Recognition of acute myocardial infarction caused by spontaneous coronary artery dissection of first septal perforator

Abstract

Aims Spontaneous coronary artery dissection (SCAD) diagnosis is challenging as angiographic findings are often subtle and differ from coronary atherosclerosis. Herein, we describe characteristics of patients with acute myocardial infarction (MI) caused by first septal perforator (S1) SCAD. Methods and results Patients were gathered from SCAD registries at Minneapolis Heart Institute and Vancouver General Hospital. First septal perforator SCAD prevalence was 11 of 1490 (0.7%). Among 11 patients, age range was 38–64 years, 9 (82%) were female. Each presented with acute chest pain, troponin elevation, and non-ST-elevation MI diagnosis. Initial electrocardiogram demonstrated ischaemia in 5 (45%); septal wall motion abnormality was present in 4 (36%). Angiographic type 2 SCAD was present in 7 (64%) patients with S1 TIMI 3 flow in 7 (64%) and TIMI 0 flow in 2 (18%). Initial angiographic interpretation failed to recognize S1-SCAD in 6 (55%) patients (no culprit, n = 5, septal embolism, n = 1). First septal perforator SCAD diagnosis was established by review of initial coronary angiogram consequent to cardiovascular magnetic resonance (CMR) demonstrating focal septal late gadolinium enhancement with corresponding oedema (n = 3), occurrence of subsequent SCAD event (n = 2), or second angiogram showing healed S1-SCAD (n = 1). Patients were treated conservatively, each with ejection fraction >50%. Conclusion First septal perforator SCAD events may be overlooked at initial angiography and mis-diagnosed as ‘no culprit’ MI. First septal perforator SCAD prevalence is likely greater than reported herein and dependent on local expertise and availability of CMR imaging. Spontaneous coronary artery dissection events may occur in intra-myocardial coronary arteries, approaching the resolution limits of invasive coronary angiography.

Acute Myocardial Infarction Caused by Spontaneous Coronary Artery Dissection of the First Septal Perforator

“…There was uncertainty about whether this was the culprit for her presentation because SCAD of the septal-perforator artery is rare. 1 Intracoronary imaging is instrumental in aiding the diagnosis in angiographically subtle cases but was prohibited here due to vessel size and acute takeoff. 2

Figure 1 Isolated SCAD of First Septal-Perforator Artery (A) Angiographic RAO view showing Type 2 SCAD of septal-perforator artery (red arrows) .

…”