Study of Ventricular Interdependence in Hemodialysis Patients

Background and objectivesStudy of respiratory variations in mitral valve (MV) Doppler flow in hemodialysis (HD) patients has not been investigated and normal adult referenced echocardiographic value is used as an echocardiographic reference to HD patients who have unique hemodynamic. This work aimed to study the respiratory variation in MV Doppler flow in HD patients to determine if it has a unique pattern in these patients, and to study any relation between this variation and volume-related parameters.MethodsWe conducted a prospective cohort study, carried out on 118 patients who underwent regular HD. A standard echocardiography was performed on the patients before and within 6 hs after dialysis. During quiet breathing, the transmitral spectral Doppler E wave was measured during inspiratory and expiratory phases using plethysmography breath-cycle chest-adhesive electrodes. The mathematic differences and the percent changes (ventricular interdependent; VI) in E wave were calculated pre-and post-dialysis. Post dialysis difference in the percent changes (∆ E wave % changes) was calculated as follows: pre-dialysis percent changes of E wave – post dialysis percent changes of E wave/pre dialysis percent changes E wave x 100. ResultsThe means of the mathematic differences between the MV inspiratory and expiratory E pre-and post-dialysis were 0.07 ± 0.18 m/s and 0.08 ± 0.22 m/s respectively with an insignificant difference between both phases; p = 0.337. Meanwhile, the means of the percent variation in the MV inspiratory and expiratory E pre-and post-dialysis were 56 ± 7 % and 44 ± 1.1 % respectively, with a significant reduction after dialysis; P = 0.000. Spearman correlation showed a significant positive correlation between post- dialysis ∆ E wave % change and post-dialysis % change of weight (r = 0.318; P = 0.000). Moreover, post- dialysis % change of weight and post- dialysis % changes of most other volume-related variable were independent predictors of post- dialysis ∆ E wave % in HD patients. ConclusionThe pre- and post- dialysis respiratory changes in the MV E wave in HD patients were higher than the normal adult referenced values. This marked variation could be explained by the unique overloading condition and could explain the LV diastolic dysfunction and the unexplained pulmonary hypertension in HD patients.

Does respiratory variation in inferior vena cava diameter predict fluid responsiveness in adult patients? A systematic review and meta-analysis of diagnostic accuracy studies

Objectives: To systematically review the diagnostic utility of the respiratory variation of the inferior vena cava diameter measured using ultrasonography for predicting fluid responsiveness in adult patients and compare the three commonly used equations, inferior vena cava distensibility, inferior vena cava collapsibility and inferior vena cava variability. Methods: We searched PubMed, Scopus, Web of Science and Cochrane library, and included studies investigating the diagnostic accuracy of the respiratory variation of the inferior vena cava measured using ultrasonography compared to a reference standard for measuring cardiac output after a fluid challenge for fluid responsiveness, and stratified participants as fluid responsive or not. We included studies conducted in the emergency department or intensive care unit. We excluded studies on paediatric, prehospital, cancer, pregnant, dialysis patients or healthy volunteers. Results: We retrieved 270 records and excluded 171 because of irrelevance, patient population or publication type. We screened the abstracts of 99 studies and then the full texts of 42 studies. Overall, 21 studies with 1321 patients were included, of whom 689 (52%) were fluid responsive. The mean threshold value for positive inferior vena cava distensibility, inferior vena cava collapsibility and inferior vena cava variability was 17%, 35% and 12%, respectively. The heterogeneity between studies was high. Bivariate diagnostic random-effects meta-analysis was used to calculate the summary receiver operating characteristics curves. The overall accuracy, sensitivity and specificity of respiratory variation of the inferior vena cava diameter were 0.85, 0.72 and 0.81, respectively. The accuracy of inferior vena cava distensibility and inferior vena cava collapsibility was similar. The diagnostic utility of respiratory variation of the inferior vena cava diameter was lower but not statistically significant in mechanically ventilated patients compared with spontaneous breathing for predicting fluid responsiveness. Conclusion: The respiratory variation of the inferior vena cava diameter has moderate diagnostic utility for predicting fluid responsiveness independent of the equation used.

Short term clinical and echocardiography outcomes of pericardiectomy in constrictive pericarditis

Introduction: Tuberculous pericarditis continues to be a leading cause of chronic constrictive pericarditis (CCP) in developing countries. Echocardiography plays a key role in the assessment and diagnosis. Methods: Twelve patients who underwent pericardiectomy for CCP in last 18 months of the study period were subjected to clinical and New York Heart Association (NYHA) functional class assessment along with comprehensive echocardiographic evaluation. The data were compared with their preprocedural status. Results: Significant reduction was noted in the incidence of inferior vena cava (IVC) congestion(P < 0.001) and mean left atrial (LA) size from 43.75 ± 4.43 mm to 31.58 ± 3.03 mm (P < 0.001), post pericardiectomy.Respiratory variation of 34.17 ± 8.76 % in the mitral E velocity was significantly reduced to 17 ± 3.69 % (P < 0.001) after surgery. Similarly, respiratory variation in tricuspid E velocities showed significant reduction from 62.17 ± 13.16 % to 32.58 ± 4.7 % (P < 0.001).Prior to pericardiectomy, medial e’ and lateral e’ mitral annular velocities was 15.5±1.24 cm/sec and13.08 ± 1.08 cm/sec, respectively. Following surgery, the medial e’ and lateral e’ was 12.5±1.17 cm/sec(P = 0.001) and 15.42±1.83 (P = 0.004), respectively. Conclusion: Echocardiography provides useful insight in pericardial constriction hemodynamics and worthwhile effects of pericardiectomy.