Diagnostic Impact of Repeated Expert Review & Long‐Term Follow‐Up in Determining Etiology of Idiopathic Cardiac Arrest

Figure 1. Schematic flow chart for the investigation of SCA survivors and the role of the MDT. MDT indicates multidisciplinary team meeting; MRI, magnetic resonance imaging; and SCA, sudden cardiac arrest.

Figure 2. Etiology of SCA in survivors who underwent secondary prevention implantable cardioverter defibrillators. A, Etiology of 327 consecutive SCA survivors at initial assessment. B, Follow‐up of unexplained SCA (n=31) following a mean duration of 93 weeks. ARVC indicates arrhythmogenic right ventricular cardiomyopathy; CPVT, catecholaminergic polymorphic ventricular tachycardia; DCM, dilated cardiomyopathy; ERS, early repolarization syndrome; HCM, hypertrophic cardiomyopathy; LQT, long QT; SCA, sudden cardiac arrest; and undiff, undifferentiated.

Figure 3. The diagnostic yield of investigations in patients with unexplained cardiac arrest at initial assessment and during follow‐up including yield of diagnosis following discussion in multidisciplinary team meetings. ARVC indicates arrhythmogenic right ventricular cardiomyopathy; MRI, magnetic resonance imaging; and PKP, Plakophillin. Yield defined according to first utilisation of the specific test.

Figure 4. Percentage of patients with no etiology for sudden cardiac arrest during a mean follow‐up of 93 weeks (n=31). No further diagnosis was made after 96 weeks of follow‐up.

Figure 5. Age distribution amongst SCA survivors after follow‐up. ARVC indicates arrhythmogenic right ventricular cardiomyopathy; CPVT, catecholaminergic polymorphic ventricular tachycardia; DCM, dilated cardiomyopathy; ERS, early repolarization syndrome; HCM, hypertrophic cardiomyopathy; LQT, long QT; and undiff, undifferentiated cardiomyopathy.

Figure 6. Fifty‐six‐year‐old man with coronary spasm and a proximal flow limiting stenosis in the right coronary artery. Heart monitor tracing (A) at the time of admission shows early repolarization changes just prior to the initiation of ventricular tachycardia and degeneration into ventricular fibrillation (B). These repolarization changes were not present in the resting initial ECG (C) suggesting that coronary spasm may have "mimicked" early repolarization.

Figure 7. ECG and transthoracic echocardiogram for case vignette 2, 70‐year‐old woman who sustained a ventricular fibrillation arrest and was successfully resuscitated. A, The 12‐lead ECG shows sinus rhythm but T‐wave inversion in leads V5, V6, and I. B, The echocardiogram reveals mitral valve prolapse with moderate mitral regurgitation and severe left atrial enlargement.