Intramyocardial Apical Dissection

Introduction

Male 47 year-old. Heavy smoker, suffering from pleuropericardial thoracic pain and febrile syndrome in the 2 previous weeks. He is admitted to Neumology to rule out pneumonia.

Case Report

We report a case of a male 47 year-old. Heavy smoker, suffering from pleuropericardial thoracic pain and febrile syndrome in the 2 previous weeks. He is admitted to Neumology to rule out pneumonia.

An ECG  performed,  during his stay in Neumology, showed a  large anterior necrosis compatible with subacute anterior wall  myocardial infarction in the previous weeks. Due to this finding the patient is transferred to  Cardiology Department.

Our patient underwent  magnetic resonance imaging, (video MRI 1 and 2), showing  severe pericardial effusion with hematic content and apical thrombus suggestive of contained cardiac rupture.

Coronary angiography   revealed significant one vessel disease with proximal left anterior descending coronary artery  100% occluded after first diagonal branch. An uncomplicated percutaneous coronary intervention of the occluded left anterior descending coronary artery was carried out, with restoration of TIMI 2 flow.

Echocardiographic follow up is shown in the next three videos, without (video  Echo  1, 2) and with the use of ultrasound contrast (video  Echo 3) to rule out cardiac rupture. An anterior wall myocardial infarction with  large apical aneurysm, and eventually  intramyocardial  apical dissection with  slight pericardial effusion are seen.  Color Doppler revealed no communication with pericardial sac. Ultrasound contrast  showed  no  findings  of  patent cardiac rupture, no  extravasation to pericardial sac. It can be observed with contrast-enhanced ultrasound persusion  of diseccted myocardium membrane. Ejection fraction: 35%. Pleural effusion.He underwent programmed  cardiac surgery operation . A dissection of myocardium was confirmed with a 4 cm hole delimited by epicardium and  endocardium. Pericardium  was severely thickened and firmly adhered to apical epicardium (fig. 6-7). Subsequent surgical remodelling was performed with a pericardial patch (“Dor” technique) (fig. 8-9).. No signs were found of past cardiac rupture, all the findings in echocardiography and surgery were compatible with apical intramyocardial dissection.

Discussion

Intramyocardial dissecting haematoma is a rare form of cardiac rupture that can occur as a complication following acute myocardial infarction or during the remodelling process. It is usually caused by a haemorrhagic dissection among the spiral myocardial fibers.

It is suggested as etiology a defectous myocardial remodellation, due to an  increased matrix metaloproteinases colagenolytic activity.
 
Sometimes is  related to thoracic trauma. However, most of the cases are usually associated with acute transmural inferior myocardial infarction. There are only a few cases reported in the medical literature associated with anterior myocardial infarction. Usually is a necropsy finding. First live-patient was reported in 1981. 
 
There is a clear difference with  pseudoaneurysm as this latter is a total rupture of the myocardial wall contained by the pericardium, whereas the dissecting intramyocardial hematoma is a bloody cavity delimited externally by part of myocardium and pericardium. Anatomophatologic exam reveals a bloody cavity externally delimited by myocardium  and pericardium and internally by the myocardium remaining and endocardium.

There is controversy regarding the procedure to follow:

1. Delimited to apical segments: conservative treatment (spontaneous reabsorption).

2. Free left-ventricle wall of interventricular septum: surgery.

Conclusion

1. Diagnosis of intramyocardial dissection requires a high clinical index of suspicion.
2. Echocardiography, together with ultrasound contrast, is a valuable and reliable tool to make prompt and bed-side diagnosis.
3. Patients benefit from early diagnosis and tailored treatment.

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References

Intramyocardial dissecting haematoma: a rare complication of acute myocardial infarction.Dias V, Cabral S, Gomes C, Antunes N, Sousa C, Vieira M, Meireles A, Oliveira F, Torres S.Eur J Echocardiogr. 2009 Jun;10(4):585-7. Epub 2009 Mar 31.

Dissecting intramyocardial hematoma: clinical presentation, pathophysiology, outcomes and delineation by echocardiography.Vargas-Barrón J, Roldán FJ, Romero-Cárdenas A, Molina-Carrión M, Vázquez-Antona CA, Zabalgoitia M, Martínez Rios MA, Pérez JE.Echocardiography. 2009 Mar;26(3):254-61. Epub 2008 Nov 1.