Hemodynamic effect of physiological dual chamber pacing in a patient with end-stage dilated cardiomyopathy: a case report

Area of Science:

• Cardiology
• Biomedical Engineering
• Electrophysiology

Background:

• Dilated cardiomyopathy (DCM) with atrioventricular (AV) block presents complex management challenges.
• Standard medical therapies often prove insufficient for end-stage DCM.
• Pacemaker therapy, specifically DDD pacing, offers a potential solution for selected patients.

Observation:

• A case of end-stage DCM with first-degree AV block resistant to medical treatment was observed.
• Invasive hemodynamic monitoring (right-heart catheterization) and Doppler echocardiography were used to assess AV interval optimization.
• Varying AV intervals demonstrated distinct effects on left ventricular filling and myocardial contractility.

Findings:

• Optimal AV delay settings between 100-200 msec enhanced left ventricular filling and myocardial contractility.
• An excessively short AV interval (50 msec) led to deteriorated left ventricular function.
• Programming the DDD pacemaker with an optimal AV delay of 100 msec improved clinical outcomes for 4 months.

Implications:

• DDD pacemaker optimization of AV delay can significantly improve cardiac function in DCM patients with AV block.
• Enhanced left ventricular filling and contractility promote the Frank-Starling mechanism, improving overall cardiac performance.
• This approach offers a valuable therapeutic strategy for managing complex cardiac conditions.