thoroughly searched to identify relevant studies. Studies were assessed for methodological quality using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system. Odds ratio (OR) and weighted mean difference (WMD) with 95% confidence interval (CI) were used to assess the strength of the association. Heterogeneity, subgroup, sensitivity analyses, and publication bias were conducted.A total of 25 studies were included. The prevalence of new-onset AF ranged from 4.1% to 46%.The random-effects pooled prevalence was 10.7%. The pooled result jumped up to 35.8% in patients with septic shock. Pooled analysis showed significant associations between new-onset AF with intensive care unit (ICU) mortality and in-hospital mortality over those patients without AF (OR = 3.11; 95%CI 2.45-3.96 and OR = 1.63; 95%CI 1.27-2.08). The pooled analysis also indicated that both ICU and hospital length of stay are longer in patients with new-onset AF than those without AF (WMD = 1.87; 95%CI 0.89-2.84 and WMD = 2.73; 95%CI 0.77-4.69). Independent risk factors included increasing age, shock, sepsis, use of a pulmonary artery catheter and mechanical ventilation, fluid loading, and organ failures.New-onset AF incidence rate is high in critically ill patients. New-onset AF is associated with worse outcomes. Further studies should be done to explore how to prevent and treat new-onset AF in critically ill patients.

Trends and Outcomes in Sepsis Hospitalizations With and Without Atrial Fibrillation: A Nationwide Inpatient Analysis

OBJECTIVES

Atrial fibrillation is frequently seen in sepsis-related hospitalizations. However, large-scale contemporary data from the United States comparing outcomes among sepsis-related hospitalizations with versus without atrial fibrillation are limited. The aim of our study was to assess the frequency of atrial fibrillation and its impact on outcomes of sepsis-related hospitalizations.

DESIGN

Retrospective cohort study.

SETTING

The National Inpatient Sample databases (2010-2014).

PATIENTS

Primary discharge diagnosis of sepsis with and without atrial fibrillation were identified using prior validated International Classification of Diseases, 9th Edition, Clinical Modification codes.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Overall, 5,808,166 hospitalizations with the primary diagnosis of sepsis, of which 19.4% (1,126,433) were associated with atrial fibrillation. The sepsis-atrial fibrillation cohort consisted of older (median [interquartile range] age of 79 yr [70-86 yr] vs 67 yr [53-79 yr]; p < 0.001) white (80.9% vs 68.8%; p < 0.001) male (51.1% vs 47.5%; p < 0.001) patients with an extended length of stay (median [interquartile range] 6 d [4-11 d] vs 5 d [3-9 d]; p < 0.001) and higher hospitalization charges (median [interquartile range] $44,765 [$23,234-$88,657] vs $35,737 [$18,767-$72,220]; p < 0.001) as compared with the nonatrial fibrillation cohort. The all-cause mortality rate in the sepsis-atrial fibrillation cohort was significantly higher (18.4% and 11.9%; p = 0.001) as compared with those without atrial fibrillation. Although all-cause mortality (20.4% vs 16.6%) and length of stay (median [interquartile range] 7 d [4-11 d] vs 6 d [4-10 d]) decreased between 2010 and 2014, hospitalization charges increased (median [interquartile range] $41,783 [$21,430-$84,465] vs $46,251 [$24,157-$89,995]) in the sepsis-atrial fibrillation cohort. The greatest predictors of mortality in the atrial fibrillation-sepsis cohort were African American race, female gender, advanced age, and the presence of medical comorbidities.

CONCLUSIONS

The presence of atrial fibrillation among sepsis-related hospitalizations is a marker of poor prognosis and increased mortality. Although we observed rising trends in sepsis and sepsis-atrial fibrillation-related hospitalizations during the study period, the rate and odds of mortality progressively decreased.

Impact of Sustained Cardiac Tachyarrhythmias Recorded in Coronary Intensive Care Unit on Short- and Long-Term Mortality and Duration of Hospitalization

BACKGROUND

Studies conducted in coronary intensive care units (CICUs) have demonstrated that tachyarrhythmias are associated with increased mortality after acute coronary syndromes (ACSs). However, the data for tachyarrhythmias occurred in CICUs due to a variety of cardiovascular disorders are limited.

METHODS

We conducted a single-center prospective observational study, which included consecutive CICU patients (January 1, 2014 to May 31, 2018). We recorded the ventricular arrhythmias (VAs), supraventricular tachycardias (SVTs), and days of CICU hospitalization. The patients were followed up for 6 months after CICU discharge.

RESULTS

A total of 943 patients (age: 66.37 ±15.4 years; 673 males [71.4%]) were included. Patients with tachyarrhythmias had higher in-CICU mortality (8.0% vs 4.1%, P = .029, odds ratio [OR]: 2.04, 95% confidence interval [CI]: 1.08-3.86) and higher 6-month all-cause mortality (12.8% vs 6.1%, P = .002, OR: 2.27, 95% CI: 1.35-3.83) than those who did not develop tachyarrhythmias. Ventricular arrhythmias was significantly associated with higher all-cause mortality than no tachyarrhythmia (15.4% vs 6.1%; P = .001) or SVTs (15.4% vs 7.0%; P = .001). The mean duration of hospitalization for the patients with tachyarrhythmias was 3.89 ± 4.90 days, while for the patients without was 2.79 ± 3.31 days (P < .001). Patients without ACS had higher short- and long-term mortality compared to patients with ACS (9.2% vs 2.9%, P < .001 and 12.9% vs 4.9%, P < .001).

CONCLUSIONS

Tachyarrhythmias were associated with prolonged CICU hospitalization, while non-ACS cardiovascular disorders and the occurrence of VAs were associated with increased short- and long-term mortality.

Low serum albumin levels and new-onset atrial fibrillation in the ICU: a prospective cohort study

PURPOSE

The aim was to determine if a low serum albumin (SA) level was associated with the occurrence of new onset atrial fibrillation (NOAF) during the first 48 h of intensive care unit (ICU) admission.

METHODS

Overall, 97 patients admitted to the ICU were included in this prospective study. NOAF during the first 48 h was defined as irregularity and absence of p-waves on the continuous electrocardiogram, lasting longer than 2 min. Association were analysed using logistic regression with correction for confounding variables in multivariable analysis.

