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.