Cardiac dysrhythmias during cardiovascular autonomic reflex tests

Area of Science:

• Cardiology
• Autonomic Nervous System Function

Background:

• Cardiovascular autonomic function tests are crucial for assessing autonomic neuropathy.
• Potential dysrhythmogenic effects of these tests require thorough investigation.

Purpose of the Study:

• To evaluate the risk of cardiac arrhythmias during a battery of cardiovascular autonomic reflex tests.
• To determine if specific patient populations or tests pose a higher risk.

Main Methods:

• Analysis of electrocardiogram (ECG) tracings from 925 subjects undergoing autonomic function tests.
• Tests included Valsalva maneuver, deep breathing, orthostatic, and isometric handgrip tests.
• Comparison of arrhythmia frequency during tests versus resting phase.

Main Results:

• Ventricular extrasystoles increased in 11% of healthy, 11% of diabetic, and 23% of post-myocardial infarction subjects.
• Orthostatic and isometric handgrip tests were most associated with arrhythmias in post-MI patients.
• Nine subjects experienced other arrhythmias (e.g., VT, AF), all asymptomatic and self-resolving.

Conclusions:

• The cardiovascular reflex test battery is generally safe.
• Occasional significant dysrhythmias warrant continuous ECG monitoring and readiness for resuscitation.
• Patients with prior myocardial infarction may be at higher risk for test-induced arrhythmias.