. 2022 Nov 28;7(1):ytac452. doi: 10.1093/ehjcr/ytac452

Table 2.

Summary of demographic and clinical features of identical twins with identical morphological phenotypes described in the literature

Report	Age at diagnosis of first twin	Sex	Morphology	Risk factors for SCD	LVOT Gradient (mmHg)	Outcomes	ICD placement
Wylie et al.⁶	62	Female	Asymmetrical septal hypertrophy	None	Unknown	Asymptomatic	None
Agirbasli et al.⁷	38	Female	Severe asymmetrical septal hypertrophy with LVOT obstruction and SAM	None	130	Both responded well to beta-blockers	None
Agirbasli et al.⁷	38	Female		None	170	Both responded well to beta-blockers	None
Maron et al.⁸	18	Male	HCM confined to posterior septum	Family history of SCD due to HCM	<30	Asymptomatic	Unknown
Zenovich et al.⁹	44	Female	Mid-ventricular hypertrophy	Apical aneurysm in both twins	<30	Asymptomatic	ICD reported in only one twin sister
Goh et al.¹⁰	62	Male	Asymmetrical septal hypertrophy	Twin brother had SCD 2 months prior	<30	Syncope with termination of malignant ventricular tachyarrhythmia by ICD shock	ICD in one twin brother
Maron et al.¹¹	49	Male	HCM confined to posterior inferior septum with LVOT obstruction	None	85	Both had paroxysmal atrial fibrillation and required septal myectomy with excellent response	None
Maron et al.¹¹	49	Male		None	75		None

HCM, hypertrophic cardiomyopathy; ICD, implantable cardioverter defibrillator; LVOT, left ventricular outflow tract obstruction; SAM, systolic anterior motion of the mitral valve; SCD, sudden cardiac death.