Non-ischemic Cardiomyopathies - Cases

1355635 - Hypertrophic Cardiomyopathy as a Presenting Feature of Noonan Syndrome: A Case Report

Friday, January 27, 2023

7:00 AM – 7:50 AM

Location: Pacific Jewel

Presenting Author(s)

OA

Omar Tayseer Al Ali, MD

MD
Rochester General Hospital
Rochester, New York, United States

Primary Author(s)

OA

Omar Tayseer Al Ali, MD

MD
Rochester General Hospital
Rochester, New York, United States

Co-Author(s)

BB

Bipul Baibhav, MD

MD
Rochester General Hospital
rochester, New York, United States

Description of Clinical Presentation: A 69-year-old Caucasian female presented with complaints of intermittent chest pain, palpitations, and dizziness for a few weeks.

Diagnostic Techniques and Their Most Important Findings: ECG showed normal sinus rhythm with repolarization changes (Image 1). A transthoracic echocardiogram revealed asymmetric septal hypertrophy with significant thickening of mid septum area of 2 cm with asymmetric hypertrophy of the left ventricle (LV) apex and right ventricle (RV) apex, but no left ventricular outflow (LVOT) obstruction. Doppler echocardiography showed dynamic gradient at LV apex with peak gradient of 56 mmHg at rest with no significant change post exercise, and with normal exercise tolerance. Cardiac Magnetic Resonance (CMR) showed severe hypertrophy of the LV and RV apex without any apical aneurysm (Image 2). The maximum thickness was 2.4 cm at the distal septal wall. On CMR, there was evidence of mid cavitary and apical obliteration during systole with hyperdynamic LV systolic function. Patchy areas of fibrosis were noted in the areas of hypertrophy consistent with Hypertrophic cardiomyopathy (HCM) (Image 3). Genetic testing was performed which revealed pathogenic mutation of PTPN11, c.1403C >T consistent with autosomal dominant Noonan syndrome

Learning Points from this Case: Although Noonan syndrome is associated with distinct external phenotypic features, the expression of those features is variable and may be unrecognized. Here we present a case of biventricular apical HCM in a patient with Noonan syndrome. This case highlights that cardiac involvement can be the first presenting feature of Noonan syndrome. HCM is one of the common cardiac anomalies in patients with Noonan syndrome, but it is usually septal hypertrophy that is associated with LVOT. Interestingly, in our case the patient had an apical variant HCM.