Congenital Heart Disease

1327949 - Tolerability and Efficacy of a Reduced Dose Adenosine stress CMR protocol under general anesthesia in Infants and Children

Thursday, January 26, 2023

4:30 PM – 5:10 PM

Location: Pacific Jewel

Presenting Author(s)

Madhusudan Ganigara, MD

Assistant Professor
The University of Chicago & Biological Sciences
Chicago, Illinois, United States

Co-Author(s)

BS

Bharti Sharma, MD

Resident
The University of Texas Southwestern Medical Center
Queens, Texas, United States
MN

Mohamed Nagiub, MD

Associate Professor
University of Virginia Technology, United States
RS

Roby Sebastian, MD

Assistant Professor
The University of Texas Southwestern Medical Center
Dallas, Texas, United States
MF

Munes Fares, MD

Assistant Professor
The University of Texas Southwestern Medical Center
Dallas, Texas, United States
JD

Jeanne Dillenbeck, MD

Pediatric Radiology
The University of Texas Southwestern Medical Center
Dallas, Texas, United States
PD

Pezad Doctor, MD

Pediatric Cardiology Fellow
The University of Texas Southwestern Medical Center
Dallas, Texas, United States

Primary Author(s)

Tarique Hussain, MD, PhD

Professor, Pediatric Cardiology & Radiology
UT Southwestern Medical Center
Dallas, Texas, United States

Background: Intravenous adenosine induces pharmacological stress by causing vasodilatation and thus carries the risk of severe hypotension when combined with vasodilatory effects of anesthetic agents. This study describes our experience with a incremental dose adenosine CMR protocol in young children under general anesthesia (GA).

Methods: This is a retrospective report of children who underwent adenosine stress CMR under GA at our institute between August 2018 to June 2022. All patients received GA with endotracheal intubation and a volatile anesthetic agent. The institute protocol for adenosine stress perfusion studies under GA consisted of a starting dose of 110 mcg/kg/min with incremental escalation to 125 mcg/kg/min and then a full dose of 140 mcg/kg/min if the clinical effect was not observed (Picture 1). The lower starting dose was implemented due to prior experiences of severe hypotension under GA and inability of these patients to report symptoms. A positive hemodynamic response to adenosine consisted of a heart rate increase of > 10 bpm from the baseline, a blood pressure decrease of > 10 mmHg or a positive splenic switch-off sign on the CMR perfusion sequence.

Results: Twenty-two children (median age 7 years; age range 8 months to 13 years) with mean weight 28.8 kg (weight range 9.1 to 57.6 kg) satisfied the inclusion criteria (Table). Two patients underwent the procedure twice. The diagnoses included Kawasaki disease (5), anomalous aortic origin of left coronary artery (3) and right coronary artery (2), coronary fistula (3), repaired d-transposition of great arteries (2), repaired anomalous left coronary artery from pulmonary artery (4), repaired truncus arteriosus with left coronary artery occlusion (1), fenestrated extracardiac-Fontan with left main coronary artery myocardial bridge (1) and post heart transplantation (1). Six patients needed dose escalation beyond the starting dose of 110 mcg/kg/min. One patient (s/p heart transplant) did not demonstrate a positive hemodynamic response to adenosine. Two patients had transient significant hypotension during testing (systemic BP drop > 25 mmHg). No patient developed significant heart block or bronchospasm. Six patients (repeat study in one) demonstrated inducible perfusion defects (27%) on stress perfusion sequences - 5 had confirmed significant coronary abnormalities on angiography or direct surgical inspection, while one patient with Kawasaki disease was continued on optimal medical management.

Conclusion: An incremental dose adenosine stress CMR protocol under GA in pediatric patients is safe and effective. This avoids severe hypotension which is both unsafe and may result in false positive results.