Preoperative abnormal P and QTc dispersion intervals in patients with metabolic syndrome

Preoperative electrocardiogram in prediction of 90-day postoperative mortality: retrospective cohort study

BACKGROUND

There are conflicting data on the relationship between preoperative electrocardiogram and postoperative mortality. We aimed to assess the predictive value of preoperative ECG on postoperative all-cause mortality in patients undergoing non-cardiac surgery (NCS).

METHODS

We retrospectively reviewed records of hospitalized patients who underwent an internal preoperative examination and subsequent NCS in the years 2015-2021. We recorded patient comorbidities, vital functions, results of biochemical tests, ECG. The primary end point was 90-day postoperative all-cause mortality, acquired from the hospital records and the nationwide registry run by the Institute of Health Information and Statistics of the Czech Republic.

RESULTS

We enrolled a total of 2219 patients of mean age 63 years (48% women). Of these, 152 (6.8%) died during the 90-day postoperative period. There were statistically significant associations between increased 90-day postoperative all-cause mortality and abnormal ECG findings in resting heart rate (≥ 80 bpm, relative risk [RR] = 1.82 and ≥ 100 bpm, RR = 2.57), presence of atrial fibrillation (RR = 4.51), intraventricular conduction delay (QRS > 0.12 s, RR = 2.57), ST segment changes and T wave alterations, left bundle branch hemiblock (RR = 1.64), and right (RR = 2.04) and left bundle branch block (RR = 4.13), but not abnormal PQ and QT intervals, paced rhythm, incomplete right bundle branch block, or other ECG abnormalities. A resting heart rate (≥ 80 bpm, relative risk [RR] = 1.95 and ≥ 100 bpm, RR = 2.20), atrial fibrillation (RR = 2.10), and right bundle branch block (RR = 2.52) were significantly associated with 90-day postoperative all-cause mortality even in subgroup of patients with pre-existing cardiac comorbidities.

CONCLUSIONS

Patients with abnormal preoperative ECG findings face an elevated risk of all-cause mortality within 90 days after surgery. The highest mortality risk is observed in patients with atrial fibrillation and left bundle branch block. Additionally, an elevated heart rate, right bundle branch block, and atrial fibrillation further increase the risk of death in patients with pre-existing cardiac conditions.

Shensong Yangxin Protects Against Metabolic Syndrome-Induced Ventricular Arrhythmias by Inhibiting Electrical Remodeling

Shensong Yangxin (SSYX) is a traditional Chinese medicine, which has been proven to improve the clinical symptoms of arrhythmia. However, the role of SSYX in metabolic syndrome (MetS)-induced electrical remodeling remains to be fully elucidated. Here, we sought to clarify whether SSYX can alter the electrophysiological remodeling of cardiac myocytes from MetS rats by regulating transient outward potassium current (I_to) and calcium current (I_Ca-L). Male Wistar rats were subjected to 16 weeks of high-carbohydrate, high-fat to produce a MetS model group. SSYX (0.4 g/kg) was administrated by daily gavage 8 weeks following high-carbohydrate, high-fat for 8 weeks. In vivo electrophysiological study was performed to evaluated ventricular arrhythmias (VA) vulnerability and electrophysiological properties. The potential electrical mechanisms were estimated by whole-cell patch-clamp and molecular analysis. The H9C2 cells were used to verify the protective role of SSYX in vitro. After 16-week high-carbohydrate, high-fat feeding, MetS model rats showed increased body weight (BW), blood pressure (BP), blood sugar (BS), heart rate (HR) and heart weights to tibia length (HW/TL) ratio. Furthermore, MetS rats depicted increased VA inducibility, shortened effective refractory period (ERP) and prolonged action potential duration (APD). Lower I_Ca-L and I_to current densities were observed in MetS rats than CTL rats. Additionally, MetS rats exhibited significantly increased cardiac fibrosis, decreased Cx43 expression and protein levels of Cav1.2, Kv4.2, Kv4.3 than CTL group. As expected, these MetS-induced effects above were reversed when SSYX was administrated. Mechanistically, SSYX administrated significantly down-regulated the TLR4/MyD88/CaMKII signaling pathway both in vivo and in vitro. Collectively, our data indicated that the electrical remodeling induced by MetS contributed to the increased VA susceptibility. SSYX protects against MetS-induced VA by inhibiting electrical remodeling through TLR4/MyD88/CaMKII signaling pathway.

