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Effects of left ventricular dysfunction on left atrial performance in previous myocardial infarction and during
T Yamasaki1, M Takeuchi, K Fujitani
1First Department of Internal Medicine, Kobe University School of Medicine, Japan.
Insights
Left atrial function adapts differently to chronic and acute left ventricular dysfunction in coronary artery disease patients. Chronic issues show altered volumes, while acute stress reveals impaired emptying and reduced ejection fraction.
Area of Science:
- Cardiology
- Cardiac Physiology
- Medical Imaging
Background:
- Left ventricular dysfunction is common in coronary artery disease (CAD).
- Left atrial function plays a crucial role in diastolic function and overall cardiac performance.
- Understanding the interplay between left ventricular dysfunction and left atrial adaptation is vital for patient management.
Purpose of the Study:
- To investigate the acute and chronic effects of left ventricular dysfunction on left atrial function in patients with CAD.
- To differentiate the responses of left atrial performance under resting (chronic) and stress (acute) conditions.
Main Methods:
- Simultaneous measurements of left atrial volume using biplane cineangiography and left ventricular pressure.
- Study included 59 patients with CAD and 11 healthy controls.
- Evaluations were performed at rest and during right atrial pacing stress test.
Main Results:
- At rest, patients with prior myocardial infarction showed impaired early diastolic filling and altered left atrial volumes (increased LA pre-ACV and LAEV).
- Left atrial ejection fraction (LAEF) remained preserved at rest but decreased during acute stress (pacing) in patients with angina and elevated left ventricular end-diastolic pressure.
- Acute pacing revealed prolonged time constant and reduced mean emptying rate of left atrial volume during early diastole.
Conclusions:
- Left atrial performance exhibits distinct responses to chronic and acute left ventricular dysfunction in CAD.
- Chronic left ventricular dysfunction is associated with altered left atrial volumes, while acute dysfunction impacts left atrial emptying and ejection fraction.
- These findings highlight the dynamic nature of left atrial adaptation to evolving left ventricular impairment.
Abstract:
This study aimed to evaluate acute and chronic response of left atrial function to left ventricular dysfunction in patients with coronary artery disease. We studied simultaneous measurements of left atrial volume by biplane cineangiography and left ventricular pressure at rest and after pacing in 59 patients with coronary artery disease and 11 normal subjects. At rest, 35 patients with previous myocardial infarction (MI group) had low left ventricular filling rate of the first third in diastolic time, large left atrial volume before contraction (LA pre-ACV) and large left atrial ejection volume (LAEV), compared with control group. Left atrial ejection fraction (LAEF), the ratio of LAEV to LA pre-ACV, was similar between both groups. LAEF was maintained within a wide range of values in accordance with left ventricular peak A pressure, except for 3 patients who had high values of left ventricular peak A pressure and low values of LAEF. After a right atrial pacing stress test, time constant was prolonged and mean emptying rate of left atrial volume during early diastole decreased in 11 patients with angina pectoris who had an increase greater than 5 mmHg in left ventricular end-diastolic pressure after pacing. In these group, LA pre-ACV increased, LAEF decreased and LAEV was unchanged. These results suggest that left atrial performance responds differently to acute and chronic left ventricular dysfunction in patients with coronary artery disease.