Exercise Induced QT Interval Changes in Response to Intermittent and Continuous Graded Exercise Tests

NCT04005027 | Suspended

• 1 other identifier: LQT004291
• Study Type: interventional
• Target: 50
• Locations: 1 country
• Sites: 1

Brief Summary

Long QT syndrome (LQTS) is an inherited heart defect where the heart takes longer to recover between beats. LQTS is a known condition predisposing young footballers to sudden cardiac death (SDC). The existence of LQTS can be established by measuring the QT interval in an electrocardiogram (ECG). Currently pre-participation cardiac screening is performed in young athletes but players may only be screened at 16 years old using only a resting ECG, and a medical check including a questionnaire on family and medical history. However, the sensitivity and specificity of the screening to investigate underlying causes of SCD could be improved with the addition of an exercise stress test or cardiopulmonary exercise test (CPET). Certain abnormalities in the heart may only become apparent when the heart has been stressed (e.g. via exercise). This is particularly important as in young athletes these abnormal rhythms manifest during rest and recovery rather than at peak exercise. The CPET measures changes in the ECG in response to exercise that increases in intensity in a continuous manner until the participant cannot exercise any long. However, football is characterised by high- intensity bouts of exercise interspersed with low-intensity bouts or pauses. Therefore, the continuous test does not reflect the movement patterns of football and may not stress the cardiovascular system in a similar manner. To address this, intermittent graded exercise tests have been developed to reflect the intermittent movement pattern. As yet there is limited evidence on whether there are any differences in ECG changes during intermittent exercise. Specifically, it is not clear how an intermittent movement pattern might affect the QT interval.

Conditions

Qt Interval, Variation in

Keywords

QT interval; Intermittent Exercise; Continuous Exercise; Cardiac; Electrocardiogram

Outcome Measures

Primary Outcomes (1)

• QT interval duration

  Duration of the QT interval calculated in each 3 minute stage using various algorithms

  Measured during exercise, and immediately following exercise (6 min recovery)

Secondary Outcomes (2)

• Maximal/ Peak Oxygen Uptake

  End of exercise (final workload stage) taken as highest value over 30 second average

• Ventilatory threshold

  During exercise determined using V slope method (10 second, and middle 5 of 7 averages)

Study Arms (2)

Intermittent graded exercise (INT)

EXPERIMENTAL

The intermittent graded exercise test (INT) increase treadmill speed incrementally using three minute stage duration on a motorised treadmill. However, the speed within each three minute exercise bout will vary every 30 s between the target speed, and a complete pause for 30 s. The acceleration of the treadmill belt will be set to its maximum capability.

Other: Intermittent graded exercise test

Continuous graded exercise (CONT)

ACTIVE COMPARATOR

The continuous graded exercise test (CONT) will increase treadmill speed incrementally using three minute stage duration on a motorised treadmill

Other: Intermittent graded exercise test

Interventions

Intermittent graded exercise test OTHER

Participants will run on a treadmill until volitional exhaustion. The speed of the treadmill belt will increase incrementally every 3 minutes. Within each 3 minute stage the speed will vary between the target speed and a complete pause (e.g target speed = 8 km/hr)

Continuous graded exercise (CONT); Intermittent graded exercise (INT)

Eligibility Criteria

• Age: 16 Years - 18 Years
• Sex: male
• Healthy Volunteers: Yes
• Age Groups: Child (0-17), Adult (18-64)

You may qualify if:

• Healthy male soccer players
• Must be participating in \~3 - 6 h of soccer training per week as part of a soccer academy or regional training centre (RTC)

You may not qualify if:

• More than one coronary artery disease risk factor
• At least one cardiovascular, respiratory or metabolic disease.
• Have suffered from a lower limb musculoskeletal injury in the past 6 months

Sponsors & Collaborators

• University of Sunderland: lead
• Sheffield Hallam University: collaborator
• Newcastle University: collaborator
• Teesside University: collaborator

Study Sites (1)

Sunderland University

Sunderland, Tyne and Wear, SR1 3SD, United Kingdom

Location

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principle Investigator

Model Details: The investigators will use a replicated randomised repeated measures crossover design in which the participants will be randomised to different sequences of four experimental conditions

Study Record Dates

• First Submitted: June 27, 2019
• First Posted: July 2, 2019
• Study Start: July 8, 2019
• Primary Completion: September 1, 2023
• Study Completion: September 1, 2023
• Last Updated: January 11, 2022

Record last verified: 2021-12

Locations

GB (1)