Patent attributes
A method for monitoring the progression of the hemodynamic status of a patient by tracking autonomic tone. For example, the method may be applied to patients suffering from heart failure, diabetic neuropathy, cardiac ischemia, sleep apnea and hypertension. An implantable or other ambulatory monitor senses a pulse amplitude signal such as a vascular plethysmography signal. Variations of the signal amplitude on a scale greater than the heartbeat to heartbeat scale are indicative of variations in autonomic tone. A significant reduction in pulse amplitude and pulse amplitude variability are indicative of a heart failure exacerbation or other disease state change. This information may be used to warn the patient or healthcare providers of changes in the patient's condition warranting attention.
