Influence of left atrial size on P-wave morphology: differential effects of dilation and hypertrophy

• Published in: Europace (London, England) Vol. 20; no. suppl_3; pp. iii36 - iii44
• Main Authors: Andlauer, Robin, Seemann, Gunnar, Baron, Lukas, Dössel, Olaf, Kohl, Peter, Platonov, Pyotr, Loewe, Axel
• Format: Journal Article
• Language: English
• Published: England 01.11.2018
• Subjects: Action Potentials; Atrial Fibrillation - diagnosis; Atrial Fibrillation - etiology; Atrial Fibrillation - physiopathology; Atrial Function, Left; Atrial Remodeling; Cardiac and Cardiovascular Systems; Cardiomegaly - complications; Cardiomegaly - diagnosis; Cardiomegaly - physiopathology; Clinical Medicine; Computer Simulation; Diagnosis, Differential; Electrocardiography; Heart Atria - diagnostic imaging; Heart Atria - physiopathology; Heart Rate; Humans; Kardiologi; Klinisk medicin; Magnetic Resonance Imaging; Medical and Health Sciences; Medicin och hälsovetenskap; Models, Cardiovascular; Predictive Value of Tests; Radiologi och bildbehandling; Radiology, Nuclear Medicine and Medical Imaging; Risk Factors; Time Factors
• ISSN: 1099-5129; 1532-2092; 1532-2092
• DOI: 10.1093/europace/euy231

Chronic left atrial enlargement (LAE) increases the risk of atrial fibrillation. Electrocardiogram (ECG) criteria might provide a means to diagnose LAE and identify patients at risk; however, current criteria perform poorly. We seek to characterize the potentially differential effects of atrial dilation vs. hypertrophy on the ECG P-wave. We predict effects on the P-wave of (i) left atrial dilation (LAD), i.e. an increase of LA cavity volume without an increase in myocardial volume, (ii) left atrial concentric hypertrophy (LACH), i.e. a thickened myocardial wall, and (iii) a combination of the two. We performed a computational study in a cohort of 72 anatomical variants, derived from four human atrial anatomies. To model LAD, pressure was applied to the LA endocardium increasing cavity volume by up to 100%. For LACH, the LA wall was thickened by up to 3.3 mm. P-waves were derived by simulating atrial excitation propagation and computing the body surface ECG. The sensitivity regarding changes beyond purely anatomical effects was analysed by altering conduction velocity by 25% in 96 additional model variants. Left atrial dilation prolonged P-wave duration (PWd) in two of four subjects; in one subject a shortening, and in the other a variable change were seen. Left atrial concentric hypertrophy, in contrast, consistently increased P-wave terminal force in lead V1 (PTF-V1) in all subjects through an enlarged amplitude while PWd was unaffected. Combined hypertrophy and dilation generally enhanced the effect of hypertrophy on PTF-V1. Isolated LAD has moderate effects on the currently used P-wave criteria, explaining the limited utility of PWd and PTF-V1 in detecting LAE in clinical practice. In contrast, PTF-V1 may be a more sensitive indicator of LA myocardial hypertrophy.