A Retrospective Study of Hemodynamic Changes in Patients After Off-Pump Coronary Artery Bypass Graft Surgery Using Impedance Cardiography

Impedance cardiogram based exploration of cardiac mechanisms in post-traumatic stress disorder during trauma recall

Post-traumatic stress disorder (PTSD) is an independent risk factor for developing heart failure; however, the underlying cardiac mechanisms are still elusive. This study aims to evaluate the real-time effects of experimentally induced PTSD symptom activation on various cardiac contractility and autonomic measures. We recorded synchronized electrocardiogram and impedance cardiogram from 137 male veterans (17 PTSD, 120 non-PTSD; 48 twin pairs, 41 unpaired singles) during a laboratory-based traumatic reminder stressor. To identify the parameters describing the cardiac mechanisms by which trauma reminders can create stress on the heart, we utilized a feature selection mechanism along with a random forest classifier distinguishing PTSD and non-PTSD. We extracted 99 parameters, including 76 biosignal-based and 23 sociodemographic, medical history, and psychiatric diagnosis features. A subject/twin-wise stratified nested cross-validation procedure was used for parameter tuning and model assessment to identify the important parameters. The identified parameters included biomarkers such as pre-ejection period, acceleration index, velocity index, Heather index, and several physiology-agnostic features. These identified parameters during trauma recall suggested a combination of increased sympathetic nervous system (SNS) activity and deteriorated cardiac contractility that may increase the heart failure risk for PTSD. This indicates that the PTSD symptom activation associates with real-time reductions in several cardiac contractility measures despite SNS activation. This finding may be useful in future cardiac prevention efforts.

Improvement of hemodynamic parameters in aortic stenosis patients with transcatheter valve replacement by using impedance cardiography

Background

The hemodynamic changes of patients with aortic stenosis (AS) who underwent transcatheter valve replacement (TAVR) have not been completely investigated.

Methods and results

We enrolled 74 patients with AS who underwent TAVR and assessed cardiac function changes at 1 week post-operation by impedance cardiography (ICG) in a supine position at rest for more than 15 min. Of the 74 patients, 47 had preserved left ventricular ejection fraction (LVEF ≥ 50%; preserved-LVEF group) and 27 had reduced LVEF (LVEF <50%; reduced-LVEF group). TAVR improved the cardiac structure and function, as evidenced by the decrease in the left ventricular end-diastolic (LVED), left atrial diameter (LAD), and an increase in the LVEF. We observed a decrease in N-terminal pro-brain natriuretic peptide (NT-proBNP) level compared to that before treatment. Moreover, patients with reduced LVEF had a more significant reduction of NT-proBNP than those with preserved LVEF. Meanwhile, the blood pressure of patients had no significant differences pre- and post-operation. Based on ICG, there were no changes in the parameter of cardiac preload [thoracic fluid content (TFC)]. We observed an improvement in parameters of diastolic cardiac function [left ventricular ejection time (LVET) and pre-ejection period (PEP)]. And we detected converse results in parameters of heart systolic function [systolic time ratio (STR), cardiac output (CO), cardiac index (CI), stroke index (SI), and stroke volume (SV)] and cardiac afterload [stroke systemic vascular resistance (SSVR) and SSVR-index (SSVRI)]. In addition, TFC level was decreased in patients with thoracic volume overload after valve replacement. Subgroup analysis showed that the changes in those parameters were more noticeable in patients with reduced LVEF than that with preserved LVEF. Moreover, we observed no effects on parameters of heart systolic function and heart afterload in the LVEF ≥ 50% group before and after TAVR.

Conclusion

Our data revealed a beneficial effect of TAVR in diastolic function and preload as detected by the ICG. But the LV systolic function and cardiac afterload were not improved in patients with LVEF <50%. The result indicated that ICG could be used as an important technique to monitor the cardiac condition of patients after aortic valve replacement.

Effects of WeChat platform-based health management on health and self-management effectiveness of patients with severe chronic heart failure

BACKGROUND

Epidemiological studies have found that the prevalence of chronic heart failure in China is 0.9%, the number of people affected is more than 4 million, and the 5-year survival rate is even lower than that of malignant tumors.

AIM

To determine the impact of WeChat platform-based health management on severe chronic heart failure patients’ health and self-management efficacy.

METHODS

A total of 120 patients suffering from chronic heart failure with cardiac function grade III-IV, under the classification of the New York Heart Association, were admitted to our hospital in May 2017. In January 2020, they were divided into two groups: A control group (with routine nursing intervention) and an observation group (with WeChat platform-based health management intervention). Changes in cardiac function, 6-min walking distance (6MWD), high-sensitivity cardiac troponin (hs-cTnT), and N-terminal pro B-type natriuretic peptide (NT-proBNP) were detected in both groups. The Self-Care Ability Scale (ESCA) score, Minnesota Living with Heart Failure Questionnaire score, and compliance score were used to evaluate self-management ability, quality of life, and compliance of the two groups. During a follow-up period of 12 mo, the occurrence of cardiovascular adverse events in both the groups was counted.

