Angiographic and hemodynamic effects of myocardial bridge during supine bicycle exercise

Abstract

The aim of this study was to evaluate the hemodynamic effect of physiological exercise during coronary angiogram with Pd/Pa, end diastolic Pd/Pa and FFR measurements in symptomatic patients with myocardial bridge (MB). We included all consecutive patients with symptomatic MB without significant coronary artery disease between 2014 and 2015. Coronary angiogram was performed with radial approach and supine bicycle set on the table. A pressure wire was placed downstream the MB. Systolic compression was assessed with quantitative coronary angiography. The exercise protocol started at 50 watts and increased by steps of 15 watts every 2 minutes. After exercise, intracoronary nitrates was used and finally intracoronary adenosine administration for FFR measurement. 9 symptomatic patients with an isolated LAD MB were included. Patients reached 73% ± 10% of maximum heart rate. No complication occurs during this protocol. FFR was significantly lower compared to rest, peak exercise and after nitrates ( P < 0.05 for all) (A). Compression during systole significantly increases in peak exercise compare to rest respectively 78% versus 37% ( P = 0.003) (B). However, Pd/Pa values and end diastolic Pd/Pa did not significantly changed at rest compared to peak exercise respectively 0.90 versus 0.87 ( P = 0.21) for Pd/Pa, and 0.85 versus 0.82 ( P = 0.35) for end diastolic Pd/Pa (C). During the protocol, no significant difference of Pd/Pawas observe between rest, peak exercise and after nitrates ( P > 0.05 for all) ( Fig. 1 ). We reported invasive hemodynamic assessment of MB during physiological exercise conditions with supine bicycle. MB increase systolic compression during exercise with a preserved hemodynamic indices.