RARE BUT DEADLY FINDINGS

DON’T MISS THESE

An Unusual Case of Intramyocardial

Dissecting Hematoma
Ho-Chuen Yuen, FHKCP, Joyce Shek, MRCP, Chun-Kit Wong, MRCP, Ping-Tim Tsui, FHKCP,
Ngai-Shing Mok, FHKCP, Ngai-Yin Chan, MD, and Ka-Yip Lo, FHKCP, Hong Kong

INTRODUCTION
VIDEO HIGHLIGHTS
Intramyocardial dissecting hematoma (IDH) is a rare but life-threat-
ening complication of acute myocardial infarction. The causative Video 1: Post-PCI day 3 echocardiogram (apical four-chamber
mechanism is postulated to be hemorrhagic dissection of spiral view) shows a newly developed mobile flap-like sheet extending
myocardial fibers after acute myocardial infarction. We present an un- from the middle of the LV anteroseptum to the apex and an
usual case of IDH after percutaneous coronary intervention (PCI) of echo-free space.
an occluded left anterior descending artery (LAD) in a patient with
Video 2: Post-PCI day 3 echocardiogram (apical long-axis
old anterior myocardial infarction.
view) shows a newly developed mobile flap-like sheet extending
from the middle of the LV anteroseptum to the apex and an
CASE PRESENTATION echo-free space.
Video 3: Post-PCI day 3 echocardiogram (apical four-chamber
A 59-year-old man who enjoyed good health in the past presented
with chest discomfort, palpitation, and shortness of breath for view with color Doppler) shows no flow between LV cavity and
2 days. Electrocardiogram (ECG) showed regular wide complex the echo-free space.
tachycardia (140 bpm) with left bundle branch block (LBBB) Video 4: Post-PCI day 7 echocardiogram (apical four-chamber
morphology (Figure 1A). The ECG morphology was compatible view) shows significant reduction in IDH.
with monomorphic ventricular tachycardia (VT). Radiography of Video 5: Post-PCI day 7 echocardiogram (apical long-axis
chest showed mild congestion of lung. He was conscious, but his view) shows significant reduction in IDH.
blood pressure (BP) was low (90/60 mm Hg). Synchronized cardio- Video 6: Post-PCI day 10 echocardiogram (apical four-cham-
version successfully reverted the VT into sinus rhythm (SR). ber view) shows complete resolution of IDH.
However, his BP remained borderline. Repeated ECG showed SR Video 7: Post-PCI day 10 echocardiogram (apical long-axis
with right bundle branch block morphology. Q wave was noted
view) shows complete resolution of IDH.
over V2 to V5, and 1 mm ST segment elevation was noted over V2
Video 8: Post-PCI day 10 echocardiogram (apical four-cham-
and V3. The corrected QT interval was prolonged (580 msec;
Figure 1B). The first troponin I was 40.0 ng/L (normal, <19.8 ng/L). ber view with echo contrast) shows complete resolution of IDH.
The next troponin I 4 hours later was 34.1 ng/L. The serial troponin Video 9: Post-PCI day 10 echocardiogram (apical long-axis
I levels did not suggest acute ST elevation myocardial infarction. His view with echo contrast) shows complete resolution of IDH.
electrolytes were normal. Creatinine was 122 mmol/L (normal, 65-
View thevideo content online at www.cvcasejournal.com.
109 mmol/L). Alanine aminotransferase was elevated (975 U/L
[normal, <53 U/L]). Echocardiogram showed dilated left ventricle
with wall thinning and akinesia of left ventricular (LV) apex and mid- Amiodarone was not used because of the prolonged QT interval.
dle-to-distal anteroseptal wall. The LV systolic function was severely Lignocaine was also not used because of liver disorder. Intravenous es-
impaired with ejection fraction at around 15%. molol was used for VT control. Emergency coronary arteriogram was
He developed several episodes of recurrent monomorphic VT of done to look for any persistent coronary ischemia. Coronary arterio-
the same morphology requiring repeated synchronized cardioversion. gram showed total occlusion at the middle part of the LAD and mod-
erate stenosis over the middle part of the right coronary artery and
From the Department of Medicine and Geriatrics, Princess Margaret Hospital, proximal part of the left circumflex artery (Figure 2A). We decided
Hong Kong. to open up all three vessels to correct any potential reversible causes
Keywords: Intramyocardial dissecting hematoma, Cardiomyopathy, Echocardio- for recurrent VT. Guide wire (Runthrough NS, Terumo Interventional
gram
Systems) successfully passed through the total occlusion part of LAD
Conflicts of Interest: The authors reported no actual or potential conflicts of interest
antegradely. Stenting was performed for all three vessels (Figure 2B).
relative to this document.
In view of his borderline BP and recurrent VT, intra-aortic balloon
Correspondence: Ho-Chuen Yuen, FHKCP, Princess Margaret Hospital 2-10 Prin-
pump (IABP) was inserted for hemodynamic support, and a tempo-
cess Margaret Hospital Road, Kwai Chung, Hong Kong. (E-mail: johnny_yuen50@
hotmail.com).
rary transvenous pacing wire was placed over the right ventricular
Copyright 2021 by the American Society of Echocardiography. Published by
apex for overdrive pacing to suppress VT. Anticoagulation with low
Elsevier Inc. This is an open access article under the CC BY-NC-ND license (http:// molecular weight heparin was started for use of IABP.
creativecommons.org/licenses/by-nc-nd/4.0/). Despite overdrive pacing of 100 bpm, the patient still had recurrent
2468-6441 monomorphic VT, so oral mexiteline was added on top of intrave-
https://doi.org/10.1016/j.case.2021.07.015 nous esmolol. His BP worsened on post-PCI day 3 with systolic BP
16
CASE: Cardiovascular Imaging Case Reports Yuen et al 17
Volume 6 Number 1

