Atrial Failure: Mechanisms, Diagnosis, and Potential Therapeutic Targets

Review Article

Austin J Cardiovasc Dis Atherosclerosis. 2023; 10(2): 1059.

Atrial Failure: Mechanisms, Diagnosis, and Potential Therapeutic Targets

Zi-Yuan Li#; Xi-Chen Liu#; Ran Yin; Xiao-Ping Peng; Jian-Bing Zhu; Jia-Ling Yin; Yuan Shu; Ru Ying*

Department of Cardiology, the First Affiliated Hospital of Nanchang University, No.17, Yongwai Main Street, Donghu District, China

*Corresponding author: Ru Ying Department of Cardiology, the First Affiliated Hospital of Nanchang University, No.17, Yongwai Main Street, Donghu District, China. Email: yingru2005@163.com

#These authors have been contributed equally to this article.

Received: November 15, 2023 Accepted: December 12, 2023 Published: December 19, 2023

Abstract

The normal atrial function includes ventricular systolic storage function, early ventricular diastolic conduit function, and auxiliary pump function in late ventricular diastolic function, which assists in ventricular filling and maintaining cardiac output. Atrial dysfunction can result in or increase cardiac dysfunction, impacting the patient’s quality of life and life expectancy, even in the absence of evident valve or ventricular problems. Atrial failure, which mostly refers to the left atrium, has recently been given new clinical meaning and is being treated as a separate condition [1]. The mechanism, diagnosis, and potential therapeutic targets of atrial failure will be discussed in this article to better comprehend and treat atrial failure in the future.

Keywords: Atrial failure; Mechanisms; Diagnosis; Therapeutic targets

Introduction

Previously, the importance of cardiomyocytes in heart failure was usually disregarded in favor of the notion that left ventricular dysfunction and neurohumoral factors were the main causes of heart failure [2]. The atria not only play an important role in storage, channeling, and pumping in the ventricular filling, but they also play a unique role in cardiac electrical activity, endocrine and regulation by pacing conduction, secretion of Atrial Natriuretic Peptide (ANP), feedback inhibition of sympathetic nerves [3,4]. Even without left ventricular dysfunction, heart failure can still happen [5,6]. Similar to ventricular failure, which eventually results in heart failure, atrial failure is an influencing factor that is even more important than previously thought [7]. Atrial failure, which generally refers to atrial dysfunction independent of Atrial Fibrillation (AF) and heart failure in the absence of obvious valvular abnormalities or ventricular dysfunction, due to atrial anatomical, mechanical, electrophysiological, and/or hemodynamic abnormalities, and the presence of clinical symptoms associated with cardiac insufficiency is currently not defined in a uniform way. This results in a decrease in quality of life and life expectancy [1]. The mechanical dysfunction of left atrial failure is accompanied by endocrine and/or atrial regulatory failure, which manifests as a lack of ANP synthesis, ANP resistance, the dominance of sympathetic nervous system excitation, excessive release of vasopressin, etc. This causes an excessive activation of neurohumoral fluids, vasoconstriction, and volume overload [8], which precipitates or exacerbates heart failure.

Mechanisms of Atrial Failure

Many conditions can impair the atria by affecting the electrical coupling between the atrioventricular and the atrium, the hemodynamics or function of the atrium, thereby promoting thrombosis, causing pulmonary hypertension, and even heart failure. Atrial remodeling can increase a patient’s susceptibility to AF, and the persistence of AF aggravates atrial remodeling and induces new atrial fibrillation, eventually forming a vicious circle. In addition, atrial failure may activate neuroendocrine pathways (renin-angiotensin-aldosterone system and sympathetic nervous system), which could result in atrial remodeling, and further impair atrial function.

Electrical Activity is Out of Synchronization

There are two main reasons why electrical activity is dyssynchrony: interatrial and atrioventricular dyssynchrony. When the mitral valve closes, left atrial agitation in the interatrial conduction block is delayed and even starts to contract, leading to an instantaneous increase in left atrial pressure and abnormal enlargement of the left atrium[9]. Pulmonary hypertension results from an increase in left atrial pressure that travels down the pulmonary veins and into the pulmonary capillary system [10]. Atrial enlargement predisposes to atrial rhythm disturbances, especially AF increasing the likelihood of thrombosis [11]. In the atrioventricular block, the atrial contracts ineffectively, and blood stasis in the atria leads to thrombosis, increasing the risk of stroke. Patients with cryptogenic stroke may have a severe atrial failure, according to research by Leong DP et al.[12]. In addition, Additionally, the AV block results in a considerable reduction in cardiac output and the loss of the AV contraction sequence. Heart failure is more likely to occur if the heart already hasunderlying lesions.

Citation: Li ZY, Liu XC, Yin R, Peng XP, Zhu JB, et al. Atrial Failure: Mechanisms, Diagnosis, and Potential Therapeutic Targets. Austin J Cardiovasc Dis Atherosclerosis. 2023; 10(2): 1059.