series [24]. A greater propensity for carriers of the Asn488Ile
mutation to express LVH has been noted than those with the
Arg302Gln variant (70% versus 42%, respectively) [17]. Cardiac
hypertrophy typically involves the left ventricle but may also involve
the right, can be massive in extent, and may be associated with left
ventricular outflow tract obstruction potentially requiring relief by
surgical septal myectomy or alcohol septal ablation [55, 56, 72,
77]. In sporadic cases bearing fatal infantile mutations, hypertrophy
involving the atrial walls has also been described, measuring over
1 cm in one case [26]. The pattern of LVH may be concentric or,
phenocopying sarcomeric HCM, preferentially involve the septumFig. 12Cardiovascular magnetic resonance images from a 48-year-old malePRKAG2mutation carrier with a
pacemaker. Upper row depicts the heart in short-axis (a) and horizontal long-axis (b) views, demonstrating
severe (up to 31 mm) interventricular septal hypertrophy (black arrows) and image artefact due to a
pacemaker lead (white arrow heads). Lower row (c,d) depicts late gadolinium-enhanced images in the
same imaging planes which show patchy enhancement in the anteroseptal hypertrophied regions (white
arrows) likely to reflect focal myocardial fibrosis (Reproduced from Po ̈yho ̈nen et al. Journal of Cardiovascular
Magnetic Resonance 2015; 17:89 [76] with permission via the CC-BY 4.0 licence. The original article is an
open access article distributed under the terms of the Creative Commons Attribution 4.0 International License
(http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction
in any medium, provided the original work is properly cited)
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