How to cite this article: Khanra D, Soni S, Ola R, Duggal B. Cor Triatriatum Sinister Presenting with Acute Myocardial Infarction. J Pract Cardiovasc Sci 2019;5:208-12
How to cite this URL: Khanra D, Soni S, Ola R, Duggal B. Cor Triatriatum Sinister Presenting with Acute Myocardial Infarction. J Pract Cardiovasc Sci [serial online] 2019 [cited 2023 Jun 4];5:208-12. Available from: https://www.j-pcs.org/text.asp?2019/5/3/208/273737
Introduction
In classic cor triatriatum sinister (CTS), a membranous partition that has the shape of a windsock separates the more proximal chamber, which receives the pulmonary veins (PVs) from the more distal left atrium (LA), which communicates with the mitral valve.[1] Failure of incorporation of the common PV into the LA is the most widely accepted theory of the embryogenesis of CTS among various theories, including malseptation involving the septum primum, malincorporation of the common PVs, and the entrapment hypothesis, whereby the left horn of the sinus venosus entraps the common PV and thus prevents its incorporation into the LA.[2],[3] Increased use of diagnostic cardiac imaging in routine clinical practice has probably contributed to the increase in reports of CTS in adults in recent years. The presentation of CTS can range from asymptomatic to congestive symptoms to cardioembolic stroke. We present a case of CTS with ostium secundum atrial septal defect (ASD) presenting with acute anterior wall myocardial infarction (AWMI) who successfully underwent primary percutaneous coronary intervention (PCI) with stenting.
Case Report
A 45-year-old male presented to our emergency department with anterior wall ST-elevated myocardial infarction (STEMI) evidenced by severe on-going retrosternal chest pain for 8 h duration and right bundle branch block (RBBB) pattern and ST-elevation across anterior leads in electrocardiogram (ECG) [Figure 1]a. He was nonsmoker and has no other risk factors for CAD. The patient was immediately admitted to the cardiology department and loading dose of aspirin 325 mg, clopidogrel 300 mg, and atorvastatin 80 mg given orally. Unfractionated heparin 5000 units bolus followed by infusion in the dose of 1000 units/h intravenous started as per the institutional protocol. The patient was dyspneic as rest with SPO2 90% in room air. On examination, his blood pressure was 90/60 mmHg and pulse rate of 120/min, irregularly irregular in nature. ECG confirmed the presence of atrial fibrillation (AF) with fast ventricular rate. His jugular venous pressure was elevated with prominent V-waves with sharp “y” descent. On auscultation, S1 was variable in intensity but mostly normal with wide and fixed splitting of second heart sound and 4/6 ejection systolic murmur in the 2nd left intercostal space with a thrill raising a possibility of associated ASD.
Figure 1: Electrocardiogram showing (a) atrial fibrillation with fast ventricular rate, ST-segment elevation in anterior precordial leads with RBBB pattern at presentation, and (b) resolution of ST-segment elevation with pathological Q waves in anterior precordial leads and normal sinus rhythm, 48 h after primary angioplasty with stenting to the left anterior descending artery.
On bedside transthoracic echocardiography (TTE), the patient had severe left ventricular (LV) dysfunction with LV ejection fraction (LVEF) of 30% with akinetic apex and hypokinetic anterior and anteroseptal wall. The presence of an ostium secundum ASD (OS-ASD) of 24 mm was also confirmed in TTE [Figure 2]a and [Figure 2]b. Furthermore, 1.8 mm × 1.5 mm clot was discovered in the left atrial appendage (LAA) [Figure 2]c. All chambers were dilated, including the right atrium, right ventricle, and pulmonary arteries [Figure 2]d, [Figure 2]e, [Figure 2]f.
Figure 2: Transthoracic echocardiography (a-d) showing ostium secundum atrial septal defect (red arrow) in the subcostal view (a) and apical four-chamber view (b); modified short-axis view demonstrating 1.8 cm × 1.5 mm clot (yellow arrow) in the left atrial appendage (c) and dilated main and branch pulmonary arteries (d); Transesophageal echocardiography (e and f) in color-compare mode showing the membrane inside the left atrium (purple arrow) and ostium secundum atrial septal defect (red arrow) in four-chamber (e) and short-axis view (f).
