CONTINUOUS CORONARY FLOW VELOCITY MONITORING DURING CORONARY INTERVENTIONS - VELOCITY TREND PATTERNS ASSOCIATED WITH ADVERSE EVENTS

Continuous measurement of brood flow velocity during interventional pr ocedures has the potential to provide an early warning of coronary flo w instability, which can lead to abrupt closure or other adverse event s before angiography. The magnitude and fluctuations of the average ve locity over time (trend) was studied by using a 0.018-inch Doppler-tip ped angioplasty guide wire in 32 patients after coronary angioplasty ( n = 20), atherectomy (n = 2), urgent stent (n = 6), urgent vein graft thrombolysis (n = 4), or acute myocardial infarction (n = 2). The pati ents (mean age 60 +/- 11 years) had postprocedural in-laboratory flow monitoring for a mean of 19 +/- 11 (range 8 to 36) minutes. The corona ry artery monitored was the left anterior descending in 13, circumflex in 6, right coronary artery in 9, and saphenous vein graft in 4. Seve n patients had flow-related events during continuous flow velocity mon itoring before serial angiographic study. These events included corona ry vasospasm (abrupt flow acceleration), vasovagal flow cessation, cyc lical flow variations resulting from accumulation of intraluminal thro mbus, and rapid decline of flow velocity. The last two patterns were a ssociated with abrupt vessel closure during angioplasty. Continuous fl ow velocity monitoring is easily incorporated into routine interventio nal procedures and provides an early indication of unstable flow and t he potential for abrupt vessel closure and other adverse events.