Value of prolonged QRS duration as a predictor of low cardiac output syndrome in patients with impaired left ventricular systolic function who undergo isolated coronary artery bypass grafting

Definitions of low cardiac output syndrome after cardiac surgery and their effect on the incidence of intraoperative LCOS: A literature review and cohort study

Objectives

Low cardiac output syndrome (LCOS) is a serious complication after cardiac surgery. Despite scientific interest in LCOS, there is no uniform definition used in current research and clinicians cannot properly compare different study findings. We aimed to collect the LCOS definitions used in literature and subsequently applied the definitions obtained to existing data to estimate their effect on the intraoperative LCOS incidences in adults, children and infants.

Design

This is a literature review, followed by a retrospective cohort study.

Setting

This is a single-institutional study from a university hospital in the Netherlands.

Participants

Patients from all ages undergoing cardiac surgery with cardiopulmonary bypass between June 2011 and August 2018.

Interventions

We obtained different definitions of LCOS used in the literature and applied these to data obtained from an anesthesia information management system to estimate intraoperative incidences of LCOS. We compared intraoperative incidences of LCOS in different populations based on age (infants, children and adults).

Measurements and main results

The literature search identified 262 LCOS definitions, that were applied to intraoperative data from 7,366 patients. Using the 10 most frequently published LCOS definitions, the obtained incidence estimates ranged from 0.4 to 82% in infants, from 0.6 to 56% in children and from 1.5 to 91% in adults.

Conclusion

There is an important variety in definitions used to describe LCOS. When applied to data obtained from clinical care, these different definitions resulted in large distribution of intraoperative LCOS incidence rates. We therefore advocate for standardization of the LCOS definition to improve clinical understanding and enable adequate comparison of outcomes and treatment effects both in daily care and in research.

Predicting adverse cardiovascular outcomes in post-coronary artery bypass grafting patients using novel ECG frequency analysis of the QRS complex

Background

A novel metric called Layered Symbolic Decomposition frequency (LSDf) has been shown to be an independent predictor of ventricular arrhythmia and mortality in patients receiving implantable cardioverter‐defibrillator (ICD) devices. This novel index studies the fragmentation of the QRS complex. However, its generalizability to predict cardiovascular events for other cardiac procedures is unknown. Herein, we investigated the applicability of LSDf as a predictive measure for major adverse cardiovascular events (MACE) in patients receiving coronary artery bypass grafting (CABG).

Methods and Results

One hundred ninety‐five patients had high‐resolution ECG recorded prior to CABG surgery in 2012/2013 and were followed for a mean duration of 7.32 ± 0.32 years for postoperative cardiovascular outcomes. These outcomes were described as a modified composite of MACE defined as hospitalization for heart failure, ventricular tachycardia, ventricular fibrillation, and cardiovascular death including stroke and cardiac arrest. One hundred seventy‐two patients were included for analysis and 18 patients experienced a postoperative cardiovascular outcome. These patients had significantly increased age (71.3 vs. 64.6 years, p = .007), prolonged QRS duration (113.22 vs. 97.35 ms, p = .003), reduced left ventricular ejection fraction (42.7% vs. 56.5%, p < .001), and lower LSDf percent (13.5% vs. 16.9%, p = .002). Patients with an LSDf below 13.25% were 4.8 (OR 1.7–13.5, p < .001) times more likely to experience a MACE and up to 19.4 (OR 4.2–90.3, p < .001) times more likely to experience a MACE when older than 70 years and an ejection fraction below 50%.

Conclusion

Layered Symbolic Decomposition frequency may be an applicable metric to predict long‐term cardiovascular outcomes in patients with ischemic heart disease.

Prolonged QRS independently predicts long-term all-cause mortality in patients with narrow QRS complex undergoing coronary artery bypass grafting surgery (9-year follow-up results)

Aim

We investigated the association of intermediate QRS prolongation with the long-term all-cause mortality in coronary artery bypass grafting (CABG) surgery patients with a narrow QRS complex in the preoperative electrocardiography (ECG).

Material and methods

A total of 221 consecutive patients with narrow QRS (< 120 ms) sinus rhythm who underwent CABG surgery were included in the study. The patients were followed up for 9.2 years postoperatively in terms of mortality outcomes.

