Does Tpeak-Tend provide an index of transmural dispersion of repolarization?

T wave peak-to-end interval in COPD

Introduction

The interval from the peak to the end of the electrocardiographic (ECG) T wave (Tp–Te) can estimate cardiovascular mortality and ventricular tachyarrhythmias.

Objectives

In this study, we aimed to define a new ECG parameter in patients with COPD.

Methods

This was a cross-sectional observational study that included COPD patients who were diagnosed previously and followed up in the outpatient clinic. All data of the patients’ demographic features, history, spirometry, and electrocardiographs were analyzed.

Results

We enrolled 134 patients with COPD and 40 healthy volunteers as controls in our study. Patients already known to be having COPD who were under follow-up for their COPD and diagnosed as having COPD according to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria were included. Men comprised 82.8% of the COPD group and 73.2% of controls. The mean age in the COPD and control group was 60.2±9.4 and 58.2±6.7 years, respectively. There was no significant difference between the groups for age or sex (p=0.207, p=0.267, respectively). There were 46 (34.3%) patients in group A, 23 (17.2%) patients in group B, 26 (19.4%) patients in group C, and 46 (29.1%) patients in group D as COPD group. There was a significant increase in Tp–Te results in all precordial leads in the COPD group compared with the control group (p<0.05). Precordial V4 lead has the most extensive area under the curve (0.831; sensitivity 76.5%, specificity 89.6%).

Conclusion

We present strong evidence that Tp–Te intervals were increased in patients with COPD, which suggests that there may be an association between COPD and ventricular arrhythmias and cardiac morbidity.

The dispersion of myocardial repolarization in ischemic stroke and intracranial hemorrhage

BACKGROUND

Markers of dispersion of myocardial repolarization have been proposed to identify the patients at higher risk of malignant arrhythmic events. The aim of the present study is to assess a possible association of the electrocardiografic (ECG) markers of the dispersion of repolarization with the type of stroke, involvement of insula, neurological severity (National Institutes of Health Stroke Scale, NIHSS score), and disability (modified Rankin Scale, mRS score) in patients with a cerebrovascular event.

METHODS

We conducted a retrospective analysis based on data prospectively collected from consecutive patients with a cerebrovascular event who underwent 12‑lead ECG at admission to the Verona Stroke Unit.

RESULTS

Of the 63 patients included in the study, 55 had ischemic stroke and 8 intracranial hemorrhage. TpTe (time between the peak and the end of the T wave) and TpTe/QTc (TpTe/corrected time between the start of the Q wave and the end of the T wave) in lead V5 were higher in intracranial hemorrhage than in ischemic stroke (p = 0.03 and p = 0.04, respectively) and QT max (the longest QT calculated in the 12 leads) was higher in patients with involvement of insula (p ≤ 0.01). A correlation was found between QTc max and NIHSS score at admission (p = 0.02), QT max and NIHSS score at discharge (p = 0.05), and QT max and mRS score at discharge (p = 0.02).

CONCLUSIONS

TpTe and TpTe/QTc in V5 lead were associated with intracranial hemorrhage and QT max was associated with involvement of insula. The prolongation of QT was correlated with neurological severity and disability.

Tpeak-Tend dispersion as a predictor for malignant arrhythmia events in patients with vasospastic angina

BACKGROUND

Tpeak-Tend interval (Tp-e interval) in electrocardiogram (ECG) has been reported to predict malignant arrhythmia events (MAE) in ST-segment elevation myocardial infarction and ion channelopathy. Tp-e interval and other ECG parameters as predictors for MAE was evaluated in patients with vasospastic angina (VA).

METHODS AND RESULTS

Sixty-two patients with VA (Non-MAE group) and 20 patients with VA complicated by MAE (MAE group) were enrolled in our Division of Cardiology between January 2010 and December 2015. Continuous variables were analyzed by t-test and categorical variables by Chi-square analysis. Patients with MAE showed greater QTc (corrected QT interval) dispersion (P=0.005), Tp-ec (corrected Tp-e) interval (P=0.001), Tp-ec dispersion (P<0.001) and Tp-e/QT ratio (P<0.001) than those in non-MAE groups when ST-segment elevated. After elevated ST-segment returned, there were no significant differences in these ECG parameters between two groups (All P>0.05). At univariate binary logistic regression analysis QTc dispersion (odds ratio(OR)=1.133; P=0.013), Tp-ec (OR=1.058; P=0.003), Tp-e/QT (OR=1.403; P=0.001), and Tp-ec dispersion (OR=1.497; P=0.004) were significantly associated with MAE. At multivariable logistic regression analysis, Tp-ec dispersion remained a predictor of MAE. Receiver operating characteristic (ROC) curve analysis showed that only AUC (Area under curve) of Tp-ec dispersion had significant difference with those in QTc dispersion (P<0.001), Tp-ec (P=0.003), and Tp-e/QT ratio (P=0.012), respectively.

CONCLUSIONS

QTc dispersion, Tp-ec, Tp-e/QT and Tp-ec dispersion were significantly increased in VA patients with MAE than those without MAE when coronary spasm was onset. Prolonged Tp-ec dispersion was the best discriminators and a strong independent predictor of MAE in VA patients.

Is There any Relationship Between Myocardial Repolarization Parameters and the Frequency of Ventricular Premature Contractions?

BACKGROUND

Ventricular premature contractions (VPCs) may trigger lethal ventricular arrhythmias in patients with structural heart disease. However, this role of VPCs in healthy people remains controversial once that not enough clinical trials are available. Recently, some myocardial repolarization markers, such as Tp-e interval, Tp-e/QT, and Tp-e/QTc ratios, have been reported to be useful for predicting lethal ventricular arrhythmias in various clinical disorders without structural heart disease.

OBJECTIVE

In this study, we aimed to investigate the relation between VPC frequent and myocardial repolarization markers in individuals without structural heart disease.

METHODS

This study included 100 patients who had complaints of dizziness and palpitations. Twelve-lead electrocardiography and 24-hour ambulatory Holter recordings were obtained from all patients. VPC burden was calculated as the total number of VPCs divided by the number of all QRS complexes in the total recording time. P-values < 0.05 were considered significant.

RESULTS

Tp-e interval and Tp-e/QTc ratio were significantly higher in patients with higher VPC burden than in patients with lower VPC burden, and a positive correlation was found between these markers and VPC burden. Tp-e (β = 1.318, p = 0.043) and Tp-e/QTc (β = -405.136, p = 0.024) in the lead V5 were identified as independent predictors of increased VPC burden.

CONCLUSIONS

Tp-e interval and Tp-e/QTc ratio increased in patients with high VPC number. Our study showed that VPCs may have a negative effect on myocardial repolarization. This interaction may lead to an increased risk of malignant arrhythmias.