RESULTS

The incidence of NOAF during the first 48 h of ICU admission was 18%. SA levels at ICU admission were significantly associated with NOAF after correction for confounders (odds ratio [OR] 0.86, 95%CI 0.77-0.97, p = .010). SA levels were also significantly associated with the number of episodes of NOAF in multivariate analysis (-0.09 episodes, 95%CI [-0.15/-0.04], p = .001), but not with the presence of sinus rhythm at 48 h (OR 1.05, 95%CI [0.93-1.12], p = .46).

CONCLUSION

In this small hypothesis generating study low levels of SA were associated with the occurrence of NOAF. It remains to be shown if increasing SA levels lowers the incidence of NOAF.

[New onset atrial fibrillation in patients with sepsis]

BACKGROUND

Atrial fibrillation is the most common new onset arrhythmia in patients hospitalized with sepsis; however, there are no specific treatment guidelines and the ideal therapeutic approaches still remain unclear.

OBJECTIVES

To begin with the current state of knowledge concerning the underling mechanisms, the incidence and prognostic impact of new onset atrial fibrillation during sepsis are presented. Then a possible therapeutic algorithm for the special situation of sepsis is derived with respect to the currently existing atrial fibrillation guidelines. Finally necessary future research topics are outlined.

MATERIAL ANS METHODS

A systematic literature search was conducted in MEDLINE. All publications (reviews and studies) relevant for the summary of the current knowledge regarding new onset atrial fibrillation in septic patients were included.

RESULTS

The underlying patchomechanism is primarily systemic inflammation. Approximately 8% of patients with sepsis and more than 20% of patients with septic shock develop new onset atrial fibrillation. The occurrence of atrial fibrillation is associated with increased morbidity and mortality. The necessity of rhythm control therapy is dependent on the hemodynamic stability. The success rate of electrical cardioversion can be increased by the administration of amiodarone. The necessity of systemic anticoagulation is based on the individual risk of thromboembolism.

CONCLUSION

Further research is needed to unveil the optimal therapeutic strategies for patients with new onset atrial fibrillation during sepsis.

Severe sepsis and cardiac arrhythmias

Background

Although sepsis is a known risk factor for cardiac arrhythmias, data on incidence and outcomes of atrial and ventricular arrhythmias in severe sepsis is limited. The purpose of this study is to examine the association of severe sepsis with cardiac arrhythmias and their impact on outcome in this patient population.

Methods

We used hospital discharge data from the Nationwide Inpatient Sample (NIS) during the year 2012. All patients 18 years or older were included in the study. The International Classification of Diseases-Clinical Modification, 9th revision (ICD-9-CM) code was used to identify patients with discharge diagnosis of severe sepsis, atrial fibrillation (A Fib), atrial flutter (AFL), ventricular fibrillation (VF) arrest and non-ventricular fibrillation (non-VF) arrest. In order to study the association of arrhythmias with severe sepsis, two groups were defined: group a-with severe sepsis was compared to group b-without severe sepsis. Univariate and multivariate logistic regression methods were used to adjust for potential confounding factors and variables associated with cardiac arrhythmias were determined.

Results

A total of 30,712,524 NIS hospital discharges (weighted for national estimate) were included in our study, of which 1,756,965 (5.7%) had severe sepsis. On multivariate analysis, after adjusting for potential confounders, severe sepsis was associated with higher risk of A Fib (OR, 1.23; 95% CI, 1.21-1.24), AFL (OR, 1.34; 95% CI, 1.30-1.40), VF arrest (OR, 2.58; 95% CI, 2.38-2.79) (OR, 3.31; 95% CI, 3.07-3.57) and non-VF arrest (OR, 4.91; 95% CI, 4.74-5.07). In the severe sepsis group, cardiac arrhythmia was associated with higher in-hospital mortality (OR, 1.41; 95% CI, 1.37-1.45), length of stay (LOS) >75% quartile (OR, 1.50; 95% CI, 1.46-1.53) and total hospital charges >75% quartile (OR, 1.37; 95% CI, 1.34-1.41). Advanced age, male sex, ischemic heart disease, diabetes mellitus (DM), congestive heart failure (CHF), valvular heart disease, respiratory failure, mechanical ventilation and use of vasopressors were independently associated with cardiac arrhythmias.

Conclusions

Patients with severe sepsis are at high risk of atrial and life threatening ventricular arrhythmias. Despite adjustment for potential confounding factors, patients hospitalized with severe sepsis carry a significantly higher risk for cardiac arrest and increased mortality.

New-onset, postoperative tachyarrhythmias in critically ill surgical patients

Tachyarrhythmias in critically ill surgical patients can have varying effects, from minimal consequence to lifetime sequelae. Atrial fibrillation can be common in the post-operative period, often a result of fluctuations in volume status and electrolyte derangements. While there is extensive literature regarding the critically ill medical or cardiac patient, there is less focusing on the critically ill surgical or trauma patient. More specifically, there is minimal regarding tachyarrhythmias in burn patients. The latter population tends to have frequent and wide variations in volume status given initial resuscitation and after major excisions, concomitant with acute blood loss anemia, which can contribute to cardiac disturbances. A literature review was conducted to investigate the incidence and consequences of tachyarrhythmias in critically ill surgical and trauma patients, with a focus on the burn population. While some similarities and conclusions can be drawn between these surgical populations, further inquiry into the unique burn patient is necessary.

Prevalence and prognostic relevance of atrial fibrillation in patients with Takotsubo syndrome

BACKGROUND

Takotsubo syndrome (TTS) is associated with a considerable risk of complications during the acute phase and substantial long-term mortality rates. Concomitant atrial fibrillation may have an impact on outcome in these patients. Aim of this study was to assess the prevalence and prognostic relevance of atrial fibrillation in TTS.

METHODS

We performed an international, multicenter study including 387 TTS patients consecutively enrolled at 3 centers. Atrial fibrillation was defined as known history before admission or documented episodes during hospital stay. Long-term mortality was evaluated in median 2.9years after the acute event.

