Rigid spine syndrome: a noninvasive cardiac evaluation

Area of Science:

• Pediatric Cardiology
• Neuromuscular Disorders
• Cardiovascular Manifestations

Background:

• Rigid spine syndrome (RSS) is a childhood-onset myopathy impacting spinal flexion.
• Cardiac abnormalities are anecdotally reported in RSS patients.
• The vacuolar variant of RSS requires comprehensive cardiac assessment.

Purpose of the Study:

• To evaluate cardiac function in nine patients with the vacuolar variant of RSS.
• To identify specific cardiac abnormalities and their potential causes.
• To investigate the relationship between cardiac findings and muscle weakness.

Main Methods:

• Noninvasive cardiac assessment including ECG, echocardiography with Doppler, and 24-h ambulatory ECG.
• Creatine kinase levels and chest roentgenograms were also performed.
• Clinical assessment included heart auscultation.

Main Results:

• Abnormal heart auscultation in 5/9 patients; normal creatine kinase MB fraction in all.
• Chest X-rays revealed scoliosis (5/9) and restrictive chest wall changes.
• Echocardiograms showed mitral valve prolapse (5/9) with regurgitation (3/5) and pulmonary hypertension (3/9).
• Ambulatory ECG detected paroxysmal tachyarrhythmias in hypoxic/hypercapnic patients (3/9).

Conclusions:

• Cardiac abnormalities in vacuolar RSS are linked to restrictive chest wall defects and respiratory muscle weakness, leading to cor pulmonale and tachyarrhythmias.
• Mitral valve prolapse/regurgitation may be developmentally associated with this congenital myopathy.
• No primary cardiomyopathy was identified, and no correlation existed between cardiac issues and patient weakness.