Elevated LV Mass and LV Mass Index Sign on the Athlete's ECG: Athletes' Hearts are Prone to Ventricular Arrhythmia

OBJECTIVES

Intense exercise elevates all heart chambers' dimensions, left ventricular mass (LV mass), and left ventricular mass index (LV mass index). The relationship between increased ventricular arrhythmias and sudden cardiac death with LV dilatation and elevated LV mass has been previously demonstrated. We investigated whether sports-related LV dilatation and elevated LV mass and LV mass index cause an increase in ventricular repolarization heterogeneity.

PATIENTS AND METHODS

This prospective observational study recruited 565 participants. There were 226 (female: 28) athletes and 339 (female: 45) healthy controls between 17 and 42 years of age. They were evaluated using 12-lead-electrocardiography and transthoracic echocardiography. Electrocardiograms were obtained at a rate of 50 mm/s and an amplitude of 10 mV, including at least 3 QRS complexes for each derivation. They were taken with 12 standard deviations. Transmural dispersion of repolarization indexes (TDR) (Tp-Te interval, Tp-Te/QT ratio and Tp-Te/QTc ratio, Tp-Te(d)) were measured from precordial derivations. Measurements weretakenwith a program which was generated with MATLAB codes.

RESULTS

Tp-Te interval, Tp-Te/QT ratio, Tp-Te/QTc ratio, Tp-Te(d), PW (posterior wall thickness), IVS (interventricular septal thickness), LVEDD (left ventricular end-diastolic diameter), LV mass (left ventricular mass), and LV mass index (left ventricular mass index) for the athlete group were significantly higher than for the control group. Correlation analyses revealed that TDR indexes significantly correlated with PW, IVS, LVEDD, LV mass, and LV mass index.

CONCLUSION

LV mass and LV mass index increase in well-trained athletes, and this increase leads to an increase in TDR indexes. The increased frequency of ventricular arrhythmia and sudden cardiac death may be explained with increasing ventricular repolarization heterogeneity in these individuals.

Myocardial repolarization is affected in patients with ascending aortic aneurysm

OBJECTIVE

Ascending aortic aneurysm (AAA) is one of the major causes of ventricular diastolic dysfunction. Diastolic dysfunction can induce ventricular repolarization dispersion. Nevertheless, myocardial repolarization dispersion is not yet to be fully evaluated in patients with AAA. We aimed to evaluate ventricular repolarization using QT and Tp-Te interval and corrected (c) Tp-Te/QT ratio in patients with AAA.

METHODS

One hundred-four patients with AAA without coronary artery disease (CAD) served as the aneurysm group and 82 patients having a normal aortic diameter as the control group. All patients underwent transthoracic echocardiography (TTE) for measurements of LV diastolic function and underwent electrocardiography (ECG) to calculate RR, QT, Tp-Te intervals and QT dispersion. Bazett's formula was used to calculate QTc and cTp-Te intervals. cTp-Te/QT ratio was also calculated.

RESULTS

The groups were similar according to basal characteristics. We found left ventricular diastolic properties were impaired and QT dispersion, QTc interval, and both of Tp-Te and cTp-Te intervals were significantly prolonged in the aneurysm group than the control group. There were also significant correlations between TTE and ECG parameters. On multivariate linear regression analysis, indexed ascending aortic dimension (AAoD), LA diameter and E/e' ratio were independent predictors of ventricular repolarization dispersion in AAA patients.

CONCLUSIONS

Our study results showed that patients with AAA may have an increased risk for ventricular arrhythmogenesis because of deteriorated the left ventricular diastolic function.

High risk electrocardiographic markers in Brugada syndrome

Several clinical, electrocardiographic (ECG) and electrophysiological markers have been proposed to provide optimal risk stratification in patients with Brugada syndrome (BrS). Of the different markers, only a spontaneous type 1 ECG pattern has clearly shown a sufficiently high predictive value. This review article highlights specific ECG markers based on depolarization and/or repolarization that have been associated with an increased risk of arrhythmic events in patients with BrS.

Heart Failure and Sudden Cardiac Death

The Centers for Diseases Control and Prevention estimates that 5.7 million adults in the United States suffer from heart failure and 1 in 9 deaths in 2009 cited heart failure as a contributing cause. Almost 50% of patients who are diagnosed with heart failure die within 5 years of diagnosis. Cardiovascular disease is a public health burden. The prognosis of patients with heart failure has improved significantly. However, the risk for death remains high. Managing sudden death risk and intervening appropriately with primary or secondary prevention strategies are of paramount importance.

Imbalance of autonomic nervous systems involved in ventricular arrhythmia after splenectomy in dogs

The role of cardiac autonomic modulation on ventricular arrhythmia, known as ventricular premature complexes (VPC), after splenectomy was investigated. Twelve dogs undergoing splenectomy were divided into 2 groups: low VPC (<1,000/day, n=6) and high VPC groups (≥1,000/day, n=6). Electrocardiograph recording was performed prior to (D0), during the first three days (D1-3) and on day 9 (D9) after surgery. Arrhythmic indices, T_peak-T_end, corrected QT interval and short-term variability of QT interval as well as heart rate variability (HRV) were evaluated. Plasma concentrations of norepinephrine (NE) and epinephrine (E) were measured. In the high VPC group, the occurrences of VPC were significantly increased (P<0.05) after surgery, and reached the levels higher than those in the low VPC group. For the arrhythmic indices, only Tp-Te in the high VPC group increased significantly (P<0.05) after surgery. For HRV analysis, enhancement of both time and frequency domains were found postoperatively in both groups. On D2, however, the high VPC group showed significantly lower total power and high frequency with higher low to high frequency ratio (P<0.05) than the low VPC group. Plasma NE concentration significantly increased in the high VPC group after surgery. Dogs in the high VPC group had shorter survival time than those in the low VPC group. In conclusion, dogs with imbalance cardiac autonomic modulation accompanied with high circulating NE concentration after splenectomy are prone to ventricular arrhythmia, which leads to short survival time.

Evaluation of Tp-e interval, Tp-e/QT ratio, and Tp-e/QTc ratio in patients with mitral valve stenosis before and after balloon valvuloplasty

Objective:

Sympathetic activity increases in patients with mitral stenosis (MS). The association between prolonged Tpeak-Tend (Tp-e) interval and increased sympathetic activity has been demonstrated. This study aimed to evaluate Tp-e interval, Tp-e/QT ratio, and Tp-e/corrected QT interval (QTc) ratio in patients with MS before and after balloon valvuloplasty.

Methods:

Thirty patients with severe MS and 30 sex-, body mass index-, and and age-matched healthy control subjects were enrolled. The severity of MS was defined following clinical, transthoracic, and transesophageal echocardiographic examinations. All patients underwent successful mitral balloon valvuloplasty. Tp-e interval, Tp-e/QT, and Tp-e/QTc ratios were measured using 12-lead electrocardiogram. First, the abovementioned parameters were compared between patients with MS and healthy control subjects. Second, these parameters were compared before and after balloon valvuloplasty in patients with MS.