RESULTS

Atrial fibrillation was found in 97 TTS patients (25.1%) and was associated with older age (p<0.01), less emotional triggers (p=0.03), higher incidence of cardiogenic shock (p<0.01), lower left ventricular ejection fraction (p<0.01), and a prolonged hospital stay (p<0.01). Determinants of atrial fibrillation at admission (n=34 patients; 9.0%) in multivariate logistic regression analysis were age (p=0.001) and cardiogenic shock (p=0.013). Long-term mortality was significantly higher in TTS patients with as compared to patients without atrial fibrillation (35.2% versus 15.3%; hazard ratio 3.02, 95% confidence interval 1.90-4.78; p<0.001). In multivariate Cox regression analysis atrial fibrillation was identified as an independent determinant of outcome even after adjustment for clinical variables, left ventricular functional parameters (ballooning pattern, ejection fraction), and cardiogenic shock.

CONCLUSIONS

In TTS patients, atrial fibrillation is frequent and associated with increased long-term mortality rates. Furthermore, our study identifies atrial fibrillation as an independent predictor of outcome and a potential tool for risk stratification in TTS.

Prognostic impact of restored sinus rhythm in patients with sepsis and new-onset atrial fibrillation

BACKGROUND

New-onset atrial fibrillation (NeOAF) is a common type of tachyarrhythmia in critically ill patients and is associated with increased mortality in patients with sepsis. However, the prognostic impact of restored sinus rhythm (SR) in septic patients with NeOAF remains unclear.

METHODS

A total of 791 patients with sepsis, who were admitted to a medical intensive care unit from January 2011 to January 2014, were screened. NeOAF was detected by continuous electrocardiographic monitoring. Patients were categorized into three groups: no NeOAF, NeOAF with restored SR (NeOAF to SR), and NeOAF with failure to restore SR (NeOAF to atrial fibrillation (AF)). The endpoint of this study was in-hospital mortality. Patients with pre-existing AF were excluded.

RESULTS

We reviewed the data of 503 eligible patients, including 263 patients with no NeOAF and 240 patients with NeOAF. Of these 240 patients, SR was restored in 165 patients, and SR could not be restored in 75 patients. The NeOAF to AF group had the highest in-hospital mortality rate of 61.3% compared with the NeOAF to SR and no NeOAF groups (26.1% and 17.5%, respectively). Moreover, multivariate logistic regression analysis revealed that failure of restored SR was independently associated with increased in-hospital mortality in patients with sepsis and NeOAF.

CONCLUSIONS

Failure to restore a sinus rhythm in patients with new-onset atrial fibrillation may be associated with increased in-hospital mortality in patients with sepsis. Further prospective studies are needed to clarify the effects of restoration of sinus rhythm on survival in patients with sepsis and new-onset atrial fibrillation.

Applicability of stroke volume variation in patients of a general intensive care unit: a longitudinal observational study

Sinus rhythm (SR) and controlled mechanical ventilation (CV) are mandatory for the applicability of respiratory changes of the arterial curve such as stroke volume variation (SVV) to predict fluid-responsiveness. Furthermore, several secondary limitations including tidal volumes <8 mL/kg and SVV-values within the "gray zone" of 9-13% impair prediction of fluid-responsiveness by SVV. Therefore, we investigated the prevalence of these four conditions in general ICU-patients. This longitudinal observational study analyzed a prospectively maintained haemodynamic database including 4801 transpulmonary thermodilution and pulse contour analysis measurements of 278 patients (APACHE-II 21.0 ± 7.4). The main underlying diseases were cirrhosis (32%), sepsis (28%), and ARDS (17%). The prevalence of SR and CV was only 19.4% (54/278) in the first measurements (primary endpoint), 18.8% (902/4801) in all measurements and 26.5% (9/34) in measurements with MAP < 65 mmHg and CI < 2.5 L/min/m² and vasopressor therapy. In 69.1% (192/278) of the first measurements and in 65.9% (3165/4801) of all measurements the patients had SR but did not have CV. In 1.8% (5/278) of the first measurements and in 2.5% (119/4801) of all measurements the patients had CV but lacked SR. In 9.7% (27/278) of the first measurements and in 12.8% (615/4801) of all measurements the patients did neither have SR nor CV. Only 20 of 278 (7.2%) of the first measurements and 8.2% of all measurements fulfilled both major criteria (CV, SR) and both minor criteria for the applicability of SVV. The applicability of SVV in ICU-patients is limited due to the absence of mandatory criteria during the majority of measurements.

Continuous intravenous antiarrhythmic agents in the intensive care unit: strategies for safe and effective use of amiodarone, lidocaine, and procainamide

The development of cardiac arrhythmias in the intensive care unit is common and associated with poor prognoses and outcomes. Because of the complexity of patients admitted to the intensive care unit, the management of arrhythmias is often difficult and may require multiple therapeutic interventions. In order for clinicians to appropriately manage arrhythmias, a thorough understanding of all available therapies, including intravenous antiarrhythmic agents, is essential. Suitable antiarrhythmic agents for use in the critical care setting include amiodarone, lidocaine, and procainamide. While these agents can be effective in managing cardiac arrhythmias, they also possess significant disadvantages and require additional monitoring during use. Therapy with these agents is often complicated because of the presence of significant associated adverse effects, clinician unfamiliarity, variable dosing strategies, and the potential for drug-drug interactions. The purpose of this review is to discuss indications and strategies for safe and effective use of amiodarone, lidocaine, and procainamide.

Incidence, Risk Factors and Outcomes of New Onset Supraventricular Arrhythmias in African American Patients with Severe Sepsis

PURPOSE

New onset supraventricular arrhythmias (SVA) are commonly reported in mixed intensive care settings. We sought to determine the incidence, risk factors and outcomes of new onset SVA in African American (AA) patients with severe sepsis admitted to medical intensive care unit (MICU).

METHODS

Patients admitted to MICU between January 2012 through December 2012 were studied. Patients with a previous history of arrhythmia or with new onset of ventricular arrhythmia were excluded. Data on risk factors, critical care interventions and outcomes were obtained.

