Cardioplegia Dose Effect on Immediate Postoperative Alterations in Coronary Artery Flow Velocities After Congenital Cardiac Surgery

Evaluation of right ventricular performance in patients with postoperative congenital heart disease using Doppler tissue imaging and cardiopulmonary bypass indices: A prospective cohort study

Background and Aims

Postoperative cardiac outcomes after intracardiac repair (ICR) are determined by numerous factors whereas right ventricle (RV) dysfunction is considered essential for them, as only few studies attempted to evaluate it postsurgically. RV's function is supposed to be the strong prognostic factor for patients diagnosed with congenital heart defects; therefore, assessing it is the main objective of the study.

Methods

This is a prospective single-centered cohort study performed on 50 pediatric patients with congenital heart disease (CHD) who underwent ICR between January 2019 and January 2022. All patients underwent echocardiographic assessment of RV function via tricuspid annular plane systolic excursion (TAPSE) and fractional area change (FAC) at 1, 24, and 48 h. After surgery, where pre- and postoperative RV pressure, cardiopulmonary bypass (CPB), and aortic cross-clamp (ACC) time were assessed. Similarly ventilation intensive care unit (ICU) and hospital stay times and mediastinal drainage were also monitored.

Results

The mean ± standard deviation for pre- and postoperative RV pressure was 49.1 ± 16.12 and 42.7 ± 2.9 mmHg, respectively, whereas that for pre- and postoperative pulmonary artery pressure was 30.4 ± 2.6 and 24.2 ± 12.9 mmHg, with p value of <0.002 and <0.001, respectively. The mean ± standard deviation of CPB and ACC times was 120.92 ± 74.17 and 78.44 ± 50.5 min accordingly, while those for mean ± standard deviation of ventilation time, mediastinum chest drainage, ICU and hospital stays were 30.36 ± 54.04, 43.78 ± 46.7 min, 5.9 ± 4.01 h, were 30.36 ± 54.0, 43.78 ± 46.7 min, 5.9 ± 4.01 and 10.3 ± 4.83 h, respectively.

Conclusions

RV dysfunction plays the important role in longer recovery and intraoperative time, while its effect is mostly transient. The use of TAPSE and FAC methods is valuable in the evaluation of postoperative outcomes, and the former proved to be more effective.

Prospective Assessment of Coronary Artery Flows Before and After Cardiopulmonary Bypass in Children With a Spectrum of Congenital Heart Disease

Background

Normative data for the effect of cardiopulmonary bypass (CPB) on coronary artery Doppler velocities by transesophageal echocardiography in paediatric patients with congenital heart disease (CHD) are lacking. The objective of the study was to prospectively examine the effects of CPB on coronary artery flow patterns by transesophageal echocardiography before and after CPB in children with CHD.

Methods

All cases undergoing CHD surgery at the Hospital for Sick Children, Toronto, were eligible. The excluded cases included Norwood operation, heart transplantation, or weight <2.5 kg. Coronary Dopplers and coronary flow reserve (CFR) for the right coronary artery (RCA) and left anterior descending (LAD) were obtained. Multivariable analyses using linear regression models were performed, adjusted for age and cross-clamp time.

Results

From May 2017 to June 2018, 69 children (median age at surgery: 0.7 years, interquartile range [IQR]: 0.4-3.7 years; median weight: 7.4 kg, IQR: 5.8-13.3 kg) were included. They were grouped into shunt lesions (N = 26), obstructive lesions (N = 26), transposition of the great arteries (N = 5), and single ventricle (N = 12). N = 39 (57%) were primary repairs, and 56 (81%) had 1 CPB run. For RCA and LAD peak velocities, there was an increase from pre- to post-CPB in RCA peak 39 cm/s (IQR: 30-54 cm/s) to 65 cm/s (IQR: 47-81 cm/s), P < 0.001, mean CFR 1.52 (IQR: 1.25-1.81), and LAD peak 49 cm/s (IQR: 39-60 cm/s) to 70 cm/s (IQR: 52-90 cm/s), P < 0.001, mean CFR 1.48 (IQR: 1.14-1.77).

Conclusions

Coronary flow velocities increase from pre- to post-CPB in congenital heart lesions. CFR is consistent across all lesions but is relatively low compared with the adult population.

Factors Affecting Cardiovascular Physiology in Cardiothoracic Surgery: Implications for Lumped-Parameter Modeling

Cardiothoracic surgeries are complex procedures during which the patient cardiovascular physiology is constantly changing due to various factors. Physiological changes begin with the induction of anesthesia, whose effects remain active into the postoperative period. Depending on the surgery, patients may require the use of cardiopulmonary bypass and cardioplegia, both of which affect postoperative physiology such as cardiac index and vascular resistance. Complications may arise due to adverse reactions to the surgery, causing hemodynamic instability. In response, fluid resuscitation and/or vasoactive agents with varying effects may be used in the intraoperative or postoperative periods to improve patient hemodynamics. These factors have important implications for lumped-parameter computational models which aim to assist surgical planning and medical device evaluation. Patient-specific models are typically tuned based on patient clinical data which may be asynchronously acquired through invasive techniques such as catheterization, during which the patient may be under the effects of drugs such as anesthesia. Due to the limited clinical data available and the inability to foresee short-term physiological regulation, models often retain preoperative parameters for postoperative predictions; however, without accounting for the physiologic changes that may occur during surgical procedures, the accuracy of these predictive models remains limited. Understanding and incorporating the effects of these factors in cardiovascular models will improve the model fidelity and predictive capabilities.

Noteworthy Literature in 2015

This article is a review of the literature published during the 12 months of 2015, which is of interest to the congenital cardiac anesthesiologist. While the review is not exhaustive, it identifies 7 themes in the literature for 2015 and cites 78 peer-reviewed publications.