Discussion
In the present case, the keys to the patient’s survival without
neurological deficits were, first, the rapid initiation of ECMO for the
CPA due to LVFWR, and second, we performed immediate TTM utilizing ECMO.
We would like to expand on the first point. Currently, there are three
possible emergency treatments for CPA due to LVFWR, and the first is
pericardiocentesis and drainage [1–4]. However, this procedure may
be difficult to perform while continuing effective chest compressions.
The second method involves pericardial drainage, primary hemostasis, and
direct cardiac massage with left intercostal thoracotomy [4]. This
method may be the quickest way to achieve drainage for a trained doctor.
However, it may be difficult to identify the bleeding point, and if the
point cannot be identified quickly, further bleeding may be promoted,
and the patient may die. In addition, even if spontaneous circulation
returns, this approach is highly invasive and may increase the risk of
infection [5]. Moreover, when spontaneous circulation returns, ECMO
may be necessary if cardiac function is severely deteriorated due to
myocardial infarction. The third approach is to use ECMO [2, 3]. We
were able to establish ECMO as early as 10 minutes after CPA, as skilled
doctors and clinical engineers were available continuously at our
university hospital. As in the present case, when CPA occurs before a
definitive diagnosis, AAD may be a cause of pericardial effusion
[6], and lifesaving is expected to be difficult with left
thoracotomy. Even if ST changes are detected on the ECG, these changes
may occur with coronary artery dissociation, so definitive diagnosis
before CT is difficult. ECMO flow may be insufficient for cardiac
tamponade, but there is a possibility of survival with concomitant
pericardiocentesis [6]. Even with CPA due to LVFWR, initiating ECMO
is considered effective with skilled staff. Furthermore, introducing
ECMO permits CAG. If there was stenosis in the remaining branch in our
patient, coronary artery bypass surgery may have been added.
Regarding the second key point, in the present case, rapid ECMO enabled
early introduction of TTM by rapid blood cooling. The patient’s body
temperature reached 34°C 30 minutes after arrival and 23 minutes after
CPA, suggesting the usefulness of ECMO from the viewpoint of brain
protection. If resuscitation is performed with left thoracotomy, even if
TTM is performed, an intravascular cooling device or body surface
cooling is necessary [7], and it is difficult to introduce TTM
promptly. Delayed brain protection can lead to post-cardiac arrest
encephalopathy.
In conclusion, ECMO for CPA due to LVFWR is considered an effective
resuscitation method because it enables rapid and minimally invasive
cardiopulmonary support and rapid introduction of TTM.