Where is the stent? CTA assists angiography: A case of jailed LAD

Stent malpositioning in the septal perforator is a serious procedural complication and especially prominent after main vessel stenting in coronary bifurcation lesions. This case report demonstrates Computed Tomography Angiography’s (CTA) role as a backup imaging tool, in cases where follow-up Coronary Angiogram (CAG) cannot be immediately completed. CTA also functions as a preferred imaging tool to follow up after stenting and assess for stent malpositioning. A 72-year-old female with history of hypertension and hyperlipidemia presented with dyspnea and was found to have STEMI. About a week after her three PCI’s to the Left Anterior Descending (LAD) artery, she returned to the hospital with recurrent dyspnea and V-Tach. Instead of completing a repeat catheterization, a noninvasive CTA was thought to be the next test. CTA imaging indicates that the failed stenting of the side-branch resulted in a jailed main vessel, which may induce ischemia and ventricular tachycardia (V-Tach). After the malpositioned stent finding on CTA, the patient was then referred to the Cath Lab for angiogram. CTA thus provided detailed anatomical information about the stent’s placement, which will greatly assist further management by the interventional cardiologist.

Left ventricular summit -- concept, anatomical description and clinical significance

The left ventricular summit (LVS) is a triangular area located at the most superior portion of the left epicardial ventricular region, surrounded by the two branches of the left coronary artery: the left anterior interventricular artery and the left circumflex artery. The triangle is bounded by the apex, septal and mitral margins and base. This review aims to provide a systematic and comprehensive anatomical description and proper terminology in the LVS region that may facilitate exchanging information among anatomists and electrophysiologists, increasing knowledge of this cardiac region. We postulate that the most dominant septal perforator (not the first septal perforator) should characterize the LVS definition. Abundant epicardial adipose tissue overlying the LVS myocardium may affect arrhythmogenic processes and electrophysiological procedures within the LVS region. The LVS is divided into two clinically significant regions: accessible and inaccessible areas. Rich arterial and venous coronary vasculature and a relatively dense network of cardiac autonomic nerve fibers are present within the LVS boundaries. Although the approach to the LVS may be challenging, it can be executed indirectly using the surrounding structures. Delivery of the proper radiofrequency energy to the arrhythmia source, avoiding coronary artery damage at the same time, may be a challenge. Therefore, coronary angiography or cardiac computed tomography imaging is strongly recommended before any procedure within the LVS region. Further research on LVS morphology and physiology should increase the safety and effectiveness of invasive electrophysiological procedures performed within this region of the human heart. Published in Diagnostics: https://doi.org/10.3390/diagnostics11081423

Left Ventricular Summit—Concept, Anatomical Structure and Clinical Significance

The left ventricular summit (LVS) is a triangular area located at the most superior portion of the left epicardial ventricular region, surrounded by the two branches of the left coronary artery: the left anterior interventricular artery and the left circumflex artery. The triangle is bounded by the apex, septal and mitral margins and base. This review aims to provide a systematic and comprehensive anatomical description and proper terminology in the LVS region that may facilitate exchanging information among anatomists and electrophysiologists, increasing knowledge of this cardiac region. We postulate that the most dominant septal perforator (not the first septal perforator) should characterize the LVS definition. Abundant epicardial adipose tissue overlying the LVS myocardium may affect arrhythmogenic processes and electrophysiological procedures within the LVS region. The LVS is divided into two clinically significant regions: accessible and inaccessible areas. Rich arterial and venous coronary vasculature and a relatively dense network of cardiac autonomic nerve fibers are present within the LVS boundaries. Although the approach to the LVS may be challenging, it can be executed indirectly using the surrounding structures. Delivery of the proper radiofrequency energy to the arrhythmia source, avoiding coronary artery damage at the same time, may be a challenge. Therefore, coronary angiography or cardiac computed tomography imaging is strongly recommended before any procedure within the LVS region. Further research on LVS morphology and physiology should increase the safety and effectiveness of invasive electrophysiological procedures performed within this region of the human heart.

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

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.

Abstract 15418: An Arrhythmogenic Isolated Septal Aneurysm

Background: Septal infarct due to isolated occlusion of a perforator branch is extremely rare. Few reported cases only describe either the EKG findings, imaging abnormalities or revascularization techniques. Objective: We report a case of an isolated septal aneurysm (ISA) caused by the acute occlusion of the second septal perforator presenting with recurrent ventricular fibrillation (VF). Results: A 63 year old woman presented to the hospital with chest pain. EKG showed an ST segment elevation localized to lead V3 (Fig1A), troponin 18.23. Angiogram showed an isolated 95% tubular stenosis of large second septal branch of LAD (Fig1B). No revascularization was performed. The patient subsequently had cardiac arrest (VF) requiring cardioversion. Repeat angiogram was unchanged. Echo showed isolated mid septal dyskinetic segment (Fig1C). LVEF was 60%. The patient was discharged with an external defibrillator. Repeat echo showed unchanged EF but presence of the isolated dyskinetic segment. An electrophysiologic study (EPS) showed VF induced with 2 extra stimuli at 250 ms with a drive cycle of 600 ms (Fig1D). An ICD was implanted for prevention of SCD. Conclusion: We describe the first case of an arrhythmogenic ISA in the presence of normal LVEF. The interventricular septum is composed of right and left ventricular endocardium. Experiments have shown that acute septal ischemia produces trans-septal asymmetry in expression of membrane ion channels and action potentials in local conduction velocity and gradients. This results in trans-mural heterogeneity of tissue excitability, a substrate for transmural re-entry and ventricular tachyarrhythmias, in septal infarction. This also explains the persistence of enhanced arrhythmogenicity in our patient during the initial and chronic phases of ischemia. ISA is rare but potentially arrhythmogenic. ISA with preserved LVEF, EPS for arrhythmogenicity and ICD for secondary prevention of SCD should be considered in such cases.

What is the mid-wall linear high intensity “lesion” on cardiovascular magnetic resonance late gadolinium enhancement?

Background Cardiovascular magnetic resonance (CMR) late gadolinium enhancement (LGE) is a valuable technique for detecting myocardial disorders and fibrosis. However, we sometimes observe a linear, mid-wall high intensity signal in the basal septum in the short axis view, which often presents diagnostic difficulties in the clinical setting. The purpose of this study was to compare the linear, mid-wall high intensity in the basal septum identified by LGE with the anterior septal perforator arteries identified by coronary computed tomography angiography (CorCTA). Methods We retrospectively selected 148 patients who underwent both CorCTA and CMR LGE within 1 year. In the interpretation of LGE, we defined a positive linear high intensity (LHI+) as follows: ① LHI in the basal septum and ② observable for 1.5 cm or more. All other patients were defined as a negative LHI (LHI-). In LHI+ patients, we assessed the correlation between the LHI length and the septal perforator artery length on CorCTA. We also compared the length of the septal perforator artery on CorCTA between LHI+ patients and LHI- patients. Results A population of 111 patients were used for further analysis. Among these , there were 55 LHI+ patients and 56 LHI- patients. In LHI+ patients, linear regression analysis revealed that there was a good agreement between LGE LHI and septal perforator arteries by CorCTA in terms of length measurements. The measured length of the anterior septal perforator arteries was significantly shorter in LHI- patients than in LHI+ patients (10 ± 8 mm vs. 21 ± 8 mm; P < 0.05). Conclusions The LHI observed in the basal septum on short axis LGE may reflect contrast enhancement of the anterior septal perforator arteries. It is important to interpret this septal LHI against knowledge of anatomic structure, to avoid misinterpretations of LGE and prevent misdiagnosis.