Results:

The mean Tp-e interval was significantly prolonged in patients with MS compared with healthy control subjects (85.02±9.12 ms vs. 75.38±6.04 ms; p<0.001). In addition, Tp-e/QT ratio and Tp-e/QTc ratio were significantly higher in patients with MS than in healthy control subjects (0.217±0.025 vs. 0.196±0.02 and 0.203±0.02 vs. 0.184±0.019; p<0.001).The mean valve area significantly increased after balloon valvuloplasty compared with that before balloon valvuloplasty (1.83±0.32 cm² vs. 1.18±0.15 cm²; p<0.001). Compared with those before balloon valvuloplasty, Tp-e interval (85.02±9.12 ms vs. 78.06±9.2 ms; p<0.001), Tp-e/QT ratio (0.217±0.02 vs. 0.201±0.02; p<0.001), and Tp-e/QTc ratio (0.203±0.02 vs. 0.184±0.02; p<0.001) decreased after balloon valvuloplasty.

Conclusion:

We revealed that Tp-e interval, Tp-e/QT ratio, and Tp-e/QTc ratio increased in patients with severe MS. Furthermore, balloon valvuloplasty had a favorable effect on parameters associated with myocardial repolarization.

Tp-e interval and Tp-e/QT ratio in patients with celiac disease

OBJECTIVES

Celiac disease is a chronic immune-mediated disease of the small intestine. It has been known that dilated cardiomyopathy and ischemic coronary artery disease have become more frequent in patients with celiac disease. The aim of the study was to assess Tp-e interval and Tp-e/QT ratio in patients with celiac disease.

MATERIAL AND METHODS

This study was conducted at a single center in collaboration with gastroenterology and cardiology clinics. Between January 2014 and June 2015, a total of 76 consecutive patients were enrolled (38 patients with celiac disease and 38 control subjects). Tp-e interval, Tp-e/QT and Tp-e/QTc ratio were measured from the 12-lead electrocardiogram.

RESULTS

Tp-e interval (64.2±11.0 vs. 44.5±6.0; p<0.001), Tp-e/QT ratio (0.18±0.02 vs. 0.13±0.02; p<0.001) and Tp-e/QTc ratio (0.16±0.02 vs. 0.11±0.01; p<0.001) were significantly higher in patients with celiac disease than control subjects. There was a significant positive correlation between Tp-e/QTc ratio and disease duration in patients with celiac disease (r=0.480, p=0.003) and also there was a significant positive correlation between Tp-e/QTc ratio and erythrocyte sedimentation rate (r=0.434, p<0.001).

CONCLUSIONS

Our study showed that Tp-e interval, Tp-e/QT and Tp-e/QTc ratios were increased in patients with celiac disease. Whether these changes increase the risk of ventricular arrhythmia deserve further studies.

Differences in Repolarization Heterogeneity Among Heart Failure With Preserved Ejection Fraction Phenotypic Subgroups

Heart failure with preserved ejection fraction (HFpEF) is a highly heterogeneous syndrome associated with multiple medical comorbidities and pathophysiologic pathways or phenotypes. We recently developed a phenomapping method combining deep phenotyping with machine learning analysis to classify HFpEF patients into 3 clinically distinct phenotypic subgroups (phenogroups) with different clinical outcomes. Phenogroup #1 was younger with lower B-type natriuretic peptide levels, phenogroup #2 had the highest prevalence of obesity and diabetes mellitus, and phenogroup #3 was the oldest with the most factors for chronic kidney disease, the most dysfunctional myocardial mechanics, and the highest adverse outcomes. The pathophysiological differences between these phenogroups, however, remain incompletely described. We sought to evaluate whether these 3 groups differ on the basis of repolarization heterogeneity, which has previously been linked to adverse outcomes in HFpEF. The T-peak to T-end (TpTe) interval, a well-validated index of repolarization heterogeneity, was measured by 2 readers blinded to each other and all other clinical data on the electrocardiograms of 201 HFpEF patients enrolled in a systematic observational study. TpTe duration was associated with higher B-type natriuretic peptide level (p = 0.006), increased QRS-T angle (p = 0.008), and lower septal e' velocity (p = 0.007). TpTe duration was greatest in phenogroup #3 (100.4 ± 24.5 ms) compared with phenogroups #1 (91.2 ± 17.3 ms) and #2 (90.2 ± 17.0 ms) (p = 0.0098). On multivariable analyses, increased TpTe was independently associated with the high-risk phenogroup #3 classification. In conclusion, repolarization heterogeneity is a marker of a specific subset of HFpEF patients identified using unsupervised machine learning analysis and therefore may be a key pathophysiologic marker in this subset of HFpEF patients.

Assessment of myocardial repolarisation parameters in patients with familial Mediterranean fever

Background:

Familial Mediterranean fever (FMF) is a chronic, recurrent auto-inflammatory disease characterised by self-terminating attacks of fever and sterile polyserositis. The main cause of death in auto-inflammatory diseasesis cardiovascular events. Additionally, auto-inflammatory diseases have potential effects on the myocardial repolarisation parameters, including the T-wave peak-to-end (Tp-Te) interval, cTp-Te interval (corrected Tp-Te) and the cTp-Te/ QT ratio. The aim of this study was to analyse the efficacy of myocardial repolarisation alterations in anticipation of cardiovascular risks in patients with FMF.

Methods:

This study included 66 patients with FMF and 58 healthy control subjects. Tp-Te and cTp-Te intervals and the cTp-Te/QT ratio were measured from the 12-lead electrocardiogram.

Results:

In electrocardiographic parameters, analysis of QT, QT dispersion, corrected QT (QTc) and QTc dispersion were similar between the groups. The Tp-Te and cTp-Te intervals and Tp-Te/QT and cTp-Te/QT ratios were significantly prolonged in FMF patients. Multivariate linear regression analyses indicated that erythrocyte sedimentation rate was an independent predictor of a prolonged cTp-Te interval.

Conclusions:

Our study revealed that when compared with control subjects, Tp-Te and cTp-Te intervals and cTp-Te/QT ratio were increased in FMF patients.

Subclinical ventricular repolarization abnormality in uncontrolled compared with controlled treated hypertension

Background

Antihypertensive medications have variable effects on the duration of the QT interval. This study aims to demonstrate the subclinical ventricular conduction defect in treating hypertensive patients taking in consideration the status of the blood pressure control with the antihypertensive agents.

Methods

This cross-section study was performed at the Departments of Physiology and Pharmacology, College of Medicine, Al-Mustansiriya University, Baghdad, Iraq. A total number of 97 hypertensive patients (30 males and 67 females) were eligible to enroll in the study. The patients were grouped into controlled hypertension (Group I) and uncontrolled hypertension (Group II). Each participant is subjected to the electrocardiograph (ECG) investigation. A QT nomogram plot used to identify the patients who are vulnerable or at risk of developing cardiac arrhythmias.