The patient was immediately taken to the catheterization laboratory for primary PCI. Femoral artery puncture was done with 7F Medtronic arterial sheaths on the right side for cardiac catheterization and 8F Arrow arterial sheath for intraaortic balloon pumping (IABP) on the left side. Forty millimeters IABP balloon was kept ready if required during the procedure. Left ventriculography showed markedly depressed LVEF with hypokinetic anterior and anteroseptal wall. LV end-diastolic pressure (LVEDP) was 30 mmHg. Coronary angiogram showed 95% stenosis in proximal LAD lesion with the thrombus [Figure 3]a, [Figure 3]b, [Figure 3]c, [Figure 3]d, [Figure 3]e, [Figure 3]f. The acute coronary syndrome could be due to coronary artery embolism in the setting of ASD, and thus, intracoronary imaging was considered, but intravascular ultrasound or optical coherence tomography was not available in our cath laboratory. The left circumflex artery and right coronary artery (dominant) were normal. Hence, stenting with drug-eluting stent to LAD was done. The procedure went uneventfully, and the patient was shifted to the intensive cardiac care unit in hemodynamically stable condition with no chest pain and BP of 110/70 mmHg.
Figure 3: Fluoroscopic images (a-f) of primary angioplasty and stenting, including (a) left main coronary artery ostium hooked with 7 French EBU 3.5 guiding catheter showing left anterior oblique view showing 95% stenosis in the proximal left anterior descending artery with the thrombus; (b) Right anterior oblique view confirming 95% stenosis in proximal left anterior descending with the thrombus; (c) the lesion crossed and measured with Fielder FC wire; (d) Sprinter 2.5 mm × 10 mm semi-compliant balloon positioned for predilation (for details, see text); (e) Xience Prime 3 mm × 33 mm everolimus-eluting stent (Abbott Vascular) positioned for the deployment (for details, see text); (f) Final result with TIMI3 flow in left anterior descending.
Subsequently, his ECG was suggestive of reversal to normal sinus rhythm (NSR) along with the resolution of RBBB and ST elevation [Figure 1]b. He was treated with aspirin 150 mg once daily, clopidogrel 75 mg once daily, pantoprazole 40 mg once daily, atorvastatin 80 mg once daily, metoprolol succinate 50 mg once daily, ramipril 2.5 mg once daily, torsemide 10 mg 12 hourly, and spironolactone 25 mg once daily. His continuous ECG monitoring was suggestive of NSR during his hospital stay for the next 5 days, and he was discharged on the 7th day and has been planned for a TEE after 2 weeks for the assessment of suitability of device closure of OS-ASD.
Outcome and follow-up
However, the patient returned to the emergency department again after 5 days with intermittent palpitations. The patient was admitted again in the cardiology department, and a 24 h Holter recording revealed frequent episodes of atrial flutter (AFL) and AF. TEE under local anesthesia confirmed clot in LAA. Moreover, surprisingly, while assessing the ASD, a membrane was found in the LA separating it into two chambers, suggestive of CTS with the proximal chamber receiving the PVs and the distal chamber connected to the right atrium through a 28-mm high OS-ASD [Figure 2]e and f]. However, the membrane was well proximal to the LAA and was not obstructing the mitral inflow [Video 1]. CTS with OS-ASD could explain the asymptomatic nature of the patient, which was unmasked when LVEDP increased due to AWMI, which may be due to the embolus dislodged from LAA during AF, but the causal relationship could not be proved as intracoronary imaging could not be done.
Follow-up
The primary cardiac anomaly was surgically correctable, and the cardiovascular surgeon's opinion was sought, who advised for the excision of the membrane, repair of ASD, and Maze procedure along with PV isolation. The patient did not felt palpitations after optimizing beta-blocker and was otherwise asymptomatic without any chest pain or dyspnea and therefore refused to undergo any surgery despite explaining pros and cons.