A new electrocardiographic parameter associated with sudden cardiac death in pulmonary sarcoidosis

INTRODUCTION

The interval from the peak to the end of the electrocardiographic T wave (Tp-Te) may correspond to malignant ventricular arrhythmias. In this study we aimed to assess Tp-Te variability and investigate the transmural dispersion of repolarisation in pulmonary sarcoidosis disease without proofed cardiac involvement.

MATERIAL AND METHODS

This was a retrospective case-control study that included patients who had a pathologic and radiologic diagnosis of sarcoidosis. All data of the patients' demographic features and electrocardiographs were analysed.

RESULTS

We enrolled 78 patients with sarcoidosis and 54 healthy volunteers as controls in our study. Men comprised 36% of the sarcoidosis group and 27% of controls. The mean age in the sarcoidosis and control group was 45.4 ±8.7 years (range: 23-58 years) and 44.6 ±11.9 years (range: 21-73 years), respectively. There was no significant difference between the groups for age or sex (p = 0.654, p = 0.246, respectively). There was a significant increase in Tp-Te results in all precordial leads in the sarcoidosis group compared with the control group (p < 0.05).

CONCLUSIONS

Pulmonary sarcoidosis is suspected to have cardiac involvement; therefore, we need to develop new approaches. We present strong evidence that Tp-Te intervals were increased in patients with pulmonary sarcoidosis, which suggests that there may be a link between sarcoidosis and ventricular arrhythmias without proofed cardiac involvement.

Very-Low-Density Lipoprotein of Metabolic Syndrome Modulates Gap Junctions and Slows Cardiac Conduction

Very-low-density lipoproteins (VLDL) is a hallmark of metabolic syndrome (MetS) and each manifestation of MetS is related to atrial fibrillation (AF) risks. Slowed atrial conduction is a mechanism of AF in MetS. We hypothesized that VLDL can modulate and reduce atrial gap junctions. VLDLs were separated from normal (Normal-VLDL) and MetS (MetS-VLDL) individuals. VLDLs (15 µg/g) and equivalent volumes of saline (CTL) were injected respectively to C57BL/6 mice for 6 weeks. Electrocardiograms demonstrated that MetS-VLDL induced prolongation of P wave (P = 0.041), PR intervals (P = 0.014), QRS duration and QTc interval (both P = 0.003), but Normal-VLDL did not. Optical mapping of perfused hearts confirmed slowed conduction on atria and ventricles of MetS-VLDL mice. Slowed cardiac conduction was associated with significant atrial and ventricular remodeling, along with systolic dysfunction and comparable intra-cardiac fibrosis. MetS-VLDL induced downregulation of Cx40 and Cx43 at transcriptional, translational and tissue levels, and it also enhanced O-GlcNAcylation of Cx40 and Cx43. Protein structure analyses predicted O-GlcNAcylation at serine 18 of Cx40 and Cx43 which may impair stability of gap junctions. In conclusion, MetS-VLDL modulates gap junctions and delays both atrial and ventricular conduction. VLDL may contribute to the pathophysiology of atrial fibrillation and ventricular arrhythmias in MetS.

The anti-arrhythmic effect of chronic intermittent hypobaric hypoxia in rats with metabolic syndrome induced with fructose

This study investigated the anti-arrhythmic effects from chronic intermittent hypobaric hypoxia (CIHH) and the cellular mechanisms in rats with metabolic syndrome. Male Sprague–Dawley rats were randomly distributed among the control, fructose-fed (fed with 10% fructose in the drinking water to induce metabolic syndrome), CIHH (42 days of hypobaric hypoxia treatment simulating an altitude of 5000 m a.s.l.: PB = 404 mm Hg, PO2 = 84 mm Hg, 6 h per day), and the CIHH plus fructose (CIHH-F) groups. In anesthetized rats, the arrhythmia score was determined after 30 min of cardiac ischemia followed by 120 min of reperfusion. Action potentials (AP) were recorded from isolated ventricular papillary muscles. The arrhythmia score was much lower in CIHH-F rats than in the fructose-fed rats. Under basic conditions, AP duration (APD) was significantly shortened in fructose-fed rats, but obviously prolonged in CIHH rats compared with that of the control rats. During ischemia, the AP amplitude, the maximal rate of rise of phase 0, APD, and resting potential, were lower in the control, fructose-fed, and CIHH-F groups, but were not changed in the CIHH rats. The lower AP during ischemia did not recover after washout for the fructose-fed rats. In conclusion, CIHH protects the heart against ischemia–reperfusion induced arrhythmia in rats with metabolic syndrome. This effect of CIHH is possibly related to baseline prolongation of the AP and attenuation of AP reduction during ischemia–reperfusion.

