Electromechanical left atrial disturbances in acute inferior myocardial infarction: An evidence for ischaemic dysfunction

Abstract

Atrial arrhythmia occurs in almost 8% of acute inferior myocardial infarction (MI) [ 1 Bunc M. Starc R. Podbregar M. Bruĉan A. Conversion of atrial fibrillation into a sinus rhythm by coronary angioplasty in a patient with acute myocardial infarction. Eur J Emerg Med. 2001; 8: 141-145 Crossref PubMed Scopus (12) Google Scholar , 2 Patane S. Marte F. Di Bella G. Chiribiri A. Conduction disturbances and paroxysmal atrial fibrillation during acute inferior myocardial infarct. Int J Cardiol. 2008; 129: e37-e40 Abstract Full Text Full Text PDF PubMed Scopus (5) Google Scholar , 3 Siu C.W. Jim M.H. Ho H.H. Miu R. Lee S.W. Lau C.P. et al. Transient atrial fibrillation complicating acute inferior myocardial infarction: implications for future risk of ischemic stroke. Chest. 2007; 132: 44-49 Crossref PubMed Scopus (88) Google Scholar ], suggesting acute disturbances in atrial function. We aimed to study the nature of left atrial (LA) disturbances in 32 patients, mean age 57±13 years, 27 male, admitted with first acute inferior STEMI during acute uncomplicated inferior MI and assess their response to pharmacological revascularisation by thrombolysis. LA function of the patients was studied during thrombolysis therapy, 7 days and 30 days after treatment, using conventional 12 lead ECG and transthoracic and Doppler echocardiography [ [4] Lang R.M. Bierig M. Devereux R.B. et al. American Society of Echocardiography's Nomenclature and Standards Committee; Task Force on Chamber Quantification; American College of Cardiology Echocardiography Committee; American Heart Association; European Association of Echocardiography, European Society of Cardiology. Eur J Echocardiogr. 2006; 7: 79-108 Crossref PubMed Scopus (2824) Google Scholar ] and compared with 30 age and gender matched healthy volunteers. The study protocol was approved by the local Ethics Committee, and all participants gave informed written consent. The P wave duration and amplitude were manually measured from lead II using electronic “digimetric” caliper from lead II [ 5 Li W. Somerville J. Gibson D.G. Henein M.Y. Disturbed atrioventricular electromechanical function long after Mustard operation for transposition of great arteries: a potential contributing factor to atrial flutter. J Am Soc Echocardiogr. 2001; 14: 1088-1093 Abstract Full Text PDF PubMed Scopus (14) Google Scholar , 6 Li W. Xiao H.B. Henein M.Y. Somerville J. Gibson D.G. Progressive ECG changes before the onset of atrial flutter in adult congenital heart disease patients. Heart. 2001; 85: 703 Crossref PubMed Google Scholar ]. LV and LA long axis amplitude (Fig. 1) and velocities were measured at the left, septal and inferior segments using the conventional methods. LV ejection fraction (EF) was measured using Teichholz's formula. LV filling velocities were also recorded, from which E/A and E/E′ were calculated to reflect LA pressure [ 7 Nagueh S.F. Middleton K.J. Kopelen H.A. Zoghbi W.A. Quinones M.A. Doppler tissue imaging: a noninvasive technique for evaluation of left ventricular relaxation and estimation of filling pressures. J Am Coll Cardiol. 1997; 30: 1527-1533 Abstract Full Text Full Text PDF PubMed Scopus (2504) Google Scholar , 8 Thomas L. Levett K. Boyd A. Leung D.Y. Schiller N.B. Ross D.L. Changes in regional left atrial function with aging: evaluation by Doppler tissue imaging. Eur J Echocardiogr. 2003; 4: 92-100 Crossref PubMed Google Scholar , 9 Quintana M. Lindell P. Saha S.K. et al. Assessment of atrial regional and global electromechanical function by tissue velocity echocardiography: a feasibility study on healthy individuals. Cardiovasc Ultrasound. 2005; 18: 3-4 Google Scholar ]. The area under A wave envelope (A-VTI) was measured (cm), and corrected to RR interval [ [10] Thomas L. Hoy M. Byth K. Schiller N.B. The left atrial function index: a rhythm independent marker of atrial function. Eur J Echocardiogr. 2008; 9: 356-362 PubMed Google Scholar ]. The LA volume was measured using the ellipsoid method of the area–length formula [ [4] Lang R.M. Bierig M. Devereux R.B. et al. American Society of Echocardiography's Nomenclature and Standards Committee; Task Force on Chamber Quantification; American College of Cardiology Echocardiography Committee; American Heart Association; European Association of Echocardiography, European Society of Cardiology. Eur J Echocardiogr. 2006; 7: 79-108 Crossref PubMed Scopus (2824) Google Scholar ].