From the Guidelines
Heart rate in atrial fibrillation (AF) should be determined using an ECG recording.
Determining Heart Rate in Atrial Fibrillation
To diagnose AF and determine heart rate, an ECG recording is necessary 1. The heart rate in AF can be calculated from a standard 12-lead ECG by multiplying the number of...
- ECG characteristics: Any arrhythmia that has the ECG characteristics of AF and lasts sufficiently long for a 12-lead ECG to be recorded, or at least 30 s on a rhythm strip, should be considered as AF 1.
- Heart rate targets: The optimal heart rate target in AF patients is unclear, but a lenient heart rate target of <110 b.p.m. is an acceptable initial approach, regardless of heart failure status, unless symptoms call for stricter rate control 1.
- Rate control criteria: Criteria for rate control vary with patient age but usually involve achieving ventricular rates between 60 and 80 beats per minute at rest and between 90 and 115 beats per minute during moderate exercise 1.
- Assessment of heart rate control: No standard method for assessment of heart rate control has been established to guide the management of patients with AF, but it may be useful to evaluate the heart rate response to submaximal or maximal exercise or to monitor the rate over an extended period (e.g., by use of 24-h Holter recording) 1.
From the Research
Determining Heart Rate in Atrial Fibrillation
To determine heart rate in atrial fibrillation, several methods can be used, including:
- Using an oscillometric blood pressure device to measure pulse rate, with the average of three measurements providing a clinically accepted estimation of mean heart rate in patients with atrial fibrillation and a pulse rate variation of 0-15 bpm 2
- Recording an electrocardiogram (ECG) for at least 30 seconds, as a 10-second recording may not provide a clinically accepted estimation of heart rate 3
- Using improved time synchronous averaging to measure pulse rate variability and detect atrial fibrillation, which can provide a new way to measure pulse rate variability and detect atrial fibrillation, especially under poor signal quality conditions 4
Factors Affecting Heart Rate Control
Several factors can affect heart rate control in patients with atrial fibrillation, including:
- The type of heart failure, with heart failure with preserved ejection fraction (HFpEF) patients having a U-shaped association between resting heart rate and cardiovascular outcomes 5
- The presence of coronary heart disease, with patients having both atrial fibrillation and coronary heart disease having a higher risk of all-cause mortality compared to those with atrial fibrillation alone 6
- The optimal resting heart rate target, with a target of 70 bpm suggested for patients with atrial fibrillation and coronary heart disease 6
Measurement Techniques
Different measurement techniques can be used to determine heart rate in atrial fibrillation, including:
- Oscillometric blood pressure devices, which can provide a clinically accepted estimation of mean heart rate in patients with atrial fibrillation and a pulse rate variation of 0-15 bpm 2
- Electrocardiogram (ECG) recordings, which can be used to measure heart rate and detect atrial fibrillation, with a recording duration of at least 30 seconds recommended 3
- Improved time synchronous averaging, which can provide a new way to measure pulse rate variability and detect atrial fibrillation, especially under poor signal quality conditions 4