Assessment of Left Ventricular Diastolic Function After Single Lung Transplantation in Patients With Severe Pulmonary Hypertension: Discussion
Our results agree with their findings regarding abnormal left ventricular filling; however, in our patients, the deformation of left ventricular geometry was seen throughout systole and diastole. Severe tricuspid regurgitation in our patients (eight of nine) may account for the difference. Regarding the mechanism of the left ventricular filling abnormalities in this setting, Louie et al hypothesized that the pattern of left ventricular filling might be altered by left ventricular geometric changes and in particular that early diastolic filling might be compromised.
Clearly, our study showed that shortly after lung transplantation, the impaired left ventricular early filling did not change, although right ventricular systolic pressure fell significantly and left ventricular geometry was restored in these patients. These findings suggest that factors other than ventricular geometry may play a role in alteration of filling dynamics. A previous study from our laboratory by Booth et al showed that in atrial septal defect patients, the left ventricular compliance and muscle stiffness were adversely affected in the setting of chronic preload reduction. We speculate that because of severe pulmonary hypertension, the left ventricle experiences underfilling for years, resulting in a delayed diastolic adaptation after preload is restored. Based on Doppler filling pattern (reduced E wave) and prolonged isovolumic relaxation time observed from our patients, the abnormal left ventricular relaxation may be a factor that causes diastolic dysfunction. http://asthma-inhalers-online.com itat on Thus, there are intrinsic factors other than ventricular interaction or geometry that may contribute to left ventricular diastolic dysfunction in patients with right ventricular volume or pressure overload.
Data from this study indicate that after transplantation, there is a temporal delay in physiologic return of normal filling patterns as assessed by transmitral Doppler, compared with the anatomic return of normal left ventricular geometry. Persistent symptoms such as shortness of breath, fatigue, and decreased exercise capacity in postoperative lung transplant patients may partially relate to this dissociation between physiologic and anatomic recovery.