Acute left ventricular dynamic effects of primary percutaneous coronary intervention from occlusion to reperfusion.

Abstract

We studied the left ventricular (LV) dynamic effects of primary percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI) by directly obtaining pressure-volume (PV) loops during the procedure. An acute myocardial infarction causes a decrease in LV compliance. The instantaneous effects of primary PCI on LV compliance are unknown. We studied 15 consecutive patients (10 males, ages 59 +/- 12 years), who presented with their first acute anterior STEMI within 6 h after onset of symptoms, and in whom coronary angiography revealed an occluded left anterior descending coronary artery. Before performing primary PCI, we inserted a pressure-conductance catheter in the LV to continuously obtain PV loops. Immediately after successful reperfusion, significant improvements were observed in LV diastolic function, as indicated by an increased end-diastolic compliance with a 6.0 +/- 2.8 mm Hg (p < 0.0001) downward shift of the compliance curve. There was a decrease in end-diastolic pressure of 24 +/- 18% (p = 0.0002), in stiffness of 27 +/- 18% (p = 0.0003), and in wall stress of 20 +/- 24% (p = 0.004). Systolic function mainly showed an immediate improvement in apical contractility from 40 +/- 17% to 54 +/- 15% (p = 0.01). Primary PCI in anterior STEMI patients causes an immediate improvement in diastolic function, assessed by online PV loop measurements.