Results

There were no significant differences in the values of the electrocardiogram determinants between Group I and Group II. Abnormal prolonged QTcB interval observed in 18 out of 80 (22.5%) patients of Group II compared with 4 out of 17. The JT index value of ≥112 was observed in 20 out of 80 (25%) patients of Group II compared with 6 out of 17 (35.3%) patients of Group I. A significant correlation between the QTcB duration with JT index observed in both Groups I and II.

Conclusion

Patients with hypertension have variability in ventricular repolarization (QTcB and JT) irrespective of their blood pressure control putting them at higher risk of cardiac arrhythmias.

Tp-e interval and Tp-e/QT ratio before and after catheter ablation in patients with premature ventricular complexes

Aim: Tp-e/QT ratio is a novel marker of ventricular repolarization. The aim of the study is to evaluate the Tp-e interval and Tp-e/QT ratio before and after radiofrequency ablation (RFA) for patients with frequent premature ventricular complexes (PVCs). Patients & methods: The study included 151 consecutive patients who underwent RFA for treatment of symptomatic frequent PVCs. Results: Tp-e interval, Tp-e/QT ratio and Tp-e/QTc ratio (all p < 0.001) were significantly different before and after RFA. After the procedure, mean left ventricular ejection fraction of the population were significantly increased than before RFA (p < 0.001). There was a significant correlation between preprocedural Tp-e/QTc ratio and PVC burden in patients (p = 0.023). Conclusion: Our study shows that PVCs may have a negative effect on ventricular repolarization.

Tp-e interval and Tp-e/QTc ratio as novel surrogate markers for prediction of ventricular arrhythmic events in hypertrophic cardiomyopathy

OBJECTIVE

Hypertrophic cardiomyopathy (HCM) as a common genetic heart disease characterized by ventricular hypertrophy and myocardial fibrosis is significantly associated with a higher risk of fatal ventricular arrhythmic events (VAEs). We aimed to assess the interval between the peak and the end of the electrocardiographic T wave (Tp-e) and Tp-e/corrected QT (QTc) ratio as candidate markers of ventricular arrhythmias in patients with HCM.

METHODS

In this single-center, prospective study, a total of 66 patients with HCM and 88 controls were enrolled. The patients were divided into two groups: those with VAEs (n=26) and those without VAEs (n=40). Tp-e interval and Tp-e/QTc ratio were measured using a 12-lead electrocardiogram.

RESULTS

Tp-e interval was significantly longer and Tp-e/QTc ratio were significantly higher in HCM patients than in the controls. In correlation analysis, maximal left ventricular (LV) thickness also has a significant positive correlation with Tp-e interval (r=0.422, p<0.001) and Tp-e/QTc ratio (r=0.348, p<0.001). Finally, multivariable regression analysis showed that a history of syncope, Tp-e interval [OR (odds ratio): 1.060; 95% confidence interval (CI): 1.005-1.117); p=0.012], Tp-e/QTc ratio (OR: 1.148; 95% CI: 1.086-1.204); p=0.049], and maximal LV thickness were independent predictors of VAEs in patients with HCM.

CONCLUSION

Our findings suggested that prolonged Tp-e interval and increased Tp-e/QTc ratio may be good surrogate markers for the prediction of VAEs in HCM.

Tp-e interval and Tp-e/QT ratio in patients with Human Immunodeficiency Virus

Human Immunodeficiency Virus (HIV) infection and AIDS are known to cause cardiovascular diseases such as premature coronary artery disease, cardiomyopathy, and arrhythmias. Recently, Tp-e interval and Tp-e/QT ratio has been shown as a novel marker of ventricular repolarization. We aimed to evaluate the ventricular repolarization using Tp-e interval and Tp-e/QT ratio in patients with Human Immunodeficiency Virus (HIV) infection. Totally 48 patients with HIV and 60 control subjects were enrolled to the study. Tp-e interval, Tp-e/QT and Tp-e/QTc ratio were measured from the 12-lead electrocardiogram. Tp-e interval, Tp-e/QT ratio and Tp-e/QTc ratio were significantly higher in patients with HIV than control subjects (all p<0.01). In correlation analysis, there were positive correlation between Tp-e interval and disease duration (r=0.298, p=0.048). and inverse correlation between Tp-e interval and CD4 count(r=-0.303, p=0.036). Our study showed that Tp-e interval, Tp-e/QT and Tp-e/QTc ratios were increased in patients with HIV than control subjects.

Utility of T-wave amplitude as a non-invasive risk marker of sudden cardiac death in hypertrophic cardiomyopathy

Objective

Sudden cardiac arrest (SCA) is the most devastating outcome in hypertrophic cardiomyopathy (HCM). We evaluated repolarisation features on the surface electrocardiogram (ECG) to identify the potential risk factors for SCA.

Methods

Data was collected from 52 patients with HCM who underwent implantable cardioverter defibrillator (ICD) implantation. Leads V2 and V5 from the ECG closest to the time of ICD implant were utilised for measuring the Tpeak-Tend interval (Tpe), QTc, Tpe/QTc, T-wave duration and T-wave amplitude. The presence of the five traditional SCA-associated risk factors was assessed, as well as the HCM risk-SCD score.

Results

16 (30%) patients experienced aborted cardiac arrest over 8.5±4.1 years, with 9 receiving an ICD shock and 7 receiving ATP. On univariate analysis, T-wave amplitude was associated with appropriate ICD therapy (HR per 0.1 mV 0.79, 95% CI 0.56 to 0.96, p=0.02). Aborted SCA was not associated with a greater mean QTc duration, Tpeak-Tend interval, T-wave duration, or Tpe/QT ratio. Multivariate analysis (adjusting for cardinal HCM SCA-risk factors) showed T-wave amplitude in Lead V2 was an independent predictor of risk (adjusted HR per 0.1 mV 0.74, 95% CI 0.57 to 0.97, p=0.03). Addition of T-wave amplitude in Lead V2 to the traditional risk factors resulted in significant improvement in risk stratification (C-statistic from 0.65 to 0.75) but did not improve the performance of the HCM SCD-risk score.

Conclusions

T-wave amplitude is a novel marker of SCA in this high risk HCM population and may provide incremental predictive value to established risk factors. Further work is needed to define the role of repolarisation abnormalities in predicting SCA in HCM.

Evaluation of Tp-e Interval, Tp-e/QT Ratio, and Tp-e/QTc Ratio in Patients with Asymptomatic Arrhythmogenic Right Ventricular Cardiomyopathy

BACKGROUND

Arrhythmogenic right ventricular dysplasia (ARVD) is characterized by progressive replacement of ventricular myocytes with variable amounts of fibrous and adipose tissue. Several studies have suggested that the interval from the peak to the end of the electrocardiographic T wave (Tp-e) may correspond to the transmural dispersion of repolarization and that increased Tp-e interval and Tp-e/QT ratio are associated with malignant ventricular arrhythmias. The aim of this study was to evaluate repolarization dispersion measured from the 12-lead surface electrocardiogram (including Tp-e interval, Tp-e/QT, and Tp-e/QTc ratio) in asymptomatic ARVD patients METHODS: We selected 27 patients with asymptomatic ARVD and 27 age- and gender-match young, healthy volunteers.