RESULTS

One hundred and thirty-one patients were identified. New onset SVA occurred in 34 (26%) patients. Of those 34, 20 (59%) had atrial fibrillation (AF), 6 (18%) had atrial flutter and 8 (24%) had other forms of SVA. Compared with patients without SVA, patients with new onset SVA were older (69 ± 12 yrs vs 59 ± 13 yrs, P=.003), had congestive heart failure (47% vs 24%, P=.015) and dyslipidemia (41% vs 15%, P=.002). Additionally, they had a higher mean mortality prediction model (MPM II) score (65 ± 25 vs 49 ± 26, P=.001) and an increased incidence of respiratory failure (85% vs 55%, P=.001). Hospital mortality in patients with new onset SVA was 18 (53%) vs 30 (31%); P=.024; however, in a multivariate analysis, new onset SVA was associated with non-significantly increased odds (OR 2.58, 95% CI 0.86-8.05) for in-hospital mortality.

CONCLUSIONS

New onset SVA was prevalent in AA patients with severe sepsis and occurred more frequently with advanced age, increased severity of illness, congestive heart failure, and acute respiratory failure; it was associated with higher unadjusted in hospital mortality. However, after multiple adjustments, new onset SVA did not remain an independent predictor of mortality.

Practice Patterns and Outcomes of Treatments for Atrial Fibrillation During Sepsis: A Propensity-Matched Cohort Study

BACKGROUND

Atrial fibrillation (AF) during sepsis is associated with increased morbidity and mortality, but practice patterns and outcomes associated with rate- and rhythm-targeted treatments for AF during sepsis are unclear.

METHODS

This was a retrospective cohort study using enhanced billing data from approximately 20% of United States hospitals. We identified factors associated with IV AF treatments (?-blockers [BBs], calcium channel blockers [CCBs], digoxin, or amiodarone) during sepsis. We used propensity score matching and instrumental variable approaches to compare mortality between AF treatments.

RESULTS

Among 39,693 patients with AF during sepsis, mean age was 77 ± 11 years, 49% were women, and 76% were white. CCBs were the most commonly selected initial AF treatment during sepsis (14,202 patients [36%]), followed by BBs (11,290 [28%]), digoxin (7,937 [20%]), and amiodarone (6,264 [16%]). Initial AF treatment selection differed according to geographic location, hospital teaching status, and physician specialty. In propensity-matched analyses, BBs were associated with lower hospital mortality when compared with CCBs (n = 18,720; relative risk [RR], 0.92; 95% CI, 0.86-0.97), digoxin (n = 13,994; RR, 0.79; 95% CI, 0.75-0.85), and amiodarone (n = 5,378; RR, 0.64; 95% CI, 0.61-0.69). Instrumental variable analysis showed similar results (adjusted RR fifth quintile vs first quintile of hospital BB use rate, 0.67; 95% CI, 0.58-0.79). Results were similar among subgroups with new-onset or preexisting AF, heart failure, vasopressor-dependent shock, or hypertension.

CONCLUSIONS

Although CCBs were the most frequently used IV medications for AF during sepsis, BBs were associated with superior clinical outcomes in all subgroups analyzed. Our findings provide rationale for clinical trials comparing the effectiveness of AF rate- and rhythm-targeted treatments during sepsis.

Atrial Fibrillation Is an Independent Predictor of Mortality in Critically Ill Patients

OBJECTIVES

Atrial fibrillation has been associated with increased mortality in critically ill patients. We sought to determine whether atrial fibrillation in the ICU is an independent risk factor for death. A secondary objective was to determine if patients with new-onset atrial fibrillation have different risk factors or outcomes compared with patients with a previous history of atrial fibrillation.

DESIGN

Prospective observational cohort study.

SETTING

Medical and general surgical ICUs in a tertiary academic medical center.

PATIENTS

One thousand seven hundred seventy critically ill patients requiring at least 2 days in the ICU.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Demographics, medical history, development of atrial fibrillation, fluid balance, echocardiographic findings, medication administration, and hospital mortality were collected during the first 4 days of ICU admission. Atrial fibrillation occurred in 236 patients (13%) (Any AF). Of these, 123 patients (7%) had no prior atrial fibrillation (New-onset AF) while the remaining 113 (6%) had recurrent atrial fibrillation (Recurrent AF). Any AF was associated with male gender, Caucasian race, increased age, cardiac disease, organ failures, and disease severity. Patients with Any AF had increased mortality compared with those without atrial fibrillation (31% vs 17%; p < 0.001), and Any AF was independently associated with death (odds ratio, 1.62; 95% CI, 1.14-2.29; p = 0.007) in multivariable analysis controlling for severity of illness and other confounders. The association of atrial fibrillation with death was magnified in patients without sepsis (odds ratio, 2.92; 95% CI, 1.52-5.60; p = 0.001). Treatment for atrial fibrillation had no effect on hospital mortality. New-onset AF and Recurrent AF were each associated with increased mortality. New-onset AF, but not Recurrent AF, was associated with increased diastolic dysfunction and vasopressor use and a greater cumulative positive fluid balance.

CONCLUSIONS

Atrial fibrillation in critical illness, whether new-onset or recurrent, is independently associated with increased hospital mortality, especially in patients without sepsis.

Cardiac Arrhythmias in a Septic ICU Population: A Review

Progressive cardiovascular deterioration plays a central role in the pathogenesis of multiple organ failure (MOF) caused by sepsis. Evidence of various cardiac arrhythmias in septic patients has been reported in many published studies. In the critically ill septic patients, compared to non-septic patients, new onset atrial fibrillation episodes are associated with high mortality rates and poor outcomes, amongst others being new episodes of stroke, heart failure and long vasopressor usage. The potential mechanisms of the development of new cardiac arrhythmias in sepsis are complex and poorly understood. Cardiac arrhythmias in critically ill septic patients are most likely to be an indicator of the severity of pre-existing critical illness.

Arrhythmias in the paediatric intensive care unit: a prospective study of the rates and predictors of arrhythmias in children without underlying cardiac disease

OBJECTIVE

Arrhythmias are common in patients admitted to the paediatric intensive care unit. We sought to identify the rates of occurrence and types of arrhythmias, and determine whether an arrhythmia was associated with illness severity and paediatric intensive care unit length of stay.

