Right atrial size and function in patients with pulmonary hypertension associated with disorders of respiratory system or hypoxemia.
OBJECTIVE
Pulmonary hypertension (PH) determines various adaptive changes in right ventricular (RV) geometry which may progressively lead to hypertrophy, mechanical dysfunction and dilatation with pump failure. Right atrium (RA) is theoretically involved in this physiopathological process, but its role has never been investigated. We hypothesized that RA increases volume and function to assist RV during the chronic pressure overload exposition due to PH.


METHODS
We prospectively enrolled 66 consecutive patients referred to our echolab with a diagnosis of PH [defined as pulmonary artery systolic pressure (PASP) >30 mmHg] associated with disorders of the respiratory system and/or hypoxemia and normal RV systolic function. Ejection force was taken up as index of RA systolic function and calculated according to the Manning's formula. Thirty-three healthy subjects for whom PH was definitely excluded by echoDoppler evaluation were used as controls.


RESULTS
PASP was 42+/-10 and 20+/-8 mmHg in PH patients and controls, respectively; p=0.00001). In comparison with controls, PH patients exhibited higher RA volume (37+/-13 vs 32+/-13 ml, p=0.04) and RA ejection force (6.7+/-3.0 vs 3.5+/-1.8 Kdynes, p=0.00001). Both variables were positively related to PASP (r=0.23 and 0.48, p=0.02 and 0.00001, respectively).


CONCLUSIONS
In patients with chronic PH, RA size and systolic function significantly increase and parallel signs of activation of the Frank-Starling mechanism in both right chambers. The magnitude of these phenomena is positively related to PASP levels.
Cioffi
Giovanni
G
Department of Cardiology, Echocardiography Laboratory, Villa Bianca Hospital, via Piave 78, 38100 Trento, Italy. gcioffi@villabiancatrento.it
de Simone
Giovanni
G
Mureddu
Gianfrancesco
G
Tarantini
Luigi
L
Stefenelli
Carlo
C
D000222:Adaptation, Physiological; D000368:Aged; D000704:Analysis of Variance; D016280:Atrial Function, Right; D016022:Case-Control Studies; D002908:Chronic Disease; D004452:Echocardiography; D005260:Female; D006325:Heart Atria / Q000000981:diagnostic imaging / Q000503:physiopathology*; D006801:Humans; D006976:Hypertension, Pulmonary / Q000000981:diagnostic imaging / Q000503:physiopathology*; D000860:Hypoxia / Q000503:physiopathology*; D008297:Male; D011446:Prospective Studies; D012044:Regression Analysis; D012140:Respiratory Tract Diseases / Q000503:physiopathology*