Evaluation of Changes in Ventricular Repolarization Parameters in Morbidly Obese Patients Undergoing Bariatric Surgery

Tpeak-Tend ECG Marker in Obesity and Cardiovascular Diseases: A Comprehensive Review

Globally, cardiovascular diseases are still the leading cause of death. Numerous methods are used to diagnose cardiovascular pathologies; there is still a place for straightforward and noninvasive techniques, such as electrocardiogram (ECG). Depolarization and repolarization parameters, including QT interval and its derivatives, are well studied. However, the Tpeak-Tend interval is a novel and promising ECG marker with growing evidence for its potential role in predicting malignant arrhythmias. In this review, we discuss the association between the Tpeak-Tend interval and several cardiovascular diseases, including long QT syndrome, cardiomyopathies, heart failure, myocardial infarction, and obesity, which constitutes one of the risk factors for cardiovascular diseases.

Sodium-glucose cotransporter type 2 inhibitors and cardiac arrhythmias

The introduction of sodium-glucose cotransporter 2 (SGLT2) inhibitors as a new and effective class of therapeutic agents for type 2 diabetes (T2D) preventing the reabsorption of glucose in the kidneys and thus facilitating glucose excretion in the urine, but also as agents with cardiovascular benefits, particularly in patients with heart failure (HF), regardless of the diabetic status, has ushered in a new era in treating patients with T2D and/or HF. In addition, data have recently emerged indicating an antiarrhythmic effect of the SGLT2 inhibitors in patients with and without diabetes. Prospective studies, randomized controlled trials and meta-analyses have provided robust evidence for a protective and beneficial effect of these agents against atrial fibrillation, ventricular arrhythmias and sudden cardiac death. The antiarrhythmic mechanisms involved include reverse atrial and ventricular remodeling, amelioration of mitochondrial function, reduction of hypoglycemic episodes with their attendant arrhythmogenic effects, attenuated sympathetic nervous system activity, regulation of sodium and calcium homeostasis, and suppression of prolonged ventricular repolarization. These new data on antiarrhythmic actions of SGLT2 inhibitors are herein reviewed, potential mechanisms involved are discussed and pictorially illustrated, and treatment results on specific arrhythmias are described and tabulated.

The relationship between premature ventricular complexes and index of cardiac-electrophysiological balance

OBJECTIVE

Premature ventricular complexes are common in healthy individuals' ambulatory monitoring. The index of cardiac-electrophysiological balance may predict malignant ventricular arrhythmias. This study investigated the relation between Premature ventricular complex burden and index of cardiac-electrophysiological balance in 24-h Holter monitoring.

METHODS

A total of 257 patients who were admitted to a cardiology outpatient clinic without structural heart disease and underwent 24-h Holter monitoring were included in the study. Demographic features, laboratory parameters, and electrocardiographic and echocardiographic values of all patients were obtained from the hospital database. Patients were categorized into the following four groups according to their premature ventricular complex burden: ≤5% premature ventricular complexes as group 1, >6 and ≤10% premature ventricular complexes as group 2, >11 and ≤20% premature ventricular complexes as group 3, and >20% premature ventricular complexes as group 4. QRS, QT, and T peak to end interval were measured by resting electrocardiography. QT interval was corrected using Bazett's formula. T peak to end interval/QT, T peak to end interval/corrected QT interval, index of cardiac-electrophysiological balance, and corrected index of cardio-electrophysiological balance ratios were calculated.

RESULTS

There was no significant difference between groups regarding cardiovascular risk factors. In group 4, beta-blocker usage was significantly higher, and the serum magnesium levels were significantly lower than in other groups. There was no difference in QT duration or index of cardiac-electrophysiological balance values; however, corrected index of cardio-electrophysiological balance was significantly lower in the highest premature ventricular complex group (5.1, 5.1, 4.8, 4.7, p=0.005). In multivariate backward logistic regression analyses, it was found that lower corrected index of cardio-electrophysiological balance, lower serum magnesium levels, lower serum creatinine levels, larger left atrium size, and higher T peak to end interval were associated with higher premature ventricular complexes.

CONCLUSION

Corrected index of cardio-electrophysiological balance is a novel and noninvasive marker that can predict premature ventricular complex burden in patients with structurally normal hearts.