DESIGN

This is a prospective, observational study of all patients admitted to the paediatric intensive care unit at the Children's Hospital at Montefiore from March to June 2012. Patients with cardiac disease or admitted for the treatment of primary arrhythmias were excluded. Clinical and laboratory data were collected and telemetry was reviewed daily. Tachyarrhythmias were identified as supraventricular tachycardia, ventricular tachycardia, and arrhythmias causing haemodynamic compromise or for which an intervention was performed.

RESULTS

A total of 278 patients met the inclusion criteria and were analysed. There were 97 incidences of arrhythmia in 53 patients (19%) and six tachyarrhythmias (2%). The most common types of arrhythmias were junctional rhythm (38%), premature atrial contractions (24%), and premature ventricular contractions (22%). Tachyarrhythmias included three supraventricular tachycardia (50%) and three ventricular tachycardia (50%). Of the six tachyarrhythmias, four were related to placement or migration of central venous lines and two occurred during aminophylline infusion. Patients with an arrhythmia had longer duration of mechanical ventilation and paediatric intensive care unit stay (p<0.001). In multivariate analysis, central venous lines (odds ratio 3.1; 95% confidence interval 1.3-7.2, p=0.009) and aminophylline use (odds ratio 5.1; 95% confidence interval 1.7-14.9, p=0.003) were independent predictors for arrhythmias.

CONCLUSIONS

Arrhythmias were common in paediatric intensive care unit patients (19%), although tachyarrhythmias occurred rarely (2%). Central venous lines and use of aminophylline were identified as two clinical factors that may be associated with development of an arrhythmia.

New-onset supraventricular arrhythmia during septic shock: prevalence, risk factors and prognosis

BACKGROUND

The aims of this study were to prospectively assess the prevalence of sustained (lasting more than 30 s) new-onset supraventricular arrhythmia (NOSVA) during septic shock, identify the associated factors (including septic myocardial dysfunction), and evaluate its impact on hemodynamics and prognosis.

METHODS

Patients with a diagnosis of septic shock were screened in a medical intensive care unit of a tertiary hospital center in France with a continuous 12-lead EKG for the occurrence of NOSVA. Biological and clinical data (including septic myocardial dysfunction characterized by echocardiography) were collected. We also assessed the hemodynamic tolerance and prognosis of NOSVA.

RESULTS

Among the 71 septic shock episodes assessed during the study, NOSVA occurred in 30 [prevalence of 42 %, 95 % confidence interval (CI) 30-53 %]. Among all recorded factors, only renal failure (as assessed by renal SOFA score at day 1) was associated with NOSVA and this difference persisted by multivariable analysis (odds ratio of 1.29, 95 % CI 1.03-1.62, p = 0.03). There was a significant increase in norepinephrine dosage during the first hour after SVA onset. NOSVA was associated with longer catecholamine use during septic shock as compared with patients in sinus rhythm, whereas ICU mortality was identical between groups.

CONCLUSIONS

We found a high prevalence of sustained NOSVA during septic shock. NOSVA was not related to septic myocardial dysfunction, but rather to acute renal failure, raising the hypothesis of an acute renocardiac syndrome.

Managing arrhythmias in the intensive care unit

Patients admitted to the intensive care unit (ICU) are at increased risk for cardiac arrhythmias, the most common of which can be subdivided into tachyarrhythmias and bradyarrhythmias. These arrhythmias may be the primary reason for ICU admission or may occur in the critically ill patient. This article addresses the occurrence of arrhythmias in the critically ill patient, and discusses their pathophysiology, implications, recognition, and management.

Pre-existing atrial fibrillation and risk of arterial thromboembolism and death in intensive care unit patients: a population-based cohort study

INTRODUCTION

Pre-existing atrial fibrillation (AF) may worsen prognosis in patients admitted to the intensive care unit (ICU).

METHODS

In a cohort study (2005-2011) including all patients with first-time ICU admissions in Denmark (n=57,110), we compared patients with and without pre-existing AF and estimated absolute risks and relative risks (RRs) of arterial thromboembolism and death within 30 days and 365 days following admission, using Kaplan-Meier methods and multivariate regression analyses. We analysed the prognostic impact of AF within strata of patient age, sex, coexisting cardiac diseases, and ICU therapies.

RESULTS

Among ICU patients, 5065 (9%) had pre-existing AF. Compared with patients without AF, those with AF were older (median age 75 vs. 62 years) and had more comorbidity. The risk of arterial thromboembolism was 2.8% in patients with AF and 2.0% in non-AF patients at 30 days, and 4.3% and 2.9%, respectively, at 365 days. Corresponding RRs were 1.41 crude and 1.14 (95% confidence interval [CI] 0.93-1.40) adjusted at 30 days, and 1.50 crude and 1.20 (95% CI 1.02-1.41) adjusted at 365 days. Thirty-day mortality was 27% in patients with pre-existing AF and 16% in non-AF patients (crude RR 1.67, adjusted RR 1.04, 95% CI 0.99-1.10). Corresponding mortality estimates at 365 days were 40.9% and 25.4%, respectively (crude RR 1.61, adjusted RR 1.03, 95% CI 1.00-1.07). In stratified analyses, pre-existing AF increased mortality in ICU patients aged <55 years (adjusted RR at 30 days 1.73, 95% CI 1.29-2.32; adjusted RR at 365 days 1.34, 95% CI 1.06-1.69) and in ICU patients treated with mechanical ventilation (adjusted RR at 30 days 1.12, 95% CI 1.05-1.20, adjusted RR at 365 days 1.09, 95% CI: 1.04-1.15). Analyses stratified by sex and coexisting cardiac diseases yielded adjusted RRs close to 1.

CONCLUSIONS

In ICU patients, pre-existing AF was associated with modestly increased risk of arterial thromboembolism when adjusted for the substantially higher age and comorbidity levels in patients with AF, whereas there was no overall association with mortality. In ICU patients aged <55 years and in those treated with mechanical ventilation, AF predicted increased mortality.

Cardiac arrhythmias in stroke unit patients. Evaluation of the cardiac monitoring data

INTRODUCTION

Cardiac arrhythmias are frequent in acute stroke. Stroke units are widely equipped with cardiac monitoring systems. Pre-existing heart diseases and heart-brain interactions may be implicated in causing cardiac arrhythmias in acute stroke. This article analyses cardiac arrhythmias detected in patients hospitalised in a stroke unit.

