Abstract:

Objective: Pulmonary hypertension (PHT) may result in right heart failure and death. Changes in right atrial function and size have been poorly studied in PHT. We aimed to determine how right atrial functions and size are affected in patients with secondary PHT with different severities and etiologies. Materials and Method: This study enrolled a total of 83 subjects with PHT secondary to left heart diseases excluding left ventricular systolic dysfunction, connective tissue disorders, and chronic respiratory diseases, and 49 healthy age- and sex-matched healthy controls. All subjects underwent 2-dimensional echocardiography and strain rate measurement to quantify right atrial size and function. Subjects with PHT were compared with the controls and with each other. Results: Subjects with PHT had significantly larger right atrial diameters and a significantly lower right atrial ejection fraction compared to controls. Although right atrial ejection fraction worsened in moderate and severe PHT, right atrial lateral wall late diastolic strain rate was preserved in different PHT severities. With increasing PHT severity, there occurred an increase in the right atrium’s reservoir/conduit ratio where right atrial emptying worsened but right atrial filling was preserved. The three PHT etiologies were comparable with respect to right atrial size and function. Conclusion: Our findings suggest that right atrium preserves its systolic function and behaves like more of a reservoir than a conduit in PHT. These changes together may help to increase right ventricular preload to sustain pulmonary and systemic output. PHT etiologies do not appear to exert any differential effect on right atrial function and size in PHT.

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