Obesity and Ventricular Repolarization: a Comprehensive Review.

Area of Science:

• Cardiology
• Obesity Medicine
• Electrophysiology

Background:

• Obesity is a significant risk factor for sudden cardiac death.
• Delayed ventricular repolarization (VR) is a suspected mechanism linking obesity to cardiac events.
• Electrocardiographic measures like corrected QT interval (QTc) and QT dispersion are used to assess VR.

Purpose of the Study:

• To investigate the relationship between obesity and delayed ventricular repolarization.
• To evaluate the impact of weight loss on VR parameters in obese individuals.
• To explore potential co-morbidities associated with obesity that may influence VR.

Main Methods:

• Review of controlled studies assessing QTc and QT dispersion in overweight/obese vs. normal weight individuals.
• Analysis of studies examining the effects of weight loss (diet, bariatric surgery) on VR parameters.
• Consideration of obesity-related co-morbidities (diabetes, hypertension, etc.) and their impact on VR.

Main Results:

• Overweight and obese subjects exhibit significantly longer QTc and greater QT dispersion compared to normal weight controls.
• Weight loss interventions (diet, bariatric surgery) lead to significant reductions in QTc and QT dispersion.
• Obesity co-morbidities such as diabetes, hypertension, and heart failure may also delay VR.

Conclusions:

• Obesity is associated with delayed ventricular repolarization, evidenced by prolonged QTc and increased QT dispersion.
• Weight loss is an effective strategy to improve VR parameters in obese patients.
• Further research is needed to determine if obesity is an independent predictor of delayed VR and if QTc prolongation sufficiently predisposes to fatal arrhythmias.