Hyperventilation, handgrip, cold pressor stress echocardiography

Abstract

Hyperventilation has been mainly used in clinical practice as a provocative test for coronary artery vasospasm. Prolonged, vigorous over-breathing decreases plasma hydrogen ion concentration, leading to metabolic alkalosis, which can trigger coronary artery spasms. The patient hyperventilates for 5 min, with increased frequency (respiratory rate of 25 or higher per min) and depth of breathing. The time window of positivity usually occurs 1-5 min after the end of hyperventilation, therefore without degrading the quality of echocardiographic imaging. Monitoring should last until 10 min after completion. The hyperventilation test should be conducted in the early morning (when the vulnerability to vasospasm is highest in susceptible patients) after at least 48 h from the administration of vasoactive drugs. In the guidelines for the diagnosis of coronary spastic angina by the Japanese Circulation Society, non-invasive coronary spasm provocation testing with a hyperventilation test is recommended in patients suspected of having vasospastic angina with a low (class 2a) or high (class 2b) frequency of attacks, but in whom coronary spasm has not been diagnosed by non-invasive evaluation (including exercise ECG test, Holter, and hyperventilation test). © The Author(s), 2023. All rights reserved.