Another important aspect of treatment in our patient was to continue triple therapy of DAPT plus anticoagulation in view of the presence of LAA clot and intermittent AFL/AF in post-PCI patient. As mentioned in most of the guidelines to assess bleeding risk and continue triple therapy for initial 1 month or more and then continuing on one antiplatelet plus one anticoagulant for 1 year followed by anticoagulant alone, thus individualizing the patient's status and choices and assessing the risk of bleeding, we decided to offer clopidogrel plus oral anticoagulants with Vitamin K antagonist (VKA) for 12 months followed by only VKA lifelong unless contraindicated targeting a target PT INR of 2–3.
Repeated TEE after 1 month revealed the incomplete resolution of LAA clot but improvement of LV function with LVEF of 40%. The patient was not deemed for electrical or pharmacological cardioversion on account of the presence of clot and due to associated structural abnormality permanent surgical correction was advised.
Discussion
In 1949, Loeffler classification of CTS, based on the number and size of membrane fenestrations, divided CTS into the following three groups: group I has no opening; Group II has one or more small openings; and Group III has a wide opening.[4] Marin-Garcia classification of CTS into diaphragmatic, hourglass, and tubular subtypes was based on the appearance of the accessory left atrial chamber.[5] There are various other classifications exist including Lucas classification and one by Rodefeld et al.[6],[7] The appearance of clinical symptoms is delayed if there is a large opening in the membrane or if associated anomalies such as an ASD or anomalous PV connection enable the reduction of PV hypertension. Our patient had large patent openings in the left atrial membrane and associated OS-ASD, which probably accounted for his late diagnosis.
On echocardiography, the membrane within the LA can be imaged as a linear echo-bright structure above the mitral valve. It is important to differentiate this from other conditions such as supramitral stenosing ring, which is located on the atrial surface of the base of the mitral valve leaflets and is relatively immobile, whereas the curvilinear membrane with the appearance of a windsock in CTS moves toward the mitral valve in the diastole.[8] The LAA and foramen ovale are located distal to the membrane of cor triatriatum, and the PVs insert into the proximal chamber, whereas the membrane in supravalvar stenosing mitral ring is usually adherent to the mitral valve and has the LAA and foramen ovale located proximal to the membrane.[8]
CTS typically presents in infancy and early childhood with respiratory distress caused by functional PV obstruction.[9] Adults with CTS most frequently present with the symptoms of dyspnea similar to those of mitral stenosis, whereas AF was more prevalent at the advanced ages of presentation.[9] Cardioembolic stroke has been reported in the association with CTS, but to our knowledge, CTS presenting as acute myocardial infarction (AMI) is reported once in the literature by E. Taguchi in a 76-year-old female.[3],[10],[11],[12] We report the second case of CTS presenting with AMI in the world literature and first from India. Our patient was only 45 years of age, and thus AFL and fibrillations were surprising to be found. In the adults with CTS reviewed by McGuire et al.,[13] AF was observed in only one of the eight patients with CTS, but in our case, it may be consequent on AWMI, resulting in high LVEDP and LAP.
The prognosis of CTS is related to the size of the orifice in the obstructing membrane.[1] In Niwayama's survey, the average survival was 3 1/3 months when the opening was <3 mm and 16 years when the opening was >3 mm.[1] Surgical treatment in the form of excision of the membrane along with the correction of other defects is indicated in patients with cor triatriatum and elevated pulmonary artery pressure, which includes the surgical resection of the obstructive membrane.[7],[14] This case of CTS had asymptomatic course until the fourth decade. The patient had the symptoms due to AMI which was treated with angioplasty and stenting to LAD.
Our case raises the possibility having coronary artery embolism in the setting of CTS with large OS-ASD and AF. However, to confirm that intracoronary imaging was mandated which we could not do but treated the obstructive lesions with angioplasty and stenting in the interest of the patient and his deteriorating symptomology.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
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