Figure 1 (A) ECG on admission showed regular wide complex tachycardia (140 bpm) with LBBB morphology. (B) ECG after synchro-
nized cardioversion showed SR with right bundle branch block morphology, Q wave in V2-V5, 1 mm ST elevation in V2-V3, and pro-
longed QTc 580 msec.

Figure 2 (A) Coronary arteriogram (right anterior oblique cranial view) showed total occlusion over middle part of LAD. (B) Coronary
angiogram (right anterior oblique cranial view) after stenting of the middle part of the LAD.
18 Yuen et al CASE: Cardiovascular Imaging Case Reports
February 2022

Figure 3 (A) Post-PCI day 4 echocardiogram showed a newly developed mobile flap-like sheet extending from the middle of the LV
anteroseptum to the apex and an echo-free space. (B) Color Doppler showed no flow between LV cavity and the echo-free space.

dropping from 100 mm Hg to 60-70 mm Hg. Echocardiogram on tomography) to confirm the diagnosis was not feasible because of
post-PCI day 4 showed similar thinning and akinesia of LV apex and the patient’s hemodynamic instability and the presence of IABP.
middle-to-distal anteroseptal wall. In addition, a new flap-like mobile The provisional diagnosis at that time was IDH causing reduction in
sheet extending from the LV middle anteroseptal wall to the apex volume of the LV cavity and reduction in LV filling and stroke volume.
was noted. There was a large echo-free space between the flap-like The cardiothoracic surgical team suggested conservative management
sheet and LV septum and apex (Figure 3A; Videos 1 and 2). The at that time and monitoring for any progression of IDH.
was no Doppler flow between the LV cavity and the echo-free space Anticoagulation was continued because of the presence of IABP.
(Figure 3B; Video 3). The differential diagnoses of the mobile flap-like Ventricular tachycardia still recurred but at a lower frequency with
sheet in echocardiogram includes LV thrombus, pseudoaneurysm, the use of overdrive pacing and anti-arrhythmic drugs. The initial
prominent trabeculation, and IDH. No Doppler flow between the plan of VT ablation if medical therapy failed was not feasible in
echo-free space and LV cavity speaks against pseudoaneurysm. The view of the presence of IDH.
presence of a newly developed flap-like sheet in the echocardiogram The hemodynamics of the patient gradually improved over days.
on post-PCI day 4 but not the echocardiogram on admission makes Repeated echocardiogram on post-PCI day 7 showed significant
prominent trabeculation unlikely. Judging from the morphology of reduction in the echo-free space (Figure 4; Videos 4 and 5). The VT
the mobile flap-like sheet on echocardiogram, the differential diag- was also well controlled with anti-arrhythmic drugs and overdrive pac-
nosis of IDH should be higher on the list than LV thrombus. Further ing. The overdrive pacing was stopped on post-PCI day 7. Intravenous
advanced imaging (e.g., magnetic resonance imaging or computed esmolol was changed to oral metoprolol. There was no recurrent VT
CASE: Cardiovascular Imaging Case Reports Yuen et al 19
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Figure 4 Post-PCI day 7 echocardiogram showed significant reduction in IDH.

