Case

The case features a 43-year old woman who was found to have the Dutch PLN R14del founder mutation during familial genetic screening.¹ Because of ventricular tachycardias, she received an internal cardioverter defibrillator (ICD) as secondary prophylaxis. Before ICD implantation, a CMR was performed which showed biventricular dilatation and a reduced biventricular function with midwall delayed enhancement in the lateral wall and in the apex. A coronary angiogram showed no coronary abnormalities.

Echocardiography

Echocardiographic follow-up

Follow-up of structural abnormalities is performed by echocardiography in this patient, because of her ICD. Like the CMR, her echocardiogram showed ventricular dilatation and a reduced biventricular function. The measurements fulfilled traditional diagnostic criteria for DCM.² Wall motion abnormalities were seen in the apex and in the mid-posterolateral wall (typical predilection place in PLN-associated cardiomyopathy).³

Speckle tracking

Speckle tracking of the left ventricle (LV) showed a reduced global contractile function (GLS 11.6%). The wall motion abnormalities in the apex and posterolateral segments were confirmed (see bullseye 1). Accordingly, there was marked post-systolic shortening in these regions, which is deemed to represent impaired myocardial viability (see bullseye 2).⁴ There was marked left ventricular mechanical dispersion (MD 54 ms), which is deemed to be a predictor for ventricular arrhythmias (see bullseye 3).⁵

Right ventricular analysis

A mixed phenotype of DCM and ARVC is frequently seen in patients with the PLN R14del mutation and therefore right ventricular (RV) evaluation is important in these patients.⁶ When evaluating the right ventricle of this particular patient, a dilated RV was seen with moderately reduced systolic function. The wall motion in the basal segment of the right ventricular free wall seemed abnormal.

The wall motion abnormality in the basal segment of the RV free wall was confirmed by strain analysis; a type III deformation pattern was seen (consisting of systolic stretching, reduced systolic peak strain and post-systolic shortening).⁷ The serious wall motion abnormalities, combined with the reduced RV function (RV-FAC 31%) and RVOT dilatation (RVOT PLAX 38 mm, RVOT PSAX 40 mm), gives this patient a major echocardiographic criterion for ARVC according to the revised 2010 Task Force Criteria.⁸

References

1. Hof IE, van der Heijden JF, Kranias EG, et al. Prevalence and cardiac phenotype of patients with a phospholamban mutation. Neth Heart J. 2019;27:64-69.
2. Mestroni L, Maisch B, McKenna WJ, et al.  Guidelines for the study of familial dilated Cardiomyopathies. European Heart Journal (1999) 20, 93–102.
3. Te Rijdt WP, Ten Sande JN, Gorter TM, et al. Myocardial fibrosis as an early feature in phospholamban p.Arg14del mutation carriers: phenotypic insights from cardiovascular magnetic resonance imaging. Eur Heart J Cardiovasc Imaging. 2019 Jan 1;20(1):92-100. doi: 10.1093/ehjci/jey047.
4. Huttin O, Marie P-Y, Benichou M, et al. Temporal deformation pattern in acute and late phases of ST-elevation myocardial infarction: incremental value of longitudinal post-systolic strain to assess myocardial viability. Clin Res Cardiol (2016) 105:815–826.
5. Kawakami H, Nerlekar N, Haugaa KH, et al. Prediction of Ventricular Arrhythmias With Left Ventricular Mechanical Dispersion: A Systematic Review and Meta-Analysis. JACC Cardiovasc Imaging. 2019 doi: 10.1016/j.jcmg.2019.03.025
6. Van der Zwaag PA, van Rijsingen IA, Asimaki A, et al. Phospholamban R14del mutation in patients diagnosed with dilated cardiomyopathy or arrhythmogenic right ventricular cardiomyopathy: evidence supporting the concept of arrhythmogenic cardiomyopathy. Eur J Heart Fail. 2012;14:1199–207. doi: 10.1093/eurjhf/hfs119
7. Mast TP, Teske AJ, Walmsley J, et al. Right Ventricular Imaging and Computer Simulation for Electromechanical Substrate Characterization in Arrhythmogenic Right Ventricular Cardiomyopathy. J Am Coll Cardiol. 2016 Nov 15;68(20):2185-2197. doi: 10.1016/j.jacc.2016.08.061.
8. Marcus FI, McKenna WJ, Sherrill D, et al. Diagnosis of arrhythmogenic right ventricular cardiomyopathy/dysplasia: proposed modification of the Task Force Criteria. Eur Heart J. 2010 Apr;31(7):806-14. doi: 10.1093/eurheartj/ehq025.