RESULTS

The left ventricular ejection fraction, stroke output, and 6MWD increased, and the hs-cTnT and NT-proBNP decreased in both the groups, as compared to those before the intervention. Further, cardiac function during the 6MWD, hs-cTnT, and NT-proBNP improved significantly in the observation group after intervention (P < 0.05). The scores of self-care responsibility, self-concept, self-care skills, and self-care health knowledge in the observation group were higher than those of the control group before intervention, and their ESCA scores were significantly improved after intervention (P < 0.05). The Minnesota heart failure quality of life (LiHFe) scores of physical restriction, disease symptoms, psychological emotion, social relations, and other items were decreased compared to those of the control group before intervention, and the LiHFe scores of the observation group were significantly improved compared to those of the control group (P < 0.05). With intervention, the compliance scores of rational diet, regular medication, healthy behavior, and timely reexamination were increased, thereby leading to the compliance scores of the observation group being significantly improved compared to those of the control group (P < 0.05). During the 12 mo follow-up, the incidence rates of acute myocardial infarction and cardiogenic rehospitalization in the observation group were lower than those of the control group, and the hospitalization time in the observation group was shorter than that of the control group, but there was no significant difference between the two groups (P > 0.05).

CONCLUSION

WeChat platform-based health management can improve the self-care ability and compliance of patients with severe chronic heart failure, improve the cardiac function and related indexes, reduce the occurrence of cardiovascular adverse events, and enable the avoidance of rehospitalization.

Regulatory role of microRNA-320 during off-pump coronary artery bypass grafting with dexmedetomidine adjunct anesthesia

The present study investigated the effects of dexmedetomidine on the expression level of microRNA-320 (miR-320) and neuroglobin (NGB) in patients undergoing off-pump coronary artery bypass grafting (OPCABG). A total of 40 patients undergoing OPCABG were recruited and randomly divided into the dexmedetomidine and normal saline groups (treated before anesthesia), respectively. The NGB levels in the blood samples before and after surgery were analyzed and compared. The CATH.a cells were cultured and induced with dexmedetomidine, and the NGB expression level was detected. CATH.a cells were treated with NGB and lipopolysaccharide (LPS), and the cell survival rate was determined. The miR-320 expression levels in the blood samples and dexmedetomidine-induced cells were detected. Dual-luciferase reporter assay was performed. Compared with control subjects, patients in the dexmedetomidine group had higher NGB levels in the blood. In the CATH.a cells, the dexmedetomidine treatment upregulated the NGB levels. Moreover, upon pre-incubation with NGB and LPS stimulation, dexmedetomidine elevated cell viability. Furthermore, miR-320 expression levels were significantly downregulated in the blood of patients in the dexmedetomidine group, as well as in the dexmedetomidine-induced cells. Dual-luciferase reporter assay confirmed that miRNA-320a directly targeted on NGB, and upregulated miRNA-320a in CATH.a cells decreased cell proliferation activity. Pre-administration of dexmedetomidine can decrease miR-320 expression level in the blood of patients undergoing OPCABG, stimulating the high expression of NGB and increasing the proliferation activity of neuronal cells, which may decrease the postoperative cognitive impairment.

The non-invasive evaluation of heart function in patients with an acute myocardial infarction: The role of impedance cardiography

BACKGROUND

The purpose of this study was to analyze hemodynamic changes in patients treated with percutaneous coronary intervention (PCI) at an early stage of acute myocardial infarction (AMI) and at 1-month follow-up.

METHODS

Patients with AMI (n = 27) who underwent PCI were analyzed using impedance cardiography (ICG). ICG data were collected continuously (beat by beat) during the whole PCI procedure and thereafter at every 60 s for the next 24 h. Blood pressure was taken every 10 min and stored for analysis. Additionally the following parameters were measured: cardiac index (CI), stroke volume index (SVi), left cardiac work index (LCWi), contractility index (CTi), ventricular ejection time (VET), systemic vascular resistance index (SVRi), thoracic fluid content index (TFCi) and heart rate (HR).

RESULTS

In the first 24 h after PCI all the contractility parameters including CI, SVi, LCWi, CTi and VET significantly decreased, whereas HR, SVRi and TFCi increased compared to baseline. All of the parameters examined got normalized at 1 month. The CI, SVi, LCWi, CTi, SVRi did not significantly differ from baseline, however the HR and VET were significantly lower compared to first day after PCI CONCLUSIONS: Cardiac performance deteriorates early after PCI and normalizes after 1 month in patients with an AMI. ICG is useful for hemodynamic monitoring of AMI patients during and after invasive therapy.