Importance of left atrial function in patients with myocardial infarction.

Abstract

SUMMARY Left atrial function was evaluated in patients with and without remote myocardial infarction. The simultaneous left atrial pressure recording and left atrial and left ventricular cineangiograms were obtained with a catheter-tip micromanometer. The pressure-volume curve of the left atrium was composed of an A-loop and a V-loop. The ratio of active atrial emptying to left ventricular stroke volume in patients with myocardial infarction was significantly larger than that in normal subjects (42 + 12% vs 29 + 10%, p < 0.05). The left atrial work was also significantly greater in patients with myocardial infarction (1690 + 717 mm Hgml) than in normal subjects (940 426 mm Hg-ml, p < 0.05). The ratio of active atrial emptying to left ventricular stroke volume and left atrial work were significantly related in both normal subjects and patients with myocardial infarction (y = 0.72, p < 0.01). The left ventricular ejection fraction correlated inversely with left atrial work (y = -0.5, p < 0.05). Left atrial work also showed a significant linear correlation with left atrial volume before active atrial emptying (y = 0.82, p < 0.01).We conclude that the left atrial contribution to left ventricular function is increased in patients with remote myocardial infarction. This left atrial contribution to the left ventricle is attributed to the FrankStarling mechanism in the left atrium.LEFT ATRIAL function and its hemodynamic importance for overall cardiac performance have been discussed.' 1-3 The left atrium may serve as a conduit for the passage of blood from the pulmonary veins to the left ventricle during early left ventricular filling, as a reservoir for storing blood during left ventricular systole, and as a contractile chamber for augmentation of left ventricular filling. Understanding each of these functions and the contribution of the left atrium to left ventricular function in normal and diseased hearts is important.In this report, we analyze left atrial pressure-volume relationships in patients with remote myocardial infarction and discuss the importance of left atrial function. MethodsData were obtained during diagnostic cardiac catheterization in two groups of patients. The normal group consisted of eight patients who had no coronary, valvular or congenital heart disease and were hemodynamically normal. These patients were referred for diagnostic cardiac catheterization to evaluate chest pain. The myocardial infarction group consisted of 10 patients who had a documented remote transmural myocardial infarction, and no other associated heart disease. The clinical data for each patient are listed in medications were discontinued for at least 2 days before the study, except for sublingual nitroglycerin, which was allowed for anginal attack, but withheld 12 hours before the study. A Millar catheter-tip micromanometer (Model PC-484A, pigtail) was used for pressure measurement and cineangiography. The transducer was calibrated electronically against mercury at the beginning of each study. The zero shift during the proc...

Early Effects of Percutaneous Mitral Valvuloplasty on Left Atrial Mechanical Functions

“…These results were correlated with the fall in LA pressure (Basnight et al 1991). In MS LA function may be disrupted due to increased LA afterload (Matsuda et al 1983;Matsuzaki et al 1991). It has been shown that LA afterload and the mean LA pressure decreases following PMV (Stefanadis ) 1.67 ± 0.16 Systolic blood pressure (mmHg) 130 ± 9 Diastolic blood pressure (mmHg) 77 ± 5 Heart rate (beat/min) 74 ± 9 et al 1998).…”

“…Because it is well known that normal LA has a reservoir, conduit and pump function (Matsuda et al 1983;Matsuzaki et al 1991). On the other hand, percutaneous balloon mitral valvuloplasty (PMV) is a therapeutic option in selected patients with MS.…”

“…The functions of LA are (a) passive transport or conduit for pulmonary venous blood to the left venticle (LV) during ventricular diastole, (b) reservoir for storage of blood during ventricular systole and (c) active transport or pump function, that provides energy for filling LV beyond that provided by ventricular systole (Matsuda et al 1983;Matsuzaki et al 1991). Left atrial maximal volume (LAVmax) was measured just at the time of the opening of the mitral valve, left atrial minimal volume (LAVmin) was measured at the time of the closure of the mitral valve and the left atrial presystolic volume (LAVp) was measured synchronously with the start of the P wave on electrocardiography.…”

<b>Value of Left Atrial Function in Predicting Exercise Capacity in Heart Failure With Moderate to Severe Left Ventricular Systolic Dysfunction</b>

“…LA function is closely related to LV diastolic filling, therefore, indices of LA function may predict exercise capacity in patients with LV dysfunction. [6][7][8] LA volume and antero-posterior diameter measurements have been used for the evaluation of left atrial function. 9,10) The objective of the present study was to evaluate the correlation between LA function and exercise capacity in patients with heart failure.…”

Left Atrial Maximum Volume Is a Recurrence Predictor in Lone Atrial Fibrillation. An Acoustic Quantification Study.

“…[15][16][17][18][19][20] LA dilatation is usually recognized on the M-mode and two-dimensional echocardiogram; ultrafast computerized tomography, magnetic resonance imaging and radionuclide methods have also been introduced to identify changes in LA volumes and functions. [21][22][23] In routine clinical practice, the most commonly used approach has been the manual tracing method, which includes tracing the LA inner surface on a two-dimensional echocardiographic window providing the best image of the LA.…”