RESULTS

Tp-e interval, Tp-e/QT and Tp-e/QTc ratio were also significantly higher in ARVD group compared to the control group (all P < 0.001). There were negative correlation between S global and Tp-e, Tp-e/QT, Tp-e/QTc ration (r = -0.57, P = 0.02; r = -0.85, P = 0.02; r = -0.63, P < 0.01; respectively). There were also negative correlation between Sm global and Tp-e, Tp-e/QT, Tp-e/QTc ration (r = -0.61, P < 0.01; r = -0.67, P < 0.01; r = -0.68, P < 0.01; respectively). Moreover, Em global were negative correlation between Tp-e, Tp-e/QT, and Tp-e/QTc (r = - 0.64, P < 0.001, r = - 0.75, P < 0.01; r = -0,69, P < 0.01; respectively) CONCLUSION: In conclusion, we have presented strong evidence suggesting that Tp-e interval, Tp-e/QT ratio, and Tp-e/QTc ratio were increased in asymptomatic ARVD patients.

Tp-e Interval, Tp-e/QTc Ratio, and Fragmented QRS Are Correlated with the Severity of Liver Cirrhosis

BACKGROUND

Arrhythmias and electrocardiographic changes are reported in several noncardiac diseases, including liver cirrhosis (LC). We intended to evaluate the interval from the peak to the end of the electrocardiographic T wave (Tp-e), Tp-e/QTc ratio, and fQRS as presumed markers of arrhythmias in LC.

METHODS

In this cross-sectional study, a total of 88 consecutive patients with LC according to clinical, biological, ultrasonographic, or histological criteria and 73 control subjects were enrolled. The severity of cirrhosis was classified according to Pugh-Child's classification and Model for End-Stage Liver Disease (MELD) score. Tp-e interval, Tp-e/QTc ratio, and fQRS rates were measured from the 12-lead electrocardiogram.

RESULTS

Tp-e interval, Tp-e/QTc ratio and fQRS rates were significantly increased in parallel to the severity of LC (P < 0.001, P < 0.001, and P = 0.003, respectively). In correlation analysis, Pugh-Child stage showed a significantly positive correlation with Tp-e interval (r = 0.462, P < 0.001), QTc interval (r = 0.373, P < 0.001), Tp-e/QTc ratio (r = 0.352, P < 0.001), and fQRS (r = 0.407, P < 0.001). Furthermore, Tp-e interval (r = 0.414, P < 0.001) and Tp-e/QTc ratio (r = 0.426, P< 0.001) had significant positive correlation with MELD score.

CONCLUSIONS

Our study demonstrated that Tp-e interval, Tp-e/QTc ratios, and fQRS rates were significantly increased in parallel to the severity of LC. Thus, these findings may implicate that Tp-e interval, Tp-e/QTc ratio, and fQRS may be novel and useful indicators for prediction of arrhythmias in LC.

Evaluation of inhomogeneities of repolarization in patients with psoriasis vulgaris

INTRODUCTION

The arrhythmia potential has not been investigated adequately in psoriatic patients. In this study, we assessed the ventricular repolarization dispersion, using the Tp-e interval and the Tp-e/QT ratio, and investigated the association with inflammation.

MATERIAL AND METHODS

Seventy-one psoriasis vulgaris patients and 70 age- and gender-matched healthy individuals were enrolled in the study. The severity of the disease was calculated using Psoriasis Area and Severity Index scoring. The QTd was defined as the difference between the maximum and minimum QT intervals. The Tp-e interval was defined as the interval from the peak of the T wave to the end of the T wave. The Tp-e interval was corrected for heart rate. The Tp-e/QT ratio was calculated using these measurements.

RESULTS

There were no significant differences between the groups with respect to basal clinical and laboratory characteristics (p > 0.05). The Tp-e interval, the corrected Tp-e interval (cTp-e) and the Tp-e/QT ratio were also significantly higher in psoriasis patients compared to the control group (78.5 ±8.0 ms vs. 71.4 ±7.6 ms, p < 0.001, 86.3 ±13.2 ms vs. 77.6 ±9.0 ms, p < 0.001 and 0.21 ±0.02 vs. 0.19 ±0.02, p < 0.001 respectively). A significant correlation was detected between the cTp-e time and the Tp-e/QT ratio and the PASI score in the group of psoriatic patients (r = 0.51, p < 0.001; r = 0.59, p < 0.001, respectively).

CONCLUSIONS

In our study, we detected a significant increase in the Tp-e interval and the Tp-e/QT ratio in patients with psoriasis vulgaris. The Tp-e interval and the Tp-e/QT ratio may be predictors for ventricular arrhythmias in patients with psoriasis vulgaris.

Novel Ventricular Repolarization Indices in Patients with Coronary Slow Flow

Background: Coronary slow flow (CSF) phenomenon is described angiographically as delayed progression of the injected contrast agents through the coronary arteries. Aim of this study was to analyze ventricular repolarization in CSF patients by using Tpeak-Tend interval, Tpeak-Tend/QT ratio, Tpeak-Tend/QTc ratio and other repolarization parameters since these parameters are used as predictors for ventricular arrhythmogenesis. Materials and Methods: We have retrospectively analyzed diagnostic coronary angiography results of 160 patients between 2010 and 2014. Patients were divided into two groups according to coronary flow results. CSF group consisted of 33 female, 82 male patients with mean age 51,9±11,5 years. Control group included patients with normal coronary flow; 13 female, 32 male with mean age 50,8±11,7 years. In all patients, ventricular repolarization parameters as well as other associated electrocardiographic intervals were measured on the twelve-lead surface electrocardiogram. Results: The ventricular repolarization parameters: QTmax interval, QTmin interval, QTc, QTI, QTcI, JTmax interval, JTmin interval, JTdispersion and JTIndex were not significantly different between the groups. However followings parameters differed significantly between patients and controls; QRS (92,8±11,5 msn versus 78,3±16,713,40 msn, respectively; p=0.001), T wave (89±20,2 msn vs. 73,3±13,3 msn respectively, p=0.001), QT dispersion (26,8±17,5 msn vs. 13,5±20,4 msn respectively, p=0.002), JTcorrected (331,6±39,8%; vs. 350,1±39,7% respectively; p=0.01). Furthermore; Tpeak-Tend duration (89±20,2 msn vs. 73,3±13,9 msn respectively; p=0.001), T wave (204±34,9 msn vs. 189,2±24,8 msn respectively; p=0.003), Tpeak-Tend/QT ratio (0,22±0,05 msn vs. 0,19±0,03 msn respectively, p=0.001) were significantly higher in patients compared to controls. Tpeak-Tend/QTc ratio was also significantly higher in the CSF group compared to the controls. (0,21±0,05 msn vs. 0,17±0,03 msn respectively, p =0.001). Conclusion: Ventricular repolarization parameters are prolonged in patients with CSF.

