Physiological significance of a proximal coronary artery stenosis on a distal intramyocardial bridge: coronary flow velocity patterns pre- and post-angioplasty.

The angiographic incidence of intramyocardial bridging (MB) is 0.7-4.5% [Angelini et al.: Prog Cardiovasc Dis 25:75-88, 1983]. Morphological and physiological patterns of MB have recently been described, observing coronary flow velocity patterns, intravascular ultrasound, and angiography [Flynn et al.: Cathet Cardiovasc Diagn 32:36-39, 1994; Ge et al.: Circ Res 89:1725-1732, 1994]. We describe a reversal of the normal flow velocity characteristics within a MB, due to a hemodynamically significant stenosis in the proximal left anterior descending artery (LAD). After successful percutaneous transluminal coronary angioplasty (PTCA) of the proximal LAD stenosis, there was normalization of the flow velocity pattern within the MB and the appearance of a spike and dome pattern distal to the MB.