Comparison Study of BNP and Thoracic Impedance Measurements on Arrhythmias

The primary aim of this study:

1. To assess the correlation between elevated brain natriuretic peptide levels and
elevated thoracic impedance/body fluid index as measured by selective biventricular
resynchronization devices and an external impedance cardiography device.

2. Correlate impedance measurements and brain natriuretic levels with occurrence of atrial
and ventricular arrhythmias as assessed by interrogation of biventricular devices.

Inclusion Criteria:

- Male or female between 18 to 85 years of age.

- All patients with biventricular implantable cardio-defibrillators(manufacturer:
Medtronic/ model: InSync 7299/7297 or newer).

- LVEF <35%

- NYHA III/IV

- QRS >120 msec

- Pt willing and able to sign informed consent.

- Conventional heart failure therapy

- Clinically stable for six months.

Exclusion Criteria:

- age less than 18 years of age

- age greater than 85 years of age

- Creatinine > 2.5 mg/dl.

- End stage liver disease complicated by ascites as determined by electronic medical
record review.

- women who are pregnant, lactating, or plan to become pregnant during the course of
the study.

- Patients who are heart transplant candidates with expected transplantation within the
next six months.

- Life expectancy due to non-cardiac cause less than one year.

- Anticipated problem with compliance.

- Critical valvular stenoses/insufficiencies.

- Morbidly obese patients(>300 lbs.)

- In patients whom impedance cardiography was not able to be performed because of
inability to place sensors.

- Planned or known need for revascularization procedures within three months.