Repolarization abnormalities in mitral valve prolapse.

Area of Science:

• Cardiology
• Clinical Electrophysiology
• Echocardiography

Background:

• Inferolateral ST depression, T wave inversion, and QT prolongation are ECG findings often reported in symptomatic mitral valve prolapse (MVP) patients.
• A recent population-based survey noted these ECG changes were less common in asymptomatic MVP subjects.
• The clinical significance of these ECG findings in relation to symptoms and hemodynamic sequelae in MVP remains unclear.

Purpose of the Study:

• To investigate the relationship between specific ECG changes (ST-T abnormalities, QT prolongation) and clinical presentation in patients with mitral valve prolapse (MVP).
• To determine if these ECG findings correlate with symptoms, physical examination findings, or hemodynamic consequences of MVP.
• To assess the utility of ECG abnormalities in identifying clinically relevant subsets of MVP patients.

Main Methods:

• Retrospective review of electrocardiograms (ECGs) from 119 patients diagnosed with MVP via echocardiography.
• Patients ranged in age from 18 to 60 years.
• Correlation of ECG findings with patient symptoms, physical exam findings (apical systolic murmurs), and echocardiographic evidence of mitral regurgitation or left atrial enlargement.

Main Results:

• ST-T wave abnormalities were observed with similar frequency in both symptomatic (27%) and asymptomatic (29%) MVP patients.
• QT prolongation was more frequent in symptomatic patients (25%) compared to asymptomatic ones (10%), but did not predict syncope.
• Neither ST-T changes nor QT prolongation were useful in identifying patients with hemodynamic sequelae such as mitral regurgitation or left atrial enlargement.

Conclusions:

• While ST-T changes and QT prolongation are frequent in mitral valve prolapse (MVP) patients compared to the general population, they are not specific.
• These ECG abnormalities do not reliably identify symptomatic patients or those with significant hemodynamic sequelae.
• The routine use of these ECG findings for risk stratification or subset identification in MVP patients is not supported by this study.