1347473 - Progression of Danon disease monitored by cardiovascular magnetic resonance.

A 14-year-old man with family history of Danon disease and sudden cardiac death was referred to the cardiology consult for screening. He was asymptomatic at the first consult and physical examination showed non abnormalities. Cardiac magnetic resonance (CMR) was requested as a part of the initial screening.  So far three CMR studies were performed as part of the follow up, showing the progression an involvement of Danon disease within the heart.

Diagnostic Techniques and Their Most Important Findings:

CMR acquisition was performed with a Philips Achieva 1.5T scanner in 2015 and 2017. 2022 CMR acquisition was performed with a Siemens Magnetom Altea 1.5 Tesla scanner. Cine images were obtained with Steady-state free precession sequences. Modified Look-Locker inversion recovery (MOLLI) technique was used to evaluated T1 myocardial values pre (native) and post gadolinium based contrast. An inversion recovery prepared T1 weighted gradient echo sequence was used for tissue characterization by late gadolinium enhancement (LGE).

The initial exam showed preserved diameters and biventricular function with no evidence of myocardial fibrosis, however LV myocardial mass was increased (mass index of 78 g/m2). (Figure 1: A1-D1).

Two years later a new CMR was performed and showed normal biventricular function, but an increase in ventricular diameters and volumes (left ventricular end diastolic diameter of 55 mm and left ventricular end diastolic volume index of 79 ml/m2), ventricular mass (mass index of 78 g/m2) and a mild increase of the native T1 map (Figure 1: A2-D2).

Recently, in 2022, a new CMR study was performed. Significant increase in ventricular diameters, volumes and asymmetric hypertrophy involving the lateral wall were observed (Table 1). Mid-wall LGE at the lateral wall and apex was observed. Furthermore, T1 mapping in myocardial areas without LGE was also increased, reaching values up to 1085 milliseconds (Figure 3)

Learning Points from this Case:

 
In patients with Danon CMR can be considered a diagnostic tool to evaluate cardiac involvement for its capacity to accurately evaluate cardiac function and structure.¹  CMR can demonstrate myocardial hypertrophy, increased left ventricular wall thickness and in late stages left ventricular dilatation (most common in female patients) and dysfunction can be noted.² In relation to LGE, Danon disease is characterized by extensive LGE with the pattern usually showing extensive subendocardial and midwall enhancement, in some cases even with some areas showing near-transmural LGE. Septal sparing is a typical imaging feature, while lateral wall and apical LGE are present in almost all patients.³ Some reports have demonstrated native T1 and extracellular volume elevations in Danon disease.⁴

CMR is an important diagnosis tool to help in the assessment of heart failure therapy, including decision on implantable cardioverter-defibrillator and consideration for cardiac transplantation.