AF in HF: The Chicken or the Egg? Role of Crt Device Based Sensor Data in Identifying a Causal Relationship between AF and Worsening HF

Purpose: Atrial Fibrillation (AF) is a common co-morbidity in Heart Failure (HF). Whether AF triggers or is triggered by worsening HF is debated, although both are likely. We present a patient diagnosed with worsening HF secondary to AF with device-based sensor data that show temporal relationship between AF and HF status. Method: MultiSENSE is an international multi-center feasibility study which collected up to 1 year of device-based sensor data including third heart sound (S3), intrathoracic impedence (Z), respiration rate (RR) and night-time heart rate (nHR). The sensor data were compared with clinical data such as adverse events and medication changes. Treating physicians were blinded to device sensor data. Results: The patient, enrolled on 7-Dec-11 with no history of AF, was seen by primary care physician on 1-Oct-12 and started on 20 mg/day furosemide for lower extremity edema. AF was subsequently diagnosed by cardiologist on 4-Oct and physical exam confirmed worsening HF secondary to new onset AF. Furosemide was uptitrated to 200 mg/day and patient was cardioverted on 20-Nov. Consistent with clinical presentation, acute progression of worsening HF immediately following the AF onset on 22-Sep is indicated by increased S3, RR and nHR and decreased Z. Signals improve briefly following the diuretic intervention but then worsen prior to cardioversion. AF cardioversion leads to substantial signal changes indicating an improved HF status. Conclusion: In this case, device-based sensor data reflect hemodynamic impact of AF on HF status and may help identify the trigger: AF or worsening HF. Additional studies are warranted to understand if such causal relationship as established by device-based monitoring can be used to guide targeted intervention.