A CASE OF ORTHOSTATIC HYPOTENSION AND RECENT ADVANCES
Gordon L. Fung, M.D., M.P.H., Ph.D., UCSF Medical Center at Mt. Zion, San Francisco, CA, USA
JM is a 78 year old man who had a history of hypertension and developed an ascending aortic aneurysm while under treatment. He presented to the hospital for elective prostate operation and was seen by Cardiology for evaluation of atypical chest pain. The patient gave a history of recurrent syncope over the past 6 years with syncope every 1-2 years. He described one incident as sitting at a stop light in his car driving home after shopping in a mall. The next thing he remembered was being awakened by EMS. Another incident was in the morning getting up to brush his teeth and his wife heard a thump and found him on the bathroom floor.
Orthostatic hypotension is a common cause of syncope, dizziness, angina or less commonly, stroke; and is estimated to have a population prevalence of 5-20%. The main pathophysiologic impairment is during autonomic dysfunction or marked intravascular volume depletion when standing or in an upright posture. A related condition, post-prandial hypotension which occurs after eating and being upright seated or standing between 15-90 minutes after a meal is also common in the elderly. The evaluation should include a good history and physical examination that includes orthostatics even if the patient is asymptomatic at the time of the examination. A thorough medication history is essential, including use of OTC agents that may lead to volume loss. An ECG and echocardiogram to rule out structural heart disease and ambulatory ECG monitoring for a sufficient amount of time to capture a rhythm strip during an event. This may include extended event monitors repeated over several months or an implantable loop recorder (which usually has a 2-3-year life of monitoring) and can be interrogated. A tilt table test can help to rule out postural tachycardia syndrome, neutrally medicated syncope or autonomic failure. Blood tests to rule out electrolyte disorders and adrenal insufficiency.
Management will depend on diagnoses. For orthostatic hypotension that is neutrally medicated, conservative measure like eliminating offending medications, rising slowly from a seated or supine position, support hosiery, and maintaining hydration, and avoiding maneuvers that decrease venous return are recommended. Fludrocortisone is recommended as first line treatment. If unable to tolerate, fludrocortisone, then midodrine can be used.