Intrathoracic Impedance and Ultrasound Lung Comets in Heart Failure Deterioration Monitoring

• Published in: Pacing and clinical electrophysiology 2011-08, Vol.34 (8), p.968-974
• Main Authors: MAINES, MASSIMILIANO, CATANZARITI, DOMENICO, ANGHEBEN, CARLO, VALSECCHI, SERGIO, COMISSO, JENNIFER, VERGARA, GIUSEPPE
• Format: Article
• Language: English
• Subjects: Aged; Algorithms; Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Biological and medical sciences; Cardiography, Impedance - instrumentation; Cardiography, Impedance - methods; Cardiology. Vascular system; Chest; Data processing; Defibrillators; Defibrillators, Implantable; Doppler effect; Echocardiography; Echocardiography, Doppler - methods; echography; Edema; Electrophysiology; Emergency and intensive cardiocirculatory care. Cardiogenic shock. Coronary intensive care; Extravascular Lung Water - diagnostic imaging; Female; Follow-Up Studies; Heart; Heart diseases; Heart failure; Heart Failure - diagnostic imaging; Heart failure, cardiogenic pulmonary edema, cardiac enlargement; Humans; implantable defibrillator; Intensive care medicine; intrathoracic impedance; Lung; Lung - diagnostic imaging; Male; Medical sciences; Middle Aged; Predictive Value of Tests; Pressure; Prospective Studies; Pulmonary Edema - diagnostic imaging; Pulmonary Wedge Pressure; Radiotherapy. Instrumental treatment. Physiotherapy. Reeducation. Rehabilitation, orthophony, crenotherapy. Diet therapy and various other treatments (general aspects); Sensitivity and Specificity; Septum; Ultrasound; ultrasound lung comets
• ISSN: 0147-8389; 1540-8159
• DOI: 10.1111/j.1540-8159.2011.03072.x

Purpose: Echographic examination of the lung surface may reveal multiple ultrasound lung comets (ULCs) originating from water‐thickened interlobular septa. These images were demonstrated to be useful for noninvasive assessment of interstitial pulmonary edema. Similarly, the correlation between implantable defibrillator‐measured intrathoracic impedance and pulmonary capillary wedge pressure (PCWP) was demonstrated in heart failure (HF) patients. The aims of this analysis were to assess the agreement between defibrillator‐detected impedance decrease and the presence of ULCs, as well as to compare the performance of the impedance‐detection algorithm and the ULCs assessment in predicting HF worsening. Methods and Results: We studied 23 HF patients implanted with a defibrillator capable of intrathoracic impedance measurement and alerting for fluid accumulation diagnosis. At regular follow‐up and at visits for HF decompensation or device alert, clinical status was assessed, chest ultrasound was performed, and PCWP was noninvasively estimated with Doppler echocardiography. During 23 ± 11 months of follow‐up, 45 paired assessments of defibrillator‐measured intrathoracic impedance and ULCs were performed. The number of ULCs resulted significantly correlated to the paired PCWP estimations (r = 0.917, P < 0.001) and to the impedance fluid index (r = 0.669, P < 0.001). During follow‐up, 12 episodes of HF decompensation were reported in 12 patients. The impedance alert detected clinical HF deterioration with 92% sensitivity and 69% positive predictive value. The presence of ≥5 ULCs showed 83% sensitivity and 91% positive predictive value. Conclusions: These data demonstrate the correlation between intrathoracic impedance and the number of ULCs at chest ultrasound, and a good agreement between the defibrillator warning for fluid index and the detection of multiple ULCs. (PACE 2011; 34:968–974)