Results

Follow-up data were obtained from 211 (173 men, 38 women) of 221 patients. Death occurred in 57 of them. We examined patients in the two groups according to survival outcomes. In multivariate COX regression analysis EuroSCORE (OR = 1.342, 95% CI: 1.167-1.544, p < 0.001), extent of coronary artery disease (OR = 1.768, 95% CI: 1.034-3.020, p = 0.037), QRS duration (OR = 1.029, 95% CI: 1.002-1.058, p = 0.035) and fasting glucose levels (OR = 0.992, 95% CI: 0.984-0.999, p = 0.029) were independent predictors of all-cause mortality. QRS duration > 89.5 ms determined all-cause mortality with a sensitivity of 73.7% and a specificity of 52% (OR = 2.07) due to ROC analysis. All-cause mortality was significantly higher in patients with preop QRS duration > 90 ms from the first year (c² = 6.724, p = 0.010).

Conclusions

In CABG patients with a narrow QRS complex, preoperative intermediate prolonged QRS is an independent predictor of all-cause mortality in long-term follow-up.

Prophylactic preoperative levosimendan for off-pump coronary artery bypass grafting in patients with left ventricular dysfunction: Single-centered randomized prospective study

Background:

Off-pump coronary artery bypass surgery (OPCAB) is often complicated by hemodynamic instability, especially in patients with prior left ventricular (LV) dysfunction and appropriate choice of inotrope plays a vital role in perioperative management of these patients.

Aim and Objective:

To study hemodynamic effects and immediate outcome of prophylactic infusion of levosimendan in patients with the LV dysfunction undergoing OPCAB surgery and whether this strategy helps in successful conduct of OPCAB surgery.

Materials and Methods:

After Institutional Ethics Committee approval, 60 patients posted for elective OPCAB surgery were randomly divided into two groups (n = 30 each). Patients with the LV ejection fraction <30% were included. Study group was started on injection levosimendan (@ 0.1 μg/kg/min) in the previous night before surgery and continued for 24 h including intraoperative period. Hemodynamic monitoring included heart rate, invasive blood pressure, cardiac index (CI), pulmonary capillary wedge pressure (PCWP), pulse oximetry, and arterial blood gases with serum lactates at as T0 (baseline), T1 (15 min after obtuse marginal and/or PDA anastomoses), T2 (at end of surgery), T3 (6 h after surgery in Intensive Care Unit [ICU]), T4 (12 h after surgery), and T5 (24 h after surgery in ICU). Vasopressor was added to maintain mean arterial pressure >60 mmHg. Chi-square/Fisher's exact/Mid P exact test and Student's t-tests were applied for categorical and continuous data.

Results:

CI was greater and PCWP reduced significantly in Group L during intraoperative and early postoperative period. Serum lactate concentration was lower in patients pretreated with levosimendan. Incidence of postoperative atrial fibrillation (POAF) (36.6 vs. 6.6%; P = 0.01), low cardiac output syndrome (LCOS) (30% vs. 6%; P = 0.02), and acute kidney injury (23.3% vs. 6.7%; P = 0.04) was less in Group L. Three patients (10%) in control group required conversion to cardiopulmonary bypass (CPB) as compared to none in the study group. There was no difference regarding ICU or hospital stay and mortality in both groups.

Conclusion:

Preoperative levosimendan helps in successful conduct of OPCAB and reduces the incidence of LCOS, POAF, conversion to CPB, and requirement of intra-aortic balloon pump.

Risk factors for decreased cardiac output after coronary artery bypass grafting: a prospective cohort study

BACKGROUND

No previous study has investigated the predictive risk factors of the nursing diagnosis of risk for decreased cardiac output after coronary artery bypass grafting (CABG).

AIMS

This study aimed to identify the predictive risk factors of the nursing diagnosis of risk for decreased cardiac output after CABG.

METHODS

This was a prospective cohort study performed at a cardiac university hospital in São Paulo, Brazil and 257 adult patients undergoing CABG were included. Potential risk factors for low cardiac output in the immediate post-operative period were investigated using the patients' medical records. Univariate analysis and logistic regression were used to identify the predictive risk factors of decreased cardiac output. The area under the receiver operating characteristic curve was calculated as a measure of accuracy. The variables that could not be analysed through logistic regression were analysed through Fisher's exact test.

