Resolution of strain abnormalities during extracorporeal rewarming from accidental hypothermic cardiac arrest: a case report

• Published in: Journal of cardiothoracic and vascular anesthesia Vol. 34; pp. S49 - S50
• Main Authors: Guensch, D., Fischer, K., Kauert-Wilms, A., Heinisch, P.-P., Kadner, A., Jenni, H., Eberle, B., Erdoes, G.
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.10.2020
• ISSN: 1053-0770; 1532-8422
• DOI: 10.1053/j.jvca.2020.09.070

Three-dimensional left (LV) and right-ventricular (RV) assessment by transesophageal echocardiography (TEE) overcomes problems of 2D TEE such as incomplete coverage and mathematical assumptions of chamber geometry. Myocardial deformation parameters (strain) are reported to allow earlier detection of subclinical abnormalities and to improve prognostic accuracy compared to global assessment. Strain data describing functional recovery of the myocardium from severe hypothermic arrest are scarce. A 55 year-old male victim of an avalanche accident arrived at the emergency department in asystole at 28°C core temperature under ongoing CPR (hypothermia stage IV). Reperfusion and rewarming was performed by percutaneous cannulation and minimized extracorporeal circulation (MiECC). Ventricular fibrillation ensued at 32°C and converted to sinus rhythm after defibrillation. At 33°C a full-volume loop (6 beats) was acquired for each ventricle, and tissue doppler interrogation was performed for assessment of diastolic function. Exams were repeated at 36°C. Images were analyzed for ventricular function and strain for all AHA segments. In hypothermia, LV ejection fraction (LVEF, 54%) and global circumferential strain (-35.9%) appeared normal but longitudinal strain was impaired (-13.5%). Basal myocardial segments showed hypo- and dyskinesia, while peak strain in more apical segments was preserved. This resulted in marked heterogeneity of strain curves. Diastology revealed restrictive LV dysfunction (III°). RV ejection fraction (RVEF, 45%) and global longitudinal strain were impaired (-15.2%). After normothermia had been reestablished, LVEF (68%) and strain had improved further (circumferential: -37.7%, longitudinal: -14.5%). Contractile function of LV segments had regained homogeneity among all segments. Time to peak systolic strain was shortened. Diastolic dysfunction had improved to pseudonormal (II°). RVEF (74%) and strain (-44.1%) also showed marked recovery. The figure shows numerical function changes for both ventricles and LV strain curves at 33°C and 36°C core temperature. In post-arrest core hypothermia at 33°C, LVEF may appear normal and RVEF only mildly impaired, whereas segmental LV and global RV strain analysis may reveal a still severely ab-nor¬mal myocardial systolic function. Such a discordant pattern in a hypothermic post-ischemic heart may show marked improvement when core temperature normalizes. Three-dimensional TEE in combination with myocardial strain analysis may be a useful adjunct for evaluating post-arrest recovery of cardiac function in victims of accidental hypothermic cardiac arrest.