The left atrial phasic functions and the relationship with plasma N-terminal pro-B-type natriuretic peptide levels and symptomatic states in patients with hypertrophic cardiomyopathy

Abstract

Objective: We aimed to evaluate left atrium (LA) phasic functions and relation with N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels and symptomatic states of the patients with hypertrophic cardiomyopathy (HCM). Methods: Left atrial volume was calculated at end-systole (Vmax), end-diastole and pre-atrial contraction by echocardiography in 75 patients with HCM and 75 control subjects. Left atrial ejection fraction (LAEF), expansion index (LAEI), active emptying volume index (LAAEVI) and fraction (LAAEFr), passive emptying volume index (LAPEVI) and fraction (LAPEFr) were calculated. NT-proBNP levels were measured. Results: Left atrial active emptying volume (LAAEV) positively correlated with Vmax (r=0.343, p=0.003) up to a point, but then reached a plateau with larger LA volumes in HCM group. The LAAEFr was the only variable which was similiar between asymptomatic patients and controls, but was significantly decreased in symptomatic patients (p<0.05). NT-proBNP was correlated with LAEF (r=-0.32, p=0.005), LAEI (r=-0387, p=0.001), and LAAEFr (r=-0.25, p=0.035) but not related with LAPEFr (p=0.4). In receiver operating characteristic curve analysis an NT-proBNP cut-off value of 1415 pg/mL identified reduced LAEF with 87% specificity and 59% sensitivity [AUC=0.77 (95% CI: 0.65-0.89), p=0.004], a cut-off value of 820 pg/mL predicted impaired LAEI with 81% specificity ve 67% sensitivity [AUC=0.78 (95% CI: 0.66-0.9), p<0.001]; while a cut-off value of 1320 pg/mL predicted impaired LAAEFr with 76% specificity and 67% sensitivity [AUC=0.79 (95% CI: 0.68-0.91), p=0.02]. Conclusion: In HCM, LA phasic functions alter according to the Frank-Starling mechanism indicating occurrence of a secondary atrial myopathy. Impairment of LA booster pump function seems to be associated with appearance of symptoms and NT-proBNP levels predict the deterioration of LA reservoir and pump functions in HCM population.

Relationships between P wave dispersion, atrial electromechanical delay, left atrial remodeling, and NT-proBNP levels, in patients with hypertrophic cardiomyopathy

“…In another study, the presence of atrial dyssynchrony during the reservoir period, but not during the atrial contraction period, was associated with future development of AF in patients with congestive heart failure [24]. The LA active emptying fraction in the HCM population has been shown to follow the Frank-Starling mechanism [1], so an increase in LA preload up to a certain point contributes to enhanced LA booster pump function, which might explain why this function does not predict development of AF. On the other hand, LA reservoir function parameters are affected mostly by atrial compliance [25], and show advanced remodeling rather than LA enlargement.…”

“…The positive correlation between phasic LAVs, and PWD and atrial dyssynchrony, may suggest that these two AF predictors are affected by LA structural remodeling. Chronic elevation of LV filling pressure in patients with HCM may cause secondary atrial myopathy [1], contributing to atrial dyssynchrony and prolongation of PWD.…”

“…The levels of the amino-terminal portion of pro-BNP (N-terminal prohormone of B-type natriuretic peptide [NT-proBNP]) are elevated in patients with HCM [1]. Studies focusing on atrial functions showed that NT-proBNP levels also reflected LA dysfunction in patients with structural heart disease [9].…”

“…Alterations in left atrial (LA) functions [1], atrial fibrosis [2], and even LA appendage dysfunction [3], have been reported in patients with hypertrophic cardiomyopathy (HCM). Changes in atria may lead to electrical remodeling and affect the conduction properties of the atria, as is true in other cardiac pathologies [4].…”

Left Atrial Mechanical Functions in Professional Soccer Players: A Pilot Study

“…Because the LA immediately response to changes in LV end-diastolic pressure, LA remodeling is common. As a result, remodeling in the LA causes the alteration in LA mechanical functions (Anwar et al, 2008;Tülüce 2014).…”