RESULTS

One hundred and ninety-five patients had low cardiac output in the immediate post-operative period. The predictive risk factors included age ⩾60 years, decreased left ventricle ejection fraction, not using the radial artery graft, positive fluid balance and post-operative arrhythmia that differed from the pre-operative arrhythmia. This model predicted the outcome with a sensitivity of 62.9%, a specificity of 87.2% and an accuracy of 81.5%. The variables analysed through Fisher's exact test included heart failure, re-exploration and bleeding-related re-exploration.

CONCLUSIONS

The predictive risk factors for the nursing diagnosis of risk for decreased cardiac output after CABG were found. These results can be used to direct nurses in patient monitoring, staff training and nursing team staffing.

The association between prolongation in QRS duration and presence of coronary collateral circulation in patients with acute myocardial infarction

BACKGROUND

It is known that QRS duration is related to prognosis in acute myocardial infarction. The relation between QRS duration and coronary collateral circulation is uncertain. In the present study, we aimed to determine the relation between QRS duration and coronary collateral circulation in patients admitted with acute myocardial infarction.

METHODS

The present study was composed of 109 consecutive patients with acute myocardial infarction. All patients had total occlusion in the left anterior descending coronary artery. Electrocardiographic recordings on admission were obtained for the assessment of QRS duration. The Rentrop classification was used to define coronary collateral circulation on coronary angiography. Patients were divided into two groups as follows: Group 1 with poor coronary collateral circulation (Rentrop 0-1) and Group 2 with good coronary collateral circulation (Rentrop 2-3).

RESULTS

Of all patients, 62 patients were included in group 1 and 47 patients in group 2, respectively. In the present study, patients in the group 1 had longer QRS duration than patients in the group 2 (p < 0.005). Additionally, we found that Rentrop grading had negative correlation with both QRS duration and white blood cell count (r: -0.28; p < 0.005 and r: -0.35; p < 0.001).

CONCLUSION

Our study showed that there was an inverse relationship between QRS duration on admission and presence of coronary collateral circulation in patients with acute myocardial infarction.

QRS duration: a novel marker of microvascular reperfusion as assessed by myocardial blush grade in ST elevation myocardial infarction patients undergoing a primary percutaneous intervention

Objectives

Prolonged QRS duration is a predictor of poor prognosis in patients with coronary artery disease. The association between the duration of QRS and myocardial reperfusion is not very well understood. Our aim was to assess the relationship between the measurements of QRS duration and myocardial blush grade (MBG) in patients with ST elevation myocardial infarction (STEMI) who were treated with a primary percutaneous intervention.

Patients and methods

A total of 213 patients (mean age: 57.5±11 years) with STEMI were included. ECG recordings were obtained for the evaluation of the QRS duration before and after primary percutaneous coronary intervention. Angiographic assessment in the infarct-related artery was performed using the MBG. Patients were categorized into two groups of those with impaired microvascular reperfusion (MBG: 0–1) and those with normal microvascular reperfusion (MBG: 2–3).

Results

Overall, 105 and 108 patients had an MBG of 0–1 or 2–3, respectively. There is no significant difference between patient’s characteristics. Despite the absence of a difference between two groups in terms of the QRS duration at presentation (P: 0.57), patients with impaired microvascular reperfusion were found to have longer QRS duration at immediately postprocedure (P: 0.003) and postprocedure 60 min time-points (P<0.001). Correlation analyses showed a positive correlation between pain-to-balloon time and QRS duration at postprocedure 60 min time-points (r: 0.137 and P: 0.04).

Conclusion

Our results suggest that longer QRS duration after angioplasty seemed to indicate the presence of impaired microvascular reperfusion in patients with STEMI.

Risk for decreased cardiac output: validation of a proposal for nursing diagnosis

AIM

To verify the content validity of the nursing diagnosis risk for decreased cardiac output (RDCO).

BACKGROUND

DCO is a phenomenon that is not restricted to individuals or environments that specifically focus on cardiovascular care. It is not only prevalent in cardiovascular care units, but also in post-anaesthesia units and non-cardiac care units among individuals with non-cardiogenic disorders. A significant decrease in cardiac output is a life-threatening situation, demonstrating the need for developing a risk nursing diagnosis for early intervention. The development of this diagnosis requires the construction of a diagnosis label, a definition of the diagnostic concept and the risk factors associated with the diagnosis.

