The Role of the Atrial Electromechanical Delay in Predicting Atrial Fibrillation in Myotonic Dystrophy Type 1 Patients.
BACKGROUND
Paroxysmal atrial tachyarrhythmias frequently occur in myotonic dystrophy type 1 (DM1) patients. The aim of the current study was to evaluate the atrial electromechanical-delay (AEMD) in a DM1-population with normal cardiac function and its relationship to atrial fibrillation (AF) onset.


RESULTS
Fifty DM1 patients (28 male; mean age 34.2 ± 11.4 years) and 50 healthy subjects used as controls, matched for age and gender, were studied for the occurrence of atrial fibrillation during a 4-year follow-up, through 30-day external loop recorder (ELR) monitoring performed every 6 months. Intra-AEMD and inter-AEMD of both atrium were measured through tissue-Doppler echocardiography. Compared to the healthy control group, the DM1 group showed a statistically significant increase in inter-AEMD and intraleft-AEMD. Dividing the DM1-group into 2 subgroups (patients with or without AF), the inter-AEMD and intraleft-AEMD were significantly higher in the subgroup with AF compared to the subgroup without AF. A cut off value of 39.2 milliseconds for intraleft-AEMD had a sensitivity of 90% and a specificity of 90% in identifying DM1 patients with AF risk. A cut off value of 57.7 milliseconds for inter-AEMD had a sensitivity of 84.2% and a specificity of 93.5% in identifying this category of patients.


CONCLUSIONS
Our results showed that the echocardiographic atrial electromechanical delay indices (intraleft and inter-AEMD) were significantly increased in DM1 subjects with normal cardiac function. Intraleft and inter-AEMD represent noninvasive, inexpensive, useful and simple parameters to assess the AF risk in DM1 patients.
Chair of Cardiology, Second University of Naples - Monaldi Hospital, Naples, Italy.
Vincenzo
V
Russo
Chair of Cardiology, Second University of Naples - Monaldi Hospital, Naples, Italy.
Anna
A
Rago
H.T. MED Pozzuoli (NA), Italy.
Carmine
C
Ciardiello
Chair of Cardiology, Second University of Naples - Monaldi Hospital, Naples, Italy.
Maria Giovanna
MG
Russo
Chair of Cardiology, Second University of Naples - Monaldi Hospital, Naples, Italy.
Paolo
P
Calabrò
Cardiomyology and Medical Genetics, Second University of Naples, Naples, Italy.
Luisa
L
Politano
Chair of Cardiology, Second University of Naples - Monaldi Hospital, Naples, Italy.
Gerardo
G
Nigro
D000200:Action Potentials; D000328:Adult; D019540:Area Under Curve; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D016279:Atrial Function, Left; D064752:Atrial Remodeling; D016022:Case-Control Studies; D015150:Echocardiography, Doppler; D004562:Electrocardiography; D005260:Female; D006325:Heart Atria / Q000000981:diagnostic imaging / Q000503:physiopathology*; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D009223:Myotonic Dystrophy / Q000150:complications* / Q000175:diagnosis; D011237:Predictive Value of Tests; D012372:ROC Curve; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D055815:Young Adult
atrial fibrillation; atrial-electromechanical-delay; myotonic dystrophy