Patient-triggered Events Poorly Predict the Presence of Atrial Tachyarrhythmia on Ambulatory Electrocardiogram Monitors in Patients With Heart Failure.

Background: Ambulatory electrocardiogram (AECG) monitoring is an attractive method for objectively identifying atrial fibrillation (AF) symptoms by documenting simultaneous arrhythmia with symptomatic episodes. However, no study yet has evaluated this simultaneous symptom-rhythm correlation in patients with heart failure (HF). We aimed to measure the correlation between symptoms and atrial arrhythmia (ATAF) episodes among patients with HF and known AF using prolonged AECG monitoring.

Methods: We analyzed ATAF events and patient-triggered symptomatic events (PTSEs) on AECG monitors in adults with a history of AF and HF.

Results: Among 959 monitors, we identified a total of 26,634 events, including 15,787 ATAF events and 4950 PTSE. The mean age was 70 years, 48% were female, and 91% were Caucasian. Among 4950 PTSEs, only 1116 demonstrated ATAF (23%). PTSE showed a low correlation with ATAF, with a moderate inverse tetrachoric correlation of -0.62 (bootstrapped 95% confidence interval: -0.61 to -0.63). The mean heart rate (HR) of symptomatic ATAF events was 115 bpm (SD: 33), compared with asymptomatic ATAF (107 bpm, SD: 33, P < 0.001). The mean HR of all symptomatic events was 92 bpm (SD: 28) and of asymptomatic events was 99 bpm (SD: 30), P < 0.001.

Conclusions: Our study found that symptomatic events on AECG monitors poorly predict ATAF episodes, ATAF episodes are rarely noted as symptomatic, and poor HR control fails to fully explain AF symptoms in patients with known AF and HF. Our study encourages further research into other symptom assessments, such as patient-reported outcomes and a more comprehensive approach to AF treatment in HF rather than primarily symptom based.