Xavier Bosch

Aims: To non-invasively characterize, by means of late gadolinium enhancement cardiac magnetic resonance (LGE-CMR), scar differences, and potential variables associated with ventricular tachycardia (VT) occurrence in chronic post-myocardial infarction (MI) patients. Methods and results: A case–control study was designed through retrospective LGE-CMR data analysis of chronic post-MI patients (i) consecutively referred for VT substrate ablation after a first VT episode (n = 66) and (ii) from a control group (n = 84) with no arrhythmia evidence. The myocardium was characterized differentiating core, border zone (BZ), and BZ channels (BZCs) using the ADAS 3D post-processing imaging platform. Clinical and scar characteristics, including a novel parameter, the BZC mass, were compared between both groups. One hundred and fifty post-MI patients were included. Four multivariable Cox proportional hazards regression models were created for total scar mass, BZ mass, core mass, and BZC mass, adjusting them by age, sex, and left ventricular ejection fraction (LVEF). A cut-off of 5.15 g of BZC mass identified the cases with 92.4% sensitivity and 86.9% specificity [area under the ROC curve (AUC) 0.93 (0.89–0.97); P < 0.001], with a significant increase in the AUC compared to other scar parameters (P < 0.001 for all pairwise comparisons). Adding BZC mass to LVEF allowed to reclassify 33.3% of the cases and 39.3% of the controls [net reclassification improvement = 0.73 (0.71–0.74)]. Conclusions: The mass of BZC is the strongest independent variable associated with the occurrence of sustained monomorphic ventricular tachycardia in post-MI patients after adjustment for age, sex, and LVEF. Border zone channel mass measurement could permit a more accurate VT risk stratification than LVEF in chronic post-MI patients.

Background: Cardiorespiratory arrest (CA) secondary to traumatic cervical spinal cord injury can occur in minor accidents with low-impact trauma and may be overlooked as the cause of CA in patients admitted in the coronary care unit. Case summary: We present two patients admitted to the coronary care unit because of suspected CA of cardiac origin. Both patients were found in CA with asystole, one after collapsing in a shopping mall and falling down a few steps and the other in the street next to his bicycle. They underwent early pharmacologically induced coma and hypothermia precluding neurological examination. Both patients remained in coma after rewarming, with preserved brainstem reflexes but absent motor response to pain. One patient had post-anoxic myoclonus in the face without limb involvement. In both patients, median nerve somatosensory evoked potentials demonstrated bilateral absence of thalamocortical N19 responses and abnormal cervicomedullary junction potentials (N13 wave). Extensive diagnostic work-up did not find a cardiac cause of the CA, pulmonary thromboembolism, or intracranial haemorrhage. In both patients, cervical spinal cord injury was diagnosed incidentally 5 and 6 days after CA, when a brain magnetic resonance imaging performed to assess post-anoxic brain injuries detected spinal cord hyperintensities with fracture and luxation of the odontoid. Both patients died 11 and 8 days after CA. Discussion: Low-impact traumatic cervical spinal cord injury should be considered in the diagnostic work-up of patients with CA of unknown cause.