Relationship between Fragmented QRS and Microvascular Dysfunction in Masked Hypertension

Area of Science:

• Cardiology
• Electrophysiology
• Hypertension Research

Background:

• Masked hypertension (MH) is associated with increased cardiovascular risk.
• Subclinical cardiac dysfunction may precede clinical manifestation in MH.
• Fragmented QRS (fQRS) is a potential marker of cardiac abnormalities.

Purpose of the Study:

• To investigate the prevalence of fQRS in patients with MH.
• To assess the association between fQRS and subclinical systolic and microvascular dysfunction in MH.
• To identify predictors of subclinical systolic dysfunction in MH.

Main Methods:

• A case-control study involving 95 patients with MH and 80 healthy controls.
• Coronary flow reserve (CFR) assessed by transthoracic echocardiography.
• Left ventricular global longitudinal strain (LVGLS) measured by speckle-tracking strain imaging.
• Patients stratified based on the presence of fQRS on electrocardiogram.

Main Results:

• fQRS was significantly more prevalent in MH patients (38.9%) than controls (6.25%).
• MH patients with fQRS exhibited lower CFR and LVGLS compared to those without fQRS and controls.
• fQRS, number of leads, and CFR were independent predictors of subclinical systolic dysfunction.

Conclusions:

• fQRS is more frequent in MH patients, indicating a higher likelihood of cardiac abnormalities.
• The presence of fQRS is associated with significant subclinical left ventricular systolic dysfunction.
• Reduced CFR in MH patients with fQRS suggests microvascular dysfunction as a key mechanism.