The Effects of Metabolic Syndrome on TpTe Interval and TpTe/QT Ratio in Patients with Normal Coronary Arteries

OBJECTIVE

T wave peak to T wave end (TpTe) interval and TpTe/QT have been accepted as predictors of ventricular arrythmia. In this study our aim is to investigate the effect of metabolic syndome on these parameters in patients with angiographically normal coronary arteries.

MATERIALS AND METHODS

Thirty patients with metabolic syndrome (4 male, mean age 52±7.8 years) and twenty patients without metabolic syndrome as control group (8 male, mean age 54±9.3 years) were included. TpTe interval and TpTe/QT ratio were measured from the 12-lead electrocardiogram. These parameters were compared between the groups.

RESULTS

When compared with to the control group the systolic and diastolic blood pressure, pulse pressure, waist circumference, triglyceride and fasting plasma glucose levels were higher and HDL cholesterol level was lower in the metabolic syndrome group. In the analysis of electrocardiography, QT dispersion (QTd) and corrected QTd were significantly increased in metabolic syndrome group as compared to the controls group (44±14 versus 30±12 ms and 433±10 versus 405±4 ms, all p value p=0.01). TpTe interval and TpTe/QT ratio were also significantly higher in patient with metabolic syndrome (112±10 versus 91±10 ms and 0.25±0.02 versus 0.22±0.01, all p value p=0.01).

CONCLUSION

According to these results, we supposed that TpTe/QT ratio and TpTe interval is prolonged and those patients with metabolic syndrome may be at greater risk of ventricular arrhythmias.

Impact of psychotropic drugs on QT interval dispersion in adult patients

Background

Drug-induced increase in QT dispersion has been associated with potentially fatal ventricular arrhythmias. Little is known about the use of psychotropic substances, alone or in combination with other drugs on QT dispersion.

Objectives

To evaluate the impact of psychotropic drugs on QT interval dispersion in adults.

Methods

An observational cohort study was designed involving 161 patients hospitalized from an emergency department at a tertiary hospital, divided into psychotropic users or non-users. Demographic, clinical, laboratory data and drugs used on a regular basis were collected on admission, in addition to 12-lead electrocardiogram with QT dispersion measurement.

Results

QT dispersion was significantly higher in the psychotropic user group compared to non-users (69.25 ± 25.5 ms vs. 57.08 ± 23.4 ms; p = 0.002). The QT interval corrected by Bazzett formula was also higher in the psychotropic drugs user group, with statistical significance. (439.79 ± 31.14 ms vs. 427.71 ± 28.42 ms; p = 0.011). A regression analysis model showed a positive association between the number of psychotropic drugs used and QT interval dispersion, with r = 0.341 and p < 0.001.

Conclusions

The use of psychotropic drugs was associated with increased QT dispersion and this increase was accentuated, as the number of psychotropic drugs used was higher.

QT dispersion in mild cognitive impairment: a possible tool for predicting the risk of progression to dementia?

OBJECTIVE

The aim of this research was to investigate relationships between cognitive function and non-invasive, repeatable cardiac parameters in elderly subjects suffering from mild cognitive impairment (MCI) or Alzheimer's disease (AD).

METHODS

Two hundred and twenty-four community-living elderly subjects, 31 AD patients, 77 MCI patients, and 116 cognitively normal subjects (CNS), were evaluated for cognitive abilities (Mini Mental State Examination score (MMSE)) and for electrocardiographic [corrected heart rate QT interval dispersion (QTcD)] and echocardiographic [Left ventricular ejection fraction (LVEF)] parameters.

RESULTS

Mean values of LVEF were not significantly different between the three groups; QTcD mean values were significantly lower in CNS group than in subjects with MCI and AD. The Pearson Product Moment Correlation test, carried out in the three study groups, showed a significant inverse correlation between QTcD and MMSE score (r = -0.357; p < 0.01) in the group of MCI patients, only. In multivariable-adjusted linear regression tests, QTcD (p = 0.030) and education (p = 0.021) are associated with MMSE score in MCI group. Only the parameter of education appears to predict MMSE in CNS group; none of these parameters appear to predict MMSE in the group of patients with AD.

CONCLUSION

The association between QTcD and MMSE requires cautious interpretation and further extensive investigation. However, if confirmed by longitudinal studies, the finding could play a role in the management of the subjects with MCI.