Disturbed Left Atrial Function is Associated with Paroxysmal Atrial Fibrillation in Hypertension

Background

Hypertension is the most prevalent and modifiable risk factor for atrialfibrillation. The pressure overload in the left atrium induces pathophysiologicalchanges leading to alterations in contractile function and electrical properties.

Objective

In this study our aim was to assess left atrial function in hypertensive patientsto determine the association between left atrial function with paroxysmal atrialfibrillation (PAF).

Method

We studied 57 hypertensive patients (age: 53±4 years; left ventricular ejectionfraction: 76±6.7%), including 30 consecutive patients with PAF and 30 age-matchedcontrol subjects. Left atrial (LA) volumes were measured using the modifiedSimpson''s biplane method. Three types of LA volume were determined: maximalLA(LAVmax), preatrial contraction LA(LAVpreA) and minimal LA volume(LAVmin). LAemptying functions were calculated. LA total emptying volume = LAVmax−LAVmin andthe LA total EF = (LAVmax-LAVmin )/LAVmax, LA passive emptying volume = LAVmax−LAVpreA and the LA passive EF = (LAVmax-LAVpreA)/LAVmax, LA active emptying volume= LAVpreA−LAVmin and LA active EF = (LAVpreA-LAVmin )/LAVpreA.

Results

The hypertensive period is longer in hypertensive group with PAF. LAVmaxsignificantly increased in hypertensive group with PAF when compared tohypertensive group without PAF (p=0.010). LAAEF was significantly decreased inhypertensive group with PAF as compared to hypertensive group without PAF(p=0.020). A'' was decreased in the hypertensive group with PAF when compared tothose without PAF (p = 0.044).

Conclusion

Increased LA volume and impaired LA active emptying function was associated withPAF in untreated hypertensive patients. Longer hypertensive period is associatedwith PAF.