Figure 5 (A) Post-PCI day 10 echocardiogram showed complete resolution of IDH. (B) Use of an ultrasound enhancing agent
confirmed complete resolution of IDH.
20 Yuen et al CASE: Cardiovascular Imaging Case Reports
February 2022

on oral mexiteline and metoprolol. Repeated echocardiogram with The management of IDH is controversial and should be individual-
echo contrast on post-PCI day 10 showed complete resolution of ized.3 The decision to proceed to surgery or not depends on multiple
the flap-like sheet and echo-free space (Figure 5A and B; Videos 6- factors including the patient’s hemodynamics and progression of IDH.
9). The IABP was removed on post-PCI day 11. Anticoagulation Conservative treatment is an option for patients with small IDH and
was stopped. He remained free of cardiac symptoms afterward. stable hemodynamics.4 Surgery is usually reserved for those with
Implantable cardioverter-defibrillator was scheduled later for second- rapid progression. Our case was successfully managed with conserva-
ary prevention. tive treatment, although his IDH was not small and his initial hemody-
namics were unstable. This case highlights the importance of
DISCUSSION individualized treatment at different time points. Frequent monitoring
of the size of the IDH is essential. From the literature we can see that
Intramyocardial dissecting hematoma is a rare but life-threatening the resolution of IDH on echocardiogram varies from around 2 weeks
complication of acute myocardial infarction. Intramyocardial dissect- to more than 3 months.4,5 The recovery after IDH in our case was sur-
ing hematoma after acute myocardial infarction is postulated to be prisingly fast, at around 1 week. The use of IABP in our case might
related to hemorrhagic dissection of spiral myocardial fibers causing play a role in the hastened resolution of IDH. The deflation of the
blood leaking within the myocardium while endocardium and epicar- IABP balloon during systole leads to a reduction in LV afterload.
dium remain intact. Intramyocardial dissecting hematoma can also Reduction in afterload and resting of the left ventricle speeds up the
occur after septal channel perforation during PCI of chronic total oc- myocardial recovery and resolution of IDH. The in-hospital mortality
clusion especially with retrograde approach. We present an unusual of IDH was high (23%) in one case series.5 The risk factors for mortal-
case of IDH after an uncomplicated antegrade PCI of an occluded ity in this case series including low ejection fraction (<35%) and ante-
LAD in a patient with old anterior myocardial infarction and VT. rior myocardial infarction were all present in our patient. Fortunately,
Our patient presented with monomorphic VT with congestive our patient survived this life-threatening complication.
heart failure. The initial ECG was a regular wide complex tachycardia
of LBBB morphology with leftward axis suggesting possible inferior
apical LV origin of VT. The post-cardioversion ECG suggested likely CONCLUSION
anterior myocardial infarction with Q waves in leads V2 to V5 and
with 1 mm ST segment elevation in leads V2 and V3. The anterior Our case shows that IDH can happen after revascularizing a chroni-
myocardial infarction shown on the ECG was probably old because cally infarcted LAD territory in a patient with old anterior myocardial
there was no typical rise and fall in cardiac enzymes in this admission. infarction. The management of IDH should be individualized depend-
The echocardiogram also showed old anterior myocardial infarction ing on the patient’s hemodynamics and progression of IDH. The role
as evidenced by the wall thinning of the LAD territory. The liver dis- of IABP in the recovery after IDH in our case is provocative and needs
order (high alanine aminotransferase level) was likely due to ischemic further study.
hepatitis related to low cardiac output during VT. Whether to revascu-
larize the likely infarcted LAD territory is controversial, but it seems
appropriate to try opening the LAD up to correct any potential revers-
ible causes of recurrent VT. Furthermore, it would be more appro- SUPPLEMENTARY DATA
priate to perform functional study (e.g., pressure wire) to document
any significant ischemia over the left circumflex artery and right coro- Supplementary data related to this article can be found at https://doi.
nary artery territories before stenting. The development of IDH in our org/10.1016/j.case.2021.07.015.
patient was unexpected because his anterior myocardial infarction
was old and there was no visible vessel perforation during the PCI pro-
cedure. Nevertheless, we could not visualize extravasation of micro-
vasculature on fluoroscopy. We could not define the exact time of REFERENCES
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