METHODS

The research was carried out in two methodological stages based on the Fehring diagnosis content validation model. The quantitative analysis consisted of the calculation of the weighted mean of the values attributed by experts to each risk factor, the level of agreement/disagreement between the experts regarding the operational definitions of risk factors and the index of diagnostic content validity (DCV).

RESULTS

The label 'risk for decreased cardiac output' was considered representative of a nursing diagnosis defined as 'at risk of developing a health status characterized by an insufficient quantity of blood pumped by the heart to meet physical metabolic demands'. Critical risk factors (DCV ≥ 0·7) were myocardial dysfunction (0·887), blood loss (0·875), increase in intrapericardial pressure (0·825), condition that leads to changes in cardiac rhythm and/or electrical conduction (0·812), deficient fluid volume (0·725), plasma loss (0·712), ineffective tissue perfusion (0·712) and electrolyte imbalance (0·7).

CONCLUSIONS

The research identified eight risk factors with valid content for assessment of RDCO.

IMPLICATIONS FOR NURSING PRACTICE

The identification of risk factors for DCO assists nurses to intervene early and minimize the consequences of a deficient cardiac function.

Defining characteristics of decreased cardiac output: a literature review

OBJECTIVE

The study aims to proceed a literature review of defining characteristics (DCs) of decreased cardiac output (DCO).

METHODS

  Medline database was used to perform this study. The descriptors used were "low cardiac output" and "nursing diagnosis."

RESULTS

Seventy-nine DCs were identified. Among them, 28 have already been approved by NANDA-I. Some data from microcirculation assessment such as high levels of serum lactate and decreased oxygen venous saturation were identified as indicators of this nursing diagnosis.

CONCLUSIONS

Some of the approved DCs were identified through literature review but others seem to be new as they have not been cited in the NANDA-I classification.

PRACTICAL IMPLICATIONS

Further content and clinical validations are needed to confirm if data from microcirculation might be considered as DCs of DCO.

QRS duration and early hemodynamic instability after coronary revascularization surgery

INTRODUCTION AND OBJECTIVES

The duration of the QRS interval measured by ECG is a marker of ventricular dysfunction and indicates a poor prognosis. Its value in patients undergoing coronary revascularization surgery has not been established.

METHODS

The study involved 203 consecutive patients (age 64+/-9 years, 74% male) scheduled for elective coronary surgery. The maximum QRS duration measured on a preoperative 12-lead ECG was recorded. Hemodynamic instability was defined as the occurrence of cardiac death, heart failure, or a need for intravenous inotropic drugs or intra-aortic balloon counterpulsation during the postoperative period.

RESULTS

The occurrence of hemodynamic instability (n=94, 46%) was associated with a longer preoperative QRS duration (97.5+/-21.14 ms vs 88.5+/-16.9 ms; P=.001). The QRS duration was also longer in patients who developed heart failure (n=23; 104.3+/-22.9 ms vs. 91.1+/-18.5 ms; P=.002), needed inotropic drugs (n=77; 96.5+/-20.5 ms vs. 90.1+/-18.2 ms; P=.007) or developed postoperative atrial fibrillation (n=58; 98.2+/-23.8 ms vs. 90.4+/-17.0 ms; P=.018). Bundle branch block was associated with a greater need for intra-aortic balloon counterpulsation (29% vs 12%; P=.012) or inotropic drugs (58% vs 35%; P=.014) and a higher incidence of hemodynamic instability (69% vs 42%; P=.006). Multivariate analysis identified the following independent predictors of hemodynamic instability: QRS duration (adjusted odds ratio [OR] per 10 ms=1.49; 95% confidence interval [CI], 1.11-2; P=.007), the lack of an arterial graft (OR=3.6; 95% CI, 1.14-11.6; P=.029) and extracorporeal circulation time (OR per min=1.013; 95% CI, 1.003-1.023; P=.013).

CONCLUSIONS

The intraventricular conduction delay, or QRS duration, was associated with a higher risk of postoperative hemodynamic instability following coronary surgery.