Historical vignette celebrating the 30th anniversary of diagnostic ambulatory electrocardiographic monitoring and data reduction systems.

The ambulatory electrocardiographic (ECG) monitor is a device developed approximately 30 years ago to detect, locate and document hemodynamic insufficiency states in target organs with compromised regional arterial circulations. These insufficiency states are usually silent until they are suddenly precipitated by secondary remote, hemodynamically significant cardiac arrhythmias, hypotensive states caused by internal hemorrhage or reduced cardiac output including cardiogenic shock. Insufficiency events cause serious regional dysfunction, resulting in transitory or permanent damage of the remote target organs (brain, heart, splanchnic and renal) often causing paralytic ileus, gangrene of the gut or rectum, myocardial infarction or cerebral stroke. Comprehensive experimental studies conducted in the author's laboratory over a period of years (1946-1971) proved that such remote ischemic states are often recurrent and can cause serious, irreparable damage, but whenever the cause of the regional ischemic state was treated promptly it could reverse the insufficiency state. Practical ambulatory ECG diagnostic monitors and data reduction systems were developed to diagnose these elusive precipitating pathophysiologic events that might coincide with the patient's symptoms and thus determine the most appropriate preventive therapy.