Comparison of Tpe Changing on ECG, in Pre and Post Dialysis and Post Transplantation

Background

High incidence of premature ventricular contractions (PVCS) and arrhythmia during and soon after dialysis have been demonstrated by Holter monitoring.

Objectives

In this study, the effects of dialysis and renal transplantation on Tpe, Tpec (corrected Tpe), QTc (corrected QT), QTd (QT dispersion), and Tpe/QT parameters as known factors in arrhythmogenicity, and also the correlation between electrolyte and arterial blood gas changing within these parameters will be assessed.

Patients and Methods

In a retrospective study, 42 renal transplant recipients were selected. Under the supervision of an electrophysiologist, information related to Tpe, Tpec, Tpe/QT, QTd, and QTc parameters before dialysis (pre-HD), after dialysis (post-HD), and two weeks after transplantation (RTX) were analyzed. Electrolyte and arterial blood gas information were also recorded. Bonferroni adjustment, repeated measures ANOVA, generalized linear models, and generalized estimating equations were used for analysis.

Results

Two weeks after transplantation, the mean Tpe decreased to 0.052 ± 0.002, which was significant compared to pre-HD (P < 0.001) and Post-HD (P = 0.019). The mean Tpec was 0.059 ± 0.002, which, just in comparison to pre-HD, was significant (P = 0.005). In addition, the mean Tpe/QT decreased to 0.143 ± 0.005, which was significant compared to pre-HD (P = 0.018). The mean QTd was 0.066 ± 0.004, which wasn’t significant compared to before or after dialysis. The mean QTc decreased to 0.386 ± 0.004, which was significant compared to post-HD (P = 0.0003).

Conclusions

Taking the role of Tpe and Tpe/QT in arrhythmia into account and amending it by a successful transplantation can be considered as a factor that decreases arrhythmia after renal transplantation compared to ESRD patients.

Tpeak-to-Tend interval corrected for heart rate: A more precise measure of increased sudden death risk?

BACKGROUND

The Tpeak to Tend (Tpe) interval on the 12-lead electrocardiogram predicts an increased risk of sudden cardiac arrest (SCA). There is controversy over whether Tpe would be more useful if corrected for heart rate (Tpec).

OBJECTIVES

We evaluated whether the predictive value of Tpe for SCA improves with heart rate correction and sought to determine an optimal cutoff value for Tpec in the context of SCA risk.

METHODS

Cases of SCA (n = 628; mean age 66.4 ± 14.5 years; n = 416, 66.2% men) from the Oregon Sudden Unexpected Death Study with an archived electrocardiogram available prior and unrelated to the SCA event were analyzed. Comparisons were made with control subjects (n = 819; mean age 66.7 ± 11.5 years; n = 559, 68.2% men). The Tpe interval was corrected for heart rate using Bazett (TpecBa) and Fridericia (TpecFd) formulas, and the predictive value of Tpec for SCA was evaluated using logistic regression models.

RESULTS

The area under the curve for Tpec predicting SCA improved with both correction formulas. TpecBa and TpecFd were shown to have an area under the curve of 0.695 and 0.672, respectively, as compared with a baseline of 0.601 with an uncorrected Tpe. A TpecBa value of >90 ms was predictive of SCA, independent of age, sex, comorbidities, QRS duration, corrected QT interval, and severely reduced left ventricular ejection fraction (≤35%; odds ratio 2.8; 95% confidence interval 1.92-4.17; P < .0001).

CONCLUSION

Correcting Tpe for heart rate, using either the Bazett or the Fridericia formula, improved the independent predictive value of this marker for the assessment of SCA risk. Prolongation of TpecBa beyond 90 ms was associated with a nearly 3-fold increased risk of SCA.

Effect of Dexmedetomidine on Heart Rate-Corrected QT and Tpeak-Tend Intervals During Robot-Assisted Laparoscopic Prostatectomy With Steep Trendelenburg Position: A Prospective, Randomized, Double-Blinded, Controlled Study

Intraperitoneal insufflation of carbon dioxide may affect the sympathetic activity that leads to changes in ventricular repolarization. This in turn can result in changes of heart rate-corrected QT (QTc) interval and Tpeak-Tend (Tp-e) interval. Dexmedetomidine is a highly selective α2-receptor agonist and has potential antiarrhythmic properties. This prospective, randomized, double-blinded, controlled study evaluated the effects of dexmedetomidine administration on QTc and Tp-e intervals during robot-assisted laparoscopic prostatectomy with steep Trendelenburg position.Fifty patients scheduled for robot-assisted laparoscopic prostatectomy randomly received either a continuous infusion of dexmedetomidine at a rate of 0.3 μg/kg/hour, from anesthetic induction until the end of the Trendelenburg position (dexmedetomidine group; n = 25), or the same volume of normal saline (control group; n = 25). Anesthesia was maintained with sevoflurane and remifentanil. The primary and secondary goals were to evaluate the effect of dexmedetomidine on the QTc and Tp-e interval changes. Mean arterial pressure, heart rate, end-tidal CO2, and end-tidal sevoflurane concentrations were assessed as well.Forty-seven patients (94%) completed the study. Dexmedetomidine significantly attenuated QTc interval prolongation and reduced the Tp-e interval, even though the baseline values of the QTc and Tp-e intervals were similar between the 2 groups (PGroup × Time = 0.001 and 0.014, respectively). Twenty-two patients (96%) in the control group and 13 (54%) in the dexmedetomidine group had QTc interval prolongation of >20 ms from the baseline value during surgery (P = 0.001). The maximum QTc interval prolongation from the baseline value during surgery was 46 ± 21 ms in the control group and 24 ± 21 ms in the dexmedetomidine group (mean ± SD, P = 0.001). Mean arterial pressure and heart rate were comparable between the groups.Continuous infusion of dexmedetomidine at a rate of 0.3 μg/kg/hour significantly attenuated the QTc interval prolongation induced by CO2 pneumoperitoneum with steep Trendelenburg position. Furthermore, dexmedetomidine reduced the Tp-e interval. Thus, dexmedetomidine administration may be effective for patients who are susceptible to the development of ventricular arrhythmia during robot-assisted laparoscopic prostatectomy.

The Assessment of Tp-e Interval and Tp-e/QT Ratio in Patients With Systemic Sclerosis

Objectives

This study aims to investigate ventricular repolarization using T-peak to T-end (Tp-e) intervals and Tp-e/QT ratios in patients with systemic sclerosis (SSc).

