Abstract: A method of sensing and analyzing electrical activity of the human heart comprises the sensing of voltage signals generated by the heart between four electrodes (E, A, S and I) located at key positions on the surface of a subject's body. The E electrode is attachable to the anterior midline of the subject body at a level selected from the group consisting of the fourth rib interspace and the fifth rib interspace. The A and I electrodes are attachable to the subject's body on opposed sides of the anterior midline below the level of the E electrode but high enough so they are positioned over the subject's ribs or intercostal spaces. The S electrode is positioned over the subject's manubrium sterni. Signal processing means combines and scales the voltage signals to produce xyz vectorcardiographic signals, electrocardiographic signals corresponding to the lead signals of a 12-lead electrocardiograph, or both.

Abstract: In a process for monitoring patients with chronic congestive heart failure, a high frequency current is passed between electrodes applied to two limbs of a patient. The current, voltage and phase angle between the measured current and voltage are measured to enable the calculation of congestive heart failure (CHF) indicia values. The calculated CHF indicia values are then compared with baseline values established when the patient is in a known, stable condition. Intervention is initiated if the differences between the calculated CHF indicia values and the baseline values are outside of established tolerances. The CHF indicia values may include resistance, reactance, impedance, total body water and extracellular water. Moreover, the CHF indicia values may include a figure of merit indicative of the hydration status of the patient.