Unexplained Cardiac Arrest After Near Drowning in a Young Experienced Swimmer: Insight from Cardiovascular Magnetic Resonance Imaging

Abstract

Cardiac magnetic resonance imaging (cMRI) is a well-established noninvasive imaging modality in clinical cardiology. Its ability to provide tissue characterization make it well suited for the study of patients with cardiac diseases. We describe a multi-modality imaging evaluation of a 45-year-old man who experienced a near drowning event during swimming. We underline the unique capability of tissue characterization provided by cMRI, which allowed detection of subtle, clinically unrecognizable myocardial damage for understanding the causes of sudden cardiac arrest and also showed the small damages caused by cardiopulmonary resuscitation.

Keywords: Cardiopulmonary Arrest; Cardiopulmonary Resuscitation; Magnetic Resonance.

Figure 1.. A 45-year-old man with a near drowning experience who underwent cardiopulmonary resuscitation. ECG shows conversion of ventricular fibrillation to sinus rhythm after the fifth 200-J transthoracic shock.

Figure 2.. A-C, Coronary angiography performed at admission shows normal coronary flow without obvious angiographic obstruction. Coronal (D, E) and sagittal (F) thin-section chest computed tomography reveals bilateral and diffuse areas of ground-glass attenuation and airspace consolidation with air bronchogram seen mainly in lung bases resulted from lung damage and ventilation-perfusion mismatching caused by water inhalation and laryngospasm secondary to hypoxia. Curved arrows in D and E show the presence of secretions in the trachea and right main bronchus.

Figure 3.. A, Short-axis T1 weighted (T1W) anatomical image shows the anterolateral (arrow) and posterior (arrowhead) muscles. In the short-axis (B) and vertical long axis (C, D) T2W-STIR images, the anterolateral (arrows in B and C) and posteromedial (arrowheads in B and D) papillary muscles have a hyperintense signal caused by increased water content (myocardial edema). On late contrast-enhanced (CE) imaging (E, F, and H), the anterolateral (arrow) and the medial portion of the posterior papillary muscles (arrowheads) are strongly enhanced. On T2W-STIR images (curved-arrow in B), a subtle hyperintensity, suggestive of edema, was detected in the middle inferior wall and CE-IR images confirmed a small (< 10 mm) correspondent subendocardial infarction (curved-arrow in E). The first-pass perfusion image (G) clearly shows a perfusion defect localized exactly at this cardiac structure. Short-axis T2W-STIR image (asterisks in B) also shows slight edema of the anterior chest wall probably due to chest compressions and transthoracic shocks.