Pregnancy Related Inappropriate Sinus Tachycardia

• Conditions: Pregnancy Related; Inappropriate Sinus Tachycardia

• Registration Number: NCT03317249
• Lead Sponsor: Cambridge University Hospitals NHS Foundation Trust

Brief Summary

A feasibility study into the exploration of possible mechanisms underlying inappropriate sinus tachycardia (IST) syndrome in pregnancy.

Detailed Description

This is a non-interventional, physiological study which will explore the feasibility of examining autonomic function and related haemodynamic variables in pregnant women with and without inappropriate sinus tachycardia, with the aim of providing scope for future research.

Sinus tachycardia (normal heart rhythm but fast heart rate) is common and usually related to an obvious cause (e.g. exercise such a running or cycling) and doesn't cause any untoward symptoms. In rare cases however, sinus tachycardia can occur without an obvious cause (i.e. it is inappropriate to the situation) and can cause distressing symptoms such as palpitations, dizziness and breathlessness at rest or with minimal exertion. This syndrome of inappropriate sinus tachycardia is poorly understood and can be difficult to manage; especially when the affected individual is pregnant. In order to understand the condition better and improve care pathways we aim to measure various features of the cardiovascular system in pregnant women with and without IST.

Study Timeline

• Study Start: 2017-10-06
• Study First Submitted: 2017-10-06
• Study First Submitted QC: 2017-10-19
• Study First Posted: 2017-10-23
• Status Verified: 2019-01
• Last Update Submitted: 2019-01-18
• Last Update Posted: 2019-01-22
• Primary Completion: 2020-10-06
• Study Completion: 2020-10-06

Recruitment & Eligibility

• Status: UNKNOWN
• Sex: Female
• Target Recruitment: 200

Inclusion Criteria

• Aged 18-45 years of age

• Able to give written informed consent and willing to participate

• The participant falls into one of the below categories:

  i. Pregnant women with IST ii. Pregnant women without IST

Exclusion Criteria

• Obesity (BMI > 29.9)
• Current or recent (within last 3 months) smoker
• Known medical condition likely to affect HRV (other than IST in relevant groups)
• Previous history of hypertensive disorders in pregnancy
• Lack of written informed consent

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
Feasibility of examining autonomic function and related haemodynamic variables in pregnant women with and without inappropriate sinus tachycardia	Up to 3 years	Number of women in each group who agree to participate in the study
Assessment of autonomic function and related haemodynamic variables in pregnant women with and without inappropriate sinus tachycardia	Up to 3 years	Baroreflex sensitivity (BRS) at rest calculated from the change in systolic pressure and change in R-R interval to give change in pressure per change in RR interval, measured in milliseconds (mmHg/ms)

Secondary Outcome Measures

Name	Time	Method
Assessment of ANS function in pregnant women with and without IST, at rest and during mild exercise	Up to 3 years	Blood Pressure in mm/Hg

Trial Locations

Locations (1)

Addenbrookes Hospital; 🇬🇧 Cambridge, United Kingdom