Right and left ventricular dysfunction and interaction in respiratory critically ill patients

ABSTRACT

This study was designed to determine the incidence of right ventricular [RV] and left ventricular [LV] dysfunctions and to relate the findings to possible mechanisms of interdependence between right and left ventricles during acute respiratory failure [ARF] in patients with chronic obstructive lung diseases [COLDs]. 58 hospitalized patients underwent pulmonary function tests and arterial blood gases. An echo-Doppler examination was performed for patients and 20-healthy subjects as control group to measure RV and LV end-diastolic and end-systolic diameters; RV and LV ejection fraction [EF], transmitral early [E] and late [A] peak flow velocities and their ratio [E/A]; isovolumic relaxation time [IRT]; trans-tricuspid early [E1] and late [A1] peak flow velocities and their ratio [E1/A1] and estimation of pulmonary artery pressure [PAP] by acceleration time [ACT] of the pulmonary systolic flow and tricuspid regurgitation [TR] jet velocity. The data showed dilated RV in 80% [50/58]; mild TR in 64% [37/58]; RV systolic dysfunction [EF<45%] in 28% [16/58] and RV diastolic dysfunction [decreased E1/A1 ratio] in 53% [31/58] of patients. On the other hand, LV systolic dysfunction [EF<45%] was found in 16% [9/58] of patients while LV diastolic dysfunction [low E, low E/A ratio and high IRT] in 72% [42/58] of patients. A linear regression analysis revealed that low E and low E/A ratio were significantly correlated with RV size [p<0.01 and p<0.05, respectively], while low E/A ratio and prolonged IRT were significantly correlated with PAP [p<0.05 and p<0.001, respectively]. No significant correlations were found between LV and RV dysfunctions or respiratory functional parameters. In conclusion, the prevalence of RV and LV dysfunctions is high in patients with ARF and LV dysfunction appears to be closely related to the RV size and the level of pulmonary hypertension