title: Limited Ventricular Preload is the Main Reason for Reduced Stress Reserve After Atrial Baffle Repair.
abstract: The atrial baffle repair (ABR) significantly improved the fate of patients with transposition of the great arteries (TGA). However, these patients show impaired exercise tolerance and some present severe decline of systemic ventricular function. Intrinsic myocardial weakness, low heart rate response to exercise and diastolic filling impairment are discussed to be causative. Forty-nine long-term survivors with TGA (median age 23.7 year) after ABR were catheterized with measured oxygen consumption in four conditions (baseline, volume, atrial pacing, dobutamine) and the results were compared to 10 normal controls. Median cardiac output was significantly lower in the ABR group (2.2 vs. 2.6 l/min/m2; p = 0.015), and systemic resistance was significantly elevated (28.9 vs. 22.2 U m2; p = 0.04) in comparison with normals. While stroke volume rose by 27% in the control group, it dropped by 7% in patients after ABR at atrial pacing (80/min). Stroke volume increase after dobutamine was significantly lower after ABR in comparison with normal controls (34 vs. 106%; p = 0.001). Higher NYHA class (p = 0.043), degree of tricuspid regurgitation (p = 0.009) and ventricular function (p = 0.028) were associated with lower stroke volume increase. Limited exercise capability of patients after ABR for TGA is primarily due to limited diastolic filling of the ventricles due to stiff non-compliant atrial pathways. Elevated systemic resistance may lead to severe myocardial hypertrophy with possible ischemia and contribute to the multifactorial decline of ventricular function in some patients.
authors.affiliation: Department of Pediatric Cardiology and Congenital Heart Disease, Deutsches Herzzentrum, München, Lazarettstr. 36, 80636, Munich, Germany. eicken@dhm.mhn.de.
authors.forename: Andreas
authors.identifier: http://orcid.org/0000-0003-3631-4899
authors.initials: A
authors.lastname: Eicken
authors.affiliation: Department of Pediatric Cardiology and Congenital Heart Disease, Deutsches Herzzentrum, München, Lazarettstr. 36, 80636, Munich, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Michel
authors.affiliation: Department of Pediatric Cardiology and Congenital Heart Disease, Deutsches Herzzentrum, München, Lazarettstr. 36, 80636, Munich, Germany.
authors.forename: Alfred
authors.initials: A
authors.lastname: Hager
authors.affiliation: Department of Pediatric Cardiology and Congenital Heart Disease, Deutsches Herzzentrum, München, Lazarettstr. 36, 80636, Munich, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Tanase
authors.affiliation: Department of Pediatric Cardiology and Congenital Heart Disease, Deutsches Herzzentrum, München, Lazarettstr. 36, 80636, Munich, Germany.
authors.forename: Harald
authors.initials: H
authors.lastname: Kaemmerer
authors.affiliation: Department of Cardiovascular Surgery, Deutsches Herzzentrum, München, Munich, Germany.
authors.forename: Julie
authors.initials: J
authors.lastname: Cleuziou
authors.affiliation: Department of Pediatric Cardiology and Congenital Heart Disease, Deutsches Herzzentrum, München, Lazarettstr. 36, 80636, Munich, Germany.
authors.forename: John
authors.initials: J
authors.lastname: Hess
authors.affiliation: Department of Pediatric Cardiology and Congenital Heart Disease, Deutsches Herzzentrum, München, Lazarettstr. 36, 80636, Munich, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Ewert
mesh_terms: D000293:Adolescent; D000328:Adult; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D016022:Case-Control Studies; D003971:Diastole; D004280:Dobutamine / Q000008:administration & dosage; D017079:Exercise Tolerance; D005260:Female; D006325:Heart Atria / Q000601:surgery*; D006801:Humans; D008297:Male; D010101:Oxygen Consumption; D013318:Stroke Volume; D014188:Transposition of Great Vessels / Q000601:surgery*; D018497:Ventricular Dysfunction, Right / Q000503:physiopathology*; D055815:Young Adult
chemical_list: D004280:Dobutamine
keywords: Cardiac output; Long-term results; Senning–Mustard operation