Related Experiment Videos
QTc interval (cardiac repolarization): lengthening after meals
D Nagy1, R DeMeersman, D Gallagher
1Obesity Research Center, St. Luke's-Roosevelt Hospital, New York, NY 10025, USA.
Obesity Research
|February 4, 1998
Summary
Eating affects heart rate corrected QT interval (QTc) duration in healthy individuals. This study found that meal ingestion, not water, prolonged the QTc interval, suggesting a need for fasting guidelines before electrocardiogram (EKG) evaluations in weight loss programs.
Area of Science:
- Cardiology
- Physiology
Background:
- Weight reduction is linked to QT interval prolongation and sudden death.
- Screening obese patients for prolonged QTc intervals before weight loss is common.
- Current guidelines lack fasting recommendations for electrocardiogram (EKG) evaluations.
Purpose of the Study:
- To determine if heart rate corrected QT (QTc) interval duration is affected by meal ingestion.
- To investigate the impact of food intake versus water intake on QTc intervals.
- To explore the role of the autonomic nervous system in meal-related QTc changes.
Main Methods:
- 11 healthy subjects ingested a 500-kcal formula meal.
- EKG recordings were taken before and up to 60 minutes after meal ingestion.
- Spectral analysis of R-R intervals assessed cardiac autonomic flow; control group received water.
Main Results:
- A significant increase in QTc interval was observed 15 minutes post-meal, persisting for 1 hour.
- Absolute QT interval slightly decreased, while R-R interval steadily declined after the meal.
- No significant QTc changes occurred when water replaced the meal, but autonomic flow markers changed with food.
Conclusions:
- Cardiac repolarization is influenced by feeding and fasting states.
- Meal intake, not just hydration, affects the QTc interval.
- Autonomic nervous system activity may mediate meal-related QTc interval alterations.