Patients and methods

Totally 65 patients (8 males, 57 females; mean age 49.8 years; range 20 to 77 years) with SSc and 63 control subjects (8 males, 55 females; mean age 49.3 years; range 20 to 77 years) were enrolled. Tp-e intervals, Tp-e/QT, and Tp-e/corrected QT (QTc) ratios were measured from the 12-lead electrocardiogram.

Results

Tp-e intervals, QT intervals, QTc intervals, Tp-e/QT, and Tp-e/QTc ratios were significantly higher in patients with SSc than control subjects (all p<0.01). There was no difference between patients with diffuse and limited cutaneous SSc in terms of electrocardiogram and echocardiographic findings. Correlation analysis revealed no correlation between Tp-e intervals, Tp-e/QT, and Tp-e/QTc ratios with disease duration and anti-Sjögren's syndrome antigen A antibody levels in patients with SSc (all p>0.05).

Conclusion

Our study showed that Tp-e intervals, Tp-e/QT, and Tp-e/QTc ratios were increased in patients with SSc than control subjects. The increased frequency of ventricular arrhythmias can be clarified by increased indexes of ventricular repolarization parameters in patients with SSc.

Evaluation of Electrocardiographic T-peak to T-end Interval in Subjects with Increased Epicardial Fat Tissue Thickness

BACKGROUND

The association between periatrial adiposity and atrial arrhythmias has been shown in previous studies. However, there are not enough available data on the association between epicardial fat tissue (EFT) thickness and parameters of ventricular repolarization. Thus, we aimed to evaluate the association of EFT thickness with indices of ventricular repolarization by using T-peak to T-end (Tp-e) interval and Tp-e/QT ratio.

METHODS

The present study included 50 patients whose EFT thickness ≥ 9 mm (group 1) and 40 control subjects with EFT thickness < 9 mm (group 2). Transthoracic echocardiographic examination was performed in all participants. QT parameters, Tp-e intervals and Tp-e/QT ratio were measured from the 12-lead electrocardiogram.

RESULTS

QTd (41.1 ± 2.5 vs 38.6 ± 3.2, p < 0.001) and corrected QTd (46.7 ± 4.7 vs 43.7 ± 4, p = 0.002) were significantly higher in group 1 when compared to group 2. The Tp-e interval (76.5 ± 6.3, 70.3 ± 6.8, p < 0.001), cTp-e interval (83.1 ± 4.3 vs. 76±4.9, p < 0.001), Tp-e/QT (0.20 ± 0.02 vs. 0.2 ± 0.02, p < 0.001) and Tp-e/QTc ratios (0.2 ± 0.01 vs. 0.18 ± 0.01, p < 0.001) were increased in group 1 in comparison to group 2. Significant positive correlations were found between EFT thickness and Tp-e interval (r = 0.548, p < 0.001), cTp-e interval (r = 0.259, p = 0.01), and Tp-e/QT (r = 0.662, p < 0.001) and Tp-e/QTc ratios (r = 0.560, p < 0.001).

CONCLUSION

The present study shows that Tp-e and cTp-e interval, Tp-e/QT and Tp-e/QTc ratios were increased in subjects with increased EFT, which may suggest an increased risk of ventricular arrhythmia.

Ventricular repolarization markers for predicting malignant arrhythmias in clinical practice

Malignant cardiac arrhythmias which result in sudden cardiac death may be present in individuals apparently healthy or be associated with other medical conditions. The way to predict their appearance represents a challenge for the medical community due to the tragic outcomes in most cases. In the last two decades some ventricular repolarization (VR) markers have been found to be useful to predict malignant cardiac arrhythmias in several clinical conditions. The corrected QT, QT dispersion, Tpeak-Tend, Tpeak-Tend dispersion and Tp-e/QT have been studied and implemented in clinical practice for this purpose. These markers are obtained from 12 lead surface electrocardiogram. In this review we discuss how these markers have demonstrated to be effective to predict malignant arrhythmias in medical conditions such as long and short QT syndromes, Brugada syndrome, early repolarization syndrome, acute myocardial ischemia, heart failure, hypertension, diabetes mellitus, obesity and highly trained athletes. Also the main pathophysiological mechanisms that explain the arrhythmogenic predisposition in these diseases and the basis for the VR markers are discussed. However, the same results have not been found in all conditions. Further studies are needed to reach a global consensus in order to incorporate these VR parameters in risk stratification of these patients.

Evaluation of Tp-E Interval and Tp-E/QT Ratio in Patients with Aortic Stenosis

BACKGROUND

The risk of syncope and sudden cardiac death due to ventricular arrhythmias increased in patients with aortic stenosis (AS). Recently, it was shown that Tp-e interval, Tp-e/QT, and Tp-e/QTc ratio can be novel indicators for prediction of ventricular arrhythmias and mortality. We aimed to investigate the association between AS and ventricular repolarization using Tp-e interval and Tp-e/QT ratio.

METHODS

Totally, 105 patients with AS and 60 control subjects were enrolled to this study. The severity of AS was defined by transthoracic echocardiographic examination. Tp-e interval, Tp-e/QT, and Tp-e/QTc ratios were measured from the 12-lead electrocardiogram.

RESULTS

Tp-e interval, Tp-e/QT, and Tp-e/QTc ratios were significantly increased in parallel to the severity of AS (P < 0.001, P = 0.001, and P = 0.001, respectively). Also, it was shown that Tp-e/QTc ratio had significant positive correlation with mean aortic gradient (r = 0.192, P = 0.049). In multivariate logistic regression analysis, Tp-e/QTc ratio and left ventricular mass were found to be independent predictors of severe AS (P = 0.03 and P = 0.04, respectively).

CONCLUSIONS

Our study showed that Tp-e interval, Tp-e/QT, and Tp-e/QTc ratios were increased in patients with severe AS. Tp-e/QTc ratio and left ventricular mass were found as independent predictors of severe AS.

Increased Tpeak-Tend interval is highly and independently related to arrhythmic events in Brugada syndrome

BACKGROUND

Risk stratification in Brugada syndrome (BS) remains controversial. The time interval between the peak and the end of the T wave (Tpe interval), a marker of transmural dispersion of repolarization, has been linked to malignant ventricular arrhythmias in various settings but leads to discordant results in BS.

OBJECTIVE

We study the correlation of the Tpe interval with arrhythmic events in a large cohort of patients with BS.

METHODS

A total of 325 consecutive patients with BS (mean age 47±13 years, 259 men-80%) with spontaneous (n=143, 44%) or drug-induced (n=182, 56%) type 1 electrocardiogram were retrospectively included. 235 were asymptomatic (70%), 80 presented with unexplained syncope (22%), and 10 presented with sudden death (SD) or appropriate implantable cardioverter-defibrillator therapy (AT) (8%) at diagnosis or over a mean follow-up of 48 ± 34 months. The Tpe interval was calculated as the difference between the QT interval and the QT peak interval as measured in each of the precordial leads.

