Objective To observe the effectiveness of intrathoracic impedance monitoring on detecting aggravation in chronic heart failure patients with InSync Sentry CRT-D.

Methods We retrospectively analysed the clinical data of 14 consecutive patients. Patients were regularly followed up every 3–6 months after the implantation. At each visit, interrogation of the device was done by specified doctors. Patients were instructed to inform the researcher in case of a device alert, and to take extra 40 mg of furosemidum if they really had aggravated symptoms later. Data about heart failure hospitalisation was collected retrospectively from the medical record.

Results During 18–48 months follow-up, a total of 7 patients encountered 28 alert events. Among the 28 alert events, 3 (10.7%) alerts were not followed by any clinical condition, and 23 (82.1%) alerts were followed by deterioration of heart failure symptoms. Besides, 2 alerts were related to the onset of pulmonary infection. In the end, only 5 patients were hospitalised 10 times for deterioration of cardiac function.

Conclusions The function of intrathoracic impedance monitoring is reliable in predicting deterioration of heart failure, so prompt medical intervention may reduce symptoms and hospitalisations due to decompensation.