METHOD

Prospective observational study of consecutive patients admitted to a stroke unit with cardiac monitoring. We collected clinical data from patients and the characteristics of their cardiac arrhythmias over a 1-year period (2013). Time of arrhythmia onset, associated predisposing factors, and the therapeutic decisions made after detection of arrhythmia were examined. All patients underwent continuous cardiac monitoring during no less than 48hours.

RESULTS

Of a total of 332 patients admitted, significant cardiac arrhythmias occurred in 98 patients (29.5%) during their stay in the stroke unit. Tachyarrhythmia (ventricular tachyarrhythmias, supraventricular tachyarrhythmias, complex ventricular ectopy) was present in 90 patients (27.1%); bradyarrhythmia was present in 13 patients (3.91%). Arrhythmias were independently associated with larger size of brain lesion and older age. In 10% of the patient total, therapeutic actions were taken after detection of significant cardiac arrhythmias. Most events occurred within the first 48hours after stroke unit admission.

CONCLUSIONS

Systematic cardiac monitoring in patients with acute stroke is useful for detecting clinically relevant cardiac arrhythmias. Incidence of arrhythmia is higher in the first 48hours after stroke unit admission. Age and lesion size were predicted appearance of arrhythmias. Detection of cardiac arrhythmias in a stroke unit has important implications for treatment.

Incidence and Predictors of New-Onset Atrial Fibrillation in Septic Shock Patients in a Medical ICU: Data from 7-Day Holter ECG Monitoring

Purpose

We investigated incidence, risk factors for new-onset atrial fibrillation (NAF), and prognostic impact during septic shock in medical Intensive Care Unit (ICU) patients.

Methods

Prospective, observational study in a university hospital. Consecutive patients from 03/2011 to 05/2013 with septic shock were eligible. Exclusion criteria were age <18 years, history of AF, transfer with prior septic shock. Included patients were equipped with long-duration (7 days) Holter ECG monitoring. NAF was defined as an AF episode lasting >30 seconds. Patient characteristics, infection criteria, cardiovascular parameters, severity of illness, support therapies were recorded.

Results

Among 66 patients, 29(44%) developed NAF; 10 (34%) would not have been diagnosed without Holter ECG monitoring. NAF patients were older, with more markers of heart failure (troponin and NT-pro-BNP), lower left ventricular ejection fraction (LVEF), longer QRS duration and more nonsustained supra ventricular arrhythmias (<30s) on day 1 than patients who maintained sinus rhythm. By multivariate analysis, age (OR: 1.06; p = 0.01) and LVEF<45% (OR: 13.01, p = 0.03) were associated with NAF. NAF did not predict 28 or 90 day mortality.

Conclusions

NAF is common, especially in older patients, and is associated with low ejection fraction. We did not find NAF to be independently associated with higher mortality.

New-onset atrial fibrillation in sepsis is associated with increased morbidity and mortality

Background

The development of new-onset atrial fibrillation in sepsis has been associated with adverse outcomes.

Methods

A systematic literature search was conducted to retrieve articles that investigated the association of new-onset atrial fibrillation in patients diagnosed with sepsis. The primary outcome of interest was the pooled risk ratio (RR) of in-hospital mortality in patients with new-onset atrial fibrillation and sepsis.

Results

Six studies included 3100 patients with new-onset atrial fibrillation in sepsis and 36,900 patients without new-onset atrial fibrillation in sepsis. The pooled RR for in-hospital mortality was 1.45 (95 % CI 1.32–1.60, p < 0.00001, I^2 =24 %). New-onset atrial fibrillation was also associated with increased ICU mortality, ICU and in-hospital length of stay and stroke. New-onset atrial fibrillation occurred more in the elderly, those with a prior history of cardiovascular and respiratory disease, and those with increased severity of illness.

Conclusion

Prospective randomised trials are needed to clarify the significance of new-onset atrial fibrillation in sepsis, optimal treatment strategies for these patients, and the benefit of systemic anticoagulation. Physicians should be aware that new-onset atrial fibrillation in sepsis is not merely an observed temporary arrhythmia but a marker of poor prognosis and should be managed accordingly.

Incidence, risk factors and outcomes of new-onset atrial fibrillation in patients with sepsis: a systematic review

Introduction

Critically ill patients with sepsis are prone to develop cardiac dysrhythmias, most commonly atrial fibrillation (AF). Systemic inflammation, circulating stress hormones, autonomic dysfunction, and volume shifts are all possible triggers for AF in this setting. We conducted a systematic review to describe the incidence, risk factors and outcomes of new-onset AF in patients with sepsis.

Methods

MEDLINE, EMBASE and Web Of Science were searched for studies reporting the incidence of new-onset AF, atrial flutter or supraventricular tachycardia in patients with sepsis admitted to an intensive care unit, excluding studies that primarily focused on postcardiotomy patients. Studies were assessed for methodological quality using the GRADE system. Risk factors were considered to have a high level of evidence if they were reported in ≥2 studies using multivariable analyses at a P value <0.05. Subsequently, the strength of association was classified as strong, moderate or weak, based on the reported odds ratios.

Results

Eleven studies were included. Overall quality was low to moderate. The weighted mean incidence of new-onset AF was 8% (range 0 to 14%), 10% (4 to 23%) and 23% (6 to 46%) in critically ill patients with sepsis, severe sepsis and septic shock, respectively. Independent risk factors with a high level of evidence included advanced age (weak strength of association), white race (moderate association), presence of a respiratory tract infection (weak association), organ failure (moderate association), and pulmonary artery catheter use (moderate association). Protective factors were a history of diabetes mellitus (weak association) and the presence of a urinary tract infection (weak association). New-onset AF was associated with increased short-term mortality in five studies (crude relative effect estimates ranging from 1.96 to 3.32; adjusted effects 1.07 to 3.28). Three studies reported a significantly increased length of stay in the ICU (weighted mean difference 9 days, range 5 to 13 days), whereas an increased risk of ischemic stroke was reported in the single study that looked at this outcome.