RESULTS

The Tpe interval from lead V1 to lead V4, maximum value of the Tpe interval (max Tpe), and Tpe dispersion in all precordial leads were significantly higher in patients with SD/AT or in patients with syncope than in asymptomatic patients (P < .001). A max Tpe of ≥100 ms was present in 47 of 226 asymptomatic patients (21%), in 48 of 73 patients with syncope (66%), and in 22 of 26 patients with SD/AT (85%) (P < .0001). In multivariate analysis, a max Tpe of ≥100 ms was independently related to arrhythmic events (odds ratio 9.61; 95% confidence interval 3.13-29.41; P < .0001).

CONCLUSION

The Tpe interval in the precordial leads is highly related to malignant ventricular arrhythmias in this large cohort of patients with BS. This simple electrocardiographic parameter could be used to refine risk stratification.

Evaluation of Tp-Te Interval and Tp-Te/QT Ratio in Patients with Coronary Slow Flow Tp-Te/QT Ratio and Coronary Slow Flow

OBJECTIVE

Coronary slow flow (CSF) phenomenon is described by angiographically normal coronary arteries with delayed opacification of the distal vasculature. Several studies have suggested that the interval from the peak to the end of the electrocardiographic T wave (Tp-Te) may correspond to the transmural dispersion of the repolarization and that increased Tp-Te interval and Tp-Te/QT ratio are associated with malignant ventricular arrhythmias. The aim of this study was to evaluate the ventricular repolarization by using Tp-Te interval and Tp-Te/QT ratio in patients with CSF.

MATERIALS AND METHODS

This study included 50 CSF patients (40 male, mean age 48.6±12.5 years) and 40 control individuals (23 male, mean age 47.8±12.5 years). Tp-Te interval and Tp-Te/QT ratio were measured from the 12-lead electrocardiogram. These parameters were compared in groups.

RESULTS

Baseline characteristics of the study groups were comparable. In electrocardiographic parameters analysis, QT and corrected QT were similar in CSF patients compared to the controls (357±35.2 vs 362±38.0 milliseconds and 419±25.8 vs 430±44.2 milliseconds, all p value >0.05). Tp-Te interval, Tp-Te/QT and Tp-Te/QTc ratio were significantly higher in CSF patients (85±13.7 vs 74±9.9 milliseconds and 0.24±0.03 vs 0.20±0.02 and 0.20±0.03 vs 0.17±0.02 all p value <0.001).

CONCLUSION

Our study revealed that QTd, Tp-Te interval and Tp-Te/QT ratio are prolonged in patients with CSF.

A Novel Electrocardiographic T-Wave Measurement (Tp-Te Interval) as a Predictor of Heart Abnormalities in Hypertension: A New Opportunity for First-Line Electrocardiographic Evaluation

The aim of the study was to evaluate the role of conventional and new markers of early cardiac organ damage (OD) on 12-lead electrocardiography (ECG) in 25 outpatients with newly diagnosed untreated essential hypertension compared with 15 normotensive, otherwise healthy individuals. Each participant underwent ECG, echocardiographic, and blood pressure (BP) measurements. Conventional and new ECG indexes for cardiac OD (Tp-Te interval, ventricular activation time, and P-wave analysis) were also measured. Clinic and 24-hour ambulatory BP levels as well as left ventricular mass indexes were significantly higher in hypertensive than in normotensive patients. No significant differences were found between the two groups for ECG and echocardiographic markers of OD. Only Tp-Te interval was higher in hypertensive than in normotensive individuals (3.06 mm vs 2.24 mm; P<.0001), even after adjustment for anthropometric and clinical parameters. Preliminary results of this study demonstrated prolonged Tp-Te interval in newly diagnosed, untreated hypertensive outpatients compared with normotensive individuals.

Arrhythmia risk in liver cirrhosis

Interactions between the functioning of the heart and the liver have been described, with heart diseases affecting the liver, liver diseases affecting the heart, and conditions that simultaneously affect both. The heart is one of the most adversely affected organs in patients with liver cirrhosis. For example, arrhythmias and electrocardiographic changes are observed in patients with liver cirrhosis. The risk for arrhythmia is influenced by factors such as cirrhotic cardiomyopathy, cardiac ion channel remodeling, electrolyte imbalances, impaired autonomic function, hepatorenal syndrome, metabolic abnormalities, advanced age, inflammatory syndrome, stressful events, impaired drug metabolism and comorbidities. Close monitoring of cirrhotic patients is needed for arrhythmias, particularly when QT interval-prolonging drugs are given, or if electrolyte imbalances or hepatorenal syndrome appear. Arrhythmia risk may persist after liver transplantation due to possible QT interval prolongation, persistence of the parasympathetic impairment, post-transplant reperfusion and chronic immunosuppression, as well as consideration of the fact that the transplant itself is a stressful event for the cardiovascular system. The aims of the present article were to provide a review of the most important data regarding the epidemiology, pathophysiology, and biomarkers of arrhythmia risk in patients with liver cirrhosis, to elucidate the association with long-term outcome, and to propose future research directions.

Augmentation of cardiac sympathetic tone by percutaneous low-level stellate ganglion stimulation in humans: a feasibility study

Modulation of human cardiac mechanical and electrophysiologic function by direct stellate ganglion stimulation has not been performed. Our aim was to assess the effect of low-level left stellate ganglion (LSG) stimulation (SGS) on arrhythmias, hemodynamic, and cardiac electrophysiological indices. Patients undergoing ablation procedures for arrhythmias were recruited for SGS. A stimulating electrode was placed next to the LSG under fluoroscopy and ultrasound imaging; and SGS (5-10 Hz, 10-20 mA) was performed. We measured hemodynamic, intracardiac and ECG parameters, and activation recovery intervals (ARIs) (surrogate for action potential duration) from a duodecapolar catheter in the right ventricular outflow tract. Five patients underwent SGS (3 males, 45 ± 20 years). Stimulating catheter placement was successful, and without complication in all patients. SGS did not change heart rate, but increased mean arterial blood pressure (78 ± 3 mmHg to 98 ± 5 mmHg, P < 0.001) and dP/dt max (1148 ± 244 mmHg/sec to 1645 ± 493 mmHg/sec, P = 0.03). SGS shortened mean ARI from 304 ± 23 msec to 283 ± 17 msec (P < 0.001), although one patient required parasympathetic blockade. Dispersion of repolarization (DOR) increased in four patients and decreased in one, consistent with animal models. QT interval, T-wave duration and amplitude at baseline and with SGS were 415 ± 15 msec versus 399 ± 15 msec (P < 0.001); 201 ± 12 msec versus 230 ± 28 msec; and 0.2 ± 0.09 mV versus 0.22 ± 0.08 mV, respectively. At the level of SGS performed, no increase in arrhythmias was seen. Percutaneous low-level SGS shortens ARI in the RVOT, and increases blood pressure and LV contractility. These observations demonstrate feasibility of percutaneous SGS in humans.