Assessment of Left Ventricular Diastolic Function After Single Lung Transplantation in Patients With Severe Pulmonary Hypertension: Conclusion
In this study, Doppler echocardiography was utilized to determine left ventricular filling dynamics. There are a number of variables affecting transmitral Doppler parameters, such as age, heart rate, mitral regurgitation, and loading conditions.
Age is unlikely to have significant impact on our results. Our patient age was relatively young (average, 32 years). As seen in the control group, the normal subjects had a predominant early filling pattern with E = 78±8 cm/s and AFF=0.37±0.10. However, the pretransplant patients had a predominant atrial filling pattern with E = 32±6 cm/s and AFF = 0.64±0.10.
There was no significant difference of heart rate between patient and control groups, although it was slightly higher in the patient group (Table 1). Thus, it is unlikely that heart rate alone affected our results.
Absence or trivial degree of mitral regurgitation was seen in all patients and did not change over time. Therefore, this variable was not considered a factor in producing an increase in E wave.
Left ventricular loading conditions are likely to have undergone dramatic changes after lung transplantation. The increases in the preload resulting from improved pulmonary blood flow and reduced pulmonary artery resistance are able to augment Doppler early filling velocity Here health and care mall. However, peak E velocity did not increase significantly until late (>1 year) after transplantation.
Left ventricular diastolic geometry was not assessed in this study. Left ventricular early diastolic geometry may be related to early filling. However, a previous study indicated that in patients with right ventricular pressure overload, the degree of septum distortion at early diastole was not significantly changed with respect to that at end-systole.
Finally, the study population was small and further large-scale studies are required.
This study observed left ventricular filling dynamics by Doppler echocardiography before and after single lung transplantation in patients with severe pulmonary hypertension. The impaired early filling persisted shortly after transplantation, despite restoration of left ventricular geometry after reversal of pulmonary hypertension. The abnormal filling was not resolved until 1 year later. The findings suggest the impaired early filling may be caused by intrinsic left ventricular abnormalities other than ventricular interaction or geometry in these patients.