We frequently hear a comment about LCX angioplasty being a tricky intervention . Even many experienced cardiologists do agree with this .
What could be the apparent explanation for this seemingly important observation in cath lab ?
- The first and foremost is the anatomical uniqueness of origin and course of LCX. LAD is direct continuation of left-main , while LCX always originate with a considerable angle at it’s origin . Further downstream it flexes circum-ferentially over the lateral free wall of left ventricle .This ensures the catheters and stents we maneuver often traverse a hair pin bend .
- The endurance of coronary stents are put into biggest test during LCX angioplasty . While any mediocre metal stent can sit comfortably in LAD , LCX is different story altogether.(A flexible multi link model like that of Abbot Vision platform seems ideal . )
- The LCX wire crossing and exchange is vested with potential threat to the much important LAD circulation . Time and again , we have observed , prolonged procedures inside LCX some how compromise the LAD flow.
- Once the LCX is opened ( especially in a CTO , ) there is a sort of stealing of LAD blood flow. We have witnessed this in at least 2 patients , who developed anterior MI after opening up of LCX CTO. (Who had a insignificant LAD lesion )
- LAD may be widow maker artery , but it remains a fact LCX has much more important role in regulating mitral valve papillary muscle . Even transient ischemia in LCX territory can result in lung congestion or even flash pulmonary edema .This is fairly frequent during complex LCX angioplasty .
- The antero-lateral pap muscle is located in a critical location especially so in post infarct remodeled left ventricle even minor degrees of ischemia can create a havoc .This is what occurs during flash pulmonary edemas in LCX angioplasties.
- Spillover of thrombus from LCX to LAD can occur during aspiration of LCX primary PCI
- Finally, ECG changes are often blind in LCX territory . It remains an Irony , we do not monitor the heart with 12 leads during sensitive procedure like a PCI.(The monitor leads easily miss LCX ischemia .This is hardly surprising, as we know LCX territory has blind spots even with 12 lead ECG !)
It is true LCX angioplasties can not be taken casually . One can not afford to have a prolonged procedure within LCX.Whether dominant or not LCX delivers blood supply to more vital areas of myocardium that typically includes lateral free wall and mitral valve function .It is possible septal ischemia is relatively well tolerated while free wall ischemia triggers an early mechanical deterioration .