A Light in the Dark: CMR and its Role in the Prevention of Sudden Death
Monday, November 13, 2017
Guest Editor: Jeannie Yu, MD FACC FSCCT
Sudden cardiac arrest accounts for 50% of cardiovascular deaths, and remains a grave concern for physicians and their patients of all ages and all comorbidities. And while ventricular tachycardia or ventricular fibrillation associated with acute coronary syndromes is a known entity with which clinicians have clear guidance and etiology for management, this leaves a large percentage of events otherwise unexplained. The medical community’s success thus far in treating or preventing these incidents has been described as disappointing with an estimated out-of-hospital survival of only 10%. The potential to make an impact in improving these statistics, therefore, continues to drive attempts to better understand the pathophysiology and mechanism of sudden cardiac death.
Last month, the AHA/ACC/HRS writing committee released the newest iteration of the guidelines regarding the Management of Patients with Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death. With this 2017 update, we see the increasing inclusion of CMR in the evaluation of cardiomyopathies, in particular non-ischemic variants. CMR has a great use in non-invasively identifying infiltrative diseases, such as amyloidosis and hemochromatosis. Late gadolinium enhancement portends a worse prognosis and is used for risk stratification in a variety of cardiomyopathies, such as hypertrophic cardiomyopathy and cardiac sarcoidosis. CMR’s superior spatial resolution to echocardiography also affords the opportunity for more accurate evaluation of structural disease, wall thickness, chamber size and systolic functional analysis. This is particularly helpful for arrhythmogenic right ventricular cardiomyopathy, in which CMR is one of the main imaging diagnostic modalities for the evaluation of RV chamber size and function.
The guidelines are an acknowledgment of CMR’s prognostic and diagnostic utility in differentiating cardiomyopathies of variable malignant potential. For more information, read the full 2017 guidelines for the management of ventricular arrhythmias here.