Right ventricular filling in dilated cardiomyopathy

Area of Science:

• Cardiology
• Echocardiography
• Cardiac Physiology

Background:

• Dilated cardiomyopathy (DCM) is characterized by impaired cardiac function.
• Understanding right ventricular (RV) filling dynamics is crucial for assessing overall cardiac health in DCM.

Purpose of the Study:

• To evaluate right ventricular filling characteristics in patients with dilated cardiomyopathy.
• To investigate the relationship between RV inflow tract dimensions and tricuspid valve function in DCM.

Main Methods:

• Pulsed Doppler and 2D/M-mode echocardiography were used to measure stroke distances, inflow/outflow tract dimensions, and atrioventricular (AV) ring excursions.
• Stroke volume and effective orifice areas of AV valves were calculated.
• 32 patients with DCM and 24 healthy controls were included.

Main Results:

• Patients with DCM exhibited significantly increased tricuspid stroke distance but reduced stroke volume compared to controls.
• The effective tricuspid orifice area was less than half normal in DCM patients, correlating inversely with RV end-diastolic inflow dimension.
• Right ventricular ring excursion showed a bimodal distribution, with a longer interval to tricuspid flow onset in a subset of patients.

Conclusions:

• Enlargement of the RV inflow tract in DCM is associated with decreased effective tricuspid orifice area and increased inflow velocities.
• Incoordinate right ventricular relaxation was observed in 28% of DCM patients.
• These RV filling disturbances can compromise cardiac function independently of left ventricular disease.