論文ID: CJ-21-0079
Left ventricular free wall rupture (LVFWR) is an uncommon complication of acute myocardial infarction (AMI) associated with high mortality.1 An extrinsic systolic compression of the coronary artery (“milking-like” effect) has been previously described as a possible predictor of LVFWR.2
We present a 71-year-old male admitted for acute anterior myocardial infarction. Emergency coronary angiography showed acute thrombotic occlusion of the left anterior descending artery (LAD) at the proximal segment (Figure A; Supplementary Movie 1). Primary percutaneous coronary intervention was performed with balloon dilatation and drug-eluting stent implantation with pain relief and ST-segment normalization (Figure B). Immediately after coronary flow was restored, a milking-like effect with systolic coronary compression was observed at the mid-segment of the LAD (Figure C,D; Supplementary Movie 2). The patient presented progressive hemodynamic derangement and cardiogenic shock, requiring inotropic and mechanical hemodynamic support (intra-aortic balloon counterpulsation [IABP]). Within the first 24 h, transthoracic echocardiography (TTE) revealed new-onset moderate pericardial effusion (circumferential) but with no tamponade physiology, intrapericardial fibrin strands or suspected LVFWR (Figure E,F). During his stay in the coronary care unit, serial TTE were performed showing no progression of the pericardial effusion. On the 4th day of admission (24 h after IABP removal), the patient presented sudden hemodynamic instability with progressive bradycardia and cardiorespiratory arrest requiring advanced life support. New TTE disclosed a large pericardial effusion with early diastolic collapse of both the right atrium and right ventricle. Immediate pericardiocentesis was performed, with drainage of hemorrhagic fluid. Despite all efforts, the patient died. The salient findings at necropsy were a wide necrotic area and thinning of the left ventricular anterior wall, the absence of a “tunneled” intramuscular course of the LAD and a myocardial rupture in the anterolateral region of the left ventricle (Figure G–I).
(A,B) Coronary angiogram before (yellow arrow indicates acute thrombotic occlusion) and after percutaneous intervention. (C,D) “Milking-like” effect in the mid-segment of the LAD (yellow arrowheads). (E,F) TTE showing moderate pericardial effusion with no tamponade physiology. (G) Macroscopic view showing a large area of necrosis and a myocardial tear in the anterolateral region (red arrow). (H,I) Macro- and microscopic images showing the relationship between the LAD (blue asterisks) and the myocardial tear (blue arrowhead), together with the lack of a “tunneled” intramuscular course of the LAD. LAD, left anterior descending; TTE, transthoracic echocardiography.
To the best of our knowledge, this is the first case of the milking-like effect with subsequent LVFWR that illustrates, with a precise anatomopathological correlation and histological findings, the lack of an intramuscular course of the LAD as the classical etiopathological basis of this unique phenomenon. The mechanisms involved in this phenomenon are multifactorial. Early myocardial remodeling with large dyskinetic areas and high left ventricular filling pressures may hamper the coronary arteries filling during diastole, leading to this angiographic finding. Thus, the milking effect may indirectly reveal extensive myocardial damage, resulting in an increased risk of LVFWR in patients presenting with AMI.
The authors have no conflicts of interest to declare.
The Ethics Committee for Research of IIS Princesa granted an exemption from requiring ethics approval.
Supplementary Movie 1. Coronary angiogram showing acute thrombotic occlusion of the LAD.
Supplementary Movie 2. Coronary angiogram revealed a “milking-like” effect in the mid-segment of the LAD.
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http://dx.doi.org/10.1253/circj.CJ-21-0079