Conclusions

New-onset AF is a common consequence of sepsis and is independently associated with poor outcome. Early risk stratification of patients may allow for pharmacological interventions to prevent this complication.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-014-0688-5) contains supplementary material, which is available to authorized users.

Acute decrease of cerebral oxygen saturation during rapid ventricular and supraventricular rhythm: a pilot study

BACKGROUND

Monitoring of cerebral tissue oxygen saturation (SctO2 ) reflects cerebral microcirculation. We sought to characterize the decrease in SctO2 during supraventricular tachycardia (SVT) and ventricular tachycardia (VT) in adults.

METHODS

Twenty patients (mean age: 46.3 ± 18.1 years, 40% men) were included. Rapid atrial and ventricular pacing (200/min) was used as a model for VT and SVT. Near-infrared spectroscopy (NIRS) was used to measure SctO2 .

RESULTS

Atrial stimulation decreased right (P = 0.014) and left (P = 0.019) hemispheric SctO2 compared to baseline. Ventricular stimulation also decreased right (P < 0.001) and left (P < 0.001) hemispheric SctO2 . A negative correlation between age and minimal value under stimulation was found for atrial (right SctO2 r = -0.641, P = 0.034; left SctO2 r = -0.694, P = 0.018) and ventricular pacing (right SctO2 r = -0.564, P = 0.01; left SctO2 r = -0.604, P = 0.005). A positive correlation was found between left ventricular ejection fraction (LVEF) and minimal value under ventricular stimulation (right SctO2 r = 0.567, P = 0.009; left SctO2 r = 0.471, P = 0.036).

CONCLUSION

Cerebral perfusion decreased during simulated SVT and VT and is influenced by age and LVEF. Clinicians can consider NIRS monitoring in patients during ablation procedures and in critical care. NIRS may especially be appropriate for the elderly and for patients with impaired LVEF.

Management of atrial fibrillation in critically ill patients

Atrial fibrillation (AF) is common in ICU patients and is associated with a two- to fivefold increase in mortality. This paper provides a reappraisal of the management of AF with a special focus on critically ill patients with haemodynamic instability. AF can cause hypotension and heart failure with subsequent organ dysfunction. The underlying mechanisms are the loss of atrial contraction and the high ventricular rate. In unstable patients, sinus rhythm must be rapidly restored by synchronised electrical cardioversion (ECV). If pharmacological treatment is indicated, clinicians can choose between the rate control and the rhythm control strategy. The optimal substance should be selected depending on its potential adverse effects. A beta-1 antagonist with a very short half-life (e.g., esmolol) is an advantage for ICU patients because the effect of beta-blockade on cardiovascular stability is unpredictable in those patients. Amiodarone is commonly used in the ICU setting but has potentially severe cardiac and noncardiac side effects. Digoxin controls the ventricular response at rest, but its benefit decreases in the presence of adrenergic stress. Vernakalant converts new-onset AF to sinus rhythm in approximately 50% of patients, but data on its efficacy and safety in critically ill patients are lacking.

New-onset atrial fibrillation in severe sepsis and risk of stroke and death: a critically appraised topic

BACKGROUND

Severe sepsis has been associated with an increased risk of new-onset arrhythmias, namely atrial fibrillation (AF). Single-center and small-center studies suggest that new-onset AF is associated with higher mortality and prolonged hospitalization during severe sepsis. However, the relationship between new-onset AF in severe sepsis to prognosis is unknown.

OBJECTIVE

To determine whether new-onset AF increases the risk of stroke and death in severe sepsis.

METHODS

The objective was addressed through the development of a structured, critically appraised topic. This incorporated a clinical scenario, background information, a structured question, literature search strategy, critical appraisal, results, evidence summary, commentary, and bottom-line conclusions. Participants included consultant and fellow-level neurologists, a medical librarian, clinical epidemiologists, and context experts in the fields of vascular neurology, hospital neurology, critical care medicine, and cardiovascular medicine.

RESULTS

A recent retrospective, population-based cohort study was selected and appraised to address this prognostic question. Patients were obtained from the California State Inpatient Database administrative claims data from nonfederal acute care hospitals from January 1 through December 31, 2007. Of the 3,144,787 patients, 49,082 (1.56%) had severe sepsis, defined by the validated International Classification of Disease, 9th Revision, Clinical Modification code 995.92. The a priori outcome measures included in-hospital ischemic stroke and mortality. New-onset AF occurred in 5.9% of patients with severe sepsis versus 0.65% of patients without severe sepsis [odds ratio, 6.82; 95% confidence interval (CI), 6.52-7.11; P<0.001]. Compared with severe sepsis patients without new-onset AF, patients with new-onset AF during severe sepsis had greater risks of in-hospital ischemic stroke (2.6% vs. 0.6% strokes; adjusted odds ratio, 2.70; 95% CI, 2.05-3.57; P<0.001) and in-hospital mortality (56% vs. 39% deaths; adjusted relative risk, 1.07; 95% CI, 1.04-1.11; P<0.001). Findings were robust across 2 separate definitions of severe sepsis and multiple sensitivity analyses.

CONCLUSIONS

In patients with severe sepsis, new-onset AF seems to increase the risk of in-hospital stroke and mortality compared with patients with no or preexisting AF.

Contemporary epidemiology and prognosis of septic shock in infective endocarditis

AIMS

The prognosis of patients with infective endocarditis (IE) remains poor despite the great advances in the last decades. One of the factors closely related to mortality is the development of septic shock (SS). The aim of our study was to describe the profile of patients with IE complicated with SS, and to identify prognostic factors of new-onset SS during hospitalization.

