TESTING Testing generally includes the evaluation of the patient with an echocardiogram (echo). At times there can be variability in the echo technique by the technician and also in the interpretation by the physician. Often, mitral valve prolapse is much more marked when the pateint is in the upright position during the recording of the echo. This reflects the hypovolemia (low blood volume) found in these patients. The presence of a "borderline study" or an echo that is interpreted as not showing definite prolapse should not rule out the presence of the syndrome.Simply relying on an echo that does not confirm this finding to make the diagnosis can make the patient feel that indeed they are "crazy" and leave them nowhere to turn for appropriate treatment.
Exercise testing is most helpful. Typically the patient has an elevated resting heart rate because of the hyperadrenergic drive, and there is an exaggerted heart rate reponse to exercise for each stage of the exercise test. Because of this a common mistake is exercising the patient to the end point of a certain heart rate that results in a much lower level than the patient is capable of achieving. We have found it most helpful to totally ignore heart rate response to exercise as an end point and simply use the borg scale of perceived exertion: Very very light, very light, fairly light, somewhat hard, hard, and very hard. We try to have the patient exercise as close to a maximal level of exercise as possible. In conducting the exercise test one should look not only for the excessive heart rate with exercise, but also blood pressure changes. A typical patient that has MVP/dysautonoia has a very blunted, or reduced increase in their blood pressure with exercise that also reflects a degree of hypovolemia. The exercise tet can also be helpful in finding patients who have a more hypervagal type of dysautonomia. These patients experience a low resting heart rate and very little rise in heart rate with exercise. Their blood pressure response can also be even hypotensive. It is also helpful to determine maximal oxygen consumption, which will depermine aerobic capacity. This is useful when prescribing an exercise program for the patient. Less frquently it is necessary to use a Holter monitor to evaluate heart rhythm abnormalities. Quite often the patient experiences what are perceived as irregularities in heart rate, yet the Holter monitor does not show any abnormalities. The patient who has syncope or near syncopal episodes can be evaluated with the use of a tilt study that helps to diagnose neurocardiogenic syncope, but the treatment is generally the same. They respond to fluid loading, beta blockers, and exercise. The important part of the evaluation is having a high degree of suspicion that the patient may have MVPS with dysautonomia