Prolonged QTc intervals and decreased left ventricular contractility in patients with propionic acidemia.
OBJECTIVE
To investigate electrophysiological and functional signs of myocardial damage in patients with propionic acidemia (PA), an inborn error of metabolism caused by deficiency of propionyl CoA carboxylase (PCC).


METHODS
In an observational longitudinal study 10 patients with PA (6 boys and 4 girls) ranging between 2.5 and 20.2 (median 9.0) years of age at last follow-up were investigated over a period of up to 20 (mean 7.4) years using 12-lead electrocardiograms (ECGs), 24-hour continuous ECG recordings, bicycle exercise testings, and echocardiography with special focus on repolarization abnormalities such as corrected QT interval (QTc) prolongation, ventricular dysrhythmias, and left ventricular systolic function.


RESULTS
QTc interval was prolonged (>440 ms) in 70% of patients beyond infanthood. Continuous ECG recordings revealed rhythm disturbances in 20% of patients. M-mode echocardiographic left ventricular function was reduced (fractional shortening [FS] <30%) in 40%. One patient showed signs of dilated cardiomyopathy.


CONCLUSIONS
The majority of patients with PA (even in clinically stable situations) have disturbances in cardiac electrophysiology that can contribute to cardiac complications. Possible mechanisms include effects of toxic metabolites or deprivation of essential substrates. To avoid life-threatening complications, we recommend regular cardiological evaluations in this group of patients.
Baumgartner
Daniela
D
Clinical Department of Pediatric Cardiology, Innsbruck Medical University, Innsbruck, Austria.
Scholl-Bürgi
Sabine
S
Sass
Jörn Oliver
JO
Sperl
Wolfgang
W
Schweigmann
Ulrich
U
Stein
Jörg-Ingolf
JI
Karall
Daniela
D
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000592:Amino Acid Metabolism, Inborn Errors / Q000175:diagnosis* / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D004452:Echocardiography; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008133:Long QT Syndrome / Q000175:diagnosis* / Q000453:epidemiology; D008137:Longitudinal Studies; D008297:Male; D009200:Myocardial Contraction / Q000502:physiology; D011422:Propionates / Q000097:blood*; D018570:Risk Assessment; D012737:Sex Factors; D013318:Stroke Volume; D015996:Survival Rate; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis* / Q000453:epidemiology
D011422:Propionates