Effect of dynamic exercise on left atrial function in conscious dogs.

1. Dynamic changes in left atrial (LA) function during treadmill exercise were studied in ten conscious dogs instrumented to measure left ventricular (LV) pressure and diameter, LA pressure and diameter, and pulmonary venous blood flow (PVF, transit time flowmeter). 2. Systolic PVF volume (reservoir volume; a measure of LA reservoir function) increased from 38 +/‐ 4% of total PVF volume at baseline to 52 +/‐ 8% of total PVF volume during exercise, and diastolic PVF volume (conduit volume; a measure of LA conduit function) decreased from 62 +/‐ 5% at baseline to 48 +/‐ 8% during exercise (P < 0.005). 3. The increases in reservoir volume and the decrease in conduit volume were due not only to a greater decrease in diastolic interval than systolic interval but were also caused by a significantly greater increase (P < 0.05) in the mean systolic filling rate (93%) than in the mean diastolic filling rate (51%). 4. During exercise the pattern of LV filling derived from changes in LV diameter showed that a greater percentage of LV filling occurred during the second half of diastole at the time of atrial contraction (P < 0.05), suggesting that LA booster function was enhanced. 5. Changes in LA dimension revealed that during exercise more blood volume was reserved in the LA during systole and that this change was associated with an increase in the LA dimension at the beginning of LA contraction (r = 0.61, P < 0.05). 6. We conclude that LA reservoir and booster functions were augmented during exercise, whereas conduit function was not. Increased reservoir function may play an important role in accelerating LV filling by helping to maintain an enhanced atrioventricular pressure gradient during diastole and also by increasing LA booster function through an increase in LA preload.

[1]  H. S. Klopfenstein,et al.  Restraining effect of intact pericardium during acute volume loading. , 1992, The American journal of physiology.

[2]  G. Christensen,et al.  Right and left atrial diameters during incremental atrial pacing in pigs. , 1991, The American journal of physiology.

[3]  A. Tajik,et al.  Relation of pulmonary vein to mitral flow velocities by transesophageal Doppler echocardiography. Effect of different loading conditions. , 1990, Circulation.

[4]  H. S. Klopfenstein,et al.  External pressure of undisturbed left ventricle. , 1990, The American journal of physiology.

[5]  J. Ross,et al.  Changes of left ventricular diastolic function in exercising dogs without and with ischemia. , 1990, Circulation.

[6]  W. Santamore,et al.  Effect of loading conditions, contractile state, and heart rate on early diastolic left ventricular filling in conscious dogs. , 1990, Circulation research.

[7]  J. Vinten-johansen,et al.  Computer acquisition and analysis of cardiovascular hemodynamic and cardiac performance data , 1990 .

[8]  M. Matsuzaki,et al.  Left atrial conduit function for left ventricular filling dynamics in patient with myocardial infarction. , 1989, Catheterization and cardiovascular diagnosis.

[9]  M. Kern,et al.  Influence of alteration in preload on the pattern of left ventricular diastolic filling as assessed by Doppler echocardiography in humans. , 1989, Circulation.

[10]  J. Jones,et al.  The contribution of atrial systole to mitral diastolic blood flow increases during exercise in humans. , 1989, The Journal of physiology.

[11]  R. Kloner,et al.  Diastolic filling in acute left ventricular dysfunction: role of the pericardium. , 1988, Journal of the American College of Cardiology.

[12]  E. Sonnenblick,et al.  Mitral anulus motion. Relation to pulmonary venous and transmitral flows in normal subjects and in patients with dilated cardiomyopathy. , 1988, Circulation.

[13]  M. Quiñones,et al.  Quantification of atrial contribution to left ventricular filling by pulsed Doppler echocardiography and the effect of age in normal and diseased hearts. , 1987, The American journal of cardiology.

[14]  L Waldman,et al.  In vivo mechanical behavior of canine pericardium. , 1986, The American journal of physiology.

[15]  Y Ishida,et al.  Left ventricular filling dynamics: influence of left ventricular relaxation and left atrial pressure. , 1986, Circulation.

[16]  S. Laniado,et al.  Pulmonary venous flow pattern--its relationship to cardiac dynamics. A pulsed Doppler echocardiographic study. , 1985, Circulation.

[17]  J. Carroll,et al.  Dynamics of left ventricular filling at rest and during exercise. , 1983, Circulation.

[18]  B. Rajagopalan,et al.  Blood flow in pulmonary veins: III. Simultaneous measurements of their dimensions, intravascular pressure and flow. , 1979, Cardiovascular research.

[19]  B. Rajagopalan,et al.  Blood flow in pulmonary veins: II. The influence of events transmitted from the right and left sides of the heart. , 1979, Cardiovascular research.

[20]  B. Rajagopalan,et al.  Blood flow in pulmonary veins: I. Studies in dog and man. , 1979, Cardiovascular research.

[21]  V. Bhargava,et al.  Alteration of the Left Ventricular Diastolic Pressure-Segment Length Relation Produced by the Pericardium: Effects of Cardiac Distension and Afterload Reduction in Conscious Dogs , 1978, Circulation.

[22]  R. Padiyar,et al.  The role of displacement of the mitral annulus in left atrial filling and emptying in the intact dog. , 1978, Canadian journal of physiology and pharmacology.

[23]  J. Weiss,et al.  Hemodynamic determinants of the time-course of fall in canine left ventricular pressure. , 1976, The Journal of clinical investigation.

[24]  S. Sasayama,et al.  Adaptations of the Left Ventricle to Chronic Pressure Overload , 1976, Circulation research.

[25]  K. Rosen,et al.  Left atrial transport function in myocardial infarction. Importance of its booster pump function. , 1975, The American journal of medicine.

[26]  H. Suga,et al.  Importance of Atrial Compliance in Cardiac Performance , 1974, Circulation research.

[27]  E. Kinnen,et al.  Pulsatile flow in pulmonary artery, capillary, and vein in the dog. , 1974, Cardiovascular research.

[28]  E J Engelken,et al.  Atrial function during volume loading. , 1971, Journal of applied physiology.

[29]  A. Benchimol,et al.  Hemodynamic consequences of atrial and ventricular pacing in patients with normal and abnormal hearts. Effect of exercise at a fixed atrial and ventricular rate. , 1965, The American journal of medicine.

[30]  A. Fishman,et al.  Pattern of blood flow in the pulmonary veins of the dog , 1965 .

[31]  D. Greene,et al.  THE RESERVOIR FUNCTION OF THE LEFT ATRIUM DURING VENTRICULAR SYSTOLE. AN ANGIOCARDIOGRAPHIC STUDY OF ATRIAL STROKE VOLUME AND WORK. , 1964, The American journal of medicine.

[32]  J. Mitchell,et al.  Relation Between Left Ventricular Diastolic Pressure and Myocardial Segment Length and Observations on the Contribution of Atrial Systole , 1960, Circulation research.

[33]  J. P. Gilmore,et al.  Regulation of Ventricular Contraction: Influence of Cardiac Sympathetic and Vagal Nerve Stimulation on Atrial and Ventricular Dynamics , 1960, Circulation research.

[34]  W. Little,et al.  Mechanism of augmented rate of left ventricular filling during exercise. , 1992, Circulation research.

[35]  J. Smallhorn,et al.  Pulsed Doppler echocardiographic assessment of extraparenchymal pulmonary vein flow. , 1987, Journal of the American College of Cardiology.

[36]  D. Mathey,et al.  Left ventricular relaxation and filling pattern in different forms of left ventricular hypertrophy: an echocardiographic study. , 1980, The American journal of cardiology.

[37]  Z. A. Wade,et al.  EFFECT OF ATRIAL VOLUME ON THE PERFORMANCE OF A SAC‐TYPE ARTIFICIAL HEART , 1973, Transactions - American Society for Artificial Internal Organs.