METHODS AND RESULTS

We conducted a prospective study including 894 episodes of IE diagnosed at three tertiary centres. A backward logistic regression analysis was undertaken to determine prognostic factors associated with SS development. Multivariable analysis identified the following as predictive of SS development: diabetes mellitus [odds ratio (OR) 2.06; confidence interval (CI) 1.16-3.68], Staphylococcus aureus infection (OR: 2.97; CI: 1.72-5.15), acute renal insufficiency (OR: 3.22; CI: 1.28-8.07), supraventricular tachycardia (OR: 3.29; CI: 1.14-9.44), vegetation size ≥15 mm (OR: 1.21; CI: 0.65-2.25), and signs of persistent infection (OR: 9.8; CI: 5.48-17.52). Risk of SS development could be stratified when combining the first five variables: one variable present: 3.8% (CI: 2-7%); two variables present: 6.3% (CI: 3.2-12.1%); three variables present: 14.6% (CI: 6.8-27.6%); four variables present: 29.1% (CI: 11.7-56.1%); and five variables present: 45.4% (95% CI: 17.5-76.6%). When adding signs of persistent infection, the risk dramatically increased, reaching 85.7% (95% CI: 61.2-95.9%) of risk.

CONCLUSIONS

In patients with IE, the presence of diabetes, acute renal insufficiency, Staphylococcus aureus infection, supraventricular tachycardia, vegetation size ≥15 mm, and signs of persistent infection are associated with the development of SS.

Role of ion channels in sepsis-induced atrial tachyarrhythmias in guinea pigs

BACKGROUND AND PURPOSE

Supraventricular tachyarrhythmias, including atrial fibrillation, are occasionally observed in patients suffering from sepsis. Modulation of cardiac ion channel function and expression by sepsis may have a role in the genesis of tachyarrhythmias.

EXPERIMENTAL APPROACH

Sepsis was induced by LPS (i.p.; 300 µg·kg(-1) ) in guinea pigs. Membrane potentials and ionic currents were measured in atrial myocytes isolated from guinea pigs 10 h after LPS, using whole cell patch-clamp methods.

KEY RESULTS

In atrial cells from LPS-treated animals, action potential duration (APD) was significantly shortened. It was associated with a reduced L-type Ca(2+) current and an increased delayed rectifier K(+) current. These electrophysiological changes were eliminated when N(G) -nitro-l-arginine methyl ester (l-NAME) or S-ethylisothiourea was given together with LPS. In atrial tissues from LPS-treated animals, Ca(2+) channel subunits (Ca(v) 1.2 and Ca(v) 1.3) decreased and delayed rectifier K(+) channel subunits (K(v) 11.1 and K(v) 7.1) increased. However, L-NAME treatment did not substantially reverse such changes in atrial expression in LPS-treated animals, with the exception that K(v) 11.1 subunits returned to control levels. After LPS injection, inducible NOS in atrial tissues was up-regulated, and atrial NO production clearly increased.

CONCLUSIONS AND IMPLICATIONS

In atrial myocytes from guinea pigs with sepsis, APD was significantly shortened. This may reflect nitration of the ion channels which would alter channel functions, rather than changes in atrial expression of the channels. Shortening of APD could serve as one of the mechanisms underlying atrial tachyarrhythmia in sepsis.

Incident stroke and mortality associated with new-onset atrial fibrillation in patients hospitalized with severe sepsis

CONTEXT

New-onset atrial fibrillation (AF) has been reported in 6% to 20% of patients with severe sepsis. Chronic AF is a known risk factor for stroke and death, but the clinical significance of new-onset AF in the setting of severe sepsis is uncertain.

OBJECTIVE

To determine the in-hospital stroke and in-hospital mortality risks associated with new-onset AF in patients with severe sepsis.

DESIGN AND SETTING

Retrospective population-based cohort of California State Inpatient Database administrative claims data from nonfederal acute care hospitals for January 1 through December 31, 2007.

PATIENTS

Data were available for 3,144,787 hospitalized adults. Severe sepsis (n = 49,082 [1.56%]) was defined by validated International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) code 995.92. New-onset AF was defined as AF that occurred during the hospital stay, after excluding AF cases present at admission.

MAIN OUTCOME MEASURES

A priori outcome measures were in-hospital ischemic stroke (ICD-9-CM codes 433, 434, or 436) and mortality.

RESULTS

Patients with severe sepsis were a mean age of 69 (SD, 16) years and 48% were women. New-onset AF occurred in 5.9% of patients with severe sepsis vs 0.65% of patients without severe sepsis (multivariable-adjusted odds ratio [OR], 6.82; 95% CI, 6.54-7.11; P < .001). Severe sepsis was present in 14% of all new-onset AF in hospitalized adults. Compared with severe sepsis patients without new-onset AF, patients with new-onset AF during severe sepsis had greater risks of in-hospital stroke (75/2896 [2.6%] vs 306/46,186 [0.6%] strokes; adjusted OR, 2.70; 95% CI, 2.05-3.57; P < .001) and in-hospital mortality (1629 [56%] vs 18,027 [39%] deaths; adjusted relative risk, 1.07; 95% CI, 1.04-1.11; P < .001). Findings were robust across 2 definitions of severe sepsis, multiple methods of addressing confounding, and multiple sensitivity analyses.

CONCLUSION

Among patients with severe sepsis, patients with new-onset AF were at increased risk of in-hospital stroke and death compared with patients with no AF and patients with preexisting AF.

Significance of new-onset prolonged sinus tachycardia in a medical intensive care unit: a prospective observational study

OBJECTIVE

Few data are available on sinus tachycardia among medical intensive care unit (ICU) patients. We investigated new critical illnesses related to new-onset prolonged sinus tachycardia (NOPST) and the relationship of NOPST with ICU mortality.

METHODS

The heart rate (HR) of all enrolled patients was monitored hourly over a 12-month period, and NOPST was defined as sinus tachycardia (>100 beats/min) with an increase in HR of more than 20% from the baseline value lasting longer than 6 hours.

RESULTS

Among the 522 patients enrolled, the average mean HR was 96.1 ± 18.4 beats/min. Fifty-two (10.0%) patients met the criteria for NOPST; pneumonia, delirium, septic shock, acute respiratory distress syndrome, catheter-related infections, and mechanical ventilator-related problems were related to the occurrence of NOPST. The ICU mortality rate in patients with a NOPST duration of more than 72 hours was higher compared with other patients with NOPST (60.0% vs 18.5%; P = .002). A high daily mean HR rather than NOPST was a significant predictor of ICU mortality (odds ratio, 1.415; 95% confidence interval, 1.177-1.700).

CONCLUSIONS

Although NOPST was not associated with ICU mortality, it indicates the